diff --git a/.gitignore b/.gitignore
index bbf358b8f4..ee778ed4e2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -102,6 +102,7 @@ csx
 AppPackages/
 
 # NCrunch
+.NCrunch_*/
 _NCrunch_*/
 *.ncrunchsolution.user
 nCrunchTemp_*
diff --git a/.ncrunch/Avalonia.Generators.Tests.v3.ncrunchproject b/.ncrunch/Avalonia.Generators.Tests.v3.ncrunchproject
new file mode 100644
index 0000000000..319cd523ce
--- /dev/null
+++ b/.ncrunch/Avalonia.Generators.Tests.v3.ncrunchproject
@@ -0,0 +1,5 @@
+<ProjectConfiguration>
+  <Settings>
+    <IgnoreThisComponentCompletely>True</IgnoreThisComponentCompletely>
+  </Settings>
+</ProjectConfiguration>
\ No newline at end of file
diff --git a/.ncrunch/Generators.Sandbox.v3.ncrunchproject b/.ncrunch/Generators.Sandbox.v3.ncrunchproject
new file mode 100644
index 0000000000..319cd523ce
--- /dev/null
+++ b/.ncrunch/Generators.Sandbox.v3.ncrunchproject
@@ -0,0 +1,5 @@
+<ProjectConfiguration>
+  <Settings>
+    <IgnoreThisComponentCompletely>True</IgnoreThisComponentCompletely>
+  </Settings>
+</ProjectConfiguration>
\ No newline at end of file
diff --git a/Avalonia.Desktop.slnf b/Avalonia.Desktop.slnf
index 477aaec6a8..d4cde99240 100644
--- a/Avalonia.Desktop.slnf
+++ b/Avalonia.Desktop.slnf
@@ -8,9 +8,9 @@
       "samples\\GpuInterop\\GpuInterop.csproj",
       "samples\\IntegrationTestApp\\IntegrationTestApp.csproj",
       "samples\\MiniMvvm\\MiniMvvm.csproj",
+      "samples\\ReactiveUIDemo\\ReactiveUIDemo.csproj",
       "samples\\SampleControls\\ControlSamples.csproj",
       "samples\\Sandbox\\Sandbox.csproj",
-      "samples\\ReactiveUIDemo\\ReactiveUIDemo.csproj",
       "src\\Avalonia.Base\\Avalonia.Base.csproj",
       "src\\Avalonia.Build.Tasks\\Avalonia.Build.Tasks.csproj",
       "src\\Avalonia.Controls.ColorPicker\\Avalonia.Controls.ColorPicker.csproj",
@@ -41,6 +41,7 @@
       "src\\Windows\\Avalonia.Direct2D1\\Avalonia.Direct2D1.csproj",
       "src\\Windows\\Avalonia.Win32.Interop\\Avalonia.Win32.Interop.csproj",
       "src\\Windows\\Avalonia.Win32\\Avalonia.Win32.csproj",
+      "src\\tools\\Avalonia.Generators\\Avalonia.Generators.csproj",
       "src\\tools\\DevAnalyzers\\DevAnalyzers.csproj",
       "src\\tools\\DevGenerators\\DevGenerators.csproj",
       "src\\tools\\PublicAnalyzers\\Avalonia.Analyzers.csproj",
@@ -63,4 +64,4 @@
       "tests\\Avalonia.UnitTests\\Avalonia.UnitTests.csproj"
     ]
   }
-}
+}
\ No newline at end of file
diff --git a/native/Avalonia.Native/src/OSX/AvnWindow.mm b/native/Avalonia.Native/src/OSX/AvnWindow.mm
index b1fb915e04..16e1486acc 100644
--- a/native/Avalonia.Native/src/OSX/AvnWindow.mm
+++ b/native/Avalonia.Native/src/OSX/AvnWindow.mm
@@ -394,7 +394,7 @@
 
 - (BOOL)windowShouldZoom:(NSWindow *_Nonnull)window toFrame:(NSRect)newFrame
 {
-    return true;
+    return _parent->CanZoom();
 }
 
 -(void)windowDidResignKey:(NSNotification *)notification
diff --git a/native/Avalonia.Native/src/OSX/WindowBaseImpl.h b/native/Avalonia.Native/src/OSX/WindowBaseImpl.h
index be7d933b6a..bc35ca670f 100644
--- a/native/Avalonia.Native/src/OSX/WindowBaseImpl.h
+++ b/native/Avalonia.Native/src/OSX/WindowBaseImpl.h
@@ -107,6 +107,8 @@ BEGIN_INTERFACE_MAP()
                            
     virtual HRESULT GetInputMethod(IAvnTextInputMethod **retOut) override;
 
+    virtual bool CanZoom() { return false; }
+                           
 protected:
     virtual NSWindowStyleMask CalculateStyleMask() = 0;
     virtual void UpdateStyle();
diff --git a/native/Avalonia.Native/src/OSX/WindowImpl.h b/native/Avalonia.Native/src/OSX/WindowImpl.h
index 29bb659039..5140124a17 100644
--- a/native/Avalonia.Native/src/OSX/WindowImpl.h
+++ b/native/Avalonia.Native/src/OSX/WindowImpl.h
@@ -97,6 +97,8 @@ BEGIN_INTERFACE_MAP()
     
     bool CanBecomeKeyWindow ();
 
+    bool CanZoom() override { return _isEnabled && _canResize; }
+    
 protected:
     virtual NSWindowStyleMask CalculateStyleMask() override;
     void UpdateStyle () override;
diff --git a/native/Avalonia.Native/src/OSX/WindowImpl.mm b/native/Avalonia.Native/src/OSX/WindowImpl.mm
index 840f2c9e88..925880534a 100644
--- a/native/Avalonia.Native/src/OSX/WindowImpl.mm
+++ b/native/Avalonia.Native/src/OSX/WindowImpl.mm
@@ -281,10 +281,13 @@ HRESULT WindowImpl::SetDecorations(SystemDecorations value) {
 
             case SystemDecorationsFull:
                 [Window setHasShadow:YES];
-                [Window setTitleVisibility:NSWindowTitleVisible];
-                [Window setTitlebarAppearsTransparent:NO];
                 [Window setTitle:_lastTitle];
 
+                if (!_isClientAreaExtended) {
+                    [Window setTitleVisibility:NSWindowTitleVisible];
+                    [Window setTitlebarAppearsTransparent:NO];
+                }
+
                 if (currentWindowState == Maximized) {
                     auto newFrame = [Window contentRectForFrameRect:[Window frame]].size;
 
@@ -611,7 +614,8 @@ void WindowImpl::UpdateStyle() {
     }
 
     bool wantsChrome = (_extendClientHints & AvnSystemChrome) || (_extendClientHints & AvnPreferSystemChrome);
-    bool hasTrafficLights = _isClientAreaExtended ? wantsChrome : _decorations == SystemDecorationsFull;
+    bool hasTrafficLights = (_decorations == SystemDecorationsFull) &&
+        (_isClientAreaExtended ? wantsChrome : true);
     
     NSButton* closeButton = [Window standardWindowButton:NSWindowCloseButton];
     NSButton* miniaturizeButton = [Window standardWindowButton:NSWindowMiniaturizeButton];
@@ -622,5 +626,5 @@ void WindowImpl::UpdateStyle() {
     [miniaturizeButton setHidden:!hasTrafficLights];
     [miniaturizeButton setEnabled:_isEnabled];
     [zoomButton setHidden:!hasTrafficLights];
-    [zoomButton setEnabled:_isEnabled && _canResize];
+    [zoomButton setEnabled:CanZoom()];
 }
diff --git a/packages/Avalonia/Avalonia.csproj b/packages/Avalonia/Avalonia.csproj
index 1d210172f0..f21d6fefb4 100644
--- a/packages/Avalonia/Avalonia.csproj
+++ b/packages/Avalonia/Avalonia.csproj
@@ -43,6 +43,10 @@
        <Pack>true</Pack>
        <PackagePath>build\;buildTransitive\</PackagePath>
     </Content>
+    <Content Include="..\..\src\tools\Avalonia.Generators\Avalonia.Generators.props">
+      <Pack>true</Pack>
+      <PackagePath>build\;buildTransitive\</PackagePath>
+    </Content>
     <Content Include="*.targets">
       <Pack>true</Pack>
       <PackagePath>build\;buildTransitive\</PackagePath>
diff --git a/packages/Avalonia/Avalonia.props b/packages/Avalonia/Avalonia.props
index 26908b1081..2334aa91bc 100644
--- a/packages/Avalonia/Avalonia.props
+++ b/packages/Avalonia/Avalonia.props
@@ -6,6 +6,7 @@
     <AvaloniaUseExternalMSBuild>false</AvaloniaUseExternalMSBuild>
   </PropertyGroup>
   <Import Project="$(MSBuildThisFileDirectory)\AvaloniaBuildTasks.props"/>
+  <Import Project="$(MSBuildThisFileDirectory)\Avalonia.Generators.props"/>
 
   <!-- Allow loading the AvaloniaVS extension when referencing the Avalonia nuget package -->
   <ItemGroup>
diff --git a/readme.md b/readme.md
index 2600cf83cc..c8135080fe 100644
--- a/readme.md
+++ b/readme.md
@@ -5,6 +5,10 @@
 <br />
 [![NuGet](https://img.shields.io/nuget/v/Avalonia.svg)](https://www.nuget.org/packages/Avalonia) [![downloads](https://img.shields.io/nuget/dt/avalonia)](https://www.nuget.org/packages/Avalonia)  ![Size](https://img.shields.io/github/repo-size/avaloniaui/avalonia.svg) 
 
+# ⚠️ **v11 Update - Pausing community contributions**
+
+for more information see [this](https://github.com/AvaloniaUI/Avalonia/discussions/10599) discussion.
+
 ## 📖 About 
 
 Avalonia is a cross-platform UI framework for dotnet, providing a flexible styling system and supporting a wide range of Operating Systems such as Windows, Linux, macOS. Avalonia is mature and production ready. We also have in beta release support for iOS, Android and in early stages support for browser via WASM.
diff --git a/samples/ControlCatalog.Android/Properties/AndroidManifest.xml b/samples/ControlCatalog.Android/Properties/AndroidManifest.xml
index 6f551d2b01..ec07a94b22 100644
--- a/samples/ControlCatalog.Android/Properties/AndroidManifest.xml
+++ b/samples/ControlCatalog.Android/Properties/AndroidManifest.xml
@@ -2,4 +2,6 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" android:installLocation="auto">
   <application android:label="ControlCatalog.Android" android:icon="@drawable/Icon"></application>
   <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+  <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
+  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE " />
 </manifest>
diff --git a/samples/ControlCatalog/MainView.xaml b/samples/ControlCatalog/MainView.xaml
index 3681298a72..9f06525821 100644
--- a/samples/ControlCatalog/MainView.xaml
+++ b/samples/ControlCatalog/MainView.xaml
@@ -241,7 +241,7 @@
               </ComboBox.Items>
             </ComboBox>
             <ComboBox HorizontalAlignment="Stretch"
-                      Items="{Binding WindowStates}"
+                      ItemsSource="{Binding WindowStates}"
                       SelectedItem="{Binding WindowState}" />
           </StackPanel>
         </Flyout>
diff --git a/samples/ControlCatalog/Pages/ComboBoxPage.xaml.cs b/samples/ControlCatalog/Pages/ComboBoxPage.xaml.cs
index 6d759597b5..47f97e63a3 100644
--- a/samples/ControlCatalog/Pages/ComboBoxPage.xaml.cs
+++ b/samples/ControlCatalog/Pages/ComboBoxPage.xaml.cs
@@ -18,7 +18,7 @@ namespace ControlCatalog.Pages
         {
             AvaloniaXamlLoader.Load(this);
             var fontComboBox = this.Get<ComboBox>("fontComboBox");
-            fontComboBox.Items = FontManager.Current.SystemFonts;
+            fontComboBox.ItemsSource = FontManager.Current.SystemFonts;
             fontComboBox.SelectedIndex = 0;
         }
     }
diff --git a/samples/ControlCatalog/Pages/CompositionPage.axaml.cs b/samples/ControlCatalog/Pages/CompositionPage.axaml.cs
index 8b12a2d663..0d3061f361 100644
--- a/samples/ControlCatalog/Pages/CompositionPage.axaml.cs
+++ b/samples/ControlCatalog/Pages/CompositionPage.axaml.cs
@@ -32,7 +32,7 @@ public partial class CompositionPage : UserControl
     protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
     {
         base.OnAttachedToVisualTree(e);
-        this.Get<ItemsControl>("Items").Items = CreateColorItems();
+        this.Get<ItemsControl>("Items").ItemsSource = CreateColorItems();
 
     }
 
diff --git a/samples/ControlCatalog/Pages/ContextFlyoutPage.xaml b/samples/ControlCatalog/Pages/ContextFlyoutPage.xaml
index 6ef6a202b6..cb294442d2 100644
--- a/samples/ControlCatalog/Pages/ContextFlyoutPage.xaml
+++ b/samples/ControlCatalog/Pages/ContextFlyoutPage.xaml
@@ -61,7 +61,7 @@
         <Border.Styles>
           <Style Selector="MenuFlyoutPresenter MenuItem" x:DataType="viewModels:MenuItemViewModel">
             <Setter Property="Header" Value="{Binding Header}"/>
-            <Setter Property="Items" Value="{Binding Items}"/>
+            <Setter Property="ItemsSource" Value="{Binding Items}"/>
             <Setter Property="Command" Value="{Binding Command}"/>
             <Setter Property="CommandParameter" Value="{Binding CommandParameter}"/>
           </Style>
diff --git a/samples/ControlCatalog/Pages/ContextMenuPage.xaml b/samples/ControlCatalog/Pages/ContextMenuPage.xaml
index 962f0308f7..06eba52605 100644
--- a/samples/ControlCatalog/Pages/ContextMenuPage.xaml
+++ b/samples/ControlCatalog/Pages/ContextMenuPage.xaml
@@ -51,13 +51,13 @@
         <Border.Styles>
           <Style Selector="ContextMenu MenuItem" x:DataType="viewModels:MenuItemViewModel">
             <Setter Property="Header" Value="{Binding Header}"/>
-            <Setter Property="Items" Value="{Binding Items}"/>
+            <Setter Property="ItemsSource" Value="{Binding Items}"/>
             <Setter Property="Command" Value="{Binding Command}"/>
             <Setter Property="CommandParameter" Value="{Binding CommandParameter}"/>
           </Style>
         </Border.Styles>
         <Border.ContextMenu>
-          <ContextMenu Items="{Binding MenuItems}" />
+          <ContextMenu ItemsSource="{Binding MenuItems}" />
         </Border.ContextMenu>
         <TextBlock Text="Dynamically Generated"/>
       </Border>
diff --git a/samples/ControlCatalog/Pages/CursorPage.xaml b/samples/ControlCatalog/Pages/CursorPage.xaml
index 30bad06d72..66f2b8b2e3 100644
--- a/samples/ControlCatalog/Pages/CursorPage.xaml
+++ b/samples/ControlCatalog/Pages/CursorPage.xaml
@@ -8,7 +8,7 @@
       <TextBlock Classes="h2">Defines a cursor (mouse pointer)</TextBlock>
     </StackPanel>
 
-    <ListBox Grid.Row="1" Items="{Binding StandardCursors}" Margin="0 8 8 8">
+    <ListBox Grid.Row="1" ItemsSource="{Binding StandardCursors}" Margin="0 8 8 8">
       <ListBox.Styles>
         <Style Selector="ListBoxItem">
           <Setter Property="Cursor" Value="{Binding Cursor}" x:DataType="viewModels:StandardCursorModel"/>
diff --git a/samples/ControlCatalog/Pages/DialogsPage.xaml.cs b/samples/ControlCatalog/Pages/DialogsPage.xaml.cs
index e5f29abb68..971a6a6718 100644
--- a/samples/ControlCatalog/Pages/DialogsPage.xaml.cs
+++ b/samples/ControlCatalog/Pages/DialogsPage.xaml.cs
@@ -106,7 +106,7 @@ namespace ControlCatalog.Pages
                     Directory = initialDirectory,
                     InitialFileName = initialFileName
                 }.ShowAsync(GetWindow());
-                results.Items = result;
+                results.ItemsSource = result;
                 resultsVisible.IsVisible = result?.Any() == true;
             };
             this.Get<Button>("OpenMultipleFiles").Click += async delegate
@@ -118,7 +118,7 @@ namespace ControlCatalog.Pages
                     Directory = lastSelectedDirectory?.Path is {IsAbsoluteUri:true} path ? path.LocalPath : null,
                     AllowMultiple = true
                 }.ShowAsync(GetWindow());
-                results.Items = result;
+                results.ItemsSource = result;
                 resultsVisible.IsVisible = result?.Any() == true;
             };
             this.Get<Button>("SaveFile").Click += async delegate
@@ -132,7 +132,7 @@ namespace ControlCatalog.Pages
                     DefaultExtension = filters?.Any() == true ? "txt" : null,
                     InitialFileName = "test.txt"
                 }.ShowAsync(GetWindow());
-                results.Items = new[] { result };
+                results.ItemsSource = new[] { result };
                 resultsVisible.IsVisible = result != null;
             };
             this.Get<Button>("SelectFolder").Click += async delegate
@@ -149,7 +149,7 @@ namespace ControlCatalog.Pages
                 else
                 {
                     SetFolder(await GetStorageProvider().TryGetFolderFromPathAsync(result));
-                    results.Items = new[] { result };
+                    results.ItemsSource = new[] { result };
                     resultsVisible.IsVisible = true;
                 }
             };
@@ -164,7 +164,7 @@ namespace ControlCatalog.Pages
                 {
                     AllowDirectorySelection = true
                 });
-                results.Items = result;
+                results.ItemsSource = result;
                 resultsVisible.IsVisible = result?.Any() == true;
             };
             this.Get<Button>("DecoratedWindow").Click += delegate
@@ -324,15 +324,15 @@ namespace ControlCatalog.Pages
                         mappedResults.Add("+> " + FullPathOrName(selectedItem));
                         if (selectedItem is IStorageFolder folder)
                         {
-                            foreach (var innerItems in await folder.GetItemsAsync())
+                            await foreach (var innerItem in folder.GetItemsAsync())
                             {
-                                mappedResults.Add("++> " + FullPathOrName(innerItems));
+                                mappedResults.Add("++> " + FullPathOrName(innerItem));
                             }
                         }
                     }
                 }
 
-                results.Items = mappedResults;
+                results.ItemsSource = mappedResults;
                 resultsVisible.IsVisible = mappedResults.Any();
             }
         }
diff --git a/samples/ControlCatalog/Pages/DragAndDropPage.xaml.cs b/samples/ControlCatalog/Pages/DragAndDropPage.xaml.cs
index 26430b4b61..7fb5bec589 100644
--- a/samples/ControlCatalog/Pages/DragAndDropPage.xaml.cs
+++ b/samples/ControlCatalog/Pages/DragAndDropPage.xaml.cs
@@ -104,8 +104,12 @@ namespace ControlCatalog.Pages
                         }
                         else if (item is IStorageFolder folder)
                         {
-                            var items = await folder.GetItemsAsync();
-                            contentStr += $"Folder {item.Name}: items {items.Count}{Environment.NewLine}{Environment.NewLine}";
+                            var childrenCount = 0;
+                            await foreach (var _ in folder.GetItemsAsync())
+                            {
+                                childrenCount++;
+                            }
+                            contentStr += $"Folder {item.Name}: items {childrenCount}{Environment.NewLine}{Environment.NewLine}";
                         }
                     }
 
diff --git a/samples/ControlCatalog/Pages/ListBoxPage.xaml b/samples/ControlCatalog/Pages/ListBoxPage.xaml
index b1b1b99c9c..eef81c25fa 100644
--- a/samples/ControlCatalog/Pages/ListBoxPage.xaml
+++ b/samples/ControlCatalog/Pages/ListBoxPage.xaml
@@ -30,7 +30,7 @@
       <Button Command="{Binding RemoveItemCommand}">Remove</Button>
       <Button Command="{Binding SelectRandomItemCommand}">Select Random Item</Button>
     </StackPanel>
-    <ListBox Items="{Binding Items}"
+    <ListBox ItemsSource="{Binding Items}"
              Selection="{Binding Selection}"
              DisplayMemberBinding="{Binding (viewModels:ItemModel).ID, StringFormat='{}Item {0:N0}'}"
              AutoScrollToSelectedItem="{Binding AutoScrollToSelectedItem}"
diff --git a/samples/ControlCatalog/Pages/MenuPage.xaml b/samples/ControlCatalog/Pages/MenuPage.xaml
index 6eb109874f..40476f91f7 100644
--- a/samples/ControlCatalog/Pages/MenuPage.xaml
+++ b/samples/ControlCatalog/Pages/MenuPage.xaml
@@ -45,11 +45,11 @@
 
             <StackPanel>
                 <TextBlock Classes="h3" Margin="4 8">Dyanamically generated</TextBlock>
-                <Menu Items="{Binding MenuItems}">
+                <Menu ItemsSource="{Binding MenuItems}">
                     <Menu.Styles>
                         <Style Selector="MenuItem" x:DataType="viewModels:MenuItemViewModel">
                             <Setter Property="Header" Value="{Binding Header}"/>
-                            <Setter Property="Items" Value="{Binding Items}"/>
+                            <Setter Property="ItemsSource" Value="{Binding Items}"/>
                             <Setter Property="Command" Value="{Binding Command}"/>
                             <Setter Property="CommandParameter" Value="{Binding CommandParameter}"/>
                         </Style>
@@ -68,7 +68,7 @@
                         <Separator/>
                         <MenuItem Header="Execu_te Script..." />
                         <Separator/>
-                        <MenuItem Header="_Recent" Items="{Binding RecentItems}">
+                        <MenuItem Header="_Recent" ItemsSource="{Binding RecentItems}">
                             <MenuItem.Styles>
                                 <Style Selector="MenuItem" x:DataType="viewModels:MenuItemViewModel">
                                     <Setter Property="Header" Value="{Binding Header}"/>
diff --git a/samples/ControlCatalog/Pages/NativeEmbedPage.xaml.cs b/samples/ControlCatalog/Pages/NativeEmbedPage.xaml.cs
index 83554c007d..5e6f035027 100644
--- a/samples/ControlCatalog/Pages/NativeEmbedPage.xaml.cs
+++ b/samples/ControlCatalog/Pages/NativeEmbedPage.xaml.cs
@@ -33,10 +33,10 @@ namespace ControlCatalog.Pages
         {
             new ContextMenu()
             {
-                Items = new List<MenuItem>
-            {
-                new MenuItem() { Header = "Test" }, new MenuItem() { Header = "Test" }
-            }
+                Items =
+                {
+                    new MenuItem() { Header = "Test" }, new MenuItem() { Header = "Test" }
+                }
             }.Open((Control)sender);
         }
 
diff --git a/samples/ControlCatalog/Pages/NumericUpDownPage.xaml b/samples/ControlCatalog/Pages/NumericUpDownPage.xaml
index e76787f184..51516ff0b1 100644
--- a/samples/ControlCatalog/Pages/NumericUpDownPage.xaml
+++ b/samples/ControlCatalog/Pages/NumericUpDownPage.xaml
@@ -27,7 +27,7 @@
       </Grid>
       <Grid Grid.Row="0" Grid.Column="1" Margin="8" ColumnDefinitions="Auto, 120" RowDefinitions="Auto,Auto,Auto,Auto,Auto">
         <TextBlock Grid.Row="0" Grid.Column="0" VerticalAlignment="Center" Margin="2">FormatString:</TextBlock>
-        <ComboBox Grid.Row="0" Grid.Column="1" Items="{Binding Formats}" SelectedItem="{Binding SelectedFormat}"
+        <ComboBox Grid.Row="0" Grid.Column="1" ItemsSource="{Binding Formats}" SelectedItem="{Binding SelectedFormat}"
                   VerticalAlignment="Center" Margin="2">
           <ComboBox.ItemTemplate>
             <DataTemplate>
@@ -41,11 +41,11 @@
         </ComboBox>
 
         <TextBlock Grid.Row="1" Grid.Column="0" VerticalAlignment="Center" Margin="2">ButtonSpinnerLocation:</TextBlock>
-        <ComboBox Grid.Row="1" Grid.Column="1" Items="{Binding SpinnerLocations}" SelectedItem="{Binding #upDown.ButtonSpinnerLocation}"
+        <ComboBox Grid.Row="1" Grid.Column="1" ItemsSource="{Binding SpinnerLocations}" SelectedItem="{Binding #upDown.ButtonSpinnerLocation}"
                   VerticalAlignment="Center" Margin="2"/>
 
         <TextBlock Grid.Row="2" Grid.Column="0" VerticalAlignment="Center" Margin="2">CultureInfo:</TextBlock>
-        <ComboBox x:Name="CultureSelector" Grid.Row="2" Grid.Column="1" Items="{Binding Cultures}"
+        <ComboBox x:Name="CultureSelector" Grid.Row="2" Grid.Column="1" ItemsSource="{Binding Cultures}"
                   VerticalAlignment="Center" Margin="2"/>
 
         <TextBlock Grid.Row="3" Grid.Column="0" VerticalAlignment="Center" Margin="2">Watermark:</TextBlock>
diff --git a/samples/ControlCatalog/Pages/RefreshContainerPage.axaml b/samples/ControlCatalog/Pages/RefreshContainerPage.axaml
index f3bf1724b4..f6ea26a84c 100644
--- a/samples/ControlCatalog/Pages/RefreshContainerPage.axaml
+++ b/samples/ControlCatalog/Pages/RefreshContainerPage.axaml
@@ -21,7 +21,7 @@
                       Margin="5">
       <ListBox HorizontalAlignment="Stretch"
                VerticalAlignment="Top"
-               Items="{Binding Items}"/>
+               ItemsSource="{Binding Items}"/>
     </RefreshContainer>
   </DockPanel>
 </UserControl>
diff --git a/samples/ControlCatalog/Pages/ScrollSnapPage.xaml b/samples/ControlCatalog/Pages/ScrollSnapPage.xaml
index 237822041b..fa206f0dff 100644
--- a/samples/ControlCatalog/Pages/ScrollSnapPage.xaml
+++ b/samples/ControlCatalog/Pages/ScrollSnapPage.xaml
@@ -16,14 +16,14 @@
         <StackPanel Orientation="Vertical"
                     Spacing="4">
           <TextBlock Text="Snap Point Type" />
-          <ComboBox Items="{Binding AvailableSnapPointsType}"
+          <ComboBox ItemsSource="{Binding AvailableSnapPointsType}"
                     SelectedItem="{Binding SnapPointsType}" />
         </StackPanel>
 
         <StackPanel Orientation="Vertical"
                     Spacing="4">
           <TextBlock Text="Snap Point Alignment" />
-          <ComboBox Items="{Binding AvailableSnapPointsAlignment}"
+          <ComboBox ItemsSource="{Binding AvailableSnapPointsAlignment}"
                     SelectedItem="{Binding SnapPointsAlignment}" />
         </StackPanel>
 
diff --git a/samples/ControlCatalog/Pages/ScrollViewerPage.xaml b/samples/ControlCatalog/Pages/ScrollViewerPage.xaml
index fa8714959b..1a3d61eb85 100644
--- a/samples/ControlCatalog/Pages/ScrollViewerPage.xaml
+++ b/samples/ControlCatalog/Pages/ScrollViewerPage.xaml
@@ -13,12 +13,12 @@
 
         <StackPanel Orientation="Vertical" Spacing="4">
           <TextBlock Text="Horizontal Scroll" />
-          <ComboBox Items="{Binding AvailableVisibility}" SelectedItem="{Binding HorizontalScrollVisibility}" />
+          <ComboBox ItemsSource="{Binding AvailableVisibility}" SelectedItem="{Binding HorizontalScrollVisibility}" />
         </StackPanel>
 
         <StackPanel Orientation="Vertical" Spacing="4">
           <TextBlock Text="Vertical Scroll" />
-          <ComboBox Items="{Binding AvailableVisibility}" SelectedItem="{Binding VerticalScrollVisibility}" />
+          <ComboBox ItemsSource="{Binding AvailableVisibility}" SelectedItem="{Binding VerticalScrollVisibility}" />
         </StackPanel>
       </StackPanel>
 
diff --git a/samples/ControlCatalog/Pages/TabStripPage.xaml b/samples/ControlCatalog/Pages/TabStripPage.xaml
index 533590b48d..b576beeb5f 100644
--- a/samples/ControlCatalog/Pages/TabStripPage.xaml
+++ b/samples/ControlCatalog/Pages/TabStripPage.xaml
@@ -18,7 +18,7 @@
         <Separator Margin="0 16"/>
 
         <TextBlock Classes="h1">Dynamically generated</TextBlock>
-        <TabStrip Items="{Binding Tabs}">
+        <TabStrip ItemsSource="{Binding Tabs}">
             <TabStrip.Styles>
                 <Style Selector="TabStripItem" x:DataType="viewModels:TabControlPageViewModelItem">
                     <Setter Property="IsEnabled" Value="{Binding IsEnabled}"/>
diff --git a/samples/ControlCatalog/Pages/ThemePage.axaml.cs b/samples/ControlCatalog/Pages/ThemePage.axaml.cs
index 5a0c4cba43..d355b399a4 100644
--- a/samples/ControlCatalog/Pages/ThemePage.axaml.cs
+++ b/samples/ControlCatalog/Pages/ThemePage.axaml.cs
@@ -12,7 +12,7 @@ namespace ControlCatalog.Pages
         {
             InitializeComponent();
 
-            Selector.Items = new[]
+            Selector.ItemsSource = new[]
             {
                 ThemeVariant.Default,
                 ThemeVariant.Dark,
diff --git a/samples/ControlCatalog/Pages/TransitioningContentControlPage.axaml b/samples/ControlCatalog/Pages/TransitioningContentControlPage.axaml
index 42042652e3..88f2aa68fc 100644
--- a/samples/ControlCatalog/Pages/TransitioningContentControlPage.axaml
+++ b/samples/ControlCatalog/Pages/TransitioningContentControlPage.axaml
@@ -53,7 +53,7 @@
             
             <StackPanel Margin="5" Spacing="5" Grid.IsSharedSizeScope="True">
                 <HeaderedContentControl Header="Select a transition">
-                     <ComboBox Items="{Binding PageTransitions}" SelectedItem="{Binding SelectedTransition}" />
+                     <ComboBox ItemsSource="{Binding PageTransitions}" SelectedItem="{Binding SelectedTransition}" />
                 </HeaderedContentControl>
                 <HeaderedContentControl Header="Duration">
                      <NumericUpDown Value="{Binding Duration}" Increment="250" Minimum="100" />
diff --git a/samples/ControlCatalog/Pages/TreeViewPage.xaml b/samples/ControlCatalog/Pages/TreeViewPage.xaml
index 1665a59c0a..2e3fca58cb 100644
--- a/samples/ControlCatalog/Pages/TreeViewPage.xaml
+++ b/samples/ControlCatalog/Pages/TreeViewPage.xaml
@@ -11,7 +11,7 @@
                 HorizontalAlignment="Center"
                 Spacing="16">
       <StackPanel Orientation="Vertical" Spacing="8">
-        <TreeView Items="{Binding Items}" SelectedItems="{Binding SelectedItems}" SelectionMode="{Binding SelectionMode}" Width="250" Height="350">
+        <TreeView ItemsSource="{Binding Items}" SelectedItems="{Binding SelectedItems}" SelectionMode="{Binding SelectionMode}" Width="250" Height="350">
           <TreeView.ItemTemplate>
             <TreeDataTemplate ItemsSource="{Binding Children}">
               <TextBlock Text="{Binding Header}"/>
diff --git a/samples/IntegrationTestApp/MainWindow.axaml b/samples/IntegrationTestApp/MainWindow.axaml
index 090cf23b33..95378ed717 100644
--- a/samples/IntegrationTestApp/MainWindow.axaml
+++ b/samples/IntegrationTestApp/MainWindow.axaml
@@ -109,7 +109,7 @@
           <StackPanel DockPanel.Dock="Bottom">
             <Button Name="ListBoxSelectionClear">Clear Selection</Button>
           </StackPanel>
-          <ListBox Name="BasicListBox" Items="{Binding ListBoxItems}" SelectionMode="Multiple"/>
+          <ListBox Name="BasicListBox" ItemsSource="{Binding ListBoxItems}" SelectionMode="Multiple"/>
         </DockPanel>
       </TabItem>
       
@@ -151,6 +151,12 @@
               <ComboBoxItem Name="ShowWindowStateMaximized">Maximized</ComboBoxItem>
               <ComboBoxItem Name="ShowWindowStateFullScreen">FullScreen</ComboBoxItem>
             </ComboBox>
+            <ComboBox Name="ShowWindowSystemDecorations" SelectedIndex="2">
+              <ComboBoxItem Name="ShowWindowSystemDecorationsNone">None</ComboBoxItem>
+              <ComboBoxItem Name="ShowWindowSystemDecorationsBorderOnly">BorderOnly</ComboBoxItem>
+              <ComboBoxItem Name="ShowWindowSystemDecorationsFull">Full</ComboBoxItem>
+            </ComboBox>
+            <CheckBox Name="ShowWindowExtendClientAreaToDecorationsHint">ExtendClientAreaToDecorationsHint</CheckBox>
             <CheckBox Name="ShowWindowCanResize" IsChecked="True">Can Resize</CheckBox>
             <Button Name="ShowWindow">Show Window</Button>
             <Button Name="SendToBack">Send to Back</Button>
@@ -167,6 +173,9 @@
       <TabItem Header="SliderTab">
           <Slider VerticalAlignment="Top" Name="Slider" Value="30"/>
       </TabItem>
+      <TabItem Header="ScrollBarTab">
+        <ScrollBar Name="MyScrollBar" Orientation="Horizontal" AllowAutoHide="False" Width="200" Height="30" Value="20"/>
+      </TabItem>
     </TabControl>
   </DockPanel>
 </Window>
diff --git a/samples/IntegrationTestApp/MainWindow.axaml.cs b/samples/IntegrationTestApp/MainWindow.axaml.cs
index 19eb1d64b0..c9c7939c1c 100644
--- a/samples/IntegrationTestApp/MainWindow.axaml.cs
+++ b/samples/IntegrationTestApp/MainWindow.axaml.cs
@@ -68,6 +68,8 @@ namespace IntegrationTestApp
             var locationComboBox = this.GetControl<ComboBox>("ShowWindowLocation");
             var stateComboBox = this.GetControl<ComboBox>("ShowWindowState");
             var size = !string.IsNullOrWhiteSpace(sizeTextBox.Text) ? Size.Parse(sizeTextBox.Text) : (Size?)null;
+            var systemDecorations = this.GetControl<ComboBox>("ShowWindowSystemDecorations");
+            var extendClientArea = this.GetControl<CheckBox>("ShowWindowExtendClientAreaToDecorationsHint");
             var canResizeCheckBox = this.GetControl<CheckBox>("ShowWindowCanResize");
             var owner = (Window)this.GetVisualRoot()!;
 
@@ -95,6 +97,8 @@ namespace IntegrationTestApp
             }
 
             sizeTextBox.Text = string.Empty;
+            window.ExtendClientAreaToDecorationsHint = extendClientArea.IsChecked ?? false;
+            window.SystemDecorations = (SystemDecorations)systemDecorations.SelectedIndex;
             window.WindowState = (WindowState)stateComboBox.SelectedIndex;
 
             switch (modeComboBox.SelectedIndex)
@@ -158,7 +162,7 @@ namespace IntegrationTestApp
             var popup = new Popup
             {
                 WindowManagerAddShadowHint = false,
-                PlacementMode = PlacementMode.AnchorAndGravity,
+                Placement = PlacementMode.AnchorAndGravity,
                 PlacementAnchor = PopupAnchor.Top,
                 PlacementGravity = PopupGravity.Bottom,
                 Width= 200,
diff --git a/samples/IntegrationTestApp/ShowWindowTest.axaml b/samples/IntegrationTestApp/ShowWindowTest.axaml
index bd6910dd4d..720ff6c344 100644
--- a/samples/IntegrationTestApp/ShowWindowTest.axaml
+++ b/samples/IntegrationTestApp/ShowWindowTest.axaml
@@ -6,7 +6,7 @@
         x:DataType="Window"
         Title="Show Window Test">
   <integrationTestApp:MeasureBorder Name="MyBorder">
-    <Grid ColumnDefinitions="Auto,Auto" RowDefinitions="Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto">
+    <Grid ColumnDefinitions="Auto,Auto" RowDefinitions="Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto">
       <Label Grid.Column="0" Grid.Row="1">Client Size</Label>
       <TextBox Name="CurrentClientSize" Grid.Column="1" Grid.Row="1" IsReadOnly="True"
                Text="{Binding ClientSize, Mode=OneWay}" />
@@ -35,13 +35,25 @@
         <ComboBoxItem Name="WindowStateFullScreen">FullScreen</ComboBoxItem>
       </ComboBox>
 
-      <Label Grid.Column="0" Grid.Row="8">Order (mac)</Label>
-      <TextBox Name="CurrentOrder" Grid.Column="1" Grid.Row="8" IsReadOnly="True" />
+      <Label Grid.Column="0" Grid.Row="8">SystemDecorations</Label>
+      <ComboBox Name="CurrentSystemDecorations" Grid.Column="1" Grid.Row="8"  SelectedIndex="{Binding SystemDecorations}">
+        <ComboBoxItem Name="SystemDecorationsNone">None</ComboBoxItem>
+        <ComboBoxItem Name="SystemDecorationsBorderOnly">BorderOnly</ComboBoxItem>
+        <ComboBoxItem Name="SystemDecorationsFull">Full</ComboBoxItem>
+      </ComboBox>
+
+      <CheckBox Name="CurrentExtendClientAreaToDecorationsHint" Grid.ColumnSpan="2" Grid.Row="9"
+                IsChecked="{Binding ExtendClientAreaToDecorationsHint}">
+        ExtendClientAreaToDecorationsHint
+      </CheckBox>
+
+      <Label Grid.Column="0" Grid.Row="10">Order (mac)</Label>
+      <TextBox Name="CurrentOrder" Grid.Column="1" Grid.Row="10" IsReadOnly="True" />
       
-      <Label Grid.Row="9" Content="MeasuredWith:" />
-      <TextBlock Grid.Column="1" Grid.Row="9" Name="CurrentMeasuredWithText" Text="{Binding #MyBorder.MeasuredWith}" />
+      <Label Grid.Row="11" Content="MeasuredWith:" />
+      <TextBlock Grid.Column="1" Grid.Row="11" Name="CurrentMeasuredWithText" Text="{Binding #MyBorder.MeasuredWith}" />
 
-      <Button Name="HideButton" Grid.Row="10" Command="{Binding $parent[Window].Hide}">Hide</Button>
+      <Button Name="HideButton" Grid.Row="12" Command="{Binding $parent[Window].Hide}">Hide</Button>
       
     </Grid>
   </integrationTestApp:MeasureBorder>
diff --git a/samples/SampleControls/HamburgerMenu/HamburgerMenu.cs b/samples/SampleControls/HamburgerMenu/HamburgerMenu.cs
index 7ff8160720..57f8a138af 100644
--- a/samples/SampleControls/HamburgerMenu/HamburgerMenu.cs
+++ b/samples/SampleControls/HamburgerMenu/HamburgerMenu.cs
@@ -57,7 +57,7 @@ namespace ControlSamples
             {
                 if (_splitView is not null && _splitView.DisplayMode == SplitViewDisplayMode.Overlay)
                 {
-                    _splitView.SetValue(SplitView.IsPaneOpenProperty, false, Avalonia.Data.BindingPriority.Animation);
+                    _splitView.SetCurrentValue(SplitView.IsPaneOpenProperty, false);
                 }
             }
         }
diff --git a/src/Android/Avalonia.Android/Avalonia.Android.csproj b/src/Android/Avalonia.Android/Avalonia.Android.csproj
index 2533016e9f..d8b0c3d534 100644
--- a/src/Android/Avalonia.Android/Avalonia.Android.csproj
+++ b/src/Android/Avalonia.Android/Avalonia.Android.csproj
@@ -10,6 +10,7 @@
   <ItemGroup>
     <ProjectReference Include="..\..\..\packages\Avalonia\Avalonia.csproj" />
     <PackageReference Include="Xamarin.AndroidX.AppCompat" Version="1.3.1.3" />
+    <PackageReference Include="Xamarin.AndroidX.DocumentFile" Version="1.0.1.16" />
     <PackageReference Include="Xamarin.AndroidX.Lifecycle.ViewModel" Version="2.3.1.3" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/Android/Avalonia.Android/Platform/Storage/AndroidStorageItem.cs b/src/Android/Avalonia.Android/Platform/Storage/AndroidStorageItem.cs
index 0a34e6077c..f0c22d7f38 100644
--- a/src/Android/Avalonia.Android/Platform/Storage/AndroidStorageItem.cs
+++ b/src/Android/Avalonia.Android/Platform/Storage/AndroidStorageItem.cs
@@ -8,7 +8,10 @@ using System.Threading.Tasks;
 using Android;
 using Android.App;
 using Android.Content;
+using Android.OS;
 using Android.Provider;
+using Android.Webkit;
+using AndroidX.DocumentFile.Provider;
 using Avalonia.Logging;
 using Avalonia.Platform.Storage;
 using Java.Lang;
@@ -22,20 +25,25 @@ internal abstract class AndroidStorageItem : IStorageBookmarkItem
 {
     private Activity? _activity;
     private readonly bool _needsExternalFilesPermission;
+    private readonly AndroidStorageFolder? _parent;
+    private readonly AndroidUri? _permissionRoot;
 
-    protected AndroidStorageItem(Activity activity, AndroidUri uri, bool needsExternalFilesPermission)
+    protected AndroidStorageItem(Activity activity, AndroidUri uri, bool needsExternalFilesPermission, AndroidStorageFolder? parent = null, AndroidUri? permissionRoot = null)
     {
         _activity = activity;
         _needsExternalFilesPermission = needsExternalFilesPermission;
+        _parent = parent;
+        _permissionRoot = permissionRoot ?? parent?.Uri ?? Uri;
         Uri = uri;
     }
 
-    internal AndroidUri Uri { get; }
+    internal AndroidUri Uri { get; set; }
     
     protected Activity Activity => _activity ?? throw new ObjectDisposedException(nameof(AndroidStorageItem));
 
     public virtual string Name => GetColumnValue(Activity, Uri, MediaStore.IMediaColumns.DisplayName)
-                          ?? Uri.PathSegments?.LastOrDefault() ?? string.Empty;
+                          ?? Document?.Name
+                          ?? Uri.PathSegments?.LastOrDefault()?.Split("/", StringSplitOptions.RemoveEmptyEntries).LastOrDefault() ?? string.Empty;
 
     public Uri Path => new(Uri.ToString()!);
 
@@ -92,6 +100,23 @@ internal abstract class AndroidStorageItem : IStorageBookmarkItem
             return null;
         }
 
+        if(_parent != null)
+        {
+            return _parent;
+        }
+
+        var document = Document;
+
+        if (document == null)
+        {
+            return null;
+        }
+
+        if(document.ParentFile != null)
+        {
+            return new AndroidStorageFolder(Activity, document.ParentFile.Uri, true);
+        }
+
         using var javaFile = new JavaFile(Uri.Path!);
 
         // Java file represents files AND directories. Don't be confused.
@@ -118,12 +143,88 @@ internal abstract class AndroidStorageItem : IStorageBookmarkItem
     {
         _activity = null;
     }
+
+    internal DocumentFile? Document
+    {
+        get
+        {
+            if (this is AndroidStorageFile)
+            {
+                return DocumentFile.FromSingleUri(Activity, Uri);
+            }
+            else
+            {
+                return DocumentFile.FromTreeUri(Activity, Uri);
+            }
+        }
+    }
+
+    internal AndroidUri? PermissionRoot => _permissionRoot;
+
+    public abstract Task DeleteAsync();
+
+    public abstract Task<IStorageItem?> MoveAsync(IStorageFolder destination);
 }
 
 internal class AndroidStorageFolder : AndroidStorageItem, IStorageBookmarkFolder
 {
-    public AndroidStorageFolder(Activity activity, AndroidUri uri, bool needsExternalFilesPermission) : base(activity, uri, needsExternalFilesPermission)
+    public AndroidStorageFolder(Activity activity, AndroidUri uri, bool needsExternalFilesPermission, AndroidStorageFolder? parent = null, AndroidUri? permissionRoot = null) : base(activity, uri, needsExternalFilesPermission, parent, permissionRoot)
+    {
+    }
+
+    public async Task<IStorageFile?> CreateFileAsync(string name)
+    {
+        var mimeType = MimeTypeMap.Singleton?.GetMimeTypeFromExtension(MimeTypeMap.GetFileExtensionFromUrl(name)) ?? "application/octet-stream";
+        var newFile = Document.CreateFile(mimeType, name);
+
+        if(newFile == null)
+        {
+            return null;
+        }
+
+        return new AndroidStorageFile(Activity, newFile.Uri, this);
+    }
+
+    public async Task<IStorageFolder?> CreateFolderAsync(string name)
     {
+        var newFolder = Document?.CreateDirectory(name);
+
+        if (newFolder == null)
+        {
+            return null;
+        }
+
+        return new AndroidStorageFolder(Activity, newFolder.Uri, false, this, PermissionRoot);
+    }
+
+    public override async Task DeleteAsync()
+    {
+        if (!await EnsureExternalFilesPermission(false))
+        {
+            return;
+        }
+
+        if (Activity != null)
+        {
+            await DeleteContents(this);
+        }
+
+        async Task DeleteContents(AndroidStorageFolder storageFolder)
+        {
+            await foreach (var file in storageFolder.GetItemsAsync())
+            {
+                if(file is AndroidStorageFolder folder)
+                {
+                    await DeleteContents(folder);
+                }
+                else if(file is AndroidStorageFile storageFile)
+                {
+                    await storageFile.DeleteAsync();
+                }
+            }
+
+            DocumentFile.FromTreeUri(Activity, storageFolder.Uri)?.Delete();
+        }
     }
 
     public override Task<StorageItemProperties> GetBasicPropertiesAsync()
@@ -131,22 +232,22 @@ internal class AndroidStorageFolder : AndroidStorageItem, IStorageBookmarkFolder
         return Task.FromResult(new StorageItemProperties());
     }
 
-    public async Task<IReadOnlyList<IStorageItem>> GetItemsAsync()
+    public async IAsyncEnumerable<IStorageItem> GetItemsAsync()
     {
         if (!await EnsureExternalFilesPermission(false))
         {
-            return Array.Empty<IStorageItem>();
+            yield break;
         }
 
-        List<IStorageItem> files = new List<IStorageItem>();
-
         var contentResolver = Activity.ContentResolver;
         if (contentResolver == null)
         {
-            return files;
+            yield break;
         }
 
-        var childrenUri = DocumentsContract.BuildChildDocumentsUriUsingTree(Uri!, DocumentsContract.GetTreeDocumentId(Uri));
+        var root = PermissionRoot ?? Uri;
+        var folderId = root != Uri ? DocumentsContract.GetDocumentId(Uri) : DocumentsContract.GetTreeDocumentId(Uri);
+        var childrenUri = DocumentsContract.BuildChildDocumentsUriUsingTree(root, folderId);
 
         var projection = new[]
         {
@@ -162,19 +263,55 @@ internal class AndroidStorageFolder : AndroidStorageItem, IStorageBookmarkFolder
                 {
                     var mime = cursor.GetString(1);
                     var id = cursor.GetString(0);
-                    var uri = DocumentsContract.BuildDocumentUriUsingTree(Uri!, id);
+
+                    bool isDirectory = mime == DocumentsContract.Document.MimeTypeDir;
+                    var uri = DocumentsContract.BuildDocumentUriUsingTree(root, id);
+
                     if (uri == null)
                     {
                         continue;
                     }
-
-                    files.Add(mime == DocumentsContract.Document.MimeTypeDir ? new AndroidStorageFolder(Activity, uri, false) :
-                        new AndroidStorageFile(Activity, uri));
+                    yield return isDirectory ? new AndroidStorageFolder(Activity, uri, false, this, root) :
+                        new AndroidStorageFile(Activity, uri, this, root);
                 }
         }
+    }
+
+    public override async Task<IStorageItem?> MoveAsync(IStorageFolder destination)
+    {
+        if (Activity != null)
+        {
+            return await MoveRecursively(this, (AndroidStorageFolder)destination);
+        }
 
-        return files;
-    }       
+        return null;
+
+        async Task<AndroidStorageFolder?> MoveRecursively(AndroidStorageFolder storageFolder, AndroidStorageFolder destination)
+        {
+            destination = await destination.CreateFolderAsync(storageFolder.Name) as AndroidStorageFolder;
+
+            if (destination == null)
+            {
+                return null;
+            }
+
+            await foreach (var file in storageFolder.GetItemsAsync())
+            {
+                if (file is AndroidStorageFolder folder)
+                {
+                    await MoveRecursively(folder, destination);
+                }
+                else if (file is AndroidStorageFile)
+                {
+                    await file.MoveAsync(destination);
+                }
+            }
+
+            await storageFolder.DeleteAsync();
+
+            return destination;
+        }
+    }
 }
 
 internal sealed class WellKnownAndroidStorageFolder : AndroidStorageFolder
@@ -186,14 +323,14 @@ internal sealed class WellKnownAndroidStorageFolder : AndroidStorageFolder
     }
 
     public override string Name { get; }
-} 
+}
 
 internal sealed class AndroidStorageFile : AndroidStorageItem, IStorageBookmarkFile
 {
-    public AndroidStorageFile(Activity activity, AndroidUri uri) : base(activity, uri, false)
+    public AndroidStorageFile(Activity activity, AndroidUri uri, AndroidStorageFolder? parent = null, AndroidUri? permissionRoot = null) : base(activity, uri, false, parent, permissionRoot)
     {
     }
-    
+
     public Task<Stream> OpenReadAsync() => Task.FromResult(OpenContentStream(Activity, Uri, false)
         ?? throw new InvalidOperationException("Failed to open content stream"));
 
@@ -317,4 +454,76 @@ internal sealed class AndroidStorageFile : AndroidStorageItem, IStorageBookmarkF
 
         return Task.FromResult(new StorageItemProperties(size, itemDate, dateModified));
     }
+
+    public override async Task DeleteAsync()
+    {
+        if (!await EnsureExternalFilesPermission(false))
+        {
+            return;
+        }
+
+        if (Activity != null)
+        {
+            DocumentsContract.DeleteDocument(Activity.ContentResolver!, Uri);
+        }
+    }
+
+    public override async Task<IStorageItem?> MoveAsync(IStorageFolder destination)
+    {
+        if (!await EnsureExternalFilesPermission(false))
+        {
+            return null;
+        }
+
+        if (Activity != null && destination is AndroidStorageFolder storageFolder)
+        {
+            if (Build.VERSION.SdkInt >= BuildVersionCodes.N)
+            {
+                try
+                {
+                    var uri = DocumentsContract.MoveDocument(Activity.ContentResolver!, Uri, ((await GetParentAsync()) as AndroidStorageFolder)!.Uri, storageFolder.Document!.Uri);
+
+                    return new AndroidStorageFile(Activity, uri, storageFolder);
+                }
+                catch (Exception ex)
+                {
+                    // There are many reason why DocumentContract will fail to move a file. We fallback to copying.
+                    return await MoveFileByCopy();
+                    
+                }
+            }
+            else
+            {
+                return await MoveFileByCopy();
+            }
+        }
+
+        async Task<AndroidStorageFile?> MoveFileByCopy()
+        {
+            var newFile = await storageFolder.CreateFileAsync(Name) as AndroidStorageFile;
+
+            try
+            {
+                if (newFile != null)
+                {
+                    using var input = await OpenReadAsync();
+                    using var output = await newFile.OpenWriteAsync();
+
+                    await input.CopyToAsync(output);
+
+                    await DeleteAsync();
+
+                    return new AndroidStorageFile(Activity, newFile.Uri, storageFolder);
+                }
+            }
+            catch
+            {
+                newFile?.DeleteAsync();
+            }
+
+            return null;
+        }
+
+        return null;
+    }
 }
diff --git a/src/Avalonia.Base/AvaloniaProperty.cs b/src/Avalonia.Base/AvaloniaProperty.cs
index 24244c5068..e98d9f0517 100644
--- a/src/Avalonia.Base/AvaloniaProperty.cs
+++ b/src/Avalonia.Base/AvaloniaProperty.cs
@@ -4,7 +4,6 @@ using System.Diagnostics.CodeAnalysis;
 using Avalonia.Data;
 using Avalonia.Data.Core;
 using Avalonia.PropertyStore;
-using Avalonia.Styling;
 using Avalonia.Utilities;
 
 namespace Avalonia
@@ -20,12 +19,20 @@ namespace Avalonia
         public static readonly object UnsetValue = new UnsetValueType();
 
         private static int s_nextId;
+
+        /// <summary>
+        /// Provides a metadata object for types which have no metadata of their own.
+        /// </summary>
         private readonly AvaloniaPropertyMetadata _defaultMetadata;
+
+        /// <summary>
+        /// Provides a fast path when the property has no metadata overrides.
+        /// </summary>
+        private KeyValuePair<Type, AvaloniaPropertyMetadata>? _singleMetadata;
+
         private readonly Dictionary<Type, AvaloniaPropertyMetadata> _metadata;
         private readonly Dictionary<Type, AvaloniaPropertyMetadata> _metadataCache = new Dictionary<Type, AvaloniaPropertyMetadata>();
 
-        private bool _hasMetadataOverrides;
-
         /// <summary>
         /// Initializes a new instance of the <see cref="AvaloniaProperty"/> class.
         /// </summary>
@@ -57,7 +64,8 @@ namespace Avalonia
             Id = s_nextId++;
 
             _metadata.Add(ownerType, metadata ?? throw new ArgumentNullException(nameof(metadata)));
-            _defaultMetadata = metadata;
+            _defaultMetadata = metadata.GenerateTypeSafeMetadata();
+            _singleMetadata = new(ownerType, metadata);
         }
 
         /// <summary>
@@ -80,9 +88,6 @@ namespace Avalonia
             Id = source.Id;
             _defaultMetadata = source._defaultMetadata;
 
-            // Properties that have different owner can't use fast path for metadata.
-            _hasMetadataOverrides = true;
-
             if (metadata != null)
             {
                 _metadata.Add(ownerType, metadata);
@@ -257,7 +262,18 @@ namespace Avalonia
             return result;
         }
 
-        /// <inheritdoc cref="Register{TOwner, TValue}" />
+        /// <summary>
+        /// Registers an attached <see cref="AvaloniaProperty"/>.
+        /// </summary>
+        /// <typeparam name="TOwner">The type of the class that is registering the property.</typeparam>
+        /// <typeparam name="TValue">The type of the property's value.</typeparam>
+        /// <param name="name">The name of the property.</param>
+        /// <param name="defaultValue">The default value of the property.</param>
+        /// <param name="inherits">Whether the property inherits its value.</param>
+        /// <param name="defaultBindingMode">The default binding mode for the property.</param>
+        /// <param name="validate">A value validation callback.</param>
+        /// <param name="coerce">A value coercion callback.</param>
+        /// <param name="enableDataValidation">if is set to true enable data validation.</param>
         /// <param name="notifying">
         /// A method that gets called before and after the property starts being notified on an
         /// object; the bool argument will be true before and false afterwards. This callback is
@@ -442,33 +458,14 @@ namespace Avalonia
         }
 
         /// <summary>
-        /// Gets the property metadata for the specified type.
+        /// Gets the <see cref="AvaloniaPropertyMetadata"/> which applies to this property when it is used with the specified type.
         /// </summary>
-        /// <typeparam name="T">The type.</typeparam>
-        /// <returns>
-        /// The property metadata.
-        /// </returns>
-        public AvaloniaPropertyMetadata GetMetadata<T>() where T : AvaloniaObject
-        {
-            return GetMetadata(typeof(T));
-        }
+        /// <typeparam name="T">The type for which to retrieve metadata.</typeparam>
+        public AvaloniaPropertyMetadata GetMetadata<T>() where T : AvaloniaObject => GetMetadata(typeof(T));
 
-        /// <summary>
-        /// Gets the property metadata for the specified type.
-        /// </summary>
-        /// <param name="type">The type.</param>
-        /// <returns>
-        /// The property metadata.
-        /// </returns>
-        public AvaloniaPropertyMetadata GetMetadata(Type type)
-        {
-            if (!_hasMetadataOverrides)
-            {
-                return _defaultMetadata;
-            }
-
-            return GetMetadataWithOverrides(type);
-        }
+        /// <inheritdoc cref="GetMetadata{T}"/>
+        /// <param name="type">The type for which to retrieve metadata.</param>
+        public AvaloniaPropertyMetadata GetMetadata(Type type) => GetMetadataWithOverrides(type);
 
         /// <summary>
         /// Checks whether the <paramref name="value"/> is valid for the property.
@@ -567,7 +564,7 @@ namespace Avalonia
             _metadata.Add(type, metadata);
             _metadataCache.Clear();
 
-            _hasMetadataOverrides = true;
+            _singleMetadata = null;
         }
 
         protected abstract IObservable<AvaloniaPropertyChangedEventArgs> GetChanged();
@@ -584,7 +581,12 @@ namespace Avalonia
                 return result;
             }
 
-            Type? currentType = type;
+            if (_singleMetadata is { } singleMetadata)
+            {
+                return _metadataCache[type] = singleMetadata.Key.IsAssignableFrom(type) ? singleMetadata.Value : _defaultMetadata;
+            }
+
+            var currentType = type;
 
             while (currentType != null)
             {
@@ -598,13 +600,11 @@ namespace Avalonia
                 currentType = currentType.BaseType;
             }
 
-            _metadataCache[type] = _defaultMetadata;
-
-            return _defaultMetadata;
+            return _metadataCache[type] = _defaultMetadata;
         }
 
         bool IPropertyInfo.CanGet => true;
-        bool IPropertyInfo.CanSet => true;
+        bool IPropertyInfo.CanSet => !IsReadOnly;
         object? IPropertyInfo.Get(object target) => ((AvaloniaObject)target).GetValue(this);
         void IPropertyInfo.Set(object target, object? value) => ((AvaloniaObject)target).SetValue(this, value);
     }
diff --git a/src/Avalonia.Base/AvaloniaPropertyMetadata.cs b/src/Avalonia.Base/AvaloniaPropertyMetadata.cs
index 62bb65351f..ec29d14693 100644
--- a/src/Avalonia.Base/AvaloniaPropertyMetadata.cs
+++ b/src/Avalonia.Base/AvaloniaPropertyMetadata.cs
@@ -5,7 +5,7 @@ namespace Avalonia
     /// <summary>
     /// Base class for avalonia property metadata.
     /// </summary>
-    public class AvaloniaPropertyMetadata
+    public abstract class AvaloniaPropertyMetadata
     {
         private BindingMode _defaultBindingMode;
 
@@ -61,5 +61,13 @@ namespace Avalonia
 
             EnableDataValidation ??= baseMetadata.EnableDataValidation;
         }
+
+        /// <summary>
+        /// Gets a copy of this object configured for use with any owner type.
+        /// </summary>
+        /// <remarks>
+        /// For example, delegates which receive the owner object should be removed.
+        /// </remarks>
+        public abstract AvaloniaPropertyMetadata GenerateTypeSafeMetadata();
     }
 }
diff --git a/src/Avalonia.Base/AvaloniaPropertyRegistry.cs b/src/Avalonia.Base/AvaloniaPropertyRegistry.cs
index fc0ca2323e..8e6f7b0983 100644
--- a/src/Avalonia.Base/AvaloniaPropertyRegistry.cs
+++ b/src/Avalonia.Base/AvaloniaPropertyRegistry.cs
@@ -364,7 +364,7 @@ namespace Avalonia
         /// <param name="property">The property.</param>
         /// <remarks>
         /// You won't usually want to call this method directly, instead use the
-        /// <see cref="AvaloniaProperty.Register{TOwner, TValue}(string, TValue, bool, Data.BindingMode, Func{TValue, bool}, Func{AvaloniaObject, TValue, TValue}, Action{AvaloniaObject, bool})"/>
+        /// <see cref="AvaloniaProperty.Register{TOwner, TValue}(string, TValue, bool, Data.BindingMode, Func{TValue, bool}, Func{AvaloniaObject, TValue, TValue}, bool)"/>
         /// method.
         /// </remarks>
         public void Register(Type type, AvaloniaProperty property)
diff --git a/src/Avalonia.Base/CornerRadius.cs b/src/Avalonia.Base/CornerRadius.cs
index 1666fac2e1..82791999d7 100644
--- a/src/Avalonia.Base/CornerRadius.cs
+++ b/src/Avalonia.Base/CornerRadius.cs
@@ -60,15 +60,6 @@ namespace Avalonia
         /// </summary>
         public double BottomLeft { get; }
 
-        /// <summary>
-        /// Gets a value indicating whether the instance has default values (all corner radii are set to 0).
-        /// </summary>
-        public bool IsDefault => TopLeft == 0 && TopRight == 0 && BottomLeft == 0 && BottomRight == 0;
-
-        /// <inheritdoc cref="IsDefault"/>
-        [Obsolete("Use IsDefault instead.")]
-        public bool IsEmpty => IsDefault;
-
         /// <summary>
         /// Gets a value indicating whether all corner radii are equal.
         /// </summary>
diff --git a/src/Avalonia.Base/DirectPropertyMetadata`1.cs b/src/Avalonia.Base/DirectPropertyMetadata`1.cs
index 451ff6ce00..5471826f9f 100644
--- a/src/Avalonia.Base/DirectPropertyMetadata`1.cs
+++ b/src/Avalonia.Base/DirectPropertyMetadata`1.cs
@@ -45,5 +45,7 @@ namespace Avalonia
                 UnsetValue ??= src.UnsetValue;
             }
         }
+
+        public override AvaloniaPropertyMetadata GenerateTypeSafeMetadata() => new DirectPropertyMetadata<TValue>(UnsetValue, DefaultBindingMode, EnableDataValidation);
     }
 }
diff --git a/src/Avalonia.Base/Input/GestureRecognizers/VelocityTracker.cs b/src/Avalonia.Base/Input/GestureRecognizers/VelocityTracker.cs
index ce41aa6308..20dd376aaa 100644
--- a/src/Avalonia.Base/Input/GestureRecognizers/VelocityTracker.cs
+++ b/src/Avalonia.Base/Input/GestureRecognizers/VelocityTracker.cs
@@ -180,7 +180,7 @@ namespace Avalonia.Input.GestureRecognizers
         internal Velocity GetVelocity()
         {
             var estimate = GetVelocityEstimate();
-            if (estimate == null || estimate.PixelsPerSecond.IsDefault)
+            if (estimate == null || estimate.PixelsPerSecond == default(Vector))
             {
                 return new Velocity(Vector.Zero);
             }
diff --git a/src/Avalonia.Base/Media/BoxShadow.cs b/src/Avalonia.Base/Media/BoxShadow.cs
index dd2c23f4ae..32b2f7a2fb 100644
--- a/src/Avalonia.Base/Media/BoxShadow.cs
+++ b/src/Avalonia.Base/Media/BoxShadow.cs
@@ -45,15 +45,6 @@ namespace Avalonia.Media
             }
         }
 
-        /// <summary>
-        /// Gets a value indicating whether the instance has default values.
-        /// </summary>
-        public bool IsDefault => OffsetX == 0 && OffsetY == 0 && Blur == 0 && Spread == 0;
-
-        /// <inheritdoc cref="IsDefault"/>
-        [Obsolete("Use IsDefault instead.")]
-        public bool IsEmpty => IsDefault;
-
         private readonly static char[] s_Separator = new char[] { ' ', '\t' };
 
         struct ArrayReader
@@ -89,7 +80,7 @@ namespace Avalonia.Media
         {
             var sb = StringBuilderCache.Acquire();
 
-            if (IsDefault)
+            if (this == default)
             {
                 return "none";
             }
diff --git a/src/Avalonia.Base/Media/BoxShadows.cs b/src/Avalonia.Base/Media/BoxShadows.cs
index 50ae7699dd..ca16452a96 100644
--- a/src/Avalonia.Base/Media/BoxShadows.cs
+++ b/src/Avalonia.Base/Media/BoxShadows.cs
@@ -21,7 +21,7 @@ namespace Avalonia.Media
         {
             _first = shadow;
             _list = null;
-            Count = _first.IsDefault ? 0 : 1;
+            Count = _first == default ? 0 : 1;
         }
 
         public BoxShadows(BoxShadow first, BoxShadow[] rest)
@@ -120,7 +120,7 @@ namespace Avalonia.Media
             get
             {
                 foreach(var boxShadow in this)
-                    if (!boxShadow.IsDefault && boxShadow.IsInset)
+                    if (boxShadow != default && boxShadow.IsInset)
                         return true;
                 return false;
             }
diff --git a/src/Avalonia.Base/Media/DrawingGroup.cs b/src/Avalonia.Base/Media/DrawingGroup.cs
index a0ed29250b..c96d2aad57 100644
--- a/src/Avalonia.Base/Media/DrawingGroup.cs
+++ b/src/Avalonia.Base/Media/DrawingGroup.cs
@@ -117,10 +117,10 @@ namespace Avalonia.Media
             // root DrawingGroup, and be the same value as the root _currentDrawingGroup.
             //
             // Either way, _rootDrawing always references the root drawing.
-            protected Drawing? _rootDrawing;
+            private Drawing? _rootDrawing;
 
             // Current DrawingGroup that new children are added to
-            protected DrawingGroup? _currentDrawingGroup;
+            private DrawingGroup? _currentDrawingGroup;
 
             // Previous values of _currentDrawingGroup
             private Stack<DrawingGroup?>? _previousDrawingGroupStack;
diff --git a/src/Avalonia.Base/Media/FontFamily.cs b/src/Avalonia.Base/Media/FontFamily.cs
index f4406bd010..498bcd43a0 100644
--- a/src/Avalonia.Base/Media/FontFamily.cs
+++ b/src/Avalonia.Base/Media/FontFamily.cs
@@ -79,11 +79,6 @@ namespace Avalonia.Media
         /// <remarks>Key is only used for custom fonts.</remarks>
         public FontFamilyKey? Key { get; }
 
-        /// <summary>
-        /// Returns <c>True</c> if this instance is the system's default.
-        /// </summary>
-        public bool IsDefault => Name.Equals(DefaultFontFamilyName);
-
         /// <summary>
         /// Implicit conversion of string to FontFamily
         /// </summary>
diff --git a/src/Avalonia.Base/Media/FontManager.cs b/src/Avalonia.Base/Media/FontManager.cs
index 5890b90954..cc9bc6f30a 100644
--- a/src/Avalonia.Base/Media/FontManager.cs
+++ b/src/Avalonia.Base/Media/FontManager.cs
@@ -119,7 +119,9 @@ namespace Avalonia.Media
                     }
                 }
 
-                if (fontCollection != null && fontCollection.TryGetGlyphTypeface(fontFamily.FamilyNames.PrimaryFamilyName,
+                var familyName = fontFamily.FamilyNames.PrimaryFamilyName.ToUpperInvariant();
+
+                if (fontCollection != null && fontCollection.TryGetGlyphTypeface(familyName,
                     typeface.Style, typeface.Weight, typeface.Stretch, out glyphTypeface))
                 {
                     return true;
@@ -133,13 +135,13 @@ namespace Avalonia.Media
 
             foreach (var familyName in fontFamily.FamilyNames)
             {
-                if (SystemFonts.TryGetGlyphTypeface(familyName, typeface.Style, typeface.Weight, typeface.Stretch, out glyphTypeface))
+                if (SystemFonts.TryGetGlyphTypeface(familyName.ToUpperInvariant(), typeface.Style, typeface.Weight, typeface.Stretch, out glyphTypeface))
                 {
                     return true;
                 }
             }
 
-            return SystemFonts.TryGetGlyphTypeface(DefaultFontFamilyName, typeface.Style, typeface.Weight, typeface.Stretch, out glyphTypeface);
+            return TryGetGlyphTypeface(new Typeface(DefaultFontFamilyName, typeface.Style, typeface.Weight, typeface.Stretch), out glyphTypeface);
         }
 
         /// <summary>
diff --git a/src/Avalonia.Base/Media/Fonts/EmbeddedFontCollection.cs b/src/Avalonia.Base/Media/Fonts/EmbeddedFontCollection.cs
index f2fb490592..3350358d68 100644
--- a/src/Avalonia.Base/Media/Fonts/EmbeddedFontCollection.cs
+++ b/src/Avalonia.Base/Media/Fonts/EmbeddedFontCollection.cs
@@ -3,7 +3,6 @@ using System.Collections;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using System.Globalization;
 using Avalonia.Platform;
 
 namespace Avalonia.Media.Fonts
@@ -43,11 +42,13 @@ namespace Avalonia.Media.Fonts
 
                 if (fontManager.TryCreateGlyphTypeface(stream, out var glyphTypeface))
                 {
-                    if (!_glyphTypefaceCache.TryGetValue(glyphTypeface.FamilyName, out var glyphTypefaces))
+                    var familyName = glyphTypeface.FamilyName.ToUpperInvariant();
+
+                    if (!_glyphTypefaceCache.TryGetValue(familyName, out var glyphTypefaces))
                     {
                         glyphTypefaces = new ConcurrentDictionary<FontCollectionKey, IGlyphTypeface>();
 
-                        if (_glyphTypefaceCache.TryAdd(glyphTypeface.FamilyName, glyphTypefaces))
+                        if (_glyphTypefaceCache.TryAdd(familyName, glyphTypefaces))
                         {
                             _fontFamilies.Add(new FontFamily(_key, glyphTypeface.FamilyName));
                         }
@@ -86,6 +87,8 @@ namespace Avalonia.Media.Fonts
         public bool TryGetGlyphTypeface(string familyName, FontStyle style, FontWeight weight,
             FontStretch stretch, [NotNullWhen(true)] out IGlyphTypeface? glyphTypeface)
         {
+            familyName = familyName.ToUpperInvariant();
+
             var key = new FontCollectionKey(style, weight, stretch);
 
             if (_glyphTypefaceCache.TryGetValue(familyName, out var glyphTypefaces))
@@ -101,9 +104,11 @@ namespace Avalonia.Media.Fonts
             {
                 var fontFamily = _fontFamilies[i];
 
-                if (fontFamily.Name.ToLower(CultureInfo.InvariantCulture).StartsWith(familyName.ToLower(CultureInfo.InvariantCulture)))
+                if (fontFamily.Name.ToUpperInvariant().StartsWith(familyName.ToUpperInvariant()))
                 {
-                    if (_glyphTypefaceCache.TryGetValue(fontFamily.Name, out glyphTypefaces) &&
+                    familyName = fontFamily.Name.ToUpperInvariant();
+
+                    if (_glyphTypefaceCache.TryGetValue(familyName, out glyphTypefaces) &&
                         TryGetNearestMatch(glyphTypefaces, key, out glyphTypeface))
                     {
                         return true;
diff --git a/src/Avalonia.Base/Media/Fonts/SystemFontCollection.cs b/src/Avalonia.Base/Media/Fonts/SystemFontCollection.cs
index fd332c6ebe..1687deb37b 100644
--- a/src/Avalonia.Base/Media/Fonts/SystemFontCollection.cs
+++ b/src/Avalonia.Base/Media/Fonts/SystemFontCollection.cs
@@ -42,6 +42,8 @@ namespace Avalonia.Media.Fonts
                 familyName = _fontManager.DefaultFontFamilyName;
             }
 
+            familyName = familyName.ToUpperInvariant();
+
             var key = new FontCollectionKey(style, weight, stretch);
 
             if (_glyphTypefaceCache.TryGetValue(familyName, out var glyphTypefaces))
diff --git a/src/Avalonia.Base/Media/FormattedText.cs b/src/Avalonia.Base/Media/FormattedText.cs
index d4640390d7..7d204ca8cd 100644
--- a/src/Avalonia.Base/Media/FormattedText.cs
+++ b/src/Avalonia.Base/Media/FormattedText.cs
@@ -1393,10 +1393,11 @@ namespace Avalonia.Media
                 }
             }
 
-            if (accumulatedBounds?.PlatformImpl == null || accumulatedBounds.PlatformImpl.Bounds.IsDefault)
+            if (accumulatedBounds?.PlatformImpl == null ||
+                (accumulatedBounds.PlatformImpl.Bounds.Width == 0 && accumulatedBounds.PlatformImpl.Bounds.Height == 0))
             {
                 return null;
-            }            
+            }
 
             return accumulatedBounds;
         }
diff --git a/src/Avalonia.Base/Media/ImageDrawing.cs b/src/Avalonia.Base/Media/ImageDrawing.cs
index d3e5c4841b..77b1c52be0 100644
--- a/src/Avalonia.Base/Media/ImageDrawing.cs
+++ b/src/Avalonia.Base/Media/ImageDrawing.cs
@@ -42,7 +42,7 @@ namespace Avalonia.Media
             var imageSource = ImageSource;
             var rect = Rect;
 
-            if (imageSource is object && !rect.IsDefault)
+            if (imageSource is object && (rect.Width != 0 || rect.Height != 0))
             {
                 context.DrawImage(imageSource, rect);
             }
diff --git a/src/Avalonia.Base/Media/Imaging/CroppedBitmap.cs b/src/Avalonia.Base/Media/Imaging/CroppedBitmap.cs
index 8e57f9a902..8cdf5b592a 100644
--- a/src/Avalonia.Base/Media/Imaging/CroppedBitmap.cs
+++ b/src/Avalonia.Base/Media/Imaging/CroppedBitmap.cs
@@ -77,7 +77,7 @@ namespace Avalonia.Media.Imaging
             {
                 if (Source is not IBitmap bmp)
                     return default;
-                if (SourceRect.IsDefault)
+                if (SourceRect.Width == 0 && SourceRect.Height == 0)
                     return Source.Size;
                 return SourceRect.Size.ToSizeWithDpi(bmp.Dpi);
             }
diff --git a/src/Avalonia.Base/Media/TextFormatting/TextFormatterImpl.cs b/src/Avalonia.Base/Media/TextFormatting/TextFormatterImpl.cs
index 12efb3c383..a40cbf95ad 100644
--- a/src/Avalonia.Base/Media/TextFormatting/TextFormatterImpl.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/TextFormatterImpl.cs
@@ -658,7 +658,7 @@ namespace Avalonia.Media.TextFormatting
         /// Performs text wrapping returns a list of text lines.
         /// </summary>
         /// <param name="textRuns"></param>
-        /// <param name="canReuseTextRunList">Whether <see cref="textRuns"/> can be reused to store the split runs.</param>
+        /// <param name="canReuseTextRunList">Whether <see cref="TextRun"/> can be reused to store the split runs.</param>
         /// <param name="firstTextSourceIndex">The first text source index.</param>
         /// <param name="paragraphWidth">The paragraph width.</param>
         /// <param name="paragraphProperties">The text paragraph properties.</param>
diff --git a/src/Avalonia.Base/Metadata/InheritDataTypeFromItemsAttribute.cs b/src/Avalonia.Base/Metadata/InheritDataTypeFromItemsAttribute.cs
index fac8cd8737..e9bd6ab89f 100644
--- a/src/Avalonia.Base/Metadata/InheritDataTypeFromItemsAttribute.cs
+++ b/src/Avalonia.Base/Metadata/InheritDataTypeFromItemsAttribute.cs
@@ -9,7 +9,7 @@ namespace Avalonia.Metadata;
 /// A typical usage example is a ListBox control, where <see cref="InheritDataTypeFromItemsAttribute"/> is defined on the ItemTemplate property,
 /// allowing the template to inherit the data type from the Items collection binding. 
 /// </remarks>
-[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
+[AttributeUsage(AttributeTargets.Property, AllowMultiple = true, Inherited = true)]
 public sealed class InheritDataTypeFromItemsAttribute : Attribute
 {
     /// <summary>
diff --git a/src/Avalonia.Base/PixelRect.cs b/src/Avalonia.Base/PixelRect.cs
index ef207a3dae..85ec1041c3 100644
--- a/src/Avalonia.Base/PixelRect.cs
+++ b/src/Avalonia.Base/PixelRect.cs
@@ -9,12 +9,6 @@ namespace Avalonia
     /// </summary>
     public readonly struct PixelRect : IEquatable<PixelRect>
     {
-        /// <summary>
-        /// An empty rectangle.
-        /// </summary>
-        [Obsolete("Use the default keyword instead.")]
-        public static readonly PixelRect Empty = default;
-
         /// <summary>
         /// Initializes a new instance of the <see cref="PixelRect"/> structure.
         /// </summary>
@@ -133,15 +127,6 @@ namespace Avalonia
         /// </summary>
         public PixelPoint Center => new PixelPoint(X + (Width / 2), Y + (Height / 2));
 
-        /// <summary>
-        /// Gets a value indicating whether the instance has default values (the rectangle is empty).
-        /// </summary>
-        public bool IsDefault => Width == 0 && Height == 0;
-
-        /// <inheritdoc cref="IsDefault"/>
-        [Obsolete("Use IsDefault instead.")]
-        public bool IsEmpty => IsDefault;
-
         /// <summary>
         /// Checks for equality between two <see cref="PixelRect"/>s.
         /// </summary>
@@ -295,11 +280,11 @@ namespace Avalonia
         /// <returns>The union.</returns>
         public PixelRect Union(PixelRect rect)
         {
-            if (IsDefault)
+            if (Width == 0 && Height == 0)
             {
                 return rect;
             }
-            else if (rect.IsDefault)
+            else if (rect.Width == 0 && rect.Height == 0)
             {
                 return this;
             }
diff --git a/src/Avalonia.Base/Platform/IDrawingContextImpl.cs b/src/Avalonia.Base/Platform/IDrawingContextImpl.cs
index 8962bc1586..ffdfa9aac1 100644
--- a/src/Avalonia.Base/Platform/IDrawingContextImpl.cs
+++ b/src/Avalonia.Base/Platform/IDrawingContextImpl.cs
@@ -128,6 +128,7 @@ namespace Avalonia.Platform
         /// Pushes an opacity value.
         /// </summary>
         /// <param name="opacity">The opacity.</param>
+        /// <param name="bounds">where to apply the opacity.</param>
         void PushOpacity(double opacity, Rect bounds);
 
         /// <summary>
diff --git a/src/Avalonia.Base/Platform/Storage/FileIO/BclStorageFile.cs b/src/Avalonia.Base/Platform/Storage/FileIO/BclStorageFile.cs
index 543fb0ab74..f9f02ec339 100644
--- a/src/Avalonia.Base/Platform/Storage/FileIO/BclStorageFile.cs
+++ b/src/Avalonia.Base/Platform/Storage/FileIO/BclStorageFile.cs
@@ -92,4 +92,22 @@ internal class BclStorageFile : IStorageBookmarkFile
         Dispose(disposing: true);
         GC.SuppressFinalize(this);
     }
+
+    public async Task DeleteAsync()
+    {
+        FileInfo.Delete();
+    }
+
+    public async Task<IStorageItem?> MoveAsync(IStorageFolder destination)
+    {
+        if (destination is BclStorageFolder storageFolder)
+        {
+            var newPath = System.IO.Path.Combine(storageFolder.DirectoryInfo.FullName, FileInfo.Name);
+            FileInfo.MoveTo(newPath);
+
+            return new BclStorageFile(new FileInfo(newPath));
+        }
+
+        return null;
+    }
 }
diff --git a/src/Avalonia.Base/Platform/Storage/FileIO/BclStorageFolder.cs b/src/Avalonia.Base/Platform/Storage/FileIO/BclStorageFolder.cs
index d8e3d91f75..8c657fb787 100644
--- a/src/Avalonia.Base/Platform/Storage/FileIO/BclStorageFolder.cs
+++ b/src/Avalonia.Base/Platform/Storage/FileIO/BclStorageFolder.cs
@@ -57,14 +57,16 @@ internal class BclStorageFolder : IStorageBookmarkFolder
         return Task.FromResult<IStorageFolder?>(null);
     }
 
-    public Task<IReadOnlyList<IStorageItem>> GetItemsAsync()
+    public async IAsyncEnumerable<IStorageItem> GetItemsAsync()
     {
-         var items = DirectoryInfo.GetDirectories()
+        var items = DirectoryInfo.EnumerateDirectories()
             .Select(d => (IStorageItem)new BclStorageFolder(d))
-            .Concat(DirectoryInfo.GetFiles().Select(f => new BclStorageFile(f)))
-            .ToArray();
+            .Concat(DirectoryInfo.EnumerateFiles().Select(f => new BclStorageFile(f)));
 
-         return Task.FromResult<IReadOnlyList<IStorageItem>>(items);
+        foreach (var item in items)
+        {
+            yield return item;
+        }
     }
 
     public virtual Task<string?> SaveBookmarkAsync()
@@ -92,4 +94,39 @@ internal class BclStorageFolder : IStorageBookmarkFolder
         Dispose(disposing: true);
         GC.SuppressFinalize(this);
     }
+
+    public async Task DeleteAsync()
+    {
+        DirectoryInfo.Delete(true);
+    }
+
+    public async Task<IStorageItem?> MoveAsync(IStorageFolder destination)
+    {
+        if (destination is BclStorageFolder storageFolder)
+        {
+            var newPath = System.IO.Path.Combine(storageFolder.DirectoryInfo.FullName, DirectoryInfo.Name);
+            DirectoryInfo.MoveTo(newPath);
+
+            return new BclStorageFolder(new DirectoryInfo(newPath));
+        }
+
+        return null;
+    }
+
+    public async Task<IStorageFile?> CreateFileAsync(string name)
+    {
+        var fileName = System.IO.Path.Combine(DirectoryInfo.FullName, name);
+        var newFile = new FileInfo(fileName);
+        
+        using var stream = newFile.Create();
+
+        return new BclStorageFile(newFile);
+    }
+
+    public async Task<IStorageFolder?> CreateFolderAsync(string name)
+    {
+        var newFolder = DirectoryInfo.CreateSubdirectory(name);
+
+        return new BclStorageFolder(newFolder);
+    }
 }
diff --git a/src/Avalonia.Base/Platform/Storage/IStorageFolder.cs b/src/Avalonia.Base/Platform/Storage/IStorageFolder.cs
index 0ffb9f41c6..a9d1ff3669 100644
--- a/src/Avalonia.Base/Platform/Storage/IStorageFolder.cs
+++ b/src/Avalonia.Base/Platform/Storage/IStorageFolder.cs
@@ -16,5 +16,19 @@ public interface IStorageFolder : IStorageItem
     /// <returns>
     /// When this method completes successfully, it returns a list of the files and folders in the current folder. Each item in the list is represented by an <see cref="IStorageItem"/> implementation object.
     /// </returns>
-    Task<IReadOnlyList<IStorageItem>> GetItemsAsync();
+    IAsyncEnumerable<IStorageItem> GetItemsAsync();
+
+    /// <summary>
+    /// Creates a file with specified name as a child of the current storage folder
+    /// </summary>
+    /// <param name="name">The display name</param>
+    /// <returns>A new <see cref="IStorageFile"/> pointing to the moved file. If not null, the current storage item becomes invalid</returns>
+    Task<IStorageFile?> CreateFileAsync(string name);
+
+    /// <summary>
+    /// Creates a folder with specified name as a child of the current storage folder
+    /// </summary>
+    /// <param name="name">The display name</param>
+    /// <returns>A new <see cref="IStorageFolder"/> pointing to the moved file. If not null, the current storage item becomes invalid</returns>
+    Task<IStorageFolder?> CreateFolderAsync(string name);
 }
diff --git a/src/Avalonia.Base/Platform/Storage/IStorageItem.cs b/src/Avalonia.Base/Platform/Storage/IStorageItem.cs
index c2c93400b0..b5873fdb27 100644
--- a/src/Avalonia.Base/Platform/Storage/IStorageItem.cs
+++ b/src/Avalonia.Base/Platform/Storage/IStorageItem.cs
@@ -50,4 +50,17 @@ public interface IStorageItem : IDisposable
     /// Gets the parent folder of the current storage item.
     /// </summary>
     Task<IStorageFolder?> GetParentAsync();
+
+    /// <summary>
+    /// Deletes the current storage item and it's contents
+    /// </summary>
+    /// <returns></returns>
+    Task DeleteAsync();
+
+    /// <summary>
+    /// Moves the current storage item and it's contents to a <see cref="IStorageFolder"/>
+    /// </summary>
+    /// <param name="destination">The <see cref="IStorageFolder"/> to move the item into</param>
+    /// <returns></returns>
+    Task<IStorageItem?> MoveAsync(IStorageFolder destination);
 }
diff --git a/src/Avalonia.Base/Point.cs b/src/Avalonia.Base/Point.cs
index 86f7adf0d1..d11596d6be 100644
--- a/src/Avalonia.Base/Point.cs
+++ b/src/Avalonia.Base/Point.cs
@@ -288,13 +288,5 @@ namespace Avalonia
             x = this._x;
             y = this._y;
         }
-
-        /// <summary>
-        /// Gets a value indicating whether the X and Y coordinates are zero.
-        /// </summary>
-        public bool IsDefault
-        {
-            get { return (_x == 0) && (_y == 0); }
-        }
     }
 }
diff --git a/src/Avalonia.Base/PropertyStore/EffectiveValue`1.cs b/src/Avalonia.Base/PropertyStore/EffectiveValue`1.cs
index 0788b39459..330034f51d 100644
--- a/src/Avalonia.Base/PropertyStore/EffectiveValue`1.cs
+++ b/src/Avalonia.Base/PropertyStore/EffectiveValue`1.cs
@@ -31,7 +31,7 @@ namespace Avalonia.PropertyStore
 
             var value = inherited is null ? _metadata.DefaultValue : inherited.Value;
 
-            if (property.HasCoercion && _metadata.CoerceValue is { } coerce)
+            if (_metadata.CoerceValue is { } coerce)
             {
                 _uncommon = new()
                 {
diff --git a/src/Avalonia.Base/Rect.cs b/src/Avalonia.Base/Rect.cs
index 49dc087933..cc030eea04 100644
--- a/src/Avalonia.Base/Rect.cs
+++ b/src/Avalonia.Base/Rect.cs
@@ -16,12 +16,6 @@ namespace Avalonia
             Animation.Animation.RegisterAnimator<RectAnimator>(prop => typeof(Rect).IsAssignableFrom(prop.PropertyType));
         }
 
-        /// <summary>
-        /// An empty rectangle.
-        /// </summary>
-        [Obsolete("Use the default keyword instead.")]
-        public static readonly Rect Empty = default;
-
         /// <summary>
         /// The X position.
         /// </summary>
@@ -170,17 +164,6 @@ namespace Avalonia
         /// </summary>
         public Point Center => new Point(_x + (_width / 2), _y + (_height / 2));
 
-        /// <summary>
-        /// Gets a value indicating whether the instance has default values (the rectangle is empty).
-        /// </summary>
-        // ReSharper disable CompareOfFloatsByEqualityOperator
-        public bool IsDefault => _width == 0 && _height == 0;
-        // ReSharper restore CompareOfFloatsByEqualityOperator
-
-        /// <inheritdoc cref="IsDefault"/>
-        [Obsolete("Use IsDefault instead.")]
-        public bool IsEmpty => IsDefault;
-
         /// <summary>
         /// Checks for equality between two <see cref="Rect"/>s.
         /// </summary>
@@ -517,19 +500,18 @@ namespace Avalonia
             return rect;
         }
 
-
-            /// <summary>
-            /// Gets the union of two rectangles.
-            /// </summary>
-            /// <param name="rect">The other rectangle.</param>
-            /// <returns>The union.</returns>
-            public Rect Union(Rect rect)
+        /// <summary>
+        /// Gets the union of two rectangles.
+        /// </summary>
+        /// <param name="rect">The other rectangle.</param>
+        /// <returns>The union.</returns>
+        public Rect Union(Rect rect)
         {
-            if (IsDefault)
+            if (Width == 0 && Height == 0)
             {
                 return rect;
             }
-            else if (rect.IsDefault)
+            else if (rect.Width == 0 && rect.Height == 0)
             {
                 return this;
             }
diff --git a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionTarget.cs b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionTarget.cs
index 977acd8470..3e88b9e77b 100644
--- a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionTarget.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionTarget.cs
@@ -130,8 +130,8 @@ namespace Avalonia.Rendering.Composition.Server
             }
 
             _renderTarget ??= _compositor.CreateRenderTarget(_surfaces());
-            
-            if(_dirtyRect.IsDefault && !_redrawRequested)
+
+            if ((_dirtyRect.Width == 0 && _dirtyRect.Height == 0) && !_redrawRequested)
                 return;
 
             Revision++;
@@ -163,7 +163,7 @@ namespace Avalonia.Rendering.Composition.Server
                     _dirtyRect = new Rect(0, 0, layerSize.Width, layerSize.Height);
                 }
 
-                if (!_dirtyRect.IsDefault)
+                if (_dirtyRect.Width != 0 || _dirtyRect.Height != 0)
                 {
                     using (var context = _layer.CreateDrawingContext())
                     {
@@ -260,7 +260,7 @@ namespace Avalonia.Rendering.Composition.Server
         
         public void AddDirtyRect(Rect rect)
         {
-            if(rect.IsDefault)
+            if (rect.Width == 0 && rect.Height == 0)
                 return;
             var snapped = SnapToDevicePixels(rect, Scaling);
             DebugEvents?.RectInvalidated(rect);
@@ -275,7 +275,7 @@ namespace Avalonia.Rendering.Composition.Server
 
         public void Dispose()
         {
-            if(_disposed)
+            if (_disposed)
                 return;
             _disposed = true;
             using (_compositor.RenderInterface.EnsureCurrent())
@@ -302,7 +302,7 @@ namespace Avalonia.Rendering.Composition.Server
         {
             if (_attachedVisuals.Remove(visual) && IsEnabled)
                 visual.Deactivate();
-            if(visual.IsVisibleInFrame)
+            if (visual.IsVisibleInFrame)
                 AddDirtyRect(visual.TransformedOwnContentBounds);
         }
 
diff --git a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionVisual.cs b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionVisual.cs
index f9492d0015..6fb5ad3741 100644
--- a/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionVisual.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionVisual.cs
@@ -23,21 +23,20 @@ namespace Avalonia.Rendering.Composition.Server
         private bool _isBackface;
         private Rect? _transformedClipBounds;
         private Rect _combinedTransformedClipBounds;
-        
+
         protected virtual void RenderCore(CompositorDrawingContextProxy canvas, Rect currentTransformedClip)
         {
-            
         }
 
         public void Render(CompositorDrawingContextProxy canvas, Rect currentTransformedClip)
         {
-            if(Visible == false || IsVisibleInFrame == false)
+            if (Visible == false || IsVisibleInFrame == false)
                 return;
-            if(Opacity == 0)
+            if (Opacity == 0)
                 return;
 
             currentTransformedClip = currentTransformedClip.Intersect(_combinedTransformedClipBounds);
-            if(currentTransformedClip.IsDefault)
+            if (currentTransformedClip.Width == 0 && currentTransformedClip.Height == 0)
                 return;
 
             Root!.RenderedVisuals++;
@@ -61,7 +60,7 @@ namespace Avalonia.Rendering.Composition.Server
                 canvas.PushClip(Root!.SnapToDevicePixels(boundsRect));
             if (Clip != null) 
                 canvas.PushGeometryClip(Clip);
-            if(OpacityMaskBrush != null)
+            if (OpacityMaskBrush != null)
                 canvas.PushOpacityMask(OpacityMaskBrush, boundsRect);
 
             RenderCore(canvas, currentTransformedClip);
@@ -78,12 +77,12 @@ namespace Avalonia.Rendering.Composition.Server
                 canvas.PopClip();
             if (AdornedVisual != null && AdornerIsClipped)
                 canvas.PopClip();
-            if(Opacity != 1)
+            if (Opacity != 1)
                 canvas.PopOpacity();
         }
 
         protected virtual bool HandlesClipToBounds => false;
-        
+
         private ReadbackData _readback0, _readback1, _readback2;
 
         /// <summary>
@@ -98,17 +97,17 @@ namespace Avalonia.Rendering.Composition.Server
                 return ref _readback1;
             return ref _readback2;
         }
-        
+
         public Matrix4x4 CombinedTransformMatrix { get; private set; } = Matrix4x4.Identity;
         public Matrix4x4 GlobalTransformMatrix { get; private set; }
 
         public virtual void Update(ServerCompositionTarget root)
         {
-            if(Parent == null && Root == null)
+            if (Parent == null && Root == null)
                 return;
-            
+
             var wasVisible = IsVisibleInFrame;
-            
+
             // Calculate new parent-relative transform
             if (_combinedTransformDirty)
             {
@@ -122,7 +121,7 @@ namespace Avalonia.Rendering.Composition.Server
             var parentTransform = (AdornedVisual ?? Parent)?.GlobalTransformMatrix ?? Matrix4x4.Identity;
 
             var newTransform = CombinedTransformMatrix * parentTransform;
-            
+
             // Check if visual was moved and recalculate face orientation
             var positionChanged = false;
             if (GlobalTransformMatrix != newTransform)
@@ -134,23 +133,23 @@ namespace Avalonia.Rendering.Composition.Server
 
             var oldTransformedContentBounds = TransformedOwnContentBounds;
             var oldCombinedTransformedClipBounds = _combinedTransformedClipBounds;
-            
+
             if (_parent?.IsDirtyComposition == true)
             {
                 IsDirtyComposition = true;
                 _isDirtyForUpdate = true;
             }
-            
+
             var invalidateOldBounds = _isDirtyForUpdate;
             var invalidateNewBounds = _isDirtyForUpdate;
 
             GlobalTransformMatrix = newTransform;
-            
+
             var ownBounds = OwnContentBounds;
             if (ownBounds != _oldOwnContentBounds || positionChanged)
             {
                 _oldOwnContentBounds = ownBounds;
-                if (ownBounds.IsDefault)
+                if (ownBounds.Width == 0 && ownBounds.Height == 0)
                     TransformedOwnContentBounds = default;
                 else
                     TransformedOwnContentBounds =
@@ -171,16 +170,16 @@ namespace Avalonia.Rendering.Composition.Server
                 AdornedVisual?._combinedTransformedClipBounds
                 ?? Parent?._combinedTransformedClipBounds
                 ?? new Rect(Root!.Size);
-            
+
             if (_transformedClipBounds != null)
                 _combinedTransformedClipBounds = _combinedTransformedClipBounds.Intersect(_transformedClipBounds.Value);
-            
+
             EffectiveOpacity = Opacity * (Parent?.EffectiveOpacity ?? 1);
 
             IsHitTestVisibleInFrame = _parent?.IsHitTestVisibleInFrame != false
                                       && Visible
                                       && !_isBackface
-                                      && !_combinedTransformedClipBounds.IsDefault;
+                                      && (_combinedTransformedClipBounds.Width != 0 || _combinedTransformedClipBounds.Height != 0);
 
             IsVisibleInFrame = IsHitTestVisibleInFrame
                                && _parent?.IsVisibleInFrame != false
@@ -213,11 +212,11 @@ namespace Avalonia.Rendering.Composition.Server
 
         void AddDirtyRect(Rect rc)
         {
-            if(rc == default)
+            if (rc == default)
                 return;
             Root?.AddDirtyRect(rc);
         }
-        
+
         /// <summary>
         /// Data that can be read from the UI thread
         /// </summary>
@@ -228,7 +227,7 @@ namespace Avalonia.Rendering.Composition.Server
             public long TargetId;
             public bool Visible;
         }
-        
+
         partial void DeserializeChangesExtra(BatchStreamReader c)
         {
             ValuesInvalidated();
@@ -245,9 +244,8 @@ namespace Avalonia.Rendering.Composition.Server
 
         protected virtual void OnDetachedFromRoot(ServerCompositionTarget target)
         {
-            
         }
-        
+
         partial void OnRootChanged()
         {
             if (Root != null)
@@ -256,12 +254,11 @@ namespace Avalonia.Rendering.Composition.Server
                 OnAttachedToRoot(Root);
             }
         }
-        
+
         protected virtual void OnAttachedToRoot(ServerCompositionTarget target)
         {
-            
         }
-        
+
         protected override void ValuesInvalidated()
         {
             _isDirtyForUpdate = true;
@@ -274,6 +271,4 @@ namespace Avalonia.Rendering.Composition.Server
         public Rect TransformedOwnContentBounds { get; set; }
         public virtual Rect OwnContentBounds => new Rect(0, 0, Size.X, Size.Y);
     }
-
-
 }
diff --git a/src/Avalonia.Base/Rendering/DirtyRects.cs b/src/Avalonia.Base/Rendering/DirtyRects.cs
index 723fe400b3..610163191d 100644
--- a/src/Avalonia.Base/Rendering/DirtyRects.cs
+++ b/src/Avalonia.Base/Rendering/DirtyRects.cs
@@ -30,7 +30,7 @@ namespace Avalonia.Rendering
         /// </remarks>
         public void Add(Rect rect)
         {
-            if (!rect.IsDefault)
+            if (rect.Width != 0 || rect.Height != 0)
             {
                 for (var i = 0; i < _rects.Count; ++i)
                 {
diff --git a/src/Avalonia.Base/Rendering/DisplayDirtyRect.cs b/src/Avalonia.Base/Rendering/DisplayDirtyRect.cs
index 7e6c3062cd..7a89e5b3cc 100644
--- a/src/Avalonia.Base/Rendering/DisplayDirtyRect.cs
+++ b/src/Avalonia.Base/Rendering/DisplayDirtyRect.cs
@@ -3,7 +3,7 @@
 namespace Avalonia.Rendering
 {
     /// <summary>
-    /// Holds the state for a dirty rect rendered when <see cref="IRenderer.DrawDirtyRects"/> is set.
+    /// Holds the state for a dirty rect rendered when <see cref="IRenderer.SceneInvalidated"/> is set.
     /// </summary>
     internal class DisplayDirtyRect
     {
diff --git a/src/Avalonia.Base/Rendering/SceneGraph/GeometryNode.cs b/src/Avalonia.Base/Rendering/SceneGraph/GeometryNode.cs
index 3ab535897a..f64a3e845d 100644
--- a/src/Avalonia.Base/Rendering/SceneGraph/GeometryNode.cs
+++ b/src/Avalonia.Base/Rendering/SceneGraph/GeometryNode.cs
@@ -17,7 +17,6 @@ namespace Avalonia.Rendering.SceneGraph
         /// <param name="brush">The fill brush.</param>
         /// <param name="pen">The stroke pen.</param>
         /// <param name="geometry">The geometry.</param>
-        /// <param name="aux">Auxiliary data required to draw the brush.</param>
         public GeometryNode(Matrix transform,
             IImmutableBrush? brush,
             IPen? pen,
diff --git a/src/Avalonia.Base/Rendering/SceneGraph/LineNode.cs b/src/Avalonia.Base/Rendering/SceneGraph/LineNode.cs
index f21791d038..61bffc3260 100644
--- a/src/Avalonia.Base/Rendering/SceneGraph/LineNode.cs
+++ b/src/Avalonia.Base/Rendering/SceneGraph/LineNode.cs
@@ -17,7 +17,6 @@ namespace Avalonia.Rendering.SceneGraph
         /// <param name="pen">The stroke pen.</param>
         /// <param name="p1">The start point of the line.</param>
         /// <param name="p2">The end point of the line.</param>
-        /// <param name="aux">Auxiliary data required to draw the brush.</param>
         public LineNode(
             Matrix transform,
             IPen pen,
diff --git a/src/Avalonia.Base/Rendering/SceneGraph/OpacityMaskNode.cs b/src/Avalonia.Base/Rendering/SceneGraph/OpacityMaskNode.cs
index e10d712c2d..b0584038a8 100644
--- a/src/Avalonia.Base/Rendering/SceneGraph/OpacityMaskNode.cs
+++ b/src/Avalonia.Base/Rendering/SceneGraph/OpacityMaskNode.cs
@@ -17,7 +17,6 @@ namespace Avalonia.Rendering.SceneGraph
         /// </summary>
         /// <param name="mask">The opacity mask to push.</param>
         /// <param name="bounds">The bounds of the mask.</param>
-        /// <param name="aux">Auxiliary data required to draw the brush.</param>
         public OpacityMaskNode(IImmutableBrush mask, Rect bounds)
             : base(default, Matrix.Identity, mask)
         {
diff --git a/src/Avalonia.Base/Rendering/SceneGraph/RectangleNode.cs b/src/Avalonia.Base/Rendering/SceneGraph/RectangleNode.cs
index cee9ce9df7..94f61df47d 100644
--- a/src/Avalonia.Base/Rendering/SceneGraph/RectangleNode.cs
+++ b/src/Avalonia.Base/Rendering/SceneGraph/RectangleNode.cs
@@ -20,7 +20,6 @@ namespace Avalonia.Rendering.SceneGraph
         /// <param name="pen">The stroke pen.</param>
         /// <param name="rect">The rectangle to draw.</param>
         /// <param name="boxShadows">The box shadow parameters</param>
-        /// <param name="aux">Auxiliary data required to draw the brush.</param>
         public RectangleNode(
             Matrix transform,
             IImmutableBrush? brush,
diff --git a/src/Avalonia.Base/Size.cs b/src/Avalonia.Base/Size.cs
index aec237afae..7781aec607 100644
--- a/src/Avalonia.Base/Size.cs
+++ b/src/Avalonia.Base/Size.cs
@@ -27,12 +27,6 @@ namespace Avalonia
         /// </summary>
         public static readonly Size Infinity = new Size(double.PositiveInfinity, double.PositiveInfinity);
 
-        /// <summary>
-        /// A size representing zero.
-        /// </summary>
-        [Obsolete("Use the default keyword instead.")]
-        public static readonly Size Empty = new Size(0, 0);
-
         /// <summary>
         /// The width.
         /// </summary>
@@ -306,10 +300,5 @@ namespace Avalonia
             width = this._width;
             height = this._height;
         }
-
-        /// <summary>
-        /// Gets a value indicating whether the Width and Height values are zero.
-        /// </summary>
-        public bool IsDefault => (_width == 0) && (_height == 0);
     }
 }
diff --git a/src/Avalonia.Base/StyledProperty.cs b/src/Avalonia.Base/StyledProperty.cs
index 5052840013..e1b88cde49 100644
--- a/src/Avalonia.Base/StyledProperty.cs
+++ b/src/Avalonia.Base/StyledProperty.cs
@@ -18,7 +18,10 @@ namespace Avalonia
         /// <param name="ownerType">The type of the class that registers the property.</param>
         /// <param name="metadata">The property metadata.</param>
         /// <param name="inherits">Whether the property inherits its value.</param>
-        /// <param name="validate">A value validation callback.</param>
+        /// <param name="validate">
+        /// <para>A method which returns "false" for values that are never valid for this property.</para>
+        /// <para>This method is not part of the property's metadata and so cannot be changed after registration.</para>
+        /// </param>
         /// <param name="notifying">A <see cref="AvaloniaProperty.Notifying"/> callback.</param>
         public StyledProperty(
             string name,
@@ -31,7 +34,6 @@ namespace Avalonia
         {
             Inherits = inherits;
             ValidateValue = validate;
-            HasCoercion |= metadata.CoerceValue != null;
 
             if (validate?.Invoke(metadata.DefaultValue) == false)
             {
@@ -41,16 +43,10 @@ namespace Avalonia
         }
 
         /// <summary>
-        /// Gets the value validation callback for the property.
+        /// A method which returns "false" for values that are never valid for this property.
         /// </summary>
         public Func<TValue, bool>? ValidateValue { get; }
 
-        /// <summary>
-        /// Gets a value indicating whether this property has any value coercion callbacks defined
-        /// in its metadata.
-        /// </summary>
-        internal bool HasCoercion { get; private set; }
-
         /// <summary>
         /// Registers the property on another type.
         /// </summary>
@@ -127,10 +123,7 @@ namespace Avalonia
         /// </summary>
         /// <typeparam name="T">The type.</typeparam>
         /// <param name="metadata">The metadata.</param>
-        public void OverrideMetadata<T>(StyledPropertyMetadata<TValue> metadata) where T : AvaloniaObject
-        {
-            base.OverrideMetadata(typeof(T), metadata);
-        }
+        public void OverrideMetadata<T>(StyledPropertyMetadata<TValue> metadata) where T : AvaloniaObject => OverrideMetadata(typeof(T), metadata);
 
         /// <summary>
         /// Overrides the metadata for the property on the specified type.
@@ -148,8 +141,6 @@ namespace Avalonia
                 }
             }
 
-            HasCoercion |= metadata.CoerceValue != null;
-
             base.OverrideMetadata(type, metadata);
         }
 
diff --git a/src/Avalonia.Base/StyledPropertyMetadata`1.cs b/src/Avalonia.Base/StyledPropertyMetadata`1.cs
index 6f10de3651..9db460dba3 100644
--- a/src/Avalonia.Base/StyledPropertyMetadata`1.cs
+++ b/src/Avalonia.Base/StyledPropertyMetadata`1.cs
@@ -58,5 +58,7 @@ namespace Avalonia
                 }
             }
         }
+
+        public override AvaloniaPropertyMetadata GenerateTypeSafeMetadata() => new StyledPropertyMetadata<TValue>(DefaultValue, DefaultBindingMode, enableDataValidation: EnableDataValidation ?? false);
     }
 }
diff --git a/src/Avalonia.Base/Styling/TypeNameAndClassSelector.cs b/src/Avalonia.Base/Styling/TypeNameAndClassSelector.cs
index 4e0d37479b..a10b3eb3ea 100644
--- a/src/Avalonia.Base/Styling/TypeNameAndClassSelector.cs
+++ b/src/Avalonia.Base/Styling/TypeNameAndClassSelector.cs
@@ -52,7 +52,7 @@ namespace Avalonia.Styling
             return result;
         }
 
-        protected TypeNameAndClassSelector(Selector? previous)
+        TypeNameAndClassSelector(Selector? previous)
         {
             _previous = previous;
         }
diff --git a/src/Avalonia.Base/Thickness.cs b/src/Avalonia.Base/Thickness.cs
index f9e4355edd..9513d04782 100644
--- a/src/Avalonia.Base/Thickness.cs
+++ b/src/Avalonia.Base/Thickness.cs
@@ -97,10 +97,6 @@ namespace Avalonia
         /// </summary>
         public double Bottom => _bottom;
 
-        /// <inheritdoc cref="IsDefault"/>
-        [Obsolete("Use IsDefault instead.")]
-        public bool IsEmpty => IsDefault;
-
         /// <summary>
         /// Gets a value indicating whether all sides are equal.
         /// </summary>
@@ -293,11 +289,5 @@ namespace Avalonia
             right = this._right;
             bottom = this._bottom;
         }
-
-        /// <summary>
-        /// Gets a value indicating whether the instance has default values
-        /// (the left, top, right and bottom values are zero).
-        /// </summary>
-        public bool IsDefault => (_left == 0) && (_top == 0) && (_right == 0) && (_bottom == 0);
     }
 }
diff --git a/src/Avalonia.Base/Vector.cs b/src/Avalonia.Base/Vector.cs
index 810530066f..085f043627 100644
--- a/src/Avalonia.Base/Vector.cs
+++ b/src/Avalonia.Base/Vector.cs
@@ -360,13 +360,5 @@ namespace Avalonia
             x = this._x;
             y = this._y;
         }
-
-        /// <summary>
-        /// Gets a value indicating whether the X and Y components are zero.
-        /// </summary>
-        public bool IsDefault
-        {
-            get { return (_x == 0) && (_y == 0); }
-        }
     }
 }
diff --git a/src/Avalonia.Base/VisualTree/VisualExtensions.cs b/src/Avalonia.Base/VisualTree/VisualExtensions.cs
index 9e38c6e7f2..cc372f7c39 100644
--- a/src/Avalonia.Base/VisualTree/VisualExtensions.cs
+++ b/src/Avalonia.Base/VisualTree/VisualExtensions.cs
@@ -204,6 +204,69 @@ namespace Avalonia.VisualTree
             }
         }
 
+        public static TransformedBounds? GetTransformedBounds(this Visual visual)
+        {
+            Rect clip = default;
+            var transform = Matrix.Identity;
+
+            bool Visit(Visual visual)
+            {
+                if (!visual.IsVisible)
+                    return false;
+
+                // The visual's bounds in local coordinates.
+                var bounds = new Rect(visual.Bounds.Size);
+
+                // If the visual has no parent, we've reached the root. We start the clip
+                // rectangle with these bounds.
+                if (visual.GetVisualParent() is not { } parent)
+                {
+                    clip = bounds;
+                    return true;
+                }
+
+                // Otherwise recurse until the root visual is found, exiting early if one of the
+                // ancestors is invisible.
+                if (!Visit(parent))
+                    return false;
+
+                // Calculate the transform for this control from its offset and render transform.
+                var renderTransform = Matrix.Identity;
+
+                if (visual.HasMirrorTransform)
+                {
+                    var mirrorMatrix = new Matrix(-1.0, 0.0, 0.0, 1.0, visual.Bounds.Width, 0);
+                    renderTransform *= mirrorMatrix;
+                }
+
+                if (visual.RenderTransform != null)
+                {
+                    var origin = visual.RenderTransformOrigin.ToPixels(bounds.Size);
+                    var offset = Matrix.CreateTranslation(origin);
+                    var finalTransform = (-offset) * visual.RenderTransform.Value * offset;
+                    renderTransform *= finalTransform;
+                }
+
+                transform = renderTransform *
+                    Matrix.CreateTranslation(visual.Bounds.Position) *
+                    transform;
+
+                // If the visual is clipped, update the clip bounds.
+                if (visual.ClipToBounds)
+                {
+                    var globalBounds = bounds.TransformToAABB(transform);
+                    var clipBounds = visual.ClipToBounds ?
+                        globalBounds.Intersect(clip) :
+                        clip;
+                    clip = clip.Intersect(clipBounds);
+                }
+
+                return true;
+            }
+
+            return Visit(visual) ? new(new(visual.Bounds.Size), clip, transform) : null;
+        }
+
         /// <summary>
         /// Gets the first visual in the visual tree whose bounds contain a point.
         /// </summary>
diff --git a/src/Avalonia.Controls.ColorPicker/Themes/Fluent/ColorPicker.xaml b/src/Avalonia.Controls.ColorPicker/Themes/Fluent/ColorPicker.xaml
index 8f52b059f1..807e4de0b1 100644
--- a/src/Avalonia.Controls.ColorPicker/Themes/Fluent/ColorPicker.xaml
+++ b/src/Avalonia.Controls.ColorPicker/Themes/Fluent/ColorPicker.xaml
@@ -165,7 +165,7 @@
                     </TabItem.Header>
                     <ListBox Theme="{StaticResource ColorViewPaletteListBoxTheme}"
                              ItemContainerTheme="{StaticResource ColorViewPaletteListBoxItemTheme}"
-                             Items="{TemplateBinding PaletteColors}"
+                             ItemsSource="{TemplateBinding PaletteColors}"
                              SelectedItem="{Binding Color, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource DoNothingForNullConverter}, Mode=TwoWay}"
                              UseLayoutRounding="False"
                              Margin="12">
diff --git a/src/Avalonia.Controls.ColorPicker/Themes/Fluent/ColorView.xaml b/src/Avalonia.Controls.ColorPicker/Themes/Fluent/ColorView.xaml
index fab5415bfb..bcf1f96d22 100644
--- a/src/Avalonia.Controls.ColorPicker/Themes/Fluent/ColorView.xaml
+++ b/src/Avalonia.Controls.ColorPicker/Themes/Fluent/ColorView.xaml
@@ -414,7 +414,7 @@
               </TabItem.Header>
               <ListBox Theme="{StaticResource ColorViewPaletteListBoxTheme}"
                        ItemContainerTheme="{StaticResource ColorViewPaletteListBoxItemTheme}"
-                       Items="{TemplateBinding PaletteColors}"
+                       ItemsSource="{TemplateBinding PaletteColors}"
                        SelectedItem="{Binding Color, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource DoNothingForNullConverter}, Mode=TwoWay}"
                        UseLayoutRounding="False"
                        Margin="12">
diff --git a/src/Avalonia.Controls.ColorPicker/Themes/Simple/ColorPicker.xaml b/src/Avalonia.Controls.ColorPicker/Themes/Simple/ColorPicker.xaml
index d44902dd70..458f67ec4c 100644
--- a/src/Avalonia.Controls.ColorPicker/Themes/Simple/ColorPicker.xaml
+++ b/src/Avalonia.Controls.ColorPicker/Themes/Simple/ColorPicker.xaml
@@ -165,7 +165,7 @@
                     </TabItem.Header>
                     <ListBox Theme="{StaticResource ColorViewPaletteListBoxTheme}"
                              ItemContainerTheme="{StaticResource ColorViewPaletteListBoxItemTheme}"
-                             Items="{TemplateBinding PaletteColors}"
+                             ItemsSource="{TemplateBinding PaletteColors}"
                              SelectedItem="{Binding Color, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource DoNothingForNullConverter}, Mode=TwoWay}"
                              UseLayoutRounding="False"
                              Margin="12">
diff --git a/src/Avalonia.Controls.ColorPicker/Themes/Simple/ColorView.xaml b/src/Avalonia.Controls.ColorPicker/Themes/Simple/ColorView.xaml
index 0ce6dd5e04..a4fb7081ca 100644
--- a/src/Avalonia.Controls.ColorPicker/Themes/Simple/ColorView.xaml
+++ b/src/Avalonia.Controls.ColorPicker/Themes/Simple/ColorView.xaml
@@ -376,7 +376,7 @@
               </TabItem.Header>
               <ListBox Theme="{StaticResource ColorViewPaletteListBoxTheme}"
                        ItemContainerTheme="{StaticResource ColorViewPaletteListBoxItemTheme}"
-                       Items="{TemplateBinding PaletteColors}"
+                       ItemsSource="{TemplateBinding PaletteColors}"
                        SelectedItem="{Binding Color, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource DoNothingForNullConverter}, Mode=TwoWay}"
                        UseLayoutRounding="False"
                        Margin="12">
diff --git a/src/Avalonia.Controls.DataGrid/DataGrid.cs b/src/Avalonia.Controls.DataGrid/DataGrid.cs
index 91b65a1f72..72ebf10984 100644
--- a/src/Avalonia.Controls.DataGrid/DataGrid.cs
+++ b/src/Avalonia.Controls.DataGrid/DataGrid.cs
@@ -6066,8 +6066,9 @@ namespace Avalonia.Controls
             var numberOfItem = clipboardRowContent.Count;
             for (int cellIndex = 0; cellIndex < numberOfItem; cellIndex++)
             {
-                var cellContent = clipboardRowContent[cellIndex];
-                text.Append(cellContent.Content);
+                var cellContent = clipboardRowContent[cellIndex].Content?.ToString();
+                cellContent = cellContent?.Replace("\"", "\"\"");
+                text.Append($"\"{cellContent}\"");
                 if (cellIndex < numberOfItem - 1)
                 {
                     text.Append('\t');
diff --git a/src/Avalonia.Controls.DataGrid/DataGridCheckBoxColumn.cs b/src/Avalonia.Controls.DataGrid/DataGridCheckBoxColumn.cs
index 39c1e4c118..5d080f5ef6 100644
--- a/src/Avalonia.Controls.DataGrid/DataGridCheckBoxColumn.cs
+++ b/src/Avalonia.Controls.DataGrid/DataGridCheckBoxColumn.cs
@@ -177,14 +177,14 @@ namespace Avalonia.Controls
                 }
 
                 bool? uneditedValue = editingCheckBox.IsChecked;
-                if(editingEventArgs is PointerPressedEventArgs args)
+                if (editingEventArgs is PointerPressedEventArgs args)
                 {
                     void ProcessPointerArgs()
                     {
                         // Editing was triggered by a mouse click
                         Point position = args.GetPosition(editingCheckBox);
                         Rect rect = new Rect(0, 0, editingCheckBox.Bounds.Width, editingCheckBox.Bounds.Height);
-                        if(rect.Contains(position))
+                        if (rect.Contains(position))
                         {
                             EditValue();
                         }
@@ -192,14 +192,14 @@ namespace Avalonia.Controls
                     
                     void OnLayoutUpdated(object sender, EventArgs e)
                     {
-                        if(!editingCheckBox.Bounds.IsDefault)
+                        if (editingCheckBox.Bounds.Width != 0 || editingCheckBox.Bounds.Height != 0)
                         {
                             editingCheckBox.LayoutUpdated -= OnLayoutUpdated;
                             ProcessPointerArgs();
                         }
                     }
 
-                    if(editingCheckBox.Bounds.IsDefault)
+                    if (editingCheckBox.Bounds.Width == 0 && editingCheckBox.Bounds.Height == 0)
                     {
                         editingCheckBox.LayoutUpdated += OnLayoutUpdated;
                     }
diff --git a/src/Avalonia.Controls.ItemsRepeater/Controls/ItemsRepeater.cs b/src/Avalonia.Controls.ItemsRepeater/Controls/ItemsRepeater.cs
index 3d3d01e06e..499904deac 100644
--- a/src/Avalonia.Controls.ItemsRepeater/Controls/ItemsRepeater.cs
+++ b/src/Avalonia.Controls.ItemsRepeater/Controls/ItemsRepeater.cs
@@ -39,7 +39,10 @@ namespace Avalonia.Controls
         /// Defines the <see cref="Items"/> property.
         /// </summary>
         public static readonly DirectProperty<ItemsRepeater, IEnumerable?> ItemsProperty =
-            ItemsControl.ItemsProperty.AddOwner<ItemsRepeater>(o => o.Items, (o, v) => o.Items = v);
+            AvaloniaProperty.RegisterDirect<ItemsRepeater, IEnumerable?>(
+                nameof(Items),
+                o => o.Items,
+                (o, v) => o.Items = v);
 
         /// <summary>
         /// Defines the <see cref="Layout"/> property.
diff --git a/src/Avalonia.Controls.ItemsRepeater/Controls/ViewportManager.cs b/src/Avalonia.Controls.ItemsRepeater/Controls/ViewportManager.cs
index 6ed817c238..6e9cf2f0cf 100644
--- a/src/Avalonia.Controls.ItemsRepeater/Controls/ViewportManager.cs
+++ b/src/Avalonia.Controls.ItemsRepeater/Controls/ViewportManager.cs
@@ -441,7 +441,7 @@ namespace Avalonia.Controls
 
             _pendingViewportShift = default;
             _unshiftableShift = default;
-            if (_visibleWindow.IsDefault)
+            if (_visibleWindow.Width == 0 && _visibleWindow.Height == 0)
             {
                 // We got cleared.
                 _layoutExtent = default;
@@ -527,7 +527,7 @@ namespace Avalonia.Controls
         private void TryInvalidateMeasure()
         {
             // Don't invalidate measure if we have an invalid window.
-            if (!_visibleWindow.IsDefault)
+            if (_visibleWindow.Width != 0 || _visibleWindow.Height != 0)
             {
                 // We invalidate measure instead of just invalidating arrange because
                 // we don't invalidate measure in UpdateViewport if the view is changing to
diff --git a/src/Avalonia.Controls/AutoCompleteBox/AutoCompleteBox.Properties.cs b/src/Avalonia.Controls/AutoCompleteBox/AutoCompleteBox.Properties.cs
index ecbe01d8b7..93b057e176 100644
--- a/src/Avalonia.Controls/AutoCompleteBox/AutoCompleteBox.Properties.cs
+++ b/src/Avalonia.Controls/AutoCompleteBox/AutoCompleteBox.Properties.cs
@@ -87,12 +87,10 @@ namespace Avalonia.Controls
         /// Identifies the <see cref="Text" /> property.
         /// </summary>
         /// <value>The identifier for the <see cref="Text" /> property.</value>
-        public static readonly DirectProperty<AutoCompleteBox, string?> TextProperty =
-            TextBlock.TextProperty.AddOwnerWithDataValidation<AutoCompleteBox>(
-                o => o.Text,
-                (o, v) => o.Text = v,
+        public static readonly StyledProperty<string?> TextProperty =
+            TextBlock.TextProperty.AddOwner<AutoCompleteBox>(new(string.Empty,
                 defaultBindingMode: BindingMode.TwoWay,
-                enableDataValidation: true);
+                enableDataValidation: true));
 
         /// <summary>
         /// Identifies the <see cref="SearchText" /> property.
@@ -317,8 +315,8 @@ namespace Avalonia.Controls
         /// <see cref="AutoCompleteBox" /> control.</value>
         public string? Text
         {
-            get => _text;
-            set => SetAndRaise(TextProperty, ref _text, value);
+            get => GetValue(TextProperty);
+            set => SetValue(TextProperty, value);
         }
 
         /// <summary>
diff --git a/src/Avalonia.Controls/AutoCompleteBox/AutoCompleteBox.cs b/src/Avalonia.Controls/AutoCompleteBox/AutoCompleteBox.cs
index 9a949e31d4..2d074ef7fa 100644
--- a/src/Avalonia.Controls/AutoCompleteBox/AutoCompleteBox.cs
+++ b/src/Avalonia.Controls/AutoCompleteBox/AutoCompleteBox.cs
@@ -198,7 +198,6 @@ namespace Avalonia.Controls
         private bool _isDropDownOpen;
         private bool _isFocused = false;
 
-        private string? _text = string.Empty;
         private string? _searchText = string.Empty;
 
         private AutoCompleteFilterPredicate<object?>? _itemFilter;
@@ -1275,7 +1274,7 @@ namespace Avalonia.Controls
             if ((userInitiated ?? true) && Text != value)
             {
                 _ignoreTextPropertyChange++;
-                Text = value;
+                SetCurrentValue(TextProperty, value);
                 callTextChanged = true;
             }
 
diff --git a/src/Avalonia.Controls/Automation/Peers/ScrollBarAutomationPeer.cs b/src/Avalonia.Controls/Automation/Peers/ScrollBarAutomationPeer.cs
new file mode 100644
index 0000000000..b8406bf20c
--- /dev/null
+++ b/src/Avalonia.Controls/Automation/Peers/ScrollBarAutomationPeer.cs
@@ -0,0 +1,29 @@
+using Avalonia.Controls.Primitives;
+
+namespace Avalonia.Automation.Peers
+{
+    public class ScrollBarAutomationPeer : RangeBaseAutomationPeer
+    {
+        public ScrollBarAutomationPeer(ScrollBar owner) : base(owner)
+        {
+        }
+
+        override protected string GetClassNameCore()
+        {
+            return "ScrollBar";
+        }
+
+        override protected AutomationControlType GetAutomationControlTypeCore()
+        {
+            return AutomationControlType.ScrollBar;
+        }
+
+        // AutomationControlType.ScrollBar must return IsContentElement false.
+        // See http://msdn.microsoft.com/en-us/library/ms743712.aspx
+        override protected bool IsContentElementCore()
+        {
+            return false;
+        }
+
+    }
+}
diff --git a/src/Avalonia.Controls/BorderVisual.cs b/src/Avalonia.Controls/BorderVisual.cs
index b0e5c30e2f..591604a3c5 100644
--- a/src/Avalonia.Controls/BorderVisual.cs
+++ b/src/Avalonia.Controls/BorderVisual.cs
@@ -50,7 +50,7 @@ class CompositionBorderVisual : CompositionDrawListVisual
             if (ClipToBounds)
             {
                 var clipRect = Root!.SnapToDevicePixels(new Rect(new Size(Size.X, Size.Y)));
-                if (_cornerRadius.IsDefault)
+                if (_cornerRadius == default)
                     canvas.PushClip(clipRect);
                 else
                     canvas.PushClip(new RoundedRect(clipRect, _cornerRadius));
diff --git a/src/Avalonia.Controls/ContainerClearingEventArgs.cs b/src/Avalonia.Controls/ContainerClearingEventArgs.cs
new file mode 100644
index 0000000000..fb0c5c4bf8
--- /dev/null
+++ b/src/Avalonia.Controls/ContainerClearingEventArgs.cs
@@ -0,0 +1,20 @@
+using System;
+
+namespace Avalonia.Controls
+{
+    /// <summary>
+    /// Provides data for the <see cref="ItemsControl.ContainerClearing"/> event.
+    /// </summary>
+    public class ContainerClearingEventArgs : EventArgs
+    {
+        public ContainerClearingEventArgs(Control container)
+        {
+            Container = container;
+        }
+
+        /// <summary>
+        /// Gets the prepared container.
+        /// </summary>
+        public Control Container { get; }
+    }
+}
diff --git a/src/Avalonia.Controls/ContainerIndexChangedEventArgs.cs b/src/Avalonia.Controls/ContainerIndexChangedEventArgs.cs
new file mode 100644
index 0000000000..80536e742c
--- /dev/null
+++ b/src/Avalonia.Controls/ContainerIndexChangedEventArgs.cs
@@ -0,0 +1,32 @@
+using System;
+
+namespace Avalonia.Controls
+{
+    /// <summary>
+    /// Provides data for the <see cref="ItemsControl.ContainerIndexChanged"/> event.
+    /// </summary>
+    public class ContainerIndexChangedEventArgs : EventArgs
+    {
+        public ContainerIndexChangedEventArgs(Control container, int oldIndex, int newIndex)
+        {
+            Container = container;
+            OldIndex = oldIndex;
+            NewIndex = newIndex;
+        }
+
+        /// <summary>
+        /// Get the container for which the index changed.
+        /// </summary>
+        public Control Container { get; }
+
+        /// <summary>
+        /// Gets the index of the container after the change.
+        /// </summary>
+        public int NewIndex { get; }
+
+        /// <summary>
+        /// Gets the index of the container before the change.
+        /// </summary>
+        public int OldIndex { get; }
+    }
+}
diff --git a/src/Avalonia.Controls/ContainerPreparedEventArgs.cs b/src/Avalonia.Controls/ContainerPreparedEventArgs.cs
new file mode 100644
index 0000000000..1acb653bd1
--- /dev/null
+++ b/src/Avalonia.Controls/ContainerPreparedEventArgs.cs
@@ -0,0 +1,26 @@
+using System;
+
+namespace Avalonia.Controls
+{
+    /// <summary>
+    /// Provides data for the <see cref="ItemsControl.ContainerPrepared"/> event.
+    /// </summary>
+    public class ContainerPreparedEventArgs : EventArgs
+    {
+        public ContainerPreparedEventArgs(Control container, int index)
+        {
+            Container = container;
+            Index = index;
+        }
+
+        /// <summary>
+        /// Gets the prepared container.
+        /// </summary>
+        public Control Container { get; }
+
+        /// <summary>
+        /// Gets the index of the item the container was prepared for.
+        /// </summary>
+        public int Index { get; }
+    }
+}
diff --git a/src/Avalonia.Controls/ContextMenu.cs b/src/Avalonia.Controls/ContextMenu.cs
index 0e7d31967c..f46594ff96 100644
--- a/src/Avalonia.Controls/ContextMenu.cs
+++ b/src/Avalonia.Controls/ContextMenu.cs
@@ -54,11 +54,17 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<PopupGravity> PlacementGravityProperty =
             Popup.PlacementGravityProperty.AddOwner<ContextMenu>();
 
+        /// <summary>
+        /// Defines the <see cref="Placement"/> property.
+        /// </summary>
+        public static readonly StyledProperty<PlacementMode> PlacementProperty =
+            Popup.PlacementProperty.AddOwner<ContextMenu>();
+
         /// <summary>
         /// Defines the <see cref="PlacementMode"/> property.
         /// </summary>
-        public static readonly StyledProperty<PlacementMode> PlacementModeProperty =
-            Popup.PlacementModeProperty.AddOwner<ContextMenu>();
+        [Obsolete("Use the Placement property instead.")]
+        public static readonly StyledProperty<PlacementMode> PlacementModeProperty = PlacementProperty;
 
         /// <summary>
         /// Defines the <see cref="PlacementRect"/> property.
@@ -108,99 +114,80 @@ namespace Avalonia.Controls
         static ContextMenu()
         {
             ItemsPanelProperty.OverrideDefaultValue<ContextMenu>(DefaultPanel);
-            PlacementModeProperty.OverrideDefaultValue<ContextMenu>(PlacementMode.Pointer);
+            PlacementProperty.OverrideDefaultValue<ContextMenu>(PlacementMode.Pointer);
             ContextMenuProperty.Changed.Subscribe(ContextMenuChanged);
             AutomationProperties.AccessibilityViewProperty.OverrideDefaultValue<ContextMenu>(AccessibilityView.Control);
             AutomationProperties.ControlTypeOverrideProperty.OverrideDefaultValue<ContextMenu>(AutomationControlType.Menu);
         }
 
-        /// <summary>
-        /// Gets or sets the Horizontal offset of the context menu in relation to the <see cref="PlacementTarget"/>.
-        /// </summary>
+        /// <inheritdoc cref="Popup.HorizontalOffset"/>
         public double HorizontalOffset
         {
-            get { return GetValue(HorizontalOffsetProperty); }
-            set { SetValue(HorizontalOffsetProperty, value); }
+            get => GetValue(HorizontalOffsetProperty);
+            set => SetValue(HorizontalOffsetProperty, value);
         }
 
-        /// <summary>
-        /// Gets or sets the Vertical offset of the context menu in relation to the <see cref="PlacementTarget"/>.
-        /// </summary>
+        /// <inheritdoc cref="Popup.VerticalOffset"/>
         public double VerticalOffset
         {
-            get { return GetValue(VerticalOffsetProperty); }
-            set { SetValue(VerticalOffsetProperty, value); }
+            get => GetValue(VerticalOffsetProperty);
+            set => SetValue(VerticalOffsetProperty, value);
         }
 
-        /// <summary>
-        /// Gets or sets the anchor point on the <see cref="PlacementRect"/> when <see cref="PlacementMode"/>
-        /// is <see cref="PlacementMode.AnchorAndGravity"/>.
-        /// </summary>
+        /// <inheritdoc cref="Popup.PlacementAnchor"/>
         public PopupAnchor PlacementAnchor
         {
-            get { return GetValue(PlacementAnchorProperty); }
-            set { SetValue(PlacementAnchorProperty, value); }
+            get => GetValue(PlacementAnchorProperty);
+            set => SetValue(PlacementAnchorProperty, value);
         }
 
-        /// <summary>
-        /// Gets or sets a value describing how the context menu position will be adjusted if the
-        /// unadjusted position would result in the context menu being partly constrained.
-        /// </summary>
+        /// <inheritdoc cref="Popup.PlacementConstraintAdjustment"/>
         public PopupPositionerConstraintAdjustment PlacementConstraintAdjustment
         {
-            get { return GetValue(PlacementConstraintAdjustmentProperty); }
-            set { SetValue(PlacementConstraintAdjustmentProperty, value); }
+            get => GetValue(PlacementConstraintAdjustmentProperty);
+            set => SetValue(PlacementConstraintAdjustmentProperty, value);
         }
 
-        /// <summary>
-        /// Gets or sets a value which defines in what direction the context menu should open
-        /// when <see cref="PlacementMode"/> is <see cref="PlacementMode.AnchorAndGravity"/>.
-        /// </summary>
+        /// <inheritdoc cref="Popup.PlacementGravity"/>
         public PopupGravity PlacementGravity
         {
-            get { return GetValue(PlacementGravityProperty); }
-            set { SetValue(PlacementGravityProperty, value); }
+            get => GetValue(PlacementGravityProperty);
+            set => SetValue(PlacementGravityProperty, value);
         }
 
-        /// <summary>
-        /// Gets or sets the placement mode of the context menu in relation to the<see cref="PlacementTarget"/>.
-        /// </summary>
+        /// <inheritdoc cref="Placement"/>
+        [Obsolete("Use the Placement property instead.")]
         public PlacementMode PlacementMode
         {
-            get { return GetValue(PlacementModeProperty); }
-            set { SetValue(PlacementModeProperty, value); }
+            get => GetValue(PlacementProperty);
+            set => SetValue(PlacementProperty, value);
+        }
+
+        /// <inheritdoc cref="Popup.Placement"/>
+        public PlacementMode Placement
+        {
+            get => GetValue(PlacementProperty);
+            set => SetValue(PlacementProperty, value);
         }
 
         public bool WindowManagerAddShadowHint
         {
-            get { return GetValue(WindowManagerAddShadowHintProperty); }
-            set { SetValue(WindowManagerAddShadowHintProperty, value); }
+            get => GetValue(WindowManagerAddShadowHintProperty);
+            set => SetValue(WindowManagerAddShadowHintProperty, value);
         }
 
-        /// <summary>
-        /// Gets or sets the the anchor rectangle within the parent that the context menu will be placed
-        /// relative to when <see cref="PlacementMode"/> is <see cref="PlacementMode.AnchorAndGravity"/>.
-        /// </summary>
-        /// <remarks>
-        /// The placement rect defines a rectangle relative to <see cref="PlacementTarget"/> around
-        /// which the popup will be opened, with <see cref="PlacementAnchor"/> determining which edge
-        /// of the placement target is used.
-        /// 
-        /// If unset, the anchor rectangle will be the bounds of the <see cref="PlacementTarget"/>.
-        /// </remarks>
+        /// <inheritdoc cref="Popup.PlacementRect"/>
         public Rect? PlacementRect
         {
-            get { return GetValue(PlacementRectProperty); }
-            set { SetValue(PlacementRectProperty, value); }
+            get => GetValue(PlacementRectProperty);
+            set => SetValue(PlacementRectProperty, value);
         }
 
-        /// <summary>
-        /// Gets or sets the control that is used to determine the popup's position.
-        /// </summary>
+        /// <inheritdoc cref="Popup.PlacementTarget"/>
         public Control? PlacementTarget
         {
-            get { return GetValue(PlacementTargetProperty); }
-            set { SetValue(PlacementTargetProperty, value); }
+            get => GetValue(PlacementTargetProperty);
+            set => SetValue(PlacementTargetProperty, value);
         }
 
         /// <summary>
@@ -343,9 +330,9 @@ namespace Avalonia.Controls
                 ((ISetLogicalParent)_popup).SetParent(control);
             }
 
-            _popup.PlacementMode = !requestedByPointer && PlacementMode == PlacementMode.Pointer
+            _popup.Placement = !requestedByPointer && Placement == PlacementMode.Pointer
                 ? PlacementMode.Bottom
-                : PlacementMode;
+                : Placement;
 
             //Position of the line below is really important. 
             //All styles are being applied only when control has logical parent.
diff --git a/src/Avalonia.Controls/DateTimePickers/DatePicker.cs b/src/Avalonia.Controls/DateTimePickers/DatePicker.cs
index 118183102a..f3faef26dd 100644
--- a/src/Avalonia.Controls/DateTimePickers/DatePicker.cs
+++ b/src/Avalonia.Controls/DateTimePickers/DatePicker.cs
@@ -389,7 +389,7 @@ namespace Avalonia.Controls
 
             _presenter.Date = SelectedDate ?? DateTimeOffset.Now;
 
-            _popup.PlacementMode = PlacementMode.AnchorAndGravity;
+            _popup.Placement = PlacementMode.AnchorAndGravity;
             _popup.PlacementAnchor = Primitives.PopupPositioning.PopupAnchor.Bottom;
             _popup.PlacementGravity = Primitives.PopupPositioning.PopupGravity.Bottom;
             _popup.PlacementConstraintAdjustment = Primitives.PopupPositioning.PopupPositionerConstraintAdjustment.SlideY;
diff --git a/src/Avalonia.Controls/DateTimePickers/TimePicker.cs b/src/Avalonia.Controls/DateTimePickers/TimePicker.cs
index 2f49a44b8c..0046e1de52 100644
--- a/src/Avalonia.Controls/DateTimePickers/TimePicker.cs
+++ b/src/Avalonia.Controls/DateTimePickers/TimePicker.cs
@@ -255,7 +255,7 @@ namespace Avalonia.Controls
 
             _presenter.Time = SelectedTime ?? DateTime.Now.TimeOfDay;
 
-            _popup.PlacementMode = PlacementMode.AnchorAndGravity;
+            _popup.Placement = PlacementMode.AnchorAndGravity;
             _popup.PlacementAnchor = Primitives.PopupPositioning.PopupAnchor.Bottom;
             _popup.PlacementGravity = Primitives.PopupPositioning.PopupGravity.Bottom;
             _popup.PlacementConstraintAdjustment = Primitives.PopupPositioning.PopupPositionerConstraintAdjustment.SlideY;
diff --git a/src/Avalonia.Controls/Documents/InlineCollection.cs b/src/Avalonia.Controls/Documents/InlineCollection.cs
index fe9f5e64a8..39750d3672 100644
--- a/src/Avalonia.Controls/Documents/InlineCollection.cs
+++ b/src/Avalonia.Controls/Documents/InlineCollection.cs
@@ -91,11 +91,11 @@ namespace Avalonia.Controls.Documents
 
         public override void Add(Inline inline)
         {
-            if (InlineHost is TextBlock textBlock && !string.IsNullOrEmpty(textBlock._text))
+            if (InlineHost is TextBlock textBlock && !string.IsNullOrEmpty(textBlock.Text))
             {
-                base.Add(new Run(textBlock._text));
+                base.Add(new Run(textBlock.Text));
 
-                textBlock._text = null;
+                textBlock.ClearTextInternal();
             }
 
             base.Add(inline);
@@ -113,7 +113,7 @@ namespace Avalonia.Controls.Documents
         {
             if (InlineHost is TextBlock textBlock && !textBlock.HasComplexContent)
             {
-                textBlock._text += text;
+                textBlock.Text += text;
             }
             else
             {
diff --git a/src/Avalonia.Controls/Flyouts/MenuFlyout.cs b/src/Avalonia.Controls/Flyouts/MenuFlyout.cs
index df973debc7..ba5489ac25 100644
--- a/src/Avalonia.Controls/Flyouts/MenuFlyout.cs
+++ b/src/Avalonia.Controls/Flyouts/MenuFlyout.cs
@@ -19,7 +19,9 @@ namespace Avalonia.Controls
         /// Defines the <see cref="Items"/> property
         /// </summary>
         public static readonly DirectProperty<MenuFlyout, IEnumerable?> ItemsProperty =
-            ItemsControl.ItemsProperty.AddOwner<MenuFlyout>(x => x.Items,
+            AvaloniaProperty.RegisterDirect<MenuFlyout, IEnumerable?>(
+                nameof(Items),
+                x => x.Items,
                 (x, v) => x.Items = v);
 
         /// <summary>
diff --git a/src/Avalonia.Controls/Flyouts/PopupFlyoutBase.cs b/src/Avalonia.Controls/Flyouts/PopupFlyoutBase.cs
index a3d05a34b7..9ed4737c7c 100644
--- a/src/Avalonia.Controls/Flyouts/PopupFlyoutBase.cs
+++ b/src/Avalonia.Controls/Flyouts/PopupFlyoutBase.cs
@@ -14,9 +14,9 @@ namespace Avalonia.Controls.Primitives
 {
     public abstract class PopupFlyoutBase : FlyoutBase, IPopupHostProvider
     {
-        /// <inheritdoc cref="Popup.PlacementModeProperty"/>
+        /// <inheritdoc cref="Popup.PlacementProperty"/>
         public static readonly StyledProperty<PlacementMode> PlacementProperty =
-            Popup.PlacementModeProperty.AddOwner<PopupFlyoutBase>();
+            Popup.PlacementProperty.AddOwner<PopupFlyoutBase>();
 
         /// <inheritdoc cref="Popup.HorizontalOffsetProperty"/>
         public static readonly StyledProperty<double> HorizontalOffsetProperty =
@@ -64,15 +64,13 @@ namespace Avalonia.Controls.Primitives
 
         protected Popup Popup => _popupLazy.Value;
 
-        /// <summary>
-        /// Gets or sets the desired placement.
-        /// </summary>
+        /// <inheritdoc cref="Popup.Placement"/>
         public PlacementMode Placement
         {
             get => GetValue(PlacementProperty);
             set => SetValue(PlacementProperty, value);
         }
-        
+
         /// <inheritdoc cref="Popup.PlacementGravity"/>
         public PopupGravity PlacementGravity
         {
@@ -407,7 +405,7 @@ namespace Avalonia.Controls.Primitives
         {
             Size sz;
             // Popup.Child can't be null here, it was set in ShowAtCore.
-            if (Popup.Child!.DesiredSize.IsDefault)
+            if (Popup.Child!.DesiredSize == default)
             {
                 // Popup may not have been shown yet. Measure content
                 sz = LayoutHelper.MeasureChild(Popup.Child, Size.Infinity, new Thickness());
@@ -423,11 +421,11 @@ namespace Avalonia.Controls.Primitives
             Popup.PlacementGravity = PlacementGravity;
             if (showAtPointer)
             {
-                Popup.PlacementMode = PlacementMode.Pointer;
+                Popup.Placement = PlacementMode.Pointer;
             }
             else
             {
-                Popup.PlacementMode = Placement;
+                Popup.Placement = Placement;
                 Popup.PlacementConstraintAdjustment =
                     PopupPositioning.PopupPositionerConstraintAdjustment.SlideX |
                     PopupPositioning.PopupPositionerConstraintAdjustment.SlideY;
diff --git a/src/Avalonia.Controls/ItemCollection.cs b/src/Avalonia.Controls/ItemCollection.cs
new file mode 100644
index 0000000000..c9265558f0
--- /dev/null
+++ b/src/Avalonia.Controls/ItemCollection.cs
@@ -0,0 +1,165 @@
+using System;
+using System.Collections;
+using System.Collections.Specialized;
+using System.Diagnostics.CodeAnalysis;
+using Avalonia.Collections;
+
+namespace Avalonia.Controls
+{
+    /// <summary>
+    /// Holds the list of items that constitute the content of an <see cref="ItemsControl"/>.
+    /// </summary>
+    public class ItemCollection : ItemsSourceView, IList
+    {
+// Suppress "Avoid zero-length array allocations": This is a sentinel value and must be unique.
+#pragma warning disable CA1825
+        private static readonly object?[] s_uninitialized = new object?[0];
+#pragma warning restore CA1825
+
+        private Mode _mode;
+
+        internal ItemCollection()
+            : base(s_uninitialized)
+        {
+        }
+
+        public new object? this[int index]
+        {
+            get => base[index];
+            set => WritableSource[index] = value;
+        }
+
+        public bool IsReadOnly => _mode == Mode.ItemsSource;
+
+        internal event EventHandler? SourceChanged;
+
+        /// <summary>
+        /// Adds an item to the <see cref="ItemsControl"/>.
+        /// </summary>
+        /// <param name="value">The item to add to the collection.</param>
+        /// <returns>
+        /// The position into which the new element was inserted, or -1 to indicate that
+        /// the item was not inserted into the collection.
+        /// </returns>
+        /// <exception cref="InvalidOperationException">
+        /// The collection is in ItemsSource mode.
+        /// </exception>
+        public int Add(object? value) => WritableSource.Add(value);
+
+        /// <summary>
+        /// Clears the collection and releases the references on all items currently in the
+        /// collection.
+        /// </summary>
+        /// <exception cref="InvalidOperationException">
+        /// The collection is in ItemsSource mode.
+        /// </exception>
+        public void Clear() => WritableSource.Clear();
+
+        /// <summary>
+        /// Inserts an element into the collection at the specified index.
+        /// </summary>
+        /// <param name="index">The zero-based index at which to insert the item.</param>
+        /// <param name="value">The item to insert.</param>
+        /// <exception cref="InvalidOperationException">
+        /// The collection is in ItemsSource mode.
+        /// </exception>
+        public void Insert(int index, object? value) => WritableSource.Insert(index, value);
+
+        /// <summary>
+        /// Removes the item at the specified index of the collection or view.
+        /// </summary>
+        /// <param name="index">The zero-based index of the item to remove.</param>
+        /// <exception cref="InvalidOperationException">
+        /// The collection is in ItemsSource mode.
+        /// </exception>
+        public void RemoveAt(int index) => WritableSource.RemoveAt(index);
+
+        /// <summary>
+        /// Removes the specified item reference from the collection or view.
+        /// </summary>
+        /// <param name="value">The object to remove.</param>
+        /// <returns>True if the item was removed; otherwise false.</returns>
+        /// <exception cref="InvalidOperationException">
+        /// The collection is in ItemsSource mode.
+        /// </exception>
+        public bool Remove(object? value)
+        {
+            var c = Count;
+            WritableSource.Remove(value);
+            return Count < c;
+        }
+
+        int IList.Add(object? value) => Add(value);
+        void IList.Clear() => Clear();
+        void IList.Insert(int index, object? value) => Insert(index, value);
+        void IList.RemoveAt(int index) => RemoveAt(index);
+
+        private IList WritableSource
+        {
+            get
+            {
+                if (IsReadOnly)
+                    ThrowIsItemsSource();
+                if (Source == s_uninitialized)
+                    SetSource(CreateDefaultCollection());
+                return Source;
+            }
+        }
+
+        internal IList? GetItemsPropertyValue()
+        {
+            if (_mode == Mode.ObsoleteItemsSetter)
+                return Source == s_uninitialized ? null : Source;
+            return this;
+        }
+
+        internal void SetItems(IList? items)
+        {
+            _mode = Mode.ObsoleteItemsSetter;
+            SetSource(items ?? s_uninitialized);
+        }
+
+        internal void SetItemsSource(IEnumerable? value)
+        {
+            if (_mode != Mode.ItemsSource && Count > 0)
+                throw new InvalidOperationException(
+                    "Items collection must be empty before using ItemsSource.");
+
+            _mode = value is not null ? Mode.ItemsSource : Mode.Items;
+            SetSource(value ?? CreateDefaultCollection());
+        }
+
+        private new void SetSource(IEnumerable source)
+        {
+            var oldSource = Source;
+
+            base.SetSource(source);
+
+            if (oldSource.Count > 0)
+                RaiseCollectionChanged(new(NotifyCollectionChangedAction.Remove, oldSource, 0));
+            if (Source.Count > 0)
+                RaiseCollectionChanged(new(NotifyCollectionChangedAction.Add, Source, 0));
+            SourceChanged?.Invoke(this, EventArgs.Empty);
+        }
+
+        private static AvaloniaList<object?> CreateDefaultCollection()
+        {
+            return new() { ResetBehavior = ResetBehavior.Remove };
+        }
+
+        [DoesNotReturn]
+        private static void ThrowIsItemsSource()
+        {
+            throw new InvalidOperationException(
+                "Operation is not valid while ItemsSource is in use." +
+                "Access and modify elements with ItemsControl.ItemsSource instead.");
+        }
+
+        private enum Mode
+        {
+            Items,
+            ItemsSource,
+            ObsoleteItemsSetter,
+        }
+    }
+}
diff --git a/src/Avalonia.Controls/ItemsControl.cs b/src/Avalonia.Controls/ItemsControl.cs
index bebf4a38f6..4460ff0486 100644
--- a/src/Avalonia.Controls/ItemsControl.cs
+++ b/src/Avalonia.Controls/ItemsControl.cs
@@ -2,6 +2,7 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Diagnostics.CodeAnalysis;
 using Avalonia.Automation.Peers;
 using Avalonia.Collections;
 using Avalonia.Controls.Generators;
@@ -34,8 +35,13 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="Items"/> property.
         /// </summary>
-        public static readonly DirectProperty<ItemsControl, IEnumerable?> ItemsProperty =
-            AvaloniaProperty.RegisterDirect<ItemsControl, IEnumerable?>(nameof(Items), o => o.Items, (o, v) => o.Items = v);
+        public static readonly DirectProperty<ItemsControl, IList?> ItemsProperty =
+            AvaloniaProperty.RegisterDirect<ItemsControl, IList?>(
+                nameof(Items),
+                o => o.Items,
+#pragma warning disable CS0618 // Type or member is obsolete
+                (o, v) => o.Items = v);
+#pragma warning restore CS0618 // Type or member is obsolete
 
         /// <summary>
         /// Defines the <see cref="ItemContainerTheme"/> property.
@@ -56,23 +62,23 @@ namespace Avalonia.Controls
             AvaloniaProperty.Register<ItemsControl, ITemplate<Panel>>(nameof(ItemsPanel), DefaultPanel);
 
         /// <summary>
-        /// Defines the <see cref="ItemTemplate"/> property.
+        /// Defines the <see cref="ItemsSource"/> property.
         /// </summary>
-        public static readonly StyledProperty<IDataTemplate?> ItemTemplateProperty =
-            AvaloniaProperty.Register<ItemsControl, IDataTemplate?>(nameof(ItemTemplate));
+        public static readonly StyledProperty<IEnumerable?> ItemsSourceProperty =
+            AvaloniaProperty.Register<ItemsControl, IEnumerable?>(nameof(ItemsSource));
 
         /// <summary>
-        /// Defines the <see cref="ItemsView"/> property.
+        /// Defines the <see cref="ItemTemplate"/> property.
         /// </summary>
-        public static readonly DirectProperty<ItemsControl, ItemsSourceView> ItemsViewProperty =
-            AvaloniaProperty.RegisterDirect<ItemsControl, ItemsSourceView>(nameof(ItemsView), o => o.ItemsView);
+        public static readonly StyledProperty<IDataTemplate?> ItemTemplateProperty =
+            AvaloniaProperty.Register<ItemsControl, IDataTemplate?>(nameof(ItemTemplate));
 
         /// <summary>
         /// Defines the <see cref="DisplayMemberBinding" /> property
         /// </summary>
         public static readonly StyledProperty<IBinding?> DisplayMemberBindingProperty =
             AvaloniaProperty.Register<ItemsControl, IBinding?>(nameof(DisplayMemberBinding));
-        
+
         /// <summary>
         /// Defines the <see cref="AreHorizontalSnapPointsRegular"/> property.
         /// </summary>
@@ -89,15 +95,15 @@ namespace Avalonia.Controls
         /// Gets or sets the <see cref="IBinding"/> to use for binding to the display member of each item.
         /// </summary>
         [AssignBinding]
+        [InheritDataTypeFromItems(nameof(ItemsSource))]
         [InheritDataTypeFromItems(nameof(Items))]
         public IBinding? DisplayMemberBinding
         {
             get => GetValue(DisplayMemberBindingProperty);
             set => SetValue(DisplayMemberBindingProperty, value);
         }
-        
-        private IEnumerable? _items = new AvaloniaList<object>();
-        private ItemsSourceView _itemsView;
+
+        private readonly ItemCollection _items = new();
         private int _itemCount;
         private ItemContainerGenerator? _itemContainerGenerator;
         private EventHandler<ChildIndexChangedEventArgs>? _childIndexChanged;
@@ -110,9 +116,8 @@ namespace Avalonia.Controls
         /// </summary>
         public ItemsControl()
         {
-            _itemsView = ItemsSourceView.GetOrCreate(_items);
-            _itemsView.PostCollectionChanged += ItemsCollectionChanged;
-            UpdatePseudoClasses(0);
+            UpdatePseudoClasses();
+            _items.CollectionChanged += OnItemsViewCollectionChanged;
         }
 
         /// <summary>
@@ -128,11 +133,45 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets or sets the items to display.
         /// </summary>
+        /// <remarks>
+        /// Since Avalonia 11, <see cref="ItemsControl"/> has both an <see cref="Items"/> property
+        /// and an <see cref="ItemsSource"/> property. The properties have the following differences:
+        /// 
+        /// <list type="bullet">
+        /// <item><see cref="Items"/> is initialized with an empty collection and is a direct property,
+        /// meaning that it cannot be styled </item>
+        /// <item><see cref="ItemsSource"/> is by default null, and is a styled property. This property
+        /// is marked as the content property and will be used for items added via inline XAML.</item>
+        /// </list>
+        /// 
+        /// In Avalonia 11 the two properties can be used almost interchangeably but this will change
+        /// in a later version. In order to be ready for this change, follow the following guidance:
+        /// 
+        /// <list type="bullet">
+        /// <item>You should use the <see cref="Items"/> property when you're assigning a collection of
+        /// item containers directly, for example adding a collection of <see cref="ListBoxItem"/>s
+        /// directly to a <see cref="ListBox"/>. Add the containers to the pre-existing list, do not
+        /// reassign the <see cref="Items"/> property via the setter or with a binding.</item>
+        /// <item>You should use the <see cref="ItemsSource"/> property when you're assigning or
+        /// binding a collection of models which will be transformed by a data template.</item>
+        /// </list>
+        /// </remarks>
         [Content]
-        public IEnumerable? Items
+        public IList? Items
         {
-            get => _items;
-            set => SetAndRaise(ItemsProperty, ref _items, value);
+            get => _items.GetItemsPropertyValue();
+
+            [Obsolete("Use ItemsSource to set or bind items.")]
+            set
+            {
+                var oldItems = _items.GetItemsPropertyValue();
+
+                if (value != oldItems)
+                {
+                    _items.SetItems(value);
+                    RaisePropertyChanged(ItemsProperty, oldItems, value);
+                }
+            }
         }
 
         /// <summary>
@@ -140,17 +179,24 @@ namespace Avalonia.Controls
         /// </summary>
         public ControlTheme? ItemContainerTheme
         {
-            get => GetValue(ItemContainerThemeProperty); 
+            get => GetValue(ItemContainerThemeProperty);
             set => SetValue(ItemContainerThemeProperty, value);
         }
 
         /// <summary>
-        /// Gets the number of items in <see cref="Items"/>.
+        /// Gets the number of items being displayed by the <see cref="ItemsControl"/>.
         /// </summary>
         public int ItemCount
         {
             get => _itemCount;
-            private set => SetAndRaise(ItemCountProperty, ref _itemCount, value);
+            private set
+            {
+                if (SetAndRaise(ItemCountProperty, ref _itemCount, value))
+                {
+                    UpdatePseudoClasses();
+                    _childIndexChanged?.Invoke(this, ChildIndexChangedEventArgs.TotalCountChanged);
+                }
+            }
         }
 
         /// <summary>
@@ -162,13 +208,46 @@ namespace Avalonia.Controls
             set => SetValue(ItemsPanelProperty, value);
         }
 
+        /// <summary>
+        /// Gets or sets a collection used to generate the content of the <see cref="ItemsControl"/>.
+        /// </summary>
+        /// <remarks>
+        /// Since Avalonia 11, <see cref="ItemsControl"/> has both an <see cref="Items"/> property
+        /// and an <see cref="ItemsSource"/> property. The properties have the following differences:
+        /// 
+        /// <list type="bullet">
+        /// <item><see cref="Items"/> is initialized with an empty collection and is a direct property,
+        /// meaning that it cannot be styled </item>
+        /// <item><see cref="ItemsSource"/> is by default null, and is a styled property. This property
+        /// is marked as the content property and will be used for items added via inline XAML.</item>
+        /// </list>
+        /// 
+        /// In Avalonia 11 the two properties can be used almost interchangeably but this will change
+        /// in a later version. In order to be ready for this change, follow the following guidance:
+        /// 
+        /// <list type="bullet">
+        /// <item>You should use the <see cref="Items"/> property when you're assigning a collection of
+        /// item containers directly, for example adding a collection of <see cref="ListBoxItem"/>s
+        /// directly to a <see cref="ListBox"/>. Add the containers to the pre-existing list, do not
+        /// reassign the <see cref="Items"/> property via the setter or with a binding.</item>
+        /// <item>You should use the <see cref="ItemsSource"/> property when you're assigning or
+        /// binding a collection of models which will be transformed by a data template.</item>
+        /// </list>
+        /// </remarks>
+        public IEnumerable? ItemsSource
+        {
+            get => GetValue(ItemsSourceProperty);
+            set => SetValue(ItemsSourceProperty, value);
+        }
+
         /// <summary>
         /// Gets or sets the data template used to display the items in the control.
         /// </summary>
+        [InheritDataTypeFromItems(nameof(ItemsSource))]
         [InheritDataTypeFromItems(nameof(Items))]
         public IDataTemplate? ItemTemplate
         {
-            get => GetValue(ItemTemplateProperty); 
+            get => GetValue(ItemTemplateProperty);
             set => SetValue(ItemTemplateProperty, value);
         }
 
@@ -183,31 +262,9 @@ namespace Avalonia.Controls
         public Panel? ItemsPanelRoot => Presenter?.Panel;
 
         /// <summary>
-        /// Gets a standardized view over <see cref="Items"/>.
+        /// Gets a read-only view of the items in the <see cref="ItemsControl"/>.
         /// </summary>
-        /// <remarks>
-        /// The <see cref="Items"/> property may be an enumerable which does not implement
-        /// <see cref="IList"/> or may be null. This view can be used to provide a standardized
-        /// view of the current items regardless of the type of the concrete collection, and
-        /// without having to deal with null values.
-        /// </remarks>
-        public ItemsSourceView ItemsView 
-        {
-            get => _itemsView;
-            private set
-            {
-                if (ReferenceEquals(_itemsView, value))
-                    return;
-
-                var oldValue = _itemsView;
-                RemoveControlItemsFromLogicalChildren(_itemsView);
-                _itemsView.PostCollectionChanged -= ItemsCollectionChanged;
-                _itemsView = value;
-                _itemsView.PostCollectionChanged += ItemsCollectionChanged;
-                AddControlItemsToLogicalChildren(_itemsView);
-                RaisePropertyChanged(ItemsViewProperty, oldValue, _itemsView);
-            }
-        }
+        public ItemsSourceView ItemsView => _items;
 
         private protected bool WrapFocus { get; set; }
 
@@ -217,6 +274,34 @@ namespace Avalonia.Controls
             remove => _childIndexChanged -= value;
         }
 
+        /// <summary>
+        /// Occurs each time a container is prepared for use.
+        /// </summary>
+        /// <remarks>
+        /// The prepared element might be newly created or an existing container that is being re-
+        /// used.
+        /// </remarks>
+        public event EventHandler<ContainerPreparedEventArgs>? ContainerPrepared;
+
+        /// <summary>
+        /// Occurs for each realized container when the index for the item it represents has changed.
+        /// </summary>
+        /// <remarks>
+        /// This event is raised for each realized container where the index for the item it
+        /// represents has changed. For example, when another item is added or removed in the data
+        /// source, the index for items that come after in the ordering will be impacted.
+        /// </remarks>
+        public event EventHandler<ContainerIndexChangedEventArgs>? ContainerIndexChanged;
+
+        /// <summary>
+        /// Occurs each time a container is cleared.
+        /// </summary>
+        /// <remarks>
+        /// This event is raised immediately each time an container is cleared, such as when it
+        /// falls outside the range of realized items or the corresponding item is removed.
+        /// </remarks>
+        public event EventHandler<ContainerClearingEventArgs>? ContainerClearing;
+
         /// <inheritdoc />
         public event EventHandler<RoutedEventArgs> HorizontalSnapPointsChanged
         {
@@ -262,7 +347,7 @@ namespace Avalonia.Controls
         /// </summary>
         public bool AreHorizontalSnapPointsRegular
         {
-            get => GetValue(AreHorizontalSnapPointsRegularProperty); 
+            get => GetValue(AreHorizontalSnapPointsRegularProperty);
             set => SetValue(AreHorizontalSnapPointsRegularProperty, value);
         }
 
@@ -271,7 +356,7 @@ namespace Avalonia.Controls
         /// </summary>
         public bool AreVerticalSnapPointsRegular
         {
-            get => GetValue(AreVerticalSnapPointsRegularProperty); 
+            get => GetValue(AreVerticalSnapPointsRegularProperty);
             set => SetValue(AreVerticalSnapPointsRegularProperty, value);
         }
 
@@ -295,7 +380,7 @@ namespace Avalonia.Controls
         /// </returns>
         public Control? ContainerFromItem(object item)
         {
-            var index = ItemsView.IndexOf(item);
+            var index = _items.IndexOf(item);
             return index >= 0 ? ContainerFromIndex(index) : null;
         }
 
@@ -319,7 +404,7 @@ namespace Avalonia.Controls
         public object? ItemFromContainer(Control container)
         {
             var index = IndexFromContainer(container);
-            return index >= 0 && index < ItemsView.Count ? ItemsView[index] : null;
+            return index >= 0 && index < _items.Count ? _items[index] : null;
         }
 
         /// <summary>
@@ -478,19 +563,13 @@ namespace Avalonia.Controls
         {
             base.OnPropertyChanged(change);
 
-            if (change.Property == ItemsProperty)
-            {
-                ItemsView = ItemsSourceView.GetOrCreate(change.GetNewValue<IEnumerable?>());
-                ItemCount = ItemsView.Count;
-            }
-            else if (change.Property == ItemCountProperty)
+            if (change.Property == ItemContainerThemeProperty && _itemContainerGenerator is not null)
             {
-                UpdatePseudoClasses(change.GetNewValue<int>());
-                _childIndexChanged?.Invoke(this, ChildIndexChangedEventArgs.TotalCountChanged);
+                RefreshContainers();
             }
-            else if (change.Property == ItemContainerThemeProperty && _itemContainerGenerator is not null)
+            else if (change.Property == ItemsSourceProperty)
             {
-                RefreshContainers();
+                _items.SetItemsSource(change.GetNewValue<IEnumerable?>());
             }
             else if (change.Property == ItemTemplateProperty)
             {
@@ -517,24 +596,27 @@ namespace Avalonia.Controls
 
         /// <summary>
         /// Called when the <see cref="INotifyCollectionChanged.CollectionChanged"/> event is
-        /// raised on <see cref="Items"/>.
+        /// raised on <see cref="ItemsView"/>.
         /// </summary>
         /// <param name="sender">The event sender.</param>
         /// <param name="e">The event args.</param>
-        protected virtual void ItemsCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
+        private protected virtual void OnItemsViewCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
         {
-            ItemCount = _itemsView.Count;
-
-            switch (e.Action)
+            if (!_items.IsReadOnly)
             {
-                case NotifyCollectionChangedAction.Add:
-                    AddControlItemsToLogicalChildren(e.NewItems);
-                    break;
+                switch (e.Action)
+                {
+                    case NotifyCollectionChangedAction.Add:
+                        AddControlItemsToLogicalChildren(e.NewItems);
+                        break;
 
-                case NotifyCollectionChangedAction.Remove:
-                    RemoveControlItemsFromLogicalChildren(e.OldItems);
-                    break;
+                    case NotifyCollectionChangedAction.Remove:
+                        RemoveControlItemsFromLogicalChildren(e.OldItems);
+                        break;
+                }
             }
+
+            ItemCount = ItemsView.Count;
         }
 
         /// <summary>
@@ -578,7 +660,7 @@ namespace Avalonia.Controls
         {
             var itemContainerTheme = ItemContainerTheme;
 
-            if (itemContainerTheme is not null && 
+            if (itemContainerTheme is not null &&
                 !container.IsSet(ThemeProperty) &&
                 ((IStyleable)container).StyleKey == itemContainerTheme.TargetType)
             {
@@ -595,24 +677,23 @@ namespace Avalonia.Controls
         {
             _childIndexChanged?.Invoke(this, new ChildIndexChangedEventArgs(container, index));
             _scrollViewer?.RegisterAnchorCandidate(container);
+            ContainerPrepared?.Invoke(this, new(container, index));
         }
 
         internal void ItemContainerIndexChanged(Control container, int oldIndex, int newIndex)
         {
             ContainerIndexChangedOverride(container, oldIndex, newIndex);
             _childIndexChanged?.Invoke(this, new ChildIndexChangedEventArgs(container, newIndex));
+            ContainerIndexChanged?.Invoke(this, new(container, oldIndex, newIndex));
         }
 
         internal void ClearItemContainer(Control container)
         {
             _scrollViewer?.UnregisterAnchorCandidate(container);
             ClearContainerForItemOverride(container);
+            ContainerClearing?.Invoke(this, new(container));
         }
 
-        /// <summary>
-        /// Given a collection of items, adds those that are controls to the logical children.
-        /// </summary>
-        /// <param name="items">The items.</param>
         private void AddControlItemsToLogicalChildren(IEnumerable? items)
         {
             if (items is null)
@@ -633,10 +714,6 @@ namespace Avalonia.Controls
                 LogicalChildren.AddRange(toAdd);
         }
 
-        /// <summary>
-        /// Given a collection of items, removes those that are controls to from logical children.
-        /// </summary>
-        /// <param name="items">The items.</param>
         private void RemoveControlItemsFromLogicalChildren(IEnumerable? items)
         {
             if (items is null)
@@ -674,10 +751,10 @@ namespace Avalonia.Controls
             return _displayMemberItemTemplate;
         }
 
-        private void UpdatePseudoClasses(int itemCount)
+        private void UpdatePseudoClasses()
         {
-            PseudoClasses.Set(":empty", itemCount == 0);
-            PseudoClasses.Set(":singleitem", itemCount == 1);
+            PseudoClasses.Set(":empty", ItemCount == 0);
+            PseudoClasses.Set(":singleitem", ItemCount == 1);
         }
 
         protected static IInputElement? GetNextControl(
diff --git a/src/Avalonia.Controls/ItemsSourceView.cs b/src/Avalonia.Controls/ItemsSourceView.cs
index c8fc76255c..614b70d0ba 100644
--- a/src/Avalonia.Controls/ItemsSourceView.cs
+++ b/src/Avalonia.Controls/ItemsSourceView.cs
@@ -7,6 +7,7 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using Avalonia.Controls.Utils;
 
@@ -17,16 +18,18 @@ namespace Avalonia.Controls
     /// and an items control.
     /// </summary>
     public class ItemsSourceView : IReadOnlyList<object?>,
+        IList,
         INotifyCollectionChanged,
         ICollectionChangedListener
     {
         /// <summary>
-        ///  Gets an empty <see cref="ItemsSourceView"/>
+        /// Gets an empty <see cref="ItemsSourceView"/>
         /// </summary>
-        public static ItemsSourceView Empty { get; } = new ItemsSourceView(Array.Empty<object>());
+        public static ItemsSourceView Empty { get; } = new ItemsSourceView(Array.Empty<object?>());
 
-        private readonly IList _inner;
+        private IList _source;
         private NotifyCollectionChangedEventHandler? _collectionChanged;
+        private NotifyCollectionChangedEventHandler? _preCollectionChanged;
         private NotifyCollectionChangedEventHandler? _postCollectionChanged;
         private bool _listening;
 
@@ -34,30 +37,17 @@ namespace Avalonia.Controls
         /// Initializes a new instance of the ItemsSourceView class for the specified data source.
         /// </summary>
         /// <param name="source">The data source.</param>
-        private protected ItemsSourceView(IEnumerable source)
-        {
-            _inner = source switch
-            {
-                ItemsSourceView => throw new ArgumentException("Cannot wrap an existing ItemsSourceView.", nameof(source)),
-                IList list => list,
-                INotifyCollectionChanged => throw new ArgumentException(
-                    "Collection implements INotifyCollectionChanged but not IList.",
-                    nameof(source)),
-                IEnumerable<object> iObj => new List<object>(iObj),
-                null => throw new ArgumentNullException(nameof(source)),
-                _ => new List<object>(source.Cast<object>())
-            };
-        }
+        private protected ItemsSourceView(IEnumerable source) => SetSource(source);
 
         /// <summary>
         /// Gets the number of items in the collection.
         /// </summary>
-        public int Count => Inner.Count;
+        public int Count => Source.Count;
 
         /// <summary>
-        /// Gets the inner collection.
+        /// Gets the source collection.
         /// </summary>
-        public IList Inner => _inner;
+        public IList Source => _source;
 
         /// <summary>
         /// Retrieves the item at the specified index.
@@ -66,12 +56,20 @@ namespace Avalonia.Controls
         /// <returns>The item.</returns>
         public object? this[int index] => GetAt(index);
 
+        bool IList.IsFixedSize => false;
+        bool IList.IsReadOnly => true;
+        bool ICollection.IsSynchronized => false;
+        object ICollection.SyncRoot => this;
+
+        object? IList.this[int index]
+        {
+            get => GetAt(index);
+            set => ThrowReadOnly();
+        }
+
         /// <summary>
-        /// Gets a value that indicates whether the items source can provide a unique key for each item.
+        /// Not implemented in Avalonia, preserved here for ItemsRepeater's usage.
         /// </summary>
-        /// <remarks>
-        /// TODO: Not yet implemented in Avalonia.
-        /// </remarks>
         internal bool HasKeyIndexMapping => false;
 
         /// <summary>
@@ -96,38 +94,37 @@ namespace Avalonia.Controls
         /// Occurs when a collection has finished changing and all <see cref="CollectionChanged"/>
         /// event handlers have been notified.
         /// </summary>
-        internal event NotifyCollectionChangedEventHandler? PostCollectionChanged
+        internal event NotifyCollectionChangedEventHandler? PreCollectionChanged
         {
             add
             {
                 AddListenerIfNecessary();
-                _postCollectionChanged += value;
+                _preCollectionChanged += value;
             }
 
             remove
             {
-                _postCollectionChanged -= value;
+                _preCollectionChanged -= value;
                 RemoveListenerIfNecessary();
             }
         }
 
-        private void AddListenerIfNecessary()
+        /// <summary>
+        /// Occurs when a collection has finished changing and all <see cref="CollectionChanged"/>
+        /// event handlers have been notified.
+        /// </summary>
+        internal event NotifyCollectionChangedEventHandler? PostCollectionChanged
         {
-            if (!_listening)
+            add
             {
-                if (_inner is INotifyCollectionChanged incc)
-                    CollectionChangedEventManager.Instance.AddListener(incc, this);
-                _listening = true;
+                AddListenerIfNecessary();
+                _postCollectionChanged += value;
             }
-        }
 
-        private void RemoveListenerIfNecessary()
-        {
-            if (_listening && _collectionChanged is null && _postCollectionChanged is null)
+            remove
             {
-                if (_inner is INotifyCollectionChanged incc)
-                    CollectionChangedEventManager.Instance.RemoveListener(incc, this);
-                _listening = false;
+                _postCollectionChanged -= value;
+                RemoveListenerIfNecessary();
             }
         }
 
@@ -136,14 +133,9 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="index">The index.</param>
         /// <returns>The item.</returns>
-        public object? GetAt(int index) => Inner[index];
-
-        /// <summary>
-        /// Determines the index of a specific item in the collection.
-        /// </summary>
-        /// <param name="item">The object to locate in the collection.</param>
-        /// <returns>The index of value if found in the list; otherwise, -1.</returns>
-        public int IndexOf(object? item) => Inner.IndexOf(item);
+        public object? GetAt(int index) => Source[index];
+        public bool Contains(object? item) => Source.Contains(item);
+        public int IndexOf(object? item) => Source.IndexOf(item);
 
         /// <summary>
         /// Gets or creates an <see cref="ItemsSourceView"/> for the specified enumerable.
@@ -181,7 +173,8 @@ namespace Avalonia.Controls
         {
             return items switch
             {
-                ItemsSourceView<T> isv => isv,
+                ItemsSourceView<T> isvt => isvt,
+                ItemsSourceView isv => new ItemsSourceView<T>(isv.Source),
                 null => ItemsSourceView<T>.Empty,
                 _ => new ItemsSourceView<T>(items)
             };
@@ -216,7 +209,7 @@ namespace Avalonia.Controls
                     yield return o;
             }
 
-            var inner = Inner;
+            var inner = Source;
 
             return inner switch
             {
@@ -225,10 +218,11 @@ namespace Avalonia.Controls
             };
         }
 
-        IEnumerator IEnumerable.GetEnumerator() => Inner.GetEnumerator();
+        IEnumerator IEnumerable.GetEnumerator() => Source.GetEnumerator();
 
         void ICollectionChangedListener.PreChanged(INotifyCollectionChanged sender, NotifyCollectionChangedEventArgs e)
         {
+            _preCollectionChanged?.Invoke(this, e);
         }
 
         void ICollectionChangedListener.Changed(INotifyCollectionChanged sender, NotifyCollectionChangedEventArgs e)
@@ -241,15 +235,69 @@ namespace Avalonia.Controls
             _postCollectionChanged?.Invoke(this, e);
         }
 
+        int IList.Add(object? value) => ThrowReadOnly();
+        void IList.Clear() => ThrowReadOnly();
+        void IList.Insert(int index, object? value) => ThrowReadOnly();
+        void IList.Remove(object? value) => ThrowReadOnly();
+        void IList.RemoveAt(int index) => ThrowReadOnly();
+        void ICollection.CopyTo(Array array, int index) => Source.CopyTo(array, index);
+
         /// <summary>
-        /// Retrieves the index of the item that has the specified unique identifier (key).
+        /// Not implemented in Avalonia, preserved here for ItemsRepeater's usage.
         /// </summary>
-        /// <param name="index">The index.</param>
-        /// <returns>The key</returns>
-        /// <remarks>
-        /// TODO: Not yet implemented in Avalonia.
-        /// </remarks>
         internal string KeyFromIndex(int index) => throw new NotImplementedException();
+
+        private protected void RaiseCollectionChanged(NotifyCollectionChangedEventArgs e)
+        {
+            _preCollectionChanged?.Invoke(this, e);
+            _collectionChanged?.Invoke(this, e);
+            _postCollectionChanged?.Invoke(this, e);
+        }
+
+        [MemberNotNull(nameof(_source))]
+        private protected void SetSource(IEnumerable source)
+        {
+            if (_listening && _source is INotifyCollectionChanged inccOld)
+                CollectionChangedEventManager.Instance.RemoveListener(inccOld, this);
+
+            _source = source switch
+            {
+                ItemsSourceView => throw new ArgumentException("Cannot wrap an existing ItemsSourceView.", nameof(source)),
+                IList list => list,
+                INotifyCollectionChanged => throw new ArgumentException(
+                    "Collection implements INotifyCollectionChanged but not IList.",
+                    nameof(source)),
+                IEnumerable<object> iObj => new List<object>(iObj),
+                null => throw new ArgumentNullException(nameof(source)),
+                _ => new List<object>(source.Cast<object>())
+            };
+
+            if (_listening && _source is INotifyCollectionChanged inccNew)
+                CollectionChangedEventManager.Instance.AddListener(inccNew, this);
+        }
+
+        private void AddListenerIfNecessary()
+        {
+            if (!_listening)
+            {
+                if (_source is INotifyCollectionChanged incc)
+                    CollectionChangedEventManager.Instance.AddListener(incc, this);
+                _listening = true;
+            }
+        }
+
+        private void RemoveListenerIfNecessary()
+        {
+            if (_listening && _collectionChanged is null && _postCollectionChanged is null)
+            {
+                if (_source is INotifyCollectionChanged incc)
+                    CollectionChangedEventManager.Instance.RemoveListener(incc, this);
+                _listening = false;
+            }
+        }
+
+        [DoesNotReturn]
+        private static int ThrowReadOnly() => throw new NotSupportedException("Collection is read-only.");
     }
 
     public sealed class ItemsSourceView<T> : ItemsSourceView, IReadOnlyList<T>
@@ -285,7 +333,7 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="index">The index.</param>
         /// <returns>The item.</returns>
-        public new T GetAt(int index) => (T)Inner[index]!;
+        public new T GetAt(int index) => (T)Source[index]!;
 
         public new IEnumerator<T> GetEnumerator()
         {
@@ -295,7 +343,7 @@ namespace Avalonia.Controls
                     yield return (T)o;
             }
 
-            var inner = Inner;
+            var inner = Source;
 
             return inner switch
             {
@@ -304,6 +352,6 @@ namespace Avalonia.Controls
             };
         }
 
-        IEnumerator IEnumerable.GetEnumerator() => Inner.GetEnumerator();
+        IEnumerator IEnumerable.GetEnumerator() => Source.GetEnumerator();
     }
 }
diff --git a/src/Avalonia.Controls/LayoutTransformControl.cs b/src/Avalonia.Controls/LayoutTransformControl.cs
index 387dc27562..f747e278f0 100644
--- a/src/Avalonia.Controls/LayoutTransformControl.cs
+++ b/src/Avalonia.Controls/LayoutTransformControl.cs
@@ -91,7 +91,7 @@ namespace Avalonia.Controls
             arrangedsize = TransformRoot.Bounds.Size;
 
             // This is the first opportunity under Silverlight to find out the Child's true DesiredSize
-            if (IsSizeSmaller(finalSizeTransformed, arrangedsize) && _childActualSize.IsDefault)
+            if (IsSizeSmaller(finalSizeTransformed, arrangedsize) && _childActualSize == default)
             {
                 //// Unfortunately, all the work so far is invalid because the wrong DesiredSize was used
                 //// Make a note of the actual DesiredSize
@@ -122,7 +122,7 @@ namespace Avalonia.Controls
             }
 
             Size measureSize;
-            if (_childActualSize.IsDefault)
+            if (_childActualSize == default)
             {
                 // Determine the largest size after the transformation
                 measureSize = ComputeLargestTransformedSize(availableSize);
diff --git a/src/Avalonia.Controls/MaskedTextBox.cs b/src/Avalonia.Controls/MaskedTextBox.cs
index d397a581dc..8fc9477dc7 100644
--- a/src/Avalonia.Controls/MaskedTextBox.cs
+++ b/src/Avalonia.Controls/MaskedTextBox.cs
@@ -15,9 +15,8 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<bool> AsciiOnlyProperty =
              AvaloniaProperty.Register<MaskedTextBox, bool>(nameof(AsciiOnly));
 
-        public static readonly DirectProperty<MaskedTextBox, CultureInfo?> CultureProperty =
-             AvaloniaProperty.RegisterDirect<MaskedTextBox, CultureInfo?>(nameof(Culture), o => o.Culture,
-                (o, v) => o.Culture = v, CultureInfo.CurrentCulture);
+        public static readonly StyledProperty<CultureInfo?> CultureProperty =
+             AvaloniaProperty.Register<MaskedTextBox, CultureInfo?>(nameof(Culture), CultureInfo.CurrentCulture);
 
         public static readonly StyledProperty<bool> HidePromptOnLeaveProperty =
              AvaloniaProperty.Register<MaskedTextBox, bool>(nameof(HidePromptOnLeave));
@@ -32,26 +31,49 @@ namespace Avalonia.Controls
              AvaloniaProperty.Register<MaskedTextBox, string?>(nameof(Mask), string.Empty);
 
         public static readonly StyledProperty<char> PromptCharProperty =
-             AvaloniaProperty.Register<MaskedTextBox, char>(nameof(PromptChar), '_');
+             AvaloniaProperty.Register<MaskedTextBox, char>(nameof(PromptChar), '_', coerce: CoercePromptChar);
 
-        public static readonly DirectProperty<MaskedTextBox, bool> ResetOnPromptProperty =
-             AvaloniaProperty.RegisterDirect<MaskedTextBox, bool>(nameof(ResetOnPrompt), o => o.ResetOnPrompt, (o, v) => o.ResetOnPrompt = v);
+        public static readonly StyledProperty<bool> ResetOnPromptProperty =
+             AvaloniaProperty.Register<MaskedTextBox, bool>(nameof(ResetOnPrompt), true);
 
-        public static readonly DirectProperty<MaskedTextBox, bool> ResetOnSpaceProperty =
-             AvaloniaProperty.RegisterDirect<MaskedTextBox, bool>(nameof(ResetOnSpace), o => o.ResetOnSpace, (o, v) => o.ResetOnSpace = v);
+        public static readonly StyledProperty<bool> ResetOnSpaceProperty =
+             AvaloniaProperty.Register<MaskedTextBox, bool>(nameof(ResetOnSpace), true);
 
-        private CultureInfo? _culture;
+        private bool _ignoreTextChanges;
 
-        private bool _resetOnPrompt = true;
+        static MaskedTextBox()
+        {
+            PasswordCharProperty.OverrideMetadata<MaskedTextBox>(new('\0', coerce: CoercePasswordChar));
+        }
 
-        private bool _ignoreTextChanges;
+        private static char CoercePasswordChar(AvaloniaObject sender, char baseValue)
+        {
+            if (!MaskedTextProvider.IsValidPasswordChar(baseValue))
+            {
+                throw new ArgumentException($"'{baseValue}' is not a valid value for PasswordChar.");
+            }
+            var textbox = (MaskedTextBox)sender;
+            if (textbox.MaskProvider is { } maskProvider && baseValue == maskProvider.PromptChar)
+            {
+                // Prompt and password chars must be different.
+                throw new InvalidOperationException("PasswordChar and PromptChar values cannot be the same.");
+            }
 
-        private bool _resetOnSpace = true;
+            return baseValue;
+        }
 
-        static MaskedTextBox()
+        private static char CoercePromptChar(AvaloniaObject sender, char baseValue)
         {
-            PasswordCharProperty
-                .OverrideDefaultValue<MaskedTextBox>('\0');
+            if (!MaskedTextProvider.IsValidInputChar(baseValue))
+            {
+                throw new ArgumentException($"'{baseValue}' is not a valid value for PromptChar.");
+            }
+            if (baseValue == sender.GetValue(PasswordCharProperty))
+            {
+                throw new InvalidOperationException("PasswordChar and PromptChar values cannot be the same.");
+            }
+
+            return baseValue;
         }
 
         public MaskedTextBox() { }
@@ -59,6 +81,9 @@ namespace Avalonia.Controls
         /// <summary>
         ///  Constructs the MaskedTextBox with the specified MaskedTextProvider object.
         /// </summary>
+        [System.Diagnostics.CodeAnalysis.SuppressMessage("AvaloniaProperty", 
+            "AVP1012:An AvaloniaObject should use SetCurrentValue when assigning its own StyledProperty or AttachedProperty values", 
+            Justification = "These values are being explicitly provided by a constructor parameter.")]
         public MaskedTextBox(MaskedTextProvider maskedTextProvider)
         {
             if (maskedTextProvider == null)
@@ -87,8 +112,8 @@ namespace Avalonia.Controls
         /// </summary>
         public CultureInfo? Culture
         {
-            get => _culture;
-            set => SetAndRaise(CultureProperty, ref _culture, value);
+            get => GetValue(CultureProperty);
+            set => SetValue(CultureProperty, value);
         }
 
         /// <summary>
@@ -131,15 +156,6 @@ namespace Avalonia.Controls
         /// </summary>
         public MaskedTextProvider? MaskProvider { get; private set; }
 
-        /// <summary>
-        /// Gets or sets the character to be displayed in substitute for user input.
-        /// </summary>
-        public new char PasswordChar
-        {
-            get => GetValue(PasswordCharProperty);
-            set => SetValue(PasswordCharProperty, value);
-        }
-
         /// <summary>
         /// Gets or sets the character used to represent the absence of user input in MaskedTextBox.
         /// </summary>
@@ -154,16 +170,8 @@ namespace Avalonia.Controls
         /// </summary>
         public bool ResetOnPrompt
         {
-            get => _resetOnPrompt;
-            set
-            {
-                SetAndRaise(ResetOnPromptProperty, ref _resetOnPrompt, value);
-                if (MaskProvider != null)
-                {
-                    MaskProvider.ResetOnPrompt = value;
-                }
-
-            }
+            get => GetValue(ResetOnPromptProperty);
+            set => SetValue(ResetOnPromptProperty, value);
         }
 
         /// <summary>
@@ -171,16 +179,8 @@ namespace Avalonia.Controls
         /// </summary>
         public bool ResetOnSpace
         {
-            get => _resetOnSpace;
-            set
-            {
-                SetAndRaise(ResetOnSpaceProperty, ref _resetOnSpace, value);
-                if (MaskProvider != null)
-                {
-                    MaskProvider.ResetOnSpace = value;
-                }
-
-            }
+            get => GetValue(ResetOnSpaceProperty);
+            set => SetValue(ResetOnSpaceProperty, value);
         }
 
         Type IStyleable.StyleKey => typeof(TextBox);
@@ -190,7 +190,7 @@ namespace Avalonia.Controls
         {
             if (HidePromptOnLeave == true && MaskProvider != null)
             {
-                Text = MaskProvider.ToDisplayString();
+                SetCurrentValue(TextProperty, MaskProvider.ToDisplayString());
             }
             base.OnGotFocus(e);
         }
@@ -225,11 +225,11 @@ namespace Avalonia.Controls
                     var index = GetNextCharacterPosition(CaretIndex);
                     if (MaskProvider.InsertAt(item, index))
                     {
-                        CaretIndex = ++index;
+                        SetCurrentValue(CaretIndexProperty, ++index);
                     }
                 }
 
-                Text = MaskProvider.ToDisplayString();
+                SetCurrentValue(TextProperty, MaskProvider.ToDisplayString());
                 e.Handled = true;
                 return;
             }
@@ -279,7 +279,7 @@ namespace Avalonia.Controls
         {
             if (HidePromptOnLeave && MaskProvider != null)
             {
-                Text = MaskProvider.ToString(!HidePromptOnLeave, true);
+                SetCurrentValue(TextProperty, MaskProvider.ToString(!HidePromptOnLeave, true));
             }
             base.OnLostFocus(e);
         }
@@ -326,15 +326,6 @@ namespace Avalonia.Controls
             }
             else if (change.Property == PasswordCharProperty)
             {
-                if (!MaskedTextProvider.IsValidPasswordChar(PasswordChar))
-                {
-                    throw new ArgumentException("Specified character value is not allowed for this property.", nameof(PasswordChar));
-                }
-                if (MaskProvider != null && PasswordChar == MaskProvider.PromptChar)
-                {
-                    // Prompt and password chars must be different.
-                    throw new InvalidOperationException("PasswordChar and PromptChar values cannot be the same.");
-                }
                 if (MaskProvider != null && MaskProvider.PasswordChar != PasswordChar)
                 {
                     UpdateMaskProvider();
@@ -342,17 +333,23 @@ namespace Avalonia.Controls
             }
             else if (change.Property == PromptCharProperty)
             {
-                if (!MaskedTextProvider.IsValidInputChar(PromptChar))
+                if (MaskProvider != null && MaskProvider.PromptChar != PromptChar)
                 {
-                    throw new ArgumentException("Specified character value is not allowed for this property.");
+                    UpdateMaskProvider();
                 }
-                if (PromptChar == PasswordChar)
+            }
+            else if (change.Property == ResetOnPromptProperty)
+            {
+                if (MaskProvider != null && change.GetNewValue<bool>() is { } newValue)
                 {
-                    throw new InvalidOperationException("PasswordChar and PromptChar values cannot be the same.");
+                    MaskProvider.ResetOnPrompt = newValue;
                 }
-                if (MaskProvider != null && MaskProvider.PromptChar != PromptChar)
+            }
+            else if (change.Property == ResetOnSpaceProperty)
+            {
+                if (MaskProvider != null && change.GetNewValue<bool>() is { } newValue)
                 {
-                    UpdateMaskProvider();
+                    MaskProvider.ResetOnSpace = newValue;
                 }
             }
             else if (change.Property == AsciiOnlyProperty && MaskProvider != null && MaskProvider.AsciiOnly != AsciiOnly
@@ -390,7 +387,7 @@ namespace Avalonia.Controls
 
                 if (CaretIndex < Text?.Length)
                 {
-                    CaretIndex = GetNextCharacterPosition(CaretIndex);
+                    SetCurrentValue(CaretIndexProperty, GetNextCharacterPosition(CaretIndex));
 
                     if (MaskProvider.InsertAt(e.Text!, CaretIndex))
                     {
@@ -399,7 +396,7 @@ namespace Avalonia.Controls
                     var nextPos = GetNextCharacterPosition(CaretIndex);
                     if (nextPos != 0 && CaretIndex != Text.Length)
                     {
-                        CaretIndex = nextPos;
+                        SetCurrentValue(CaretIndexProperty, nextPos);
                     }
                 }
 
@@ -434,8 +431,8 @@ namespace Avalonia.Controls
         {
             if (provider != null)
             {
-                Text = provider.ToDisplayString();
-                CaretIndex = position;
+                SetCurrentValue(TextProperty, provider.ToDisplayString());
+                SetCurrentValue(CaretIndexProperty, position);
             }
         }
 
diff --git a/src/Avalonia.Controls/NativeControlHost.cs b/src/Avalonia.Controls/NativeControlHost.cs
index a94a1ee983..aa3d6db9e0 100644
--- a/src/Avalonia.Controls/NativeControlHost.cs
+++ b/src/Avalonia.Controls/NativeControlHost.cs
@@ -141,7 +141,7 @@ namespace Avalonia.Controls
 
             if (IsEffectivelyVisible && bounds.HasValue)
             {
-                if (bounds.Value.IsDefault)
+                if (bounds.Value.Width == 0 && bounds.Value.Height == 0)
                     return false;
                 _attachment?.ShowInBounds(bounds.Value);
             }
diff --git a/src/Avalonia.Controls/Platform/IInsetsManager.cs b/src/Avalonia.Controls/Platform/IInsetsManager.cs
index 6288142805..072bace154 100644
--- a/src/Avalonia.Controls/Platform/IInsetsManager.cs
+++ b/src/Avalonia.Controls/Platform/IInsetsManager.cs
@@ -36,7 +36,7 @@ namespace Avalonia.Controls.Platform
             SafeAreaPadding = safeArePadding;
         }
 
-        /// <inheritdoc cref="IInsetsManager.GetSafeAreaPadding"/>
+        /// <inheritdoc cref="IInsetsManager.SafeAreaPadding"/>
         public Thickness SafeAreaPadding { get; }
     }
 
diff --git a/src/Avalonia.Controls/Platform/IPopupImpl.cs b/src/Avalonia.Controls/Platform/IPopupImpl.cs
index cd86045dee..320130bc91 100644
--- a/src/Avalonia.Controls/Platform/IPopupImpl.cs
+++ b/src/Avalonia.Controls/Platform/IPopupImpl.cs
@@ -9,7 +9,7 @@ namespace Avalonia.Platform
     [Unstable]
     public interface IPopupImpl : IWindowBaseImpl
     {
-        IPopupPositioner PopupPositioner { get; }
+        IPopupPositioner? PopupPositioner { get; }
 
         void SetWindowManagerAddShadowHint(bool enabled);
     }
diff --git a/src/Avalonia.Controls/Presenters/PanelContainerGenerator.cs b/src/Avalonia.Controls/Presenters/PanelContainerGenerator.cs
index a2df8c3e5f..796ee8433a 100644
--- a/src/Avalonia.Controls/Presenters/PanelContainerGenerator.cs
+++ b/src/Avalonia.Controls/Presenters/PanelContainerGenerator.cs
@@ -22,7 +22,6 @@ namespace Avalonia.Controls.Presenters
             Debug.Assert(presenter.Panel is not null or VirtualizingPanel);
             
             _presenter = presenter;
-            _presenter.ItemsControl.PropertyChanged += OnItemsControlPropertyChanged;
             _presenter.ItemsControl.ItemsView.PostCollectionChanged += OnItemsChanged;
 
             OnItemsChanged(null, CollectionUtils.ResetEventArgs);
@@ -32,9 +31,7 @@ namespace Avalonia.Controls.Presenters
         {
             if (_presenter.ItemsControl is { } itemsControl)
             {
-                itemsControl.PropertyChanged -= OnItemsControlPropertyChanged;
                 itemsControl.ItemsView.PostCollectionChanged -= OnItemsChanged;
-
                 ClearItemsControlLogicalChildren();
             }
 
@@ -43,18 +40,6 @@ namespace Avalonia.Controls.Presenters
 
         internal void Refresh() => OnItemsChanged(null, CollectionUtils.ResetEventArgs);
 
-        private void OnItemsControlPropertyChanged(object? sender, AvaloniaPropertyChangedEventArgs e)
-        {
-            if (e.Property == ItemsControl.ItemsProperty)
-            {
-                if (e.OldValue is INotifyCollectionChanged inccOld)
-                    inccOld.CollectionChanged -= OnItemsChanged;
-                OnItemsChanged(null, CollectionUtils.ResetEventArgs);
-                if (e.NewValue is INotifyCollectionChanged inccNew)
-                    inccNew.CollectionChanged += OnItemsChanged;
-            }
-        }
-
         private void OnItemsChanged(object? sender, NotifyCollectionChangedEventArgs e)
         {
             if (_presenter.Panel is null || _presenter.ItemsControl is null)
@@ -84,8 +69,7 @@ namespace Avalonia.Controls.Presenters
                     var c = children[index + i];
                     if (!c.IsSet(ItemIsOwnContainerProperty))
                         itemsControl.RemoveLogicalChild(children[i + index]);
-                    else
-                        generator.ClearItemContainer(c);
+                    generator.ClearItemContainer(c);
                 }
 
                 children.RemoveRange(index, count);
diff --git a/src/Avalonia.Controls/Presenters/TextPresenter.cs b/src/Avalonia.Controls/Presenters/TextPresenter.cs
index 089a2c1168..e4167425cd 100644
--- a/src/Avalonia.Controls/Presenters/TextPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/TextPresenter.cs
@@ -9,17 +9,13 @@ using Avalonia.VisualTree;
 using Avalonia.Layout;
 using Avalonia.Media.Immutable;
 using Avalonia.Controls.Documents;
-using Avalonia.Input.TextInput;
-using Avalonia.Data;
 
 namespace Avalonia.Controls.Presenters
 {
     public class TextPresenter : Control
     {
-        public static readonly DirectProperty<TextPresenter, int> CaretIndexProperty =
-            TextBox.CaretIndexProperty.AddOwner<TextPresenter>(
-                o => o.CaretIndex,
-                (o, v) => o.CaretIndex = v);
+        public static readonly StyledProperty<int> CaretIndexProperty =
+            TextBox.CaretIndexProperty.AddOwner<TextPresenter>(new(coerce: TextBox.CoerceCaretIndex));
 
         public static readonly StyledProperty<bool> RevealPasswordProperty =
             AvaloniaProperty.Register<TextPresenter, bool>(nameof(RevealPassword));
@@ -36,33 +32,23 @@ namespace Avalonia.Controls.Presenters
         public static readonly StyledProperty<IBrush?> CaretBrushProperty =
             AvaloniaProperty.Register<TextPresenter, IBrush?>(nameof(CaretBrush));
 
-        public static readonly DirectProperty<TextPresenter, int> SelectionStartProperty =
-            TextBox.SelectionStartProperty.AddOwner<TextPresenter>(
-                o => o.SelectionStart,
-                (o, v) => o.SelectionStart = v);
+        public static readonly StyledProperty<int> SelectionStartProperty =
+            TextBox.SelectionStartProperty.AddOwner<TextPresenter>(new(coerce: TextBox.CoerceCaretIndex));
 
-        public static readonly DirectProperty<TextPresenter, int> SelectionEndProperty =
-            TextBox.SelectionEndProperty.AddOwner<TextPresenter>(
-                o => o.SelectionEnd,
-                (o, v) => o.SelectionEnd = v);
+        public static readonly StyledProperty<int> SelectionEndProperty =
+            TextBox.SelectionEndProperty.AddOwner<TextPresenter>(new(coerce: TextBox.CoerceCaretIndex));
 
         /// <summary>
         /// Defines the <see cref="Text"/> property.
         /// </summary>
-        public static readonly DirectProperty<TextPresenter, string?> TextProperty =
-            AvaloniaProperty.RegisterDirect<TextPresenter, string?>(
-                nameof(Text),
-                o => o.Text,
-                (o, v) => o.Text = v, defaultBindingMode: BindingMode.OneWay);
+        public static readonly StyledProperty<string?> TextProperty =
+            TextBlock.TextProperty.AddOwner<TextPresenter>(new(string.Empty));
 
         /// <summary>
         /// Defines the <see cref="PreeditText"/> property.
         /// </summary>
-        public static readonly DirectProperty<TextPresenter, string?> PreeditTextProperty =
-            AvaloniaProperty.RegisterDirect<TextPresenter, string?>(
-                nameof(PreeditText),
-                o => o.PreeditText,
-                 (o, v) => o.PreeditText = v);
+        public static readonly StyledProperty<string?> PreeditTextProperty =
+            AvaloniaProperty.Register<TextPresenter, string?>(nameof(PreeditText));
 
         /// <summary>
         /// Defines the <see cref="CompositionRegion"/> property.
@@ -104,18 +90,13 @@ namespace Avalonia.Controls.Presenters
             Border.BackgroundProperty.AddOwner<TextPresenter>();
 
         private readonly DispatcherTimer _caretTimer;
-        private int _caretIndex;
-        private int _selectionStart;
-        private int _selectionEnd;
         private bool _caretBlink;
-        internal string? _text;
         private TextLayout? _textLayout;
         private Size _constraint;
 
         private CharacterHit _lastCharacterHit;
         private Rect _caretBounds;
         private Point _navigationPosition;
-        private string? _preeditText;
         private TextRange? _compositionRegion;
 
         static TextPresenter()
@@ -125,7 +106,6 @@ namespace Avalonia.Controls.Presenters
 
         public TextPresenter()
         {
-            _text = string.Empty;
             _caretTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(500) };
             _caretTimer.Tick += CaretTimerTick;
         }
@@ -147,14 +127,14 @@ namespace Avalonia.Controls.Presenters
         [Content]
         public string? Text
         {
-            get => _text;
-            set => SetAndRaise(TextProperty, ref _text, value);
+            get => GetValue(TextProperty);
+            set => SetValue(TextProperty, value);
         }
 
         public string? PreeditText
         {
-            get => _preeditText;
-            set => SetAndRaise(PreeditTextProperty, ref _preeditText, value);
+            get => GetValue(PreeditTextProperty);
+            set => SetValue(PreeditTextProperty, value);
         }
 
         public TextRange? CompositionRegion
@@ -275,17 +255,8 @@ namespace Avalonia.Controls.Presenters
 
         public int CaretIndex
         {
-            get
-            {
-                return _caretIndex;
-            }
-            set
-            {
-                if (value != _caretIndex)
-                {
-                    MoveCaretToTextPosition(value);
-                }
-            }
+            get => GetValue(CaretIndexProperty);
+            set => SetValue(CaretIndexProperty, value);
         }
 
         public char PasswordChar
@@ -320,30 +291,14 @@ namespace Avalonia.Controls.Presenters
 
         public int SelectionStart
         {
-            get
-            {
-                return _selectionStart;
-            }
-
-            set
-            {
-                value = CoerceCaretIndex(value);
-                SetAndRaise(SelectionStartProperty, ref _selectionStart, value);
-            }
+            get => GetValue(SelectionStartProperty);
+            set => SetValue(SelectionStartProperty, value);
         }
 
         public int SelectionEnd
         {
-            get
-            {
-                return _selectionEnd;
-            }
-
-            set
-            {
-                value = CoerceCaretIndex(value);
-                SetAndRaise(SelectionEndProperty, ref _selectionEnd, value);
-            }
+            get => GetValue(SelectionEndProperty);
+            set => SetValue(SelectionEndProperty, value);
         }
 
         protected override bool BypassFlowDirectionPolicies => true;
@@ -535,12 +490,12 @@ namespace Avalonia.Controls.Presenters
         {
             TextLayout result;
 
-            var text = _text;
+            var text = Text;
 
             var typeface = new Typeface(FontFamily, FontStyle, FontWeight);
 
-            var selectionStart = CoerceCaretIndex(SelectionStart);
-            var selectionEnd = CoerceCaretIndex(SelectionEnd);
+            var selectionStart = SelectionStart;
+            var selectionEnd = SelectionEnd;
             var start = Math.Min(selectionStart, selectionEnd);
             var length = Math.Max(selectionStart, selectionEnd) - start;
 
@@ -561,9 +516,9 @@ namespace Avalonia.Controls.Presenters
                 };
 
             }
-            else if (!string.IsNullOrEmpty(_preeditText))
+            else if (!string.IsNullOrEmpty(PreeditText))
             {
-                var preeditHighlight = new ValueSpan<TextRunProperties>(_caretIndex, _preeditText.Length,
+                var preeditHighlight = new ValueSpan<TextRunProperties>(CaretIndex, PreeditText.Length,
                         new GenericTextRunProperties(typeface, FontSize,
                         foregroundBrush: foreground,
                         textDecorations: TextDecorations.Underline));
@@ -643,13 +598,6 @@ namespace Avalonia.Controls.Presenters
             return finalSize;
         }
 
-        private int CoerceCaretIndex(int value)
-        {
-            var text = Text;
-            var length = text?.Length ?? 0;
-            return Math.Max(0, Math.Min(length, value));
-        }
-
         private void CaretTimerTick(object? sender, EventArgs e)
         {
             _caretBlink = !_caretBlink;
@@ -865,7 +813,7 @@ namespace Avalonia.Controls.Presenters
 
             if (notify)
             {
-                SetAndRaise(CaretIndexProperty, ref _caretIndex, caretIndex);
+                SetCurrentValue(CaretIndexProperty, caretIndex);
             }
         }
 
@@ -887,6 +835,11 @@ namespace Avalonia.Controls.Presenters
         {
             base.OnPropertyChanged(change);
 
+            if (change.Property == CaretIndexProperty)
+            {
+                MoveCaretToTextPosition(change.GetNewValue<int>());
+            }
+
             switch (change.Property.Name)
             {
                 case nameof(PreeditText):
diff --git a/src/Avalonia.Controls/Primitives/Popup.cs b/src/Avalonia.Controls/Primitives/Popup.cs
index 0c6c434713..eda794f33a 100644
--- a/src/Avalonia.Controls/Primitives/Popup.cs
+++ b/src/Avalonia.Controls/Primitives/Popup.cs
@@ -65,11 +65,17 @@ namespace Avalonia.Controls.Primitives
         public static readonly StyledProperty<PopupGravity> PlacementGravityProperty =
             AvaloniaProperty.Register<Popup, PopupGravity>(nameof(PlacementGravity));
 
+        /// <summary>
+        /// Defines the <see cref="Placement"/> property.
+        /// </summary>
+        public static readonly StyledProperty<PlacementMode> PlacementProperty =
+            AvaloniaProperty.Register<Popup, PlacementMode>(nameof(Placement), defaultValue: PlacementMode.Bottom);
+
         /// <summary>
         /// Defines the <see cref="PlacementMode"/> property.
         /// </summary>
-        public static readonly StyledProperty<PlacementMode> PlacementModeProperty =
-            AvaloniaProperty.Register<Popup, PlacementMode>(nameof(PlacementMode), defaultValue: PlacementMode.Bottom);
+        [Obsolete("Use the Placement property instead.")]
+        public static readonly StyledProperty<PlacementMode> PlacementModeProperty = PlacementProperty;
 
         /// <summary>
         /// Defines the <see cref="PlacementRect"/> property.
@@ -146,8 +152,8 @@ namespace Avalonia.Controls.Primitives
 
         public bool WindowManagerAddShadowHint
         {
-            get { return GetValue(WindowManagerAddShadowHintProperty); }
-            set { SetValue(WindowManagerAddShadowHintProperty, value); }
+            get => GetValue(WindowManagerAddShadowHintProperty);
+            set => SetValue(WindowManagerAddShadowHintProperty, value);
         }
 
         /// <summary>
@@ -156,8 +162,8 @@ namespace Avalonia.Controls.Primitives
         [Content]
         public Control? Child
         {
-            get { return GetValue(ChildProperty); }
-            set { SetValue(ChildProperty, value); }
+            get => GetValue(ChildProperty);
+            set => SetValue(ChildProperty, value);
         }
 
         /// <summary>
@@ -205,13 +211,13 @@ namespace Avalonia.Controls.Primitives
         }
 
         /// <summary>
-        /// Gets or sets the anchor point on the <see cref="PlacementRect"/> when <see cref="PlacementMode"/>
+        /// Gets or sets the anchor point on the <see cref="PlacementRect"/> when <see cref="Placement"/>
         /// is <see cref="PlacementMode.AnchorAndGravity"/>.
         /// </summary>
         public PopupAnchor PlacementAnchor
         {
-            get { return GetValue(PlacementAnchorProperty); }
-            set { SetValue(PlacementAnchorProperty, value); }
+            get => GetValue(PlacementAnchorProperty);
+            set => SetValue(PlacementAnchorProperty, value);
         }
 
         /// <summary>
@@ -220,32 +226,40 @@ namespace Avalonia.Controls.Primitives
         /// </summary>
         public PopupPositionerConstraintAdjustment PlacementConstraintAdjustment
         {
-            get { return GetValue(PlacementConstraintAdjustmentProperty); }
-            set { SetValue(PlacementConstraintAdjustmentProperty, value); }
+            get => GetValue(PlacementConstraintAdjustmentProperty);
+            set => SetValue(PlacementConstraintAdjustmentProperty, value);
         }
 
         /// <summary>
         /// Gets or sets a value which defines in what direction the popup should open
-        /// when <see cref="PlacementMode"/> is <see cref="PlacementMode.AnchorAndGravity"/>.
+        /// when <see cref="Placement"/> is <see cref="PlacementMode.AnchorAndGravity"/>.
         /// </summary>
         public PopupGravity PlacementGravity
         {
-            get { return GetValue(PlacementGravityProperty); }
-            set { SetValue(PlacementGravityProperty, value); }
+            get => GetValue(PlacementGravityProperty);
+            set => SetValue(PlacementGravityProperty, value);
+        }
+
+        /// <inheritdoc cref="Placement"/>
+        [Obsolete("Use the Placement property instead.")]
+        public PlacementMode PlacementMode
+        {
+            get => GetValue(PlacementProperty);
+            set => SetValue(PlacementProperty, value);
         }
 
         /// <summary>
-        /// Gets or sets the placement mode of the popup in relation to the <see cref="PlacementTarget"/>.
+        /// Gets or sets the desired placement of the popup in relation to the <see cref="PlacementTarget"/>.
         /// </summary>
-        public PlacementMode PlacementMode
+        public PlacementMode Placement
         {
-            get { return GetValue(PlacementModeProperty); }
-            set { SetValue(PlacementModeProperty, value); }
+            get => GetValue(PlacementProperty);
+            set => SetValue(PlacementProperty, value);
         }
 
         /// <summary>
         /// Gets or sets the the anchor rectangle within the parent that the popup will be placed
-        /// relative to when <see cref="PlacementMode"/> is <see cref="PlacementMode.AnchorAndGravity"/>.
+        /// relative to when <see cref="Placement"/> is <see cref="PlacementMode.AnchorAndGravity"/>.
         /// </summary>
         /// <remarks>
         /// The placement rect defines a rectangle relative to <see cref="PlacementTarget"/> around
@@ -256,8 +270,8 @@ namespace Avalonia.Controls.Primitives
         /// </remarks>
         public Rect? PlacementRect
         {
-            get { return GetValue(PlacementRectProperty); }
-            set { SetValue(PlacementRectProperty, value); }
+            get => GetValue(PlacementRectProperty);
+            set => SetValue(PlacementRectProperty, value);
         }
 
         /// <summary>
@@ -266,8 +280,8 @@ namespace Avalonia.Controls.Primitives
         [ResolveByName]
         public Control? PlacementTarget
         {
-            get { return GetValue(PlacementTargetProperty); }
-            set { SetValue(PlacementTargetProperty, value); }
+            get => GetValue(PlacementTargetProperty);
+            set => SetValue(PlacementTargetProperty, value);
         }
 
         /// <summary>
@@ -301,8 +315,8 @@ namespace Avalonia.Controls.Primitives
         /// </summary>
         public double HorizontalOffset
         {
-            get { return GetValue(HorizontalOffsetProperty); }
-            set { SetValue(HorizontalOffsetProperty, value); }
+            get => GetValue(HorizontalOffsetProperty);
+            set => SetValue(HorizontalOffsetProperty, value);
         }
 
         /// <summary>
@@ -310,8 +324,8 @@ namespace Avalonia.Controls.Primitives
         /// </summary>
         public double VerticalOffset
         {
-            get { return GetValue(VerticalOffsetProperty); }
-            set { SetValue(VerticalOffsetProperty, value); }
+            get => GetValue(VerticalOffsetProperty);
+            set => SetValue(VerticalOffsetProperty, value);
         }
 
         /// <summary>
@@ -319,8 +333,8 @@ namespace Avalonia.Controls.Primitives
         /// </summary>
         public bool Topmost
         {
-            get { return GetValue(TopmostProperty); }
-            set { SetValue(TopmostProperty, value); }
+            get => GetValue(TopmostProperty);
+            set => SetValue(TopmostProperty, value);
         }
 
         IPopupHost? IPopupHostProvider.PopupHost => Host;
@@ -404,7 +418,7 @@ namespace Avalonia.Controls.Primitives
                     (x, handler) => x.LostFocus -= handler).DisposeWith(handlerCleanup);
 
                 // Recalculate popup position on parent moved/resized, but not if placement was on pointer
-                if (PlacementMode != PlacementMode.Pointer)
+                if (Placement != PlacementMode.Pointer)
                 {
                     SubscribeToEventHandler<IWindowImpl, Action<PixelPoint>>(window.PlatformImpl, WindowPositionChanged,
                         (x, handler) => x.PositionChanged += handler,
@@ -534,7 +548,7 @@ namespace Avalonia.Controls.Primitives
                     UpdateHostSizing(_openState.PopupHost, _openState.TopLevel, _openState.PlacementTarget);
                 }
                 else if (change.Property == PlacementTargetProperty ||
-                         change.Property == PlacementModeProperty ||
+                         change.Property == PlacementProperty ||
                          change.Property == HorizontalOffsetProperty ||
                          change.Property == VerticalOffsetProperty ||
                          change.Property == PlacementAnchorProperty ||
@@ -567,7 +581,7 @@ namespace Avalonia.Controls.Primitives
         {
             popupHost.ConfigurePosition(
                 placementTarget,
-                PlacementMode,
+                Placement,
                 new Point(HorizontalOffset, VerticalOffset),
                 PlacementAnchor,
                 PlacementGravity,
@@ -615,7 +629,7 @@ namespace Avalonia.Controls.Primitives
                     return;
                 _openState.PopupHost.ConfigurePosition(
                     placementTarget,
-                    PlacementMode,
+                    Placement,
                     new Point(HorizontalOffset, VerticalOffset),
                     PlacementAnchor,
                     PlacementGravity,
diff --git a/src/Avalonia.Controls/Primitives/PopupPositioning/ManagedPopupPositioner.cs b/src/Avalonia.Controls/Primitives/PopupPositioning/ManagedPopupPositioner.cs
index 62e5f37273..9a60725c7e 100644
--- a/src/Avalonia.Controls/Primitives/PopupPositioning/ManagedPopupPositioner.cs
+++ b/src/Avalonia.Controls/Primitives/PopupPositioning/ManagedPopupPositioner.cs
@@ -112,7 +112,8 @@ namespace Avalonia.Controls.Primitives.PopupPositioning
                                    ?? screens.FirstOrDefault(s => s.Bounds.Intersects(parentGeometry))
                                    ?? screens.FirstOrDefault();
 
-                if (targetScreen != null && targetScreen.WorkingArea.IsDefault)
+                if (targetScreen != null &&
+                    (targetScreen.WorkingArea.Width == 0 && targetScreen.WorkingArea.Height == 0))
                 {
                     return targetScreen.Bounds;
                 }
diff --git a/src/Avalonia.Controls/Primitives/PopupRoot.cs b/src/Avalonia.Controls/Primitives/PopupRoot.cs
index b3436d4176..952ba92e9b 100644
--- a/src/Avalonia.Controls/Primitives/PopupRoot.cs
+++ b/src/Avalonia.Controls/Primitives/PopupRoot.cs
@@ -95,7 +95,7 @@ namespace Avalonia.Controls.Primitives
 
         private void UpdatePosition()
         {
-            PlatformImpl?.PopupPositioner.Update(_positionerParameters);
+            PlatformImpl?.PopupPositioner?.Update(_positionerParameters);
         }
 
         public void ConfigurePosition(Visual target, PlacementMode placement, Point offset,
diff --git a/src/Avalonia.Controls/Primitives/ScrollBar.cs b/src/Avalonia.Controls/Primitives/ScrollBar.cs
index e524db5444..8b2321e40b 100644
--- a/src/Avalonia.Controls/Primitives/ScrollBar.cs
+++ b/src/Avalonia.Controls/Primitives/ScrollBar.cs
@@ -5,6 +5,7 @@ using Avalonia.Input;
 using Avalonia.Layout;
 using Avalonia.Threading;
 using Avalonia.Controls.Metadata;
+using Avalonia.Automation.Peers;
 
 namespace Avalonia.Controls.Primitives
 {
@@ -286,6 +287,8 @@ namespace Avalonia.Controls.Primitives
             }
         }
 
+        protected override AutomationPeer OnCreateAutomationPeer() => new ScrollBarAutomationPeer(this);
+
         private void InvokeAfterDelay(Action handler, TimeSpan delay)
         {
             if (_timer != null)
diff --git a/src/Avalonia.Controls/Primitives/SelectingItemsControl.cs b/src/Avalonia.Controls/Primitives/SelectingItemsControl.cs
index 2ee32b0dda..b89a75787f 100644
--- a/src/Avalonia.Controls/Primitives/SelectingItemsControl.cs
+++ b/src/Avalonia.Controls/Primitives/SelectingItemsControl.cs
@@ -145,6 +145,11 @@ namespace Avalonia.Controls.Primitives
         private BindingHelper? _bindingHelper;
         private bool _isSelectionChangeActive;
 
+        public SelectingItemsControl()
+        {
+            ((ItemCollection)ItemsView).SourceChanged += OnItemsViewSourceChanged;
+        }
+
         /// <summary>
         /// Initializes static members of the <see cref="SelectingItemsControl"/> class.
         /// </summary>
@@ -229,6 +234,7 @@ namespace Avalonia.Controls.Primitives
         /// <see cref="SelectedValue"/> property
         /// </summary>
         [AssignBinding]
+        [InheritDataTypeFromItems(nameof(ItemsSource))]
         [InheritDataTypeFromItems(nameof(Items))]
         public IBinding? SelectedValueBinding
         {
@@ -322,7 +328,7 @@ namespace Avalonia.Controls.Primitives
                 }
                 else if (_selection != value)
                 {
-                    if (value.Source != null && value.Source != Items)
+                    if (value.Source != null && value.Source != ItemsView.Source)
                     {
                         throw new ArgumentException(
                             "The supplied ISelectionModel already has an assigned Source but this " +
@@ -434,10 +440,9 @@ namespace Avalonia.Controls.Primitives
             return null;
         }
 
-        /// <inheritdoc />
-        protected override void ItemsCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
+        private protected override void OnItemsViewCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
         {
-            base.ItemsCollectionChanged(sender!, e);
+            base.OnItemsViewCollectionChanged(sender!, e);
 
             if (AlwaysSelected && SelectedIndex == -1 && ItemCount > 0)
             {
@@ -547,7 +552,7 @@ namespace Avalonia.Controls.Primitives
 
             if (_selection is object)
             {
-                _selection.Source = Items;
+                _selection.Source = ItemsView.Source;
             }
         }
 
@@ -635,16 +640,6 @@ namespace Avalonia.Controls.Primitives
             {
                 AutoScrollToSelectedItemIfNecessary();
             }
-            if (change.Property == ItemsProperty && _updateState is null && _selection is object)
-            {
-                var newValue = change.GetNewValue<IEnumerable?>();
-                _selection.Source = newValue;
-
-                if (newValue is null)
-                {
-                    _selection.Clear();
-                }
-            }
             else if (change.Property == SelectionModeProperty && _selection is object)
             {
                 var newValue = change.GetNewValue<SelectionMode>();
@@ -880,6 +875,12 @@ namespace Avalonia.Controls.Primitives
             return false;
         }
 
+        private void OnItemsViewSourceChanged(object? sender, EventArgs e)
+        {
+            if (_selection is not null && _updateState is null)
+                _selection.Source = ItemsView.Source;
+        }
+
         /// <summary>
         /// Called when <see cref="INotifyPropertyChanged.PropertyChanged"/> is raised on
         /// <see cref="Selection"/>.
@@ -968,7 +969,7 @@ namespace Avalonia.Controls.Primitives
         /// <param name="e">The event args.</param>
         private void OnSelectionModelLostSelection(object? sender, EventArgs e)
         {
-            if (AlwaysSelected && Items is object)
+            if (AlwaysSelected && ItemsView.Count > 0)
             {
                 SelectedIndex = 0;
             }
@@ -998,14 +999,14 @@ namespace Avalonia.Controls.Primitives
             }
         }
 
-        private object FindItemWithValue(object? value)
+        private object? FindItemWithValue(object? value)
         {
             if (ItemCount == 0 || value is null)
             {
                 return AvaloniaProperty.UnsetValue;
             }
 
-            var items = Items;
+            var items = ItemsView;
             var binding = SelectedValueBinding;
 
             if (binding is null)
@@ -1169,7 +1170,7 @@ namespace Avalonia.Controls.Primitives
         {
             if (_updateState is null)
             {
-                model.Source = Items;
+                model.Source = ItemsView.Source;
             }
 
             model.PropertyChanged += OnSelectionModelPropertyChanged;
@@ -1231,16 +1232,18 @@ namespace Avalonia.Controls.Primitives
                     Selection = state.Selection.Value;
                 }
 
-                if (state.SelectedItems.HasValue)
+                if (_selection is InternalSelectionModel s)
                 {
-                    SelectedItems = state.SelectedItems.Value;
+                    s.Update(ItemsView.Source, state.SelectedItems);
                 }
-
-                Selection.Source = Items;
-
-                if (Items is null)
+                else
                 {
-                    Selection.Clear();
+                    if (state.SelectedItems.HasValue)
+                    {
+                        SelectedItems = state.SelectedItems.Value;
+                    }
+
+                    Selection.Source = ItemsView.Source;
                 }
 
                 if (state.SelectedValue.HasValue)
diff --git a/src/Avalonia.Controls/SelectableTextBlock.cs b/src/Avalonia.Controls/SelectableTextBlock.cs
index a737c94719..1007001f05 100644
--- a/src/Avalonia.Controls/SelectableTextBlock.cs
+++ b/src/Avalonia.Controls/SelectableTextBlock.cs
@@ -17,17 +17,11 @@ namespace Avalonia.Controls
     /// </summary>
     public class SelectableTextBlock : TextBlock, IInlineHost
     {
-        public static readonly DirectProperty<SelectableTextBlock, int> SelectionStartProperty =
-            AvaloniaProperty.RegisterDirect<SelectableTextBlock, int>(
-                nameof(SelectionStart),
-                o => o.SelectionStart,
-                (o, v) => o.SelectionStart = v);
-
-        public static readonly DirectProperty<SelectableTextBlock, int> SelectionEndProperty =
-            AvaloniaProperty.RegisterDirect<SelectableTextBlock, int>(
-                nameof(SelectionEnd),
-                o => o.SelectionEnd,
-                (o, v) => o.SelectionEnd = v);
+        public static readonly StyledProperty<int> SelectionStartProperty =
+            TextBox.SelectionStartProperty.AddOwner<SelectableTextBlock>(new(coerce: TextBox.CoerceCaretIndex));
+
+        public static readonly StyledProperty<int> SelectionEndProperty =
+            TextBox.SelectionEndProperty.AddOwner<SelectableTextBlock>(new(coerce: TextBox.CoerceCaretIndex));
 
         public static readonly DirectProperty<SelectableTextBlock, string> SelectedTextProperty =
             AvaloniaProperty.RegisterDirect<SelectableTextBlock, string>(
@@ -35,21 +29,16 @@ namespace Avalonia.Controls
                 o => o.SelectedText);
 
         public static readonly StyledProperty<IBrush?> SelectionBrushProperty =
-            AvaloniaProperty.Register<SelectableTextBlock, IBrush?>(nameof(SelectionBrush), Brushes.Blue);
-
+            TextBox.SelectionBrushProperty.AddOwner<SelectableTextBlock>(new(new Data.Optional<IBrush?>(Brushes.Blue)));
 
         public static readonly DirectProperty<SelectableTextBlock, bool> CanCopyProperty =
-            AvaloniaProperty.RegisterDirect<SelectableTextBlock, bool>(
-                nameof(CanCopy),
-                o => o.CanCopy);
+            TextBox.CanCopyProperty.AddOwner<SelectableTextBlock>(o => o.CanCopy);
 
         public static readonly RoutedEvent<RoutedEventArgs> CopyingToClipboardEvent =
             RoutedEvent.Register<SelectableTextBlock, RoutedEventArgs>(
                 nameof(CopyingToClipboard), RoutingStrategies.Bubble);
 
         private bool _canCopy;
-        private int _selectionStart;
-        private int _selectionEnd;
         private int _wordSelectionStart = -1;
 
         static SelectableTextBlock()
@@ -78,16 +67,8 @@ namespace Avalonia.Controls
         /// </summary>
         public int SelectionStart
         {
-            get => _selectionStart;
-            set
-            {
-                if (SetAndRaise(SelectionStartProperty, ref _selectionStart, value))
-                {
-                    RaisePropertyChanged(SelectedTextProperty, "", "");
-
-                    UpdateCommandStates();
-                }
-            }
+            get => GetValue(SelectionStartProperty);
+            set => SetValue(SelectionStartProperty, value);
         }
 
         /// <summary>
@@ -95,16 +76,8 @@ namespace Avalonia.Controls
         /// </summary>
         public int SelectionEnd
         {
-            get => _selectionEnd;
-            set
-            {
-                if (SetAndRaise(SelectionEndProperty, ref _selectionEnd, value))
-                {
-                    RaisePropertyChanged(SelectedTextProperty, "", "");
-
-                    UpdateCommandStates();
-                }
-            }
+            get => GetValue(SelectionEndProperty);
+            set => SetValue(SelectionEndProperty, value);
         }
 
         /// <summary>
@@ -150,7 +123,7 @@ namespace Avalonia.Controls
                 await ((IClipboard)AvaloniaLocator.Current.GetRequiredService(typeof(IClipboard)))
                     .SetTextAsync(text);
             }
-        }        
+        }
 
         /// <summary>
         /// Select all text in the TextBox
@@ -159,8 +132,8 @@ namespace Avalonia.Controls
         {
             var text = Text;
 
-            SelectionStart = 0;
-            SelectionEnd = text?.Length ?? 0;
+            SetCurrentValue(SelectionStartProperty, 0);
+            SetCurrentValue(SelectionEndProperty, text?.Length ?? 0);
         }
 
         /// <summary>
@@ -168,7 +141,7 @@ namespace Avalonia.Controls
         /// </summary>
         public void ClearSelection()
         {
-            SelectionEnd = SelectionStart;
+            SetCurrentValue(SelectionEndProperty, SelectionStart);
         }
 
         protected override void OnGotFocus(GotFocusEventArgs e)
@@ -240,6 +213,17 @@ namespace Avalonia.Controls
             e.Handled = handled;
         }
 
+        protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
+        {
+            base.OnPropertyChanged(change);
+
+            if (change.Property == SelectionStartProperty || change.Property == SelectionEndProperty)
+            {
+                RaisePropertyChanged(SelectedTextProperty, "", "");
+                UpdateCommandStates();
+            }
+        }
+
         protected override void OnPointerPressed(PointerPressedEventArgs e)
         {
             base.OnPointerPressed(e);
@@ -271,25 +255,26 @@ namespace Avalonia.Controls
 
                                 if (index > _wordSelectionStart)
                                 {
-                                    SelectionEnd = StringUtils.NextWord(text, index);
+                                    SetCurrentValue(SelectionEndProperty, StringUtils.NextWord(text, index));
                                 }
 
                                 if (index < _wordSelectionStart || previousWord == _wordSelectionStart)
                                 {
-                                    SelectionStart = previousWord;
+                                    SetCurrentValue(SelectionStartProperty, previousWord);
                                 }
                             }
                             else
                             {
-                                SelectionStart = Math.Min(oldIndex, index);
-                                SelectionEnd = Math.Max(oldIndex, index);
+                                SetCurrentValue(SelectionStartProperty, Math.Min(oldIndex, index));
+                                SetCurrentValue(SelectionEndProperty, Math.Max(oldIndex, index));
                             }
                         }
                         else
                         {
                             if (_wordSelectionStart == -1 || index < SelectionStart || index > SelectionEnd)
                             {
-                                SelectionStart = SelectionEnd = index;
+                                SetCurrentValue(SelectionStartProperty, index);
+                                SetCurrentValue(SelectionEndProperty, index);
 
                                 _wordSelectionStart = -1;
                             }
@@ -299,16 +284,16 @@ namespace Avalonia.Controls
                     case 2:
                         if (!StringUtils.IsStartOfWord(text, index))
                         {
-                            SelectionStart = StringUtils.PreviousWord(text, index);
+                            SetCurrentValue(SelectionStartProperty, StringUtils.PreviousWord(text, index));
                         }
 
                         _wordSelectionStart = SelectionStart;
 
                         if (!StringUtils.IsEndOfWord(text, index))
                         {
-                            SelectionEnd = StringUtils.NextWord(text, index);
+                            SetCurrentValue(SelectionEndProperty, StringUtils.NextWord(text, index));
                         }
-                        
+
                         break;
                     case 3:
                         _wordSelectionStart = -1;
@@ -347,22 +332,22 @@ namespace Avalonia.Controls
 
                     if (distance <= 0)
                     {
-                        SelectionStart = StringUtils.PreviousWord(text, textPosition);
+                        SetCurrentValue(SelectionStartProperty, StringUtils.PreviousWord(text, textPosition));
                     }
 
                     if (distance >= 0)
                     {
                         if (SelectionStart != _wordSelectionStart)
                         {
-                            SelectionStart = _wordSelectionStart;
+                            SetCurrentValue(SelectionStartProperty, _wordSelectionStart);
                         }
 
-                        SelectionEnd = StringUtils.NextWord(text, textPosition);
+                        SetCurrentValue(SelectionEndProperty, StringUtils.NextWord(text, textPosition));
                     }
                 }
                 else
                 {
-                    SelectionEnd = textPosition;
+                    SetCurrentValue(SelectionEndProperty, textPosition);
                 }
 
             }
@@ -395,7 +380,8 @@ namespace Avalonia.Controls
                                           caretIndex >= firstSelection && caretIndex <= lastSelection;
                 if (!didClickInSelection)
                 {
-                    SelectionStart = SelectionEnd = caretIndex;
+                    SetCurrentValue(SelectionStartProperty, caretIndex);
+                    SetCurrentValue(SelectionEndProperty, caretIndex);
                 }
             }
 
@@ -411,9 +397,8 @@ namespace Avalonia.Controls
 
         private string GetSelection()
         {
-            var text = GetText();
-
-            if (string.IsNullOrEmpty(text))
+            var textLength = Text?.Length ?? 0;
+            if (textLength == 0)
             {
                 return "";
             }
@@ -423,14 +408,14 @@ namespace Avalonia.Controls
             var start = Math.Min(selectionStart, selectionEnd);
             var end = Math.Max(selectionStart, selectionEnd);
 
-            if (start == end || text.Length < end)
+            if (start == end || textLength < end)
             {
                 return "";
             }
 
             var length = Math.Max(0, end - start);
 
-            var selectedText = text.Substring(start, length);
+            var selectedText = Text!.Substring(start, length);
 
             return selectedText;
         }
diff --git a/src/Avalonia.Controls/Selection/InternalSelectionModel.cs b/src/Avalonia.Controls/Selection/InternalSelectionModel.cs
index d0715e402d..c8ad9bd88b 100644
--- a/src/Avalonia.Controls/Selection/InternalSelectionModel.cs
+++ b/src/Avalonia.Controls/Selection/InternalSelectionModel.cs
@@ -5,6 +5,7 @@ using System.Collections.Specialized;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using Avalonia.Collections;
+using Avalonia.Data;
 
 namespace Avalonia.Controls.Selection
 {
@@ -13,6 +14,7 @@ namespace Avalonia.Controls.Selection
         private IList? _writableSelectedItems;
         private int _ignoreModelChanges;
         private bool _ignoreSelectedItemsChanges;
+        private bool _skipSyncFromSelectedItems;
         private bool _isResetting;
 
         public InternalSelectionModel()
@@ -60,6 +62,29 @@ namespace Avalonia.Controls.Selection
             }
         }
 
+        internal void Update(IEnumerable? source, Optional<IList?> selectedItems)
+        {
+            var previousSource = Source;
+            var previousWritableSelectedItems = _writableSelectedItems;
+
+            try
+            {
+                _skipSyncFromSelectedItems = true;
+                SetSource(source);
+                if (selectedItems.HasValue)
+                    WritableSelectedItems = selectedItems.Value;
+            }
+            finally 
+            { 
+                _skipSyncFromSelectedItems = false;
+            }
+
+            // We skipped the sync from WritableSelectedItems before; do it now that both
+            // the source and WritableSelectedItems are updated.
+            if (previousSource != Source || previousWritableSelectedItems != _writableSelectedItems)
+                SyncFromSelectedItems();
+        }
+
         private protected override void SetSource(IEnumerable? value)
         {
             if (Source == value)
@@ -121,7 +146,7 @@ namespace Avalonia.Controls.Selection
 
         private void SyncFromSelectedItems()
         {
-            if (Source is null || _writableSelectedItems is null)
+            if (_skipSyncFromSelectedItems || Source is null || _writableSelectedItems is null)
             {
                 return;
             }
@@ -203,7 +228,7 @@ namespace Avalonia.Controls.Selection
             }
         }
 
-        private protected override void OnSourceCollectionChanged(NotifyCollectionChangedEventArgs e)
+        protected override void OnSourceCollectionChanged(NotifyCollectionChangedEventArgs e)
         {
             if (e.Action == NotifyCollectionChangedAction.Reset)
             {
diff --git a/src/Avalonia.Controls/Selection/SelectedItems.cs b/src/Avalonia.Controls/Selection/SelectedItems.cs
index ef642b7bdc..74007805cd 100644
--- a/src/Avalonia.Controls/Selection/SelectedItems.cs
+++ b/src/Avalonia.Controls/Selection/SelectedItems.cs
@@ -5,7 +5,7 @@ using System.Diagnostics.CodeAnalysis;
 
 namespace Avalonia.Controls.Selection
 {
-    internal class SelectedItems<T> : IReadOnlyList<T>
+    internal class SelectedItems<T> : IReadOnlyList<T?>
     {
         private readonly SelectionModel<T>? _owner;
         private readonly ItemsSourceView<T>? _items;
@@ -19,12 +19,9 @@ namespace Avalonia.Controls.Selection
             _items = items;
         }
 
-        [MaybeNull]
-        public T this[int index]
+        public T? this[int index]
         {
-#pragma warning disable CS8766
             get
-#pragma warning restore CS8766
             {
                 if (index >= Count)
                 {
@@ -64,15 +61,13 @@ namespace Avalonia.Controls.Selection
         private ItemsSourceView<T>? Items => _items ?? _owner?.ItemsView;
         private IReadOnlyList<IndexRange>? Ranges => _ranges ?? _owner!.Ranges;
 
-        public IEnumerator<T> GetEnumerator()
+        public IEnumerator<T?> GetEnumerator()
         {
             if (_owner?.SingleSelect == true)
             {
                 if (_owner.SelectedIndex >= 0)
                 {
-#pragma warning disable CS8603
                     yield return _owner.SelectedItem;
-#pragma warning restore CS8603
                 }
             }
             else
@@ -83,9 +78,7 @@ namespace Avalonia.Controls.Selection
                 {
                     for (var i = range.Begin; i <= range.End; ++i)
                     {
-#pragma warning disable CS8603
                         yield return items is object ? items[i] : default;
-#pragma warning restore CS8603
                     }
                 }
             }
@@ -102,8 +95,8 @@ namespace Avalonia.Controls.Selection
 
         public class Untyped : IReadOnlyList<object?>
         {
-            private readonly IReadOnlyList<T> _source;
-            public Untyped(IReadOnlyList<T> source) => _source = source;
+            private readonly IReadOnlyList<T?> _source;
+            public Untyped(IReadOnlyList<T?> source) => _source = source;
             public object? this[int index] => _source[index];
             public int Count => _source.Count;
             IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
diff --git a/src/Avalonia.Controls/Selection/SelectionModel.cs b/src/Avalonia.Controls/Selection/SelectionModel.cs
index affe762ea7..68bad598d0 100644
--- a/src/Avalonia.Controls/Selection/SelectionModel.cs
+++ b/src/Avalonia.Controls/Selection/SelectionModel.cs
@@ -19,6 +19,7 @@ namespace Avalonia.Controls.Selection
         private SelectedItems<T>.Untyped? _selectedItemsUntyped;
         private EventHandler<SelectionModelSelectionChangedEventArgs>? _untypedSelectionChanged;
         private IList? _initSelectedItems;
+        private bool _isSourceCollectionChanging;
 
         public SelectionModel()
         {
@@ -29,9 +30,9 @@ namespace Avalonia.Controls.Selection
             Source = source;
         }
 
-        public new IEnumerable<T>? Source
+        public new IEnumerable? Source
         {
-            get => base.Source as IEnumerable<T>;
+            get => base.Source;
             set => SetSource(value);
         }
 
@@ -55,7 +56,7 @@ namespace Avalonia.Controls.Selection
 
                     if (RangesEnabled && _selectedIndex >= 0)
                     {
-                        CommitSelect(new IndexRange(_selectedIndex));
+                        CommitSelect(_selectedIndex, _selectedIndex);
                     }
 
                     RaisePropertyChanged(nameof(SingleSelect));
@@ -80,7 +81,7 @@ namespace Avalonia.Controls.Selection
         {
             get
             {
-                if (ItemsView is object)
+                if (ItemsView is not null)
                 {
                     return GetItemAt(_selectedIndex);
                 }
@@ -93,21 +94,19 @@ namespace Avalonia.Controls.Selection
             }
             set
             {
-                if (ItemsView is object)
+                if (ItemsView is not null)
                 {
                     SelectedIndex = ItemsView.IndexOf(value!);
                 }
                 else
                 {
                     Clear();
-#pragma warning disable CS8601
-                    SetInitSelectedItems(new T[] { value });
-#pragma warning restore CS8601
+                    SetInitSelectedItems(new T[] { value! });
                 }
             }
         }
 
-        public IReadOnlyList<T> SelectedItems
+        public IReadOnlyList<T?> SelectedItems
         {
             get
             {
@@ -206,7 +205,7 @@ namespace Avalonia.Controls.Selection
             {
                 // If the collection is currently changing, commit the update when the
                 // collection change finishes.
-                if (!IsSourceCollectionChanging)
+                if (!_isSourceCollectionChanging)
                 {
                     CommitOperation(_operation);
                 }
@@ -278,7 +277,7 @@ namespace Avalonia.Controls.Selection
         {
             if (base.Source != value)
             {
-                if (_operation is object)
+                if (_operation is not null)
                 {
                     throw new InvalidOperationException("Cannot change source while update is in progress.");
                 }
@@ -296,7 +295,7 @@ namespace Avalonia.Controls.Selection
                 {
                     update.Operation.IsSourceUpdate = true;
 
-                    if (_initSelectedItems is object && ItemsView is object)
+                    if (_initSelectedItems is object && ItemsView is not null)
                     {
                         foreach (T i in _initSelectedItems)
                         {
@@ -315,17 +314,23 @@ namespace Avalonia.Controls.Selection
             }
         }
 
-        private protected override void OnIndexesChanged(int shiftIndex, int shiftDelta)
+        protected override void OnIndexesChanged(int shiftIndex, int shiftDelta)
         {
             IndexesChanged?.Invoke(this, new SelectionModelIndexesChangedEventArgs(shiftIndex, shiftDelta));
         }
 
-        private protected override void OnSourceReset()
+        protected override void OnSourceCollectionChangeStarted()
+        {
+            base.OnSourceCollectionChangeStarted();
+            _isSourceCollectionChanging = true;
+        }
+
+        protected override void OnSourceReset()
         {
             _selectedIndex = _anchorIndex = -1;
-            CommitDeselect(new IndexRange(0, int.MaxValue));
+            CommitDeselect(0, int.MaxValue);
 
-            if (SourceReset is object)
+            if (SourceReset is not null)
             {
                 SourceReset.Invoke(this, EventArgs.Empty);
             }
@@ -339,7 +344,7 @@ namespace Avalonia.Controls.Selection
             }
         }
 
-        private protected override void OnSelectionChanged(IReadOnlyList<T> deselectedItems)
+        protected override void OnSelectionRemoved(int index, int count, IReadOnlyList<T> deselectedItems)
         {
             // Note: We're *not* putting this in a using scope. A collection update is still in progress
             // so the operation won't get committed by normal means: we have to commit it manually.
@@ -347,7 +352,7 @@ namespace Avalonia.Controls.Selection
 
             update.Operation.DeselectedItems = deselectedItems;
 
-            if (_selectedIndex == -1 && LostSelection is object)
+            if (_selectedIndex == -1 && LostSelection is not null)
             {
                 LostSelection(this, EventArgs.Empty);
             }
@@ -357,7 +362,7 @@ namespace Avalonia.Controls.Selection
             CommitOperation(update.Operation, raisePropertyChanged: false);
         }
 
-        private protected override CollectionChangeState OnItemsAdded(int index, IList items)
+        protected override CollectionChangeState OnItemsAdded(int index, IList items)
         {
             var count = items.Count;
             var shifted = SelectedIndex >= index;
@@ -420,7 +425,7 @@ namespace Avalonia.Controls.Selection
             };
         }
 
-        private protected override void OnSourceCollectionChanged(NotifyCollectionChangedEventArgs e)
+        protected override void OnSourceCollectionChanged(NotifyCollectionChangedEventArgs e)
         {
             if (_operation?.UpdateCount > 0)
             {
@@ -451,6 +456,16 @@ namespace Avalonia.Controls.Selection
             }
         }
 
+        private protected void SetInitSelectedItems(IList items)
+        {
+            if (Source is object)
+            {
+                throw new InvalidOperationException("Cannot set init selected items when Source is set.");
+            }
+
+            _initSelectedItems = items;
+        }
+
         private protected override bool IsValidCollectionChange(NotifyCollectionChangedEventArgs e)
         {
             if (!base.IsValidCollectionChange(e))
@@ -474,19 +489,11 @@ namespace Avalonia.Controls.Selection
             return true;
         }
 
-        private protected void SetInitSelectedItems(IList items)
-        {
-            if (Source is object)
-            {
-                throw new InvalidOperationException("Cannot set init selected items when Source is set.");
-            }
-
-            _initSelectedItems = items;
-        }
-
         protected override void OnSourceCollectionChangeFinished()
         {
-            if (_operation is object)
+            _isSourceCollectionChanging = false;
+
+            if (_operation is not null)
             {
                 CommitOperation(_operation);
             }
@@ -575,7 +582,7 @@ namespace Avalonia.Controls.Selection
         {
             index = Math.Max(index, -1);
 
-            if (ItemsView is object && index >= ItemsView.Count)
+            if (ItemsView is not null && index >= ItemsView.Count)
             {
                 index = -1;
             }
@@ -585,7 +592,7 @@ namespace Avalonia.Controls.Selection
 
         private IndexRange CoerceRange(int start, int end)
         {
-            var max = ItemsView is object ? ItemsView.Count - 1 : int.MaxValue;
+            var max = ItemsView is not null ? ItemsView.Count - 1 : int.MaxValue;
 
             if (start > max || (start < 0 && end < 0))
             {
@@ -643,7 +650,7 @@ namespace Avalonia.Controls.Selection
                 var oldSelectedIndex = _selectedIndex;
                 var indexesChanged = false;
 
-                if (operation.SelectedIndex == -1 && LostSelection is object && !operation.SkipLostSelection)
+                if (operation.SelectedIndex == -1 && LostSelection is not null && !operation.SkipLostSelection)
                 {
                     operation.UpdateCount++;
                     LostSelection?.Invoke(this, EventArgs.Empty);
@@ -652,17 +659,23 @@ namespace Avalonia.Controls.Selection
                 _selectedIndex = operation.SelectedIndex;
                 _anchorIndex = operation.AnchorIndex;
 
-                if (operation.SelectedRanges is object)
+                if (operation.SelectedRanges is not null)
                 {
-                    indexesChanged |= CommitSelect(operation.SelectedRanges) > 0;
+                    foreach (var range in operation.SelectedRanges)
+                    {
+                        indexesChanged |= CommitSelect(range.Begin, range.End) > 0;
+                    }
                 }
 
-                if (operation.DeselectedRanges is object)
+                if (operation.DeselectedRanges is not null)
                 {
-                    indexesChanged |= CommitDeselect(operation.DeselectedRanges) > 0;
+                    foreach (var range in operation.DeselectedRanges)
+                    {
+                        indexesChanged |= CommitDeselect(range.Begin, range.End) > 0;
+                    }
                 }
 
-                if (SelectionChanged is object || _untypedSelectionChanged is object)
+                if (SelectionChanged is not null || _untypedSelectionChanged is not null)
                 {
                     IReadOnlyList<IndexRange>? deselected = operation.DeselectedRanges;
                     IReadOnlyList<IndexRange>? selected = operation.SelectedRanges;
@@ -690,14 +703,14 @@ namespace Avalonia.Controls.Selection
                         // CollectionChanged event. LostFocus may have caused another item to have been
                         // selected, but it can't have caused a deselection (as it was called due to
                         // selection being lost) so we're ok to discard `deselected` here.
-                        var deselectedItems = operation.DeselectedItems ??
+                        var deselectedItems = (IReadOnlyList<T?>?)operation.DeselectedItems ??
                             SelectedItems<T>.Create(deselected, deselectedSource);
 
                         var e = new SelectionModelSelectionChangedEventArgs<T>(
                             SelectedIndexes<T>.Create(deselected),
                             SelectedIndexes<T>.Create(selected),
                             deselectedItems,
-                            SelectedItems<T>.Create(selected, ItemsView));
+                            SelectedItems<T>.Create(selected, Source is not null ? ItemsView : null));
                         SelectionChanged?.Invoke(this, e);
                         _untypedSelectionChanged?.Invoke(this, e);
                     }
diff --git a/src/Avalonia.Controls/Selection/SelectionModelSelectionChangedEventArgs.cs b/src/Avalonia.Controls/Selection/SelectionModelSelectionChangedEventArgs.cs
index 64c1b14253..8f6d256847 100644
--- a/src/Avalonia.Controls/Selection/SelectionModelSelectionChangedEventArgs.cs
+++ b/src/Avalonia.Controls/Selection/SelectionModelSelectionChangedEventArgs.cs
@@ -39,8 +39,8 @@ namespace Avalonia.Controls.Selection
         public SelectionModelSelectionChangedEventArgs(
             IReadOnlyList<int>? deselectedIndices = null,
             IReadOnlyList<int>? selectedIndices = null,
-            IReadOnlyList<T>? deselectedItems = null,
-            IReadOnlyList<T>? selectedItems = null)
+            IReadOnlyList<T?>? deselectedItems = null,
+            IReadOnlyList<T?>? selectedItems = null)
         {
             DeselectedIndexes = deselectedIndices ?? Array.Empty<int>();
             SelectedIndexes = selectedIndices ?? Array.Empty<int>();
@@ -61,12 +61,12 @@ namespace Avalonia.Controls.Selection
         /// <summary>
         /// Gets the items that were removed from the selection.
         /// </summary>
-        public new IReadOnlyList<T> DeselectedItems { get; }
+        public new IReadOnlyList<T?> DeselectedItems { get; }
 
         /// <summary>
         /// Gets the items that were added to the selection.
         /// </summary>
-        public new IReadOnlyList<T> SelectedItems { get; }
+        public new IReadOnlyList<T?> SelectedItems { get; }
 
         protected override IReadOnlyList<object?> GetUntypedDeselectedItems()
         {
diff --git a/src/Avalonia.Controls/Selection/SelectionNodeBase.cs b/src/Avalonia.Controls/Selection/SelectionNodeBase.cs
index 69a651aca6..caeff61f07 100644
--- a/src/Avalonia.Controls/Selection/SelectionNodeBase.cs
+++ b/src/Avalonia.Controls/Selection/SelectionNodeBase.cs
@@ -2,37 +2,62 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Collections.Specialized;
-using System.Linq;
-using Avalonia.Controls.Utils;
 
 namespace Avalonia.Controls.Selection
 {
-    public abstract class SelectionNodeBase<T> : ICollectionChangedListener
+    /// <summary>
+    /// Base class for selection models.
+    /// </summary>
+    /// <typeparam name="T">The type of the element being selected.</typeparam>
+    public abstract class SelectionNodeBase<T>
     {
         private IEnumerable? _source;
         private bool _rangesEnabled;
         private List<IndexRange>? _ranges;
-        private int _collectionChanging;
 
+        /// <summary>
+        /// Gets or sets the source collection.
+        /// </summary>
         protected IEnumerable? Source
         {
             get => _source;
             set
             {
+                void OnPreChanged(object? sender, NotifyCollectionChangedEventArgs e) => OnSourceCollectionChangeStarted();
+                void OnChanged(object? sender, NotifyCollectionChangedEventArgs e) => OnSourceCollectionChanged(e);
+                void OnPostChanged(object? sender, NotifyCollectionChangedEventArgs e) => OnSourceCollectionChangeFinished();
+
                 if (_source != value)
                 {
-                    if (ItemsView?.Inner is INotifyCollectionChanged inccOld)
-                        CollectionChangedEventManager.Instance.RemoveListener(inccOld, this);
+                    if (ItemsView is not null)
+                    {
+                        ItemsView.PreCollectionChanged -= OnPreChanged;
+                        ItemsView.CollectionChanged -= OnChanged;
+                        ItemsView.PostCollectionChanged -= OnPostChanged;
+                    }
+
                     _source = value;
-                    ItemsView = value is object ? ItemsSourceView.GetOrCreate<T>(value) : null;
-                    if (ItemsView?.Inner is INotifyCollectionChanged inccNew)
-                        CollectionChangedEventManager.Instance.AddListener(inccNew, this);
+                    ItemsView = value is not null ? ItemsSourceView.GetOrCreate<T>(value) : null;
+
+                    if (ItemsView is not null)
+                    {
+                        ItemsView.PreCollectionChanged += OnPreChanged;
+                        ItemsView.CollectionChanged += OnChanged;
+                        ItemsView.PostCollectionChanged += OnPostChanged;
+                    }
                 }
             }
         }
 
-        protected bool IsSourceCollectionChanging => _collectionChanging > 0;
+        /// <summary>
+        /// Gets an <see cref="ItemsSourceView{T}"/> of the <see cref="Source"/>.
+        /// </summary>
+        protected internal ItemsSourceView<T>? ItemsView { get; set; }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether range selection is currently enabled for
+        /// the selection node.
+        /// </summary>
         protected bool RangesEnabled
         {
             get => _rangesEnabled;
@@ -50,8 +75,6 @@ namespace Avalonia.Controls.Selection
             }
         }
 
-        internal ItemsSourceView<T>? ItemsView { get; set; }
-
         internal IReadOnlyList<IndexRange> Ranges
         {
             get
@@ -65,81 +88,170 @@ namespace Avalonia.Controls.Selection
             }
         }
 
-        void ICollectionChangedListener.PreChanged(INotifyCollectionChanged sender, NotifyCollectionChangedEventArgs e)
+        /// <summary>
+        /// Called when the source collection starts changing.
+        /// </summary>
+        protected virtual void OnSourceCollectionChangeStarted()
         {
-            ++_collectionChanging;
         }
 
-        void ICollectionChangedListener.Changed(INotifyCollectionChanged sender, NotifyCollectionChangedEventArgs e)
+        /// <summary>
+        /// Called when the <see cref="Source"/> collection changes.
+        /// </summary>
+        /// <param name="e">The details of the collection change.</param>
+        /// <remarks>
+        /// The implementation in <see cref="SelectionNodeBase{T}"/> calls
+        /// <see cref="OnItemsAdded(int, IList)"/> and <see cref="OnItemsRemoved(int, IList)"/>
+        /// in order to calculate how the collection change affects the currently selected items.
+        /// It then calls <see cref="OnIndexesChanged(int, int)"/> and
+        /// <see cref="OnSelectionRemoved(int, int, IReadOnlyList{T})"/> if necessary, according
+        /// to the <see cref="CollectionChangeState"/> returned by those methods.
+        /// 
+        /// Override this method and <see cref="OnSourceCollectionChangeFinished"/> to provide
+        /// custom handling of source collection changes.
+        /// </remarks>
+        protected virtual void OnSourceCollectionChanged(NotifyCollectionChangedEventArgs e)
         {
-            OnSourceCollectionChanged(e);
-        }
+            var shiftDelta = 0;
+            var shiftIndex = -1;
+            List<T>? removed = null;
 
-        void ICollectionChangedListener.PostChanged(INotifyCollectionChanged sender, NotifyCollectionChangedEventArgs e)
-        {
-            if (--_collectionChanging == 0)
+            if (!IsValidCollectionChange(e))
             {
-                OnSourceCollectionChangeFinished();
+                return;
             }
-        }
-
-        protected abstract void OnSourceCollectionChangeFinished();
-
-        private protected abstract void OnIndexesChanged(int shiftIndex, int shiftDelta);
-
-        private protected abstract void OnSourceReset();
 
-        private protected abstract void OnSelectionChanged(IReadOnlyList<T> deselectedItems);
-
-        private protected int CommitSelect(IndexRange range)
-        {
-            if (RangesEnabled)
+            switch (e.Action)
             {
-                _ranges ??= new List<IndexRange>();
-                return IndexRange.Add(_ranges, range);
+                case NotifyCollectionChangedAction.Add:
+                    {
+                        var change = OnItemsAdded(e.NewStartingIndex, e.NewItems!);
+                        shiftIndex = change.ShiftIndex;
+                        shiftDelta = change.ShiftDelta;
+                        break;
+                    }
+                case NotifyCollectionChangedAction.Remove:
+                    {
+                        var change = OnItemsRemoved(e.OldStartingIndex, e.OldItems!);
+                        shiftIndex = change.ShiftIndex;
+                        shiftDelta = change.ShiftDelta;
+                        removed = change.RemovedItems;
+                        break;
+                    }
+                case NotifyCollectionChangedAction.Replace:
+                case NotifyCollectionChangedAction.Move:
+                    {
+                        var removeChange = OnItemsRemoved(e.OldStartingIndex, e.OldItems!);
+                        var addChange = OnItemsAdded(e.NewStartingIndex, e.NewItems!);
+                        shiftIndex = removeChange.ShiftIndex;
+                        shiftDelta = removeChange.ShiftDelta + addChange.ShiftDelta;
+                        removed = removeChange.RemovedItems;
+                    }
+                    break;
+                case NotifyCollectionChangedAction.Reset:
+                    OnSourceReset();
+                    break;
             }
 
-            return 0;
+            if (shiftDelta != 0)
+                OnIndexesChanged(shiftIndex, shiftDelta);
+            if (removed is not null)
+                OnSelectionRemoved(shiftIndex, -shiftDelta, removed);
         }
 
-        private protected int CommitSelect(IReadOnlyList<IndexRange> ranges)
+        /// <summary>
+        /// Called when the source collection has finished changing, and all CollectionChanged
+        /// handlers have run.
+        /// </summary>
+        /// <remarks>
+        /// Override this method to respond to the end of a collection change instead of acting at
+        /// the end of <see cref="OnSourceCollectionChanged(NotifyCollectionChangedEventArgs)"/>
+        /// in order to ensure that all UI subscribers to the source collection change event have
+        /// had chance to run.
+        /// </remarks>
+        protected virtual void OnSourceCollectionChangeFinished()
         {
-            if (RangesEnabled)
-            {
-                _ranges ??= new List<IndexRange>();
-                return IndexRange.Add(_ranges, ranges);
-            }
+        }
 
-            return 0;
+        /// <summary>
+        /// Called by <see cref="OnSourceCollectionChanged(NotifyCollectionChangedEventArgs)"/>,
+        /// detailing the indexes changed by the collection changing.
+        /// </summary>
+        /// <param name="shiftIndex">The first index that was shifted.</param>
+        /// <param name="shiftDelta">
+        /// If positive, the number of items inserted, or if negative the number of items removed.
+        /// </param>
+        protected virtual void OnIndexesChanged(int shiftIndex, int shiftDelta)
+        {
+        }
+
+        /// <summary>
+        /// Called by <see cref="OnSourceCollectionChanged(NotifyCollectionChangedEventArgs)"/>,
+        /// on collection reset.
+        /// </summary>
+        protected abstract void OnSourceReset();
+
+        /// <summary>
+        /// Called by <see cref="OnSourceCollectionChanged(NotifyCollectionChangedEventArgs)"/>,
+        /// detailing the items removed by a collection change.
+        /// </summary>
+        protected virtual void OnSelectionRemoved(int index, int count, IReadOnlyList<T> deselectedItems)
+        {
         }
 
-        private protected int CommitDeselect(IndexRange range)
+        /// <summary>
+        /// If <see cref="RangesEnabled"/>, adds the specified range to the selection.
+        /// </summary>
+        /// <param name="begin">The inclusive index of the start of the range to select.</param>
+        /// <param name="end">The inclusive index of the end of the range to select.</param>
+        /// <returns>The number of items selected.</returns>
+        protected int CommitSelect(int begin, int end)
         {
             if (RangesEnabled)
             {
                 _ranges ??= new List<IndexRange>();
-                return IndexRange.Remove(_ranges, range);
+                return IndexRange.Add(_ranges, new IndexRange(begin, end));
             }
 
             return 0;
         }
 
-        private protected int CommitDeselect(IReadOnlyList<IndexRange> ranges)
+        /// <summary>
+        /// If <see cref="RangesEnabled"/>, removes the specified range from the selection.
+        /// </summary>
+        /// <param name="begin">The inclusive index of the start of the range to deselect.</param>
+        /// <param name="end">The inclusive index of the end of the range to deselect.</param>
+        /// <returns>The number of items selected.</returns>
+        protected int CommitDeselect(int begin, int end)
         {
-            if (RangesEnabled && _ranges is object)
+            if (RangesEnabled)
             {
-                return IndexRange.Remove(_ranges, ranges);
+                _ranges ??= new List<IndexRange>();
+                return IndexRange.Remove(_ranges, new IndexRange(begin, end));
             }
 
             return 0;
         }
 
-        private protected virtual CollectionChangeState OnItemsAdded(int index, IList items)
+        /// <summary>
+        /// Called by <see cref="OnSourceCollectionChanged(NotifyCollectionChangedEventArgs)"/>
+        /// when items are added to the source collection.
+        /// </summary>
+        /// <returns>
+        /// A <see cref="CollectionChangeState"/> struct containing the details of the adjusted
+        /// selection.
+        /// </returns>
+        /// <remarks>
+        /// The implementation in <see cref="SelectionNodeBase{T}"/> adjusts the selected ranges, 
+        /// assigning new indexes. Override this method to carry out additional computation when
+        /// items are added.
+        /// </remarks>
+        protected virtual CollectionChangeState OnItemsAdded(int index, IList items)
         {
             var count = items.Count;
             var shifted = false;
 
-            if (_ranges is object)
+            if (_ranges is not null)
             {
                 List<IndexRange>? toAdd = null;
 
@@ -150,7 +262,7 @@ namespace Avalonia.Controls.Selection
                     // The range is after the inserted items, need to shift the range right
                     if (range.End >= index)
                     {
-                        int begin = range.Begin;
+                        var begin = range.Begin;
 
                         // If the index left of newIndex is inside the range,
                         // Split the range and remember the left piece to add later
@@ -167,7 +279,7 @@ namespace Avalonia.Controls.Selection
                     }
                 }
 
-                if (toAdd is object)
+                if (toAdd is not null)
                 {
                     foreach (var range in toAdd)
                     {
@@ -183,14 +295,27 @@ namespace Avalonia.Controls.Selection
             };
         }
 
+        /// <summary>
+        /// Called by <see cref="OnSourceCollectionChanged(NotifyCollectionChangedEventArgs)"/>
+        /// when items are removed from the source collection.
+        /// </summary>
+        /// <returns>
+        /// A <see cref="CollectionChangeState"/> struct containing the details of the adjusted
+        /// selection.
+        /// </returns>
+        /// <remarks>
+        /// The implementation in <see cref="SelectionNodeBase{T}"/> adjusts the selected ranges, 
+        /// assigning new indexes. Override this method to carry out additional computation when
+        /// items are removed.
+        /// </remarks>
         private protected virtual CollectionChangeState OnItemsRemoved(int index, IList items)
         {
             var count = items.Count;
             var removedRange = new IndexRange(index, index + count - 1);
-            bool shifted = false;
+            var shifted = false;
             List<T>? removed = null;
 
-            if (_ranges is object)
+            if (_ranges is not null)
             {
                 var deselected = new List<IndexRange>();
 
@@ -227,60 +352,6 @@ namespace Avalonia.Controls.Selection
             };
         }
 
-        private protected virtual void OnSourceCollectionChanged(NotifyCollectionChangedEventArgs e)
-        {
-            var shiftDelta = 0;
-            var shiftIndex = -1;
-            List<T>? removed = null;
-
-            if (!IsValidCollectionChange(e))
-            {
-                return;
-            }
-
-            switch (e.Action)
-            {
-                case NotifyCollectionChangedAction.Add:
-                    {
-                        var change = OnItemsAdded(e.NewStartingIndex, e.NewItems!);
-                        shiftIndex = change.ShiftIndex;
-                        shiftDelta = change.ShiftDelta;
-                        break;
-                    }
-                case NotifyCollectionChangedAction.Remove:
-                    {
-                        var change = OnItemsRemoved(e.OldStartingIndex, e.OldItems!);
-                        shiftIndex = change.ShiftIndex;
-                        shiftDelta = change.ShiftDelta;
-                        removed = change.RemovedItems;
-                        break;
-                    }
-                case NotifyCollectionChangedAction.Replace:
-                case NotifyCollectionChangedAction.Move:
-                    {
-                        var removeChange = OnItemsRemoved(e.OldStartingIndex, e.OldItems!);
-                        var addChange = OnItemsAdded(e.NewStartingIndex, e.NewItems!);
-                        shiftIndex = removeChange.ShiftIndex;
-                        shiftDelta = removeChange.ShiftDelta + addChange.ShiftDelta;
-                        removed = removeChange.RemovedItems;
-                    }
-                    break;
-                case NotifyCollectionChangedAction.Reset:
-                    OnSourceReset();
-                    break;
-            }
-
-            if (shiftDelta != 0)
-            {
-                OnIndexesChanged(shiftIndex, shiftDelta);
-            }
-
-            if (removed is object)
-            {
-                OnSelectionChanged(removed);
-            }
-        }
-
         private protected virtual bool IsValidCollectionChange(NotifyCollectionChangedEventArgs e)
         {
             // If the selection is modified in a CollectionChanged handler before the selection
@@ -309,11 +380,27 @@ namespace Avalonia.Controls.Selection
             return true;
         }
 
-        private protected struct CollectionChangeState
+        /// <summary>
+        /// Details the results of a collection change on the current selection;
+        /// </summary>
+        protected class CollectionChangeState
         {
-            public int ShiftIndex;
-            public int ShiftDelta;
-            public List<T>? RemovedItems;
+            /// <summary>
+            /// Gets or sets the first index that was shifted as a result of the collection
+            /// changing.
+            /// </summary>
+            public int ShiftIndex { get; set; }
+
+            /// <summary>
+            /// Gets or sets a value indicating how the indexes after <see cref="ShiftIndex"/>
+            /// were shifted.
+            /// </summary>
+            public int ShiftDelta { get; set; }
+
+            /// <summary>
+            /// Gets or sets the items removed by the collection change, if any.
+            /// </summary>
+            public List<T>? RemovedItems { get; set; }
         }
     }
 }
diff --git a/src/Avalonia.Controls/SplitButton/SplitButton.cs b/src/Avalonia.Controls/SplitButton/SplitButton.cs
index 19d2b1c5da..7f10c632c5 100644
--- a/src/Avalonia.Controls/SplitButton/SplitButton.cs
+++ b/src/Avalonia.Controls/SplitButton/SplitButton.cs
@@ -172,7 +172,7 @@ namespace Avalonia.Controls
                 flyout.Opened += Flyout_Opened;
                 flyout.Closed += Flyout_Closed;
 
-                _flyoutPropertyChangedDisposable = flyout.GetPropertyChangedObservable(Popup.PlacementModeProperty).Subscribe(Flyout_PlacementPropertyChanged);
+                _flyoutPropertyChangedDisposable = flyout.GetPropertyChangedObservable(Popup.PlacementProperty).Subscribe(Flyout_PlacementPropertyChanged);
             }
         }
 
@@ -432,7 +432,7 @@ namespace Avalonia.Controls
         }
 
         /// <summary>
-        /// Called when the <see cref="FlyoutBase.Placement"/> property changes.
+        /// Called when the <see cref="PopupFlyoutBase.Placement"/> property changes.
         /// </summary>
         private void Flyout_PlacementPropertyChanged(AvaloniaPropertyChangedEventArgs e)
         {
diff --git a/src/Avalonia.Controls/TextBlock.cs b/src/Avalonia.Controls/TextBlock.cs
index df98d1073e..b55ae74965 100644
--- a/src/Avalonia.Controls/TextBlock.cs
+++ b/src/Avalonia.Controls/TextBlock.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using Avalonia.Automation.Peers;
 using Avalonia.Controls.Documents;
 using Avalonia.Layout;
@@ -13,6 +14,7 @@ namespace Avalonia.Controls
     /// <summary>
     /// A control that displays a block of text.
     /// </summary>
+    [DebuggerDisplay("Text = {" + nameof(DebugText) + "}")]
     public class TextBlock : Control, IInlineHost
     {
         /// <summary>
@@ -103,11 +105,8 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="Text"/> property.
         /// </summary>
-        public static readonly DirectProperty<TextBlock, string?> TextProperty =
-            AvaloniaProperty.RegisterDirect<TextBlock, string?>(
-                nameof(Text),
-                o => o.GetText(),
-                (o, v) => o.SetText(v));
+        public static readonly StyledProperty<string?> TextProperty =
+            AvaloniaProperty.Register<TextBlock, string?>(nameof(Text));
 
         /// <summary>
         /// Defines the <see cref="TextAlignment"/> property.
@@ -142,14 +141,14 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="Inlines"/> property.
         /// </summary>
-        public static readonly StyledProperty<InlineCollection?> InlinesProperty =
-            AvaloniaProperty.Register<TextBlock, InlineCollection?>(
-                nameof(Inlines));
+        public static readonly DirectProperty<TextBlock, InlineCollection?> InlinesProperty =
+            AvaloniaProperty.RegisterDirect<TextBlock, InlineCollection?>(
+                nameof(Inlines), t => t.Inlines, (t, v) => t.Inlines = v);
 
-        internal string? _text;
         protected TextLayout? _textLayout;
         protected Size _constraint;
         private IReadOnlyList<TextRun>? _textRuns;
+        private InlineCollection? _inlines;
 
         /// <summary>
         /// Initializes static members of the <see cref="TextBlock"/> class.
@@ -173,7 +172,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets the <see cref="TextLayout"/> used to render the text.
         /// </summary>
-        public TextLayout TextLayout => _textLayout ??= CreateTextLayout(_text);
+        public TextLayout TextLayout => _textLayout ??= CreateTextLayout(Text);
 
         /// <summary>
         /// Gets or sets the padding to place around the <see cref="Text"/>.
@@ -198,10 +197,12 @@ namespace Avalonia.Controls
         /// </summary>
         public string? Text
         {
-            get => GetText();
-            set => SetText(value);
+            get => GetValue(TextProperty);
+            set => SetValue(TextProperty, value);
         }
 
+        private string? DebugText => Text ?? Inlines?.Text;
+
         /// <summary>
         /// Gets or sets the font family used to draw the control's text.
         /// </summary>
@@ -325,8 +326,8 @@ namespace Avalonia.Controls
         [Content]
         public InlineCollection? Inlines
         {
-            get => GetValue(InlinesProperty);
-            set => SetValue(InlinesProperty, value);
+            get => _inlines;
+            set => SetAndRaise(InlinesProperty, ref _inlines, value);
         }
 
         protected override bool BypassFlowDirectionPolicies => true;
@@ -590,19 +591,18 @@ namespace Avalonia.Controls
             TextLayout.Draw(context, origin);
         }
 
-        protected virtual string? GetText()
-        {
-            return _text ?? Inlines?.Text;
-        }
-
-        protected virtual void SetText(string? text)
+        private bool _clearTextInternal;
+        internal void ClearTextInternal()
         {
-            if (HasComplexContent)
+            _clearTextInternal = true;
+            try
+            {
+                SetCurrentValue(TextProperty, null);
+            }
+            finally
             {
-                Inlines?.Clear();
+                _clearTextInternal = false;
             }
-           
-            SetAndRaise(TextProperty, ref _text, text);           
         }
 
         /// <summary>
@@ -780,6 +780,14 @@ namespace Avalonia.Controls
         {
             base.OnPropertyChanged(change);
 
+            if (change.Property == TextProperty)
+            {
+                if (HasComplexContent && !_clearTextInternal)
+                {
+                    Inlines?.Clear();
+                }
+            }
+
             switch (change.Property.Name)
             {
                 case nameof(FontSize):
@@ -794,10 +802,10 @@ namespace Avalonia.Controls
 
                 case nameof(FlowDirection):
 
-                case nameof (Padding):
-                case nameof (LineHeight):
-                case nameof (LetterSpacing):
-                case nameof (MaxLines):
+                case nameof(Padding):
+                case nameof(LineHeight):
+                case nameof(LetterSpacing):
+                case nameof(MaxLines):
 
                 case nameof(Text):
                 case nameof(TextDecorations):
@@ -899,7 +907,7 @@ namespace Avalonia.Controls
                         continue;
                     }
 
-                    if (textRun is TextCharacters)                 
+                    if (textRun is TextCharacters)
                     {
                         var skip = Math.Max(0, textSourceIndex - currentPosition);
 
diff --git a/src/Avalonia.Controls/TextBox.cs b/src/Avalonia.Controls/TextBox.cs
index ac1b5cd417..d244290c89 100644
--- a/src/Avalonia.Controls/TextBox.cs
+++ b/src/Avalonia.Controls/TextBox.cs
@@ -61,11 +61,9 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="CaretIndex"/> property
         /// </summary>
-        public static readonly DirectProperty<TextBox, int> CaretIndexProperty =
-            AvaloniaProperty.RegisterDirect<TextBox, int>(
-                nameof(CaretIndex),
-                o => o.CaretIndex,
-                (o, v) => o.CaretIndex = v);
+        public static readonly StyledProperty<int> CaretIndexProperty =
+            AvaloniaProperty.Register<TextBox, int>(nameof(CaretIndex),
+                coerce: CoerceCaretIndex);
 
         /// <summary>
         /// Defines the <see cref="IsReadOnly"/> property
@@ -100,42 +98,37 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="SelectionStart"/> property
         /// </summary>
-        public static readonly DirectProperty<TextBox, int> SelectionStartProperty =
-            AvaloniaProperty.RegisterDirect<TextBox, int>(
-                nameof(SelectionStart),
-                o => o.SelectionStart,
-                (o, v) => o.SelectionStart = v);
+        public static readonly StyledProperty<int> SelectionStartProperty =
+            AvaloniaProperty.Register<TextBox, int>(nameof(SelectionStart), 
+                coerce: CoerceCaretIndex);
 
         /// <summary>
         /// Defines the <see cref="SelectionEnd"/> property
         /// </summary>
-        public static readonly DirectProperty<TextBox, int> SelectionEndProperty =
-            AvaloniaProperty.RegisterDirect<TextBox, int>(
-                nameof(SelectionEnd),
-                o => o.SelectionEnd,
-                (o, v) => o.SelectionEnd = v);
+        public static readonly StyledProperty<int> SelectionEndProperty =
+            AvaloniaProperty.Register<TextBox, int>(nameof(SelectionEnd),
+                coerce: CoerceCaretIndex);
 
         /// <summary>
         /// Defines the <see cref="MaxLength"/> property
         /// </summary>
         public static readonly StyledProperty<int> MaxLengthProperty =
-            AvaloniaProperty.Register<TextBox, int>(nameof(MaxLength), defaultValue: 0);
+            AvaloniaProperty.Register<TextBox, int>(nameof(MaxLength));
 
         /// <summary>
         /// Defines the <see cref="MaxLines"/> property
         /// </summary>
         public static readonly StyledProperty<int> MaxLinesProperty =
-            AvaloniaProperty.Register<TextBox, int>(nameof(MaxLines), defaultValue: 0);
+            AvaloniaProperty.Register<TextBox, int>(nameof(MaxLines));
 
         /// <summary>
         /// Defines the <see cref="Text"/> property
         /// </summary>
-        public static readonly DirectProperty<TextBox, string?> TextProperty =
-            TextBlock.TextProperty.AddOwnerWithDataValidation<TextBox>(
-                o => o.Text,
-                (o, v) => o.Text = v,
+        public static readonly StyledProperty<string?> TextProperty =
+            TextBlock.TextProperty.AddOwner<TextBox>(new(
+                coerce: CoerceText,
                 defaultBindingMode: BindingMode.TwoWay,
-                enableDataValidation: true);
+                enableDataValidation: true));
 
         /// <summary>
         /// Defines the <see cref="TextAlignment"/> property
@@ -185,9 +178,8 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="NewLine"/> property
         /// </summary>
-        public static readonly DirectProperty<TextBox, string> NewLineProperty =
-            AvaloniaProperty.RegisterDirect<TextBox, string>(nameof(NewLine),
-                textbox => textbox.NewLine, (textbox, newline) => textbox.NewLine = newline);
+        public static readonly StyledProperty<string> NewLineProperty =
+            AvaloniaProperty.Register<TextBox, string>(nameof(NewLine), Environment.NewLine);
 
         /// <summary>
         /// Defines the <see cref="InnerLeftContent"/> property
@@ -242,12 +234,8 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="UndoLimit"/> property
         /// </summary>
-        public static readonly DirectProperty<TextBox, int> UndoLimitProperty =
-            AvaloniaProperty.RegisterDirect<TextBox, int>(
-                nameof(UndoLimit),
-                o => o.UndoLimit,
-                (o, v) => o.UndoLimit = v,
-                unsetValue: -1);
+        public static readonly StyledProperty<int> UndoLimitProperty =
+            AvaloniaProperty.Register<TextBox, int>(nameof(UndoLimit), UndoRedoHelper<UndoRedoState>.DefaultUndoLimit);
 
         /// <summary>
         /// Defines the <see cref="CanUndo"/> property
@@ -318,18 +306,13 @@ namespace Avalonia.Controls
             public override int GetHashCode() => Text?.GetHashCode() ?? 0;
         }
 
-        private string? _text;
-        private int _caretIndex;
-        private int _selectionStart;
-        private int _selectionEnd;
         private TextPresenter? _presenter;
-        private TextBoxTextInputMethodClient _imClient = new TextBoxTextInputMethodClient();
-        private UndoRedoHelper<UndoRedoState> _undoRedoHelper;
+        private readonly TextBoxTextInputMethodClient _imClient = new();
+        private readonly UndoRedoHelper<UndoRedoState> _undoRedoHelper;
         private bool _isUndoingRedoing;
         private bool _canCut;
         private bool _canCopy;
         private bool _canPaste;
-        private string _newLine = Environment.NewLine;
         private static readonly string[] invalidCharacters = new String[1] { "\u007f" };
         private bool _canUndo;
         private bool _canRedo;
@@ -399,18 +382,19 @@ namespace Avalonia.Controls
         /// </summary>
         public int CaretIndex
         {
-            get => _caretIndex;
-            set
-            {
-                value = CoerceCaretIndex(value);
-                SetAndRaise(CaretIndexProperty, ref _caretIndex, value);
+            get => GetValue(CaretIndexProperty);
+            set => SetValue(CaretIndexProperty, value);
+        }
 
-                UndoRedoState state;
-                if (IsUndoEnabled && _undoRedoHelper.TryGetLastState(out state) && state.Text == Text)
-                    _undoRedoHelper.UpdateLastState();
+        private void OnCaretIndexChanged(AvaloniaPropertyChangedEventArgs e)
+        {
+            UndoRedoState state;
+            if (IsUndoEnabled && _undoRedoHelper.TryGetLastState(out state) && state.Text == Text)
+                _undoRedoHelper.UpdateLastState();
 
-                SelectionStart = SelectionEnd = value;
-            }
+            var newValue = e.GetNewValue<int>();
+            SetCurrentValue(SelectionStartProperty, newValue);
+            SetCurrentValue(SelectionEndProperty, newValue);
         }
 
         /// <summary>
@@ -463,21 +447,18 @@ namespace Avalonia.Controls
         /// </summary>
         public int SelectionStart
         {
-            get => _selectionStart;
-            set
-            {
-                value = CoerceCaretIndex(value);
-                var changed = SetAndRaise(SelectionStartProperty, ref _selectionStart, value);
+            get => GetValue(SelectionStartProperty);
+            set => SetValue(SelectionStartProperty, value);
+        }
 
-                if (changed)
-                {
-                    UpdateCommandStates();
-                }
+        private void OnSelectionStartChanged(AvaloniaPropertyChangedEventArgs e)
+        {
+            UpdateCommandStates();
 
-                if (SelectionEnd == value && CaretIndex != value)
-                {
-                    CaretIndex = value;
-                }
+            var value = e.GetNewValue<int>();
+            if (SelectionEnd == value && CaretIndex != value)
+            {
+                SetCurrentValue(CaretIndexProperty, value);
             }
         }
 
@@ -490,21 +471,18 @@ namespace Avalonia.Controls
         /// </remarks>
         public int SelectionEnd
         {
-            get => _selectionEnd;
-            set
-            {
-                value = CoerceCaretIndex(value);
-                var changed = SetAndRaise(SelectionEndProperty, ref _selectionEnd, value);
-
-                if (changed)
-                {
-                    UpdateCommandStates();
-                }
+            get => GetValue(SelectionEndProperty);
+            set => SetValue(SelectionEndProperty, value);
+        }
+        
+        private void OnSelectionEndChanged(AvaloniaPropertyChangedEventArgs e)
+        {
+            UpdateCommandStates();
 
-                if (SelectionStart == value && CaretIndex != value)
-                {
-                    CaretIndex = value;
-                }
+            var value = e.GetNewValue<int>();
+            if (SelectionStart == value && CaretIndex != value)
+            {
+                SetCurrentValue(CaretIndexProperty, value);
             }
         }
         
@@ -550,36 +528,27 @@ namespace Avalonia.Controls
         [Content]
         public string? Text
         {
-            get => _text;
-            set
-            {
-                var caretIndex = CaretIndex;
-                var selectionStart = SelectionStart;
-                var selectionEnd = SelectionEnd;
-
-                CaretIndex = CoerceCaretIndex(caretIndex, value);
-                SelectionStart = CoerceCaretIndex(selectionStart, value);
-                SelectionEnd = CoerceCaretIndex(selectionEnd, value);
-
-                // Before #9490, snapshot here was done AFTER text change - this doesn't make sense
-                // since intial state would never be no text and you'd always have to make a text 
-                // change before undo would be available
-                // The undo/redo stacks were also cleared at this point, which also doesn't make sense
-                // as it is still valid to want to undo a programmatic text set
-                // So we snapshot text now BEFORE the change so we can always revert
-                // Also don't need to check IsUndoEnabled here, that's done in SnapshotUndoRedo
-                if (!_isUndoingRedoing)
-                {
-                    SnapshotUndoRedo();
-                }
-
-                var textChanged = SetAndRaise(TextProperty, ref _text, value);
+            get => GetValue(TextProperty);
+            set => SetValue(TextProperty, value);
+        }
 
-                if (textChanged)
-                {
-                    RaiseTextChangeEvents();
-                }
+        private static string? CoerceText(AvaloniaObject sender, string? value)
+        {
+            var textBox = (TextBox)sender;
+            
+            // Before #9490, snapshot here was done AFTER text change - this doesn't make sense
+            // since intial state would never be no text and you'd always have to make a text 
+            // change before undo would be available
+            // The undo/redo stacks were also cleared at this point, which also doesn't make sense
+            // as it is still valid to want to undo a programmatic text set
+            // So we snapshot text now BEFORE the change so we can always revert
+            // Also don't need to check IsUndoEnabled here, that's done in SnapshotUndoRedo
+            if (!textBox._isUndoingRedoing)
+            {
+                textBox.SnapshotUndoRedo();
             }
+
+            return value;
         }
 
         /// <summary>
@@ -691,8 +660,8 @@ namespace Avalonia.Controls
         /// </summary>
         public string NewLine
         {
-            get => _newLine;
-            set => SetAndRaise(NewLineProperty, ref _newLine, value);
+            get => GetValue(NewLineProperty);
+            set => SetValue(NewLineProperty, value);
         }
 
         /// <summary>
@@ -700,7 +669,8 @@ namespace Avalonia.Controls
         /// </summary>
         public void ClearSelection()
         {
-            CaretIndex = SelectionStart;
+            SetCurrentValue(CaretIndexProperty, SelectionStart);
+            SetCurrentValue(SelectionEndProperty, SelectionStart);
         }
 
         /// <summary>
@@ -744,25 +714,20 @@ namespace Avalonia.Controls
         /// </summary>
         public int UndoLimit
         {
-            get => _undoRedoHelper.Limit;
-            set
-            {
-                if (_undoRedoHelper.Limit != value)
-                {
-                    // can't use SetAndRaise due to using _undoRedoHelper.Limit
-                    // (can't send a ref of a property to SetAndRaise),
-                    // so use RaisePropertyChanged instead.
-                    var oldValue = _undoRedoHelper.Limit;
-                    _undoRedoHelper.Limit = value;
-                    RaisePropertyChanged(UndoLimitProperty, oldValue, value);
-                }
-                // from docs at
-                // https://docs.microsoft.com/en-us/dotnet/api/system.windows.controls.primitives.textboxbase.isundoenabled:
-                // "Setting UndoLimit clears the undo queue."
-                _undoRedoHelper.Clear();
-                _selectedTextChangesMadeSinceLastUndoSnapshot = 0;
-                _hasDoneSnapshotOnce = false;
-            }
+            get => GetValue(UndoLimitProperty);
+            set => SetValue(UndoLimitProperty, value);
+        }
+
+        private void OnUndoLimitChanged(int newValue)
+        {
+            _undoRedoHelper.Limit = newValue;
+
+            // from docs at
+            // https://docs.microsoft.com/en-us/dotnet/api/system.windows.controls.primitives.textboxbase.isundoenabled:
+            // "Setting UndoLimit clears the undo queue."
+            _undoRedoHelper.Clear();
+            _selectedTextChangesMadeSinceLastUndoSnapshot = 0;
+            _hasDoneSnapshotOnce = false;
         }
 
         /// <summary>
@@ -866,9 +831,31 @@ namespace Avalonia.Controls
 
             if (change.Property == TextProperty)
             {
+                CoerceValue(CaretIndexProperty);
+                CoerceValue(SelectionStartProperty);
+                CoerceValue(SelectionEndProperty);
+
+                RaiseTextChangeEvents();
+
                 UpdatePseudoclasses();
                 UpdateCommandStates();
             }
+            else if (change.Property == CaretIndexProperty)
+            {
+                OnCaretIndexChanged(change);
+            }
+            else if (change.Property == SelectionStartProperty)
+            {
+                OnSelectionStartChanged(change);
+            }
+            else if (change.Property == SelectionEndProperty)
+            {
+                OnSelectionEndChanged(change);
+            }
+            else if (change.Property == UndoLimitProperty)
+            {
+                OnUndoLimitChanged(change.GetNewValue<int>());
+            }
             else if (change.Property == IsUndoEnabledProperty && change.GetNewValue<bool>() == false)
             {
                 // from docs at
@@ -920,7 +907,7 @@ namespace Avalonia.Controls
                 (ContextMenu == null || !ContextMenu.IsOpen))
             {
                 ClearSelection();
-                RevealPassword = false;
+                SetCurrentValue(RevealPasswordProperty, false);
             }
 
             UpdateCommandStates();
@@ -986,35 +973,44 @@ namespace Avalonia.Controls
                 }
             }
 
-            var text = Text ?? string.Empty;
-            var newLength = input.Length + text.Length - Math.Abs(SelectionStart - SelectionEnd);
+            var currentText = Text ?? string.Empty;
+            var selectionLength = Math.Abs(SelectionStart - SelectionEnd);
+            var newLength = input.Length + currentText.Length - selectionLength;
 
             if (MaxLength > 0 && newLength > MaxLength)
             {
                 input = input.Remove(Math.Max(0, input.Length - (newLength - MaxLength)));
+                newLength = MaxLength;
             }
 
             if (!string.IsNullOrEmpty(input))
             {
-                var oldText = _text;
-
-                DeleteSelection(false);
+                var textBuilder = StringBuilderCache.Acquire(Math.Max(currentText.Length, newLength));
+                textBuilder.Append(currentText);
+                
                 var caretIndex = CaretIndex;
-                text = Text ?? string.Empty;
-                SetTextInternal(text.Substring(0, caretIndex) + input + text.Substring(caretIndex));
-                ClearSelection();
 
-                if (IsUndoEnabled)
+                if (selectionLength != 0)
                 {
-                    _undoRedoHelper.DiscardRedo();
+                    var (start, _) = GetSelectionRange();
+
+                    textBuilder.Remove(start, selectionLength);
+
+                    caretIndex = start;
                 }
 
-                if (_text != oldText)
+                textBuilder.Insert(caretIndex, input);
+
+                SetCurrentValue(TextProperty, StringBuilderCache.GetStringAndRelease(textBuilder));
+
+                ClearSelection();
+
+                if (IsUndoEnabled)
                 {
-                    RaisePropertyChanged(TextProperty, oldText, _text);
+                    _undoRedoHelper.DiscardRedo();
                 }
 
-                CaretIndex = caretIndex + input.Length;
+                SetCurrentValue(CaretIndexProperty, caretIndex + input.Length);
             }
         }
 
@@ -1168,7 +1164,7 @@ namespace Avalonia.Controls
                 movement = true;
                 selection = false;
                 handled = true;
-                CaretIndex = _presenter.CaretIndex;
+                SetCurrentValue(CaretIndexProperty, _presenter.CaretIndex);
             }
             else if (Match(keymap.MoveCursorToTheEndOfDocument))
             {
@@ -1176,7 +1172,7 @@ namespace Avalonia.Controls
                 movement = true;
                 selection = false;
                 handled = true;
-                CaretIndex = _presenter.CaretIndex;
+                SetCurrentValue(CaretIndexProperty, _presenter.CaretIndex);
             }
             else if (Match(keymap.MoveCursorToTheStartOfLine))
             {
@@ -1184,7 +1180,7 @@ namespace Avalonia.Controls
                 movement = true;
                 selection = false;
                 handled = true;
-                CaretIndex = _presenter.CaretIndex;
+                SetCurrentValue(CaretIndexProperty, _presenter.CaretIndex);
             }
             else if (Match(keymap.MoveCursorToTheEndOfLine))
             {
@@ -1192,31 +1188,31 @@ namespace Avalonia.Controls
                 movement = true;
                 selection = false;
                 handled = true;
-                CaretIndex = _presenter.CaretIndex;
+                SetCurrentValue(CaretIndexProperty, _presenter.CaretIndex);
             }
             else if (Match(keymap.MoveCursorToTheStartOfDocumentWithSelection))
             {
-                SelectionStart = caretIndex;
+                SetCurrentValue(SelectionStartProperty, caretIndex);
                 MoveHome(true);
-                SelectionEnd = _presenter.CaretIndex;
+                SetCurrentValue(SelectionEndProperty, _presenter.CaretIndex);
                 movement = true;
                 selection = true;
                 handled = true;
             }
             else if (Match(keymap.MoveCursorToTheEndOfDocumentWithSelection))
             {
-                SelectionStart = caretIndex;
+                SetCurrentValue(SelectionStartProperty, caretIndex);
                 MoveEnd(true);
-                SelectionEnd = _presenter.CaretIndex;
+                SetCurrentValue(SelectionEndProperty, _presenter.CaretIndex);
                 movement = true;
                 selection = true;
                 handled = true;
             }
             else if (Match(keymap.MoveCursorToTheStartOfLineWithSelection))
             {
-                SelectionStart = caretIndex;
+                SetCurrentValue(SelectionStartProperty, caretIndex);
                 MoveHome(false);
-                SelectionEnd = _presenter.CaretIndex;
+                SetCurrentValue(SelectionEndProperty, _presenter.CaretIndex);
                 movement = true;
                 selection = true;
                 handled = true;
@@ -1224,9 +1220,9 @@ namespace Avalonia.Controls
             }
             else if (Match(keymap.MoveCursorToTheEndOfLineWithSelection))
             {
-                SelectionStart = caretIndex;
+                SetCurrentValue(SelectionStartProperty, caretIndex);
                 MoveEnd(false);
-                SelectionEnd = _presenter.CaretIndex;
+                SetCurrentValue(SelectionEndProperty, _presenter.CaretIndex);
                 movement = true;
                 selection = true;
                 handled = true;
@@ -1261,11 +1257,11 @@ namespace Avalonia.Controls
 
                             if (selection)
                             {
-                                SelectionEnd = _presenter.CaretIndex;
+                                SetCurrentValue(SelectionEndProperty, _presenter.CaretIndex);
                             }
                             else
                             {
-                                CaretIndex = _presenter.CaretIndex;
+                                SetCurrentValue(CaretIndexProperty, _presenter.CaretIndex);
                             }
 
                             break;
@@ -1283,11 +1279,11 @@ namespace Avalonia.Controls
 
                             if (selection)
                             {
-                                SelectionEnd = _presenter.CaretIndex;
+                                SetCurrentValue(SelectionEndProperty, _presenter.CaretIndex);
                             }
                             else
                             {
-                                CaretIndex = _presenter.CaretIndex;
+                                SetCurrentValue(CaretIndexProperty, _presenter.CaretIndex);
                             }
 
                             break;
@@ -1314,11 +1310,13 @@ namespace Avalonia.Controls
 
                                     var length = end - start;
 
-                                    var editedText = text.Substring(0, start) + text.Substring(Math.Min(end, text.Length));
+                                    var sb = StringBuilderCache.Acquire(text.Length);
+                                    sb.Append(text);
+                                    sb.Remove(start, end - start);
 
-                                    SetTextInternal(editedText);
+                                    SetCurrentValue(TextProperty, StringBuilderCache.GetStringAndRelease(sb));
 
-                                    CaretIndex = start;
+                                    SetCurrentValue(CaretIndexProperty, start);
                                 }
                             }
 
@@ -1346,9 +1344,11 @@ namespace Avalonia.Controls
                                 var start = Math.Min(nextPosition, caretIndex);
                                 var end = Math.Max(nextPosition, caretIndex);
 
-                                var editedText = text.Substring(0, start) + text.Substring(Math.Min(end, text.Length));
+                                var sb = StringBuilderCache.Acquire(text.Length);
+                                sb.Append(text);
+                                sb.Remove(start, end - start);
 
-                                SetTextInternal(editedText);
+                                SetCurrentValue(TextProperty, StringBuilderCache.GetStringAndRelease(sb));
                             }
                         }
 
@@ -1425,7 +1425,7 @@ namespace Avalonia.Controls
 
                 var clickToSelect = e.KeyModifiers.HasFlag(KeyModifiers.Shift);
 
-                SetAndRaise(CaretIndexProperty, ref _caretIndex, index);
+                SetCurrentValue(CaretIndexProperty, index);
 
                 switch (e.ClickCount)
                 {
@@ -1438,25 +1438,26 @@ namespace Avalonia.Controls
 
                                 if (index > _wordSelectionStart)
                                 {
-                                    SelectionEnd = StringUtils.NextWord(text, index);
+                                    SetCurrentValue(SelectionEndProperty, StringUtils.NextWord(text, index));
                                 }
 
                                 if (index < _wordSelectionStart || previousWord == _wordSelectionStart)
                                 {
-                                    SelectionStart = previousWord;
+                                    SetCurrentValue(SelectionStartProperty, previousWord);
                                 }
                             }
                             else
                             {
-                                SelectionStart = Math.Min(oldIndex, index);
-                                SelectionEnd = Math.Max(oldIndex, index);
+                                SetCurrentValue(SelectionStartProperty, Math.Min(oldIndex, index));
+                                SetCurrentValue(SelectionEndProperty, Math.Max(oldIndex, index));
                             }
                         }
                         else
                         {
                             if(_wordSelectionStart == -1 || index < SelectionStart || index > SelectionEnd)
                             {
-                                SelectionStart = SelectionEnd = index;
+                                SetCurrentValue(SelectionStartProperty, index);
+                                SetCurrentValue(SelectionEndProperty, index);
                                 _wordSelectionStart = -1;
                             }                           
                         }
@@ -1466,14 +1467,14 @@ namespace Avalonia.Controls
 
                         if (!StringUtils.IsStartOfWord(text, index))
                         {
-                            SelectionStart = StringUtils.PreviousWord(text, index);
+                            SetCurrentValue(SelectionStartProperty, StringUtils.PreviousWord(text, index));
                         }
 
                         _wordSelectionStart = SelectionStart;
 
                         if (!StringUtils.IsEndOfWord(text, index))
                         {
-                            SelectionEnd = StringUtils.NextWord(text, index);
+                            SetCurrentValue(SelectionEndProperty, StringUtils.NextWord(text, index));
                         }
 
                         break;
@@ -1517,22 +1518,22 @@ namespace Avalonia.Controls
 
                     if (distance <= 0)
                     {
-                        SelectionStart = StringUtils.PreviousWord(text, caretIndex);
+                        SetCurrentValue(SelectionStartProperty, StringUtils.PreviousWord(text, caretIndex));
                     }
 
                     if (distance >= 0)
                     {
                         if(SelectionStart != _wordSelectionStart)
                         {
-                            SelectionStart = _wordSelectionStart;
+                            SetCurrentValue(SelectionStartProperty, _wordSelectionStart);
                         }
 
-                        SelectionEnd = StringUtils.NextWord(text, caretIndex);
+                        SetCurrentValue(SelectionEndProperty, StringUtils.NextWord(text, caretIndex));
                     }
                 }
                 else
                 {
-                    SelectionEnd = caretIndex;
+                    SetCurrentValue(SelectionEndProperty, caretIndex);
                 }
             }
         }
@@ -1565,7 +1566,9 @@ namespace Avalonia.Controls
                                           caretIndex >= firstSelection && caretIndex <= lastSelection;
                 if (!didClickInSelection)
                 {
-                    CaretIndex = SelectionEnd = SelectionStart = caretIndex;
+                    SetCurrentValue(CaretIndexProperty, caretIndex);
+                    SetCurrentValue(SelectionEndProperty, caretIndex);
+                    SetCurrentValue(SelectionStartProperty, caretIndex);
                 }
             }
 
@@ -1588,10 +1591,10 @@ namespace Avalonia.Controls
             }
         }
 
-        private int CoerceCaretIndex(int value) => CoerceCaretIndex(value, Text);
-
-        private static int CoerceCaretIndex(int value, string? text)
+        internal static int CoerceCaretIndex(AvaloniaObject sender, int value)
         {
+            var text = sender.GetValue(TextProperty); // method also used by TextPresenter and SelectableTextBlock
+
             if (text == null)
             {
                 return 0;
@@ -1619,10 +1622,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Clears the text in the TextBox
         /// </summary>
-        public void Clear()
-        {
-            Text = string.Empty;
-        }
+        public void Clear() => SetCurrentValue(TextProperty, string.Empty);
 
         private void MoveHorizontal(int direction, bool wholeWord, bool isSelecting)
         {
@@ -1645,7 +1645,7 @@ namespace Avalonia.Controls
                         LogicalDirection.Forward :
                         LogicalDirection.Backward);
 
-                    SelectionEnd = _presenter.CaretIndex;
+                    SetCurrentValue(SelectionEndProperty, _presenter.CaretIndex);
                 }
                 else
                 {
@@ -1662,7 +1662,7 @@ namespace Avalonia.Controls
                             LogicalDirection.Backward);
                     }
 
-                    CaretIndex = _presenter.CaretIndex;
+                    SetCurrentValue(CaretIndexProperty, _presenter.CaretIndex);
                 }
             }
             else
@@ -1678,17 +1678,17 @@ namespace Avalonia.Controls
                     offset = StringUtils.PreviousWord(text, selectionEnd) - selectionEnd;
                 }
 
-                SelectionEnd += offset;
+                SetCurrentValue(SelectionEndProperty, SelectionEnd + offset);
 
                 _presenter.MoveCaretToTextPosition(SelectionEnd);
 
                 if (!isSelecting)
                 {
-                    CaretIndex = SelectionEnd;
+                    SetCurrentValue(CaretIndexProperty, SelectionEnd);
                 }
                 else
                 {
-                    SelectionStart = selectionStart;
+                    SetCurrentValue(SelectionStartProperty, selectionStart);
                 }
             }
         }
@@ -1747,36 +1747,45 @@ namespace Avalonia.Controls
         /// </summary>
         public void SelectAll()
         {
-            SelectionStart = 0;
-            SelectionEnd = Text?.Length ?? 0;
+            SetCurrentValue(SelectionStartProperty, 0);
+            SetCurrentValue(SelectionEndProperty, Text?.Length ?? 0);
         }
 
-        internal bool DeleteSelection(bool raiseTextChanged = true)
+        private (int start, int end) GetSelectionRange()
+        {
+            var selectionStart = SelectionStart;
+            var selectionEnd = SelectionEnd;
+
+            return (Math.Min(selectionStart, selectionEnd), Math.Max(selectionStart, selectionEnd));
+        }
+
+        internal bool DeleteSelection()
         {
             if (IsReadOnly)
                 return true;
 
-            var selectionStart = SelectionStart;
-            var selectionEnd = SelectionEnd;
+            var (start, end) = GetSelectionRange();
 
-            if (selectionStart != selectionEnd)
+            if (start != end)
             {
-                var start = Math.Min(selectionStart, selectionEnd);
-                var end = Math.Max(selectionStart, selectionEnd);
                 var text = Text!;
+                var textBuilder = StringBuilderCache.Acquire(text.Length);
 
-                SetTextInternal(text.Substring(0, start) + text.Substring(end), raiseTextChanged);
+                textBuilder.Append(text);
+                textBuilder.Remove(start, end - start);
+
+                SetCurrentValue(TextProperty, textBuilder.ToString());
 
                 _presenter?.MoveCaretToTextPosition(start);
 
-                CaretIndex = start;
+                SetCurrentValue(CaretIndexProperty, start);
 
                 ClearSelection();
 
                 return true;
             }
 
-            CaretIndex = SelectionStart;
+            SetCurrentValue(CaretIndexProperty, SelectionStart);
 
             return false;
         }
@@ -1826,46 +1835,30 @@ namespace Avalonia.Controls
             }, DispatcherPriority.Normal);
         }
 
-        private void SetTextInternal(string value, bool raiseTextChanged = true)
-        {
-            if (raiseTextChanged)
-            {
-                bool textChanged = SetAndRaise(TextProperty, ref _text, value);
-
-                if (textChanged)
-                {
-                    RaiseTextChangeEvents();
-                }
-            }
-            else
-            {
-                _text = value;
-            }
-        }
-
         private void SetSelectionForControlBackspace()
         {
             var selectionStart = CaretIndex;
 
             MoveHorizontal(-1, true, false);
 
-            SelectionStart = selectionStart;
+            SetCurrentValue(SelectionStartProperty, selectionStart);
         }
 
         private void SetSelectionForControlDelete()
         {
-            if (_text == null || _presenter == null)
+            var textLength = Text?.Length ?? 0;
+            if (_presenter == null || textLength == 0)
             {
                 return;
             }
 
-            SelectionStart = CaretIndex;
+            SetCurrentValue(SelectionStartProperty, CaretIndex);
 
             MoveHorizontal(1, true, true);
 
-            if (SelectionEnd < _text.Length && _text[SelectionEnd] == ' ')
+            if (SelectionEnd < textLength && Text![SelectionEnd] == ' ')
             {
-                SelectionEnd++;
+                SetCurrentValue(SelectionEndProperty, SelectionEnd + 1);
             }
         }
 
@@ -1881,8 +1874,8 @@ namespace Avalonia.Controls
             get => new UndoRedoState(Text, CaretIndex);
             set
             {
-                Text = value.Text;
-                CaretIndex = value.CaretPosition;
+                SetCurrentValue(TextProperty, value.Text);
+                SetCurrentValue(CaretIndexProperty, value.CaretPosition);
                 ClearSelection();
             }
         }
diff --git a/src/Avalonia.Controls/TextBoxTextInputMethodClient.cs b/src/Avalonia.Controls/TextBoxTextInputMethodClient.cs
index deace4084c..e999d0bb74 100644
--- a/src/Avalonia.Controls/TextBoxTextInputMethodClient.cs
+++ b/src/Avalonia.Controls/TextBoxTextInputMethodClient.cs
@@ -106,7 +106,7 @@ namespace Avalonia.Controls
         {
             if (_presenter != null && _textEditable != null)
             {
-                _presenter.CompositionRegion = new TextRange(_textEditable.CompositionStart, _textEditable.CompositionEnd);
+                _presenter.SetCurrentValue(TextPresenter.CompositionRegionProperty, new TextRange(_textEditable.CompositionStart, _textEditable.CompositionEnd));
             }
         }
 
@@ -177,9 +177,9 @@ namespace Avalonia.Controls
 
             var text = GetText(preeditText);
 
-            _presenter._text = text;
+            _presenter.SetCurrentValue(TextPresenter.TextProperty, text);
 
-            _presenter.PreeditText = preeditText;
+            _presenter.SetCurrentValue(TextPresenter.PreeditTextProperty, preeditText);
 
             _presenter.UpdateCaret(new CharacterHit(_compositionStart + (preeditText != null ? preeditText.Length : 0)), false);
 
@@ -201,9 +201,12 @@ namespace Avalonia.Controls
                 return preeditText;
             }
 
-            var text = _presenterText.Substring(0, _compositionStart) + preeditText + _presenterText.Substring(_compositionStart);
+            var sb = StringBuilderCache.Acquire(_presenterText.Length + preeditText.Length);
 
-            return text;
+            sb.Append(_presenterText);
+            sb.Insert(_compositionStart, preeditText);
+
+            return StringBuilderCache.GetStringAndRelease(sb);
         }
 
         public void SetComposingRegion(TextRange? region)
@@ -213,7 +216,7 @@ namespace Avalonia.Controls
                 return;
             }
 
-            _presenter.CompositionRegion = region;
+            _presenter.SetCurrentValue(TextPresenter.CompositionRegionProperty, region);
         }
 
         public void SelectInSurroundingText(int start, int end)
@@ -252,9 +255,9 @@ namespace Avalonia.Controls
 
             if (_presenter != null)
             {
-                _presenter.PreeditText = null;
+                _presenter.ClearValue(TextPresenter.PreeditTextProperty);
 
-                _presenter.CompositionRegion = null;
+                _presenter.ClearValue(TextPresenter.CompositionRegionProperty);
 
                 _presenter.CaretBoundsChanged -= OnCaretBoundsChanged;
             }
diff --git a/src/Avalonia.Controls/ToolTipService.cs b/src/Avalonia.Controls/ToolTipService.cs
index 9ec9013679..d983309a72 100644
--- a/src/Avalonia.Controls/ToolTipService.cs
+++ b/src/Avalonia.Controls/ToolTipService.cs
@@ -42,11 +42,12 @@ namespace Avalonia.Controls
                 {
                     Close(control);
                 }
-                else
+                else 
                 {
-                    var tip = control.GetValue(ToolTip.ToolTipProperty);
-
-                    tip!.Content = e.NewValue;
+                    if (control.GetValue(ToolTip.ToolTipProperty) is { } tip)
+                    {
+                        tip.Content = e.NewValue;
+                    }
                 }
             }
         }
diff --git a/src/Avalonia.Controls/Utils/SelectingItemsControlSelectionAdapter.cs b/src/Avalonia.Controls/Utils/SelectingItemsControlSelectionAdapter.cs
index 3c1b1262ae..5f528e2c72 100644
--- a/src/Avalonia.Controls/Utils/SelectingItemsControlSelectionAdapter.cs
+++ b/src/Avalonia.Controls/Utils/SelectingItemsControlSelectionAdapter.cs
@@ -144,13 +144,13 @@ namespace Avalonia.Controls.Utils
         {
             get
             {
-                return SelectorControl?.Items;
+                return SelectorControl?.ItemsSource;
             }
             set
             {
                 if (SelectorControl != null)
                 {
-                    SelectorControl.Items = value;
+                    SelectorControl.ItemsSource = value;
                 }
             }
         }
diff --git a/src/Avalonia.Controls/Utils/UndoRedoHelper.cs b/src/Avalonia.Controls/Utils/UndoRedoHelper.cs
index 7b663dd017..3452b8bb03 100644
--- a/src/Avalonia.Controls/Utils/UndoRedoHelper.cs
+++ b/src/Avalonia.Controls/Utils/UndoRedoHelper.cs
@@ -4,6 +4,8 @@ namespace Avalonia.Controls.Utils
 {
     class UndoRedoHelper<TState>
     {
+        public const int DefaultUndoLimit = 10;
+
         private readonly IUndoRedoHost _host;
 
         public interface IUndoRedoHost
@@ -23,7 +25,7 @@ namespace Avalonia.Controls.Utils
         /// Maximum number of states this helper can store for undo/redo.
         /// If -1, no limit is imposed.
         /// </summary>
-        public int Limit { get; set; } = 10;
+        public int Limit { get; set; } = DefaultUndoLimit;
 
         public bool CanUndo => _currentNode?.Previous != null;
 
diff --git a/src/Avalonia.Controls/VirtualizingPanel.cs b/src/Avalonia.Controls/VirtualizingPanel.cs
index 7780843eb5..a95d4f1ffa 100644
--- a/src/Avalonia.Controls/VirtualizingPanel.cs
+++ b/src/Avalonia.Controls/VirtualizingPanel.cs
@@ -34,7 +34,8 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets the items to display.
         /// </summary>
-        protected IReadOnlyList<object?> Items => ItemsControl?.ItemsView ?? ItemsSourceView.Empty;
+        protected IReadOnlyList<object?> Items => (IReadOnlyList<object?>?)ItemsControl?.ItemsView ?? 
+            Array.Empty<object?>();
 
         /// <summary>
         /// Gets the <see cref="ItemsControl"/> that the panel is displaying items for.
@@ -192,17 +193,13 @@ namespace Avalonia.Controls
                 throw new InvalidOperationException("The VirtualizingPanel is already attached to an ItemsControl");
 
             ItemsControl = itemsControl;
-            ItemsControl.PropertyChanged += OnItemsControlPropertyChanged;
             ItemsControl.ItemsView.PostCollectionChanged += OnItemsControlItemsChanged;
         }
 
         internal void Detach()
         {
             var itemsControl = EnsureItemsControl();
-
-            itemsControl.PropertyChanged -= OnItemsControlPropertyChanged;
             itemsControl.ItemsView.PostCollectionChanged -= OnItemsControlItemsChanged;
-
             ItemsControl = null;
             Children.Clear();
         }
@@ -216,20 +213,9 @@ namespace Avalonia.Controls
             return ItemsControl;
         }
 
-        private protected virtual void OnItemsControlPropertyChanged(object? sender, AvaloniaPropertyChangedEventArgs e)
-        {
-            if (e.Property == ItemsControl.ItemsViewProperty)
-            {
-                var (oldValue, newValue) = e.GetOldAndNewValue<ItemsSourceView>();
-                oldValue.PostCollectionChanged -= OnItemsControlItemsChanged;
-                Refresh();
-                newValue.PostCollectionChanged += OnItemsControlItemsChanged;
-            }
-        }
-
         private void OnItemsControlItemsChanged(object? sender, NotifyCollectionChangedEventArgs e)
         {
-            OnItemsChanged(_itemsControl?.ItemsView ?? ItemsSourceView.Empty, e);
+            OnItemsChanged(Items, e);
         }
 
         [DoesNotReturn]
diff --git a/src/Avalonia.Controls/VirtualizingStackPanel.cs b/src/Avalonia.Controls/VirtualizingStackPanel.cs
index 4970a333a5..dfacb93eeb 100644
--- a/src/Avalonia.Controls/VirtualizingStackPanel.cs
+++ b/src/Avalonia.Controls/VirtualizingStackPanel.cs
@@ -459,7 +459,8 @@ namespace Avalonia.Controls
 
             while (c is not null)
             {
-                if (!c.Bounds.IsDefault && c.TransformToVisual(this) is Matrix transform)
+                if ((c.Bounds.Width != 0 || c.Bounds.Height != 0) &&
+                    c.TransformToVisual(this) is Matrix transform)
                 {
                     viewport = new Rect(0, 0, c.Bounds.Width, c.Bounds.Height)
                         .TransformToAABB(transform);
@@ -1078,7 +1079,7 @@ namespace Avalonia.Controls
                     // elements after the insertion point.
                     var elementCount = _elements.Count;
                     var start = Math.Max(realizedIndex, 0);
-                    var newIndex = first + count;
+                    var newIndex = realizedIndex + count;
 
                     for (var i = start; i < elementCount; ++i)
                     {
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Controls/FilterTextBox.cs b/src/Avalonia.Diagnostics/Diagnostics/Controls/FilterTextBox.cs
index 66fad557d5..1e5674cc21 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Controls/FilterTextBox.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/Controls/FilterTextBox.cs
@@ -7,23 +7,18 @@ namespace Avalonia.Diagnostics.Controls
 {
     internal class FilterTextBox : TextBox, IStyleable
     {
-        public static readonly DirectProperty<FilterTextBox, bool> UseRegexFilterProperty =
-            AvaloniaProperty.RegisterDirect<FilterTextBox, bool>(nameof(UseRegexFilter),
-                o => o.UseRegexFilter, (o, v) => o.UseRegexFilter = v,
+        public static readonly StyledProperty<bool> UseRegexFilterProperty =
+            AvaloniaProperty.Register<FilterTextBox, bool>(nameof(UseRegexFilter),
                 defaultBindingMode: BindingMode.TwoWay);
 
-        public static readonly DirectProperty<FilterTextBox, bool> UseCaseSensitiveFilterProperty =
-            AvaloniaProperty.RegisterDirect<FilterTextBox, bool>(nameof(UseCaseSensitiveFilter),
-                o => o.UseCaseSensitiveFilter, (o, v) => o.UseCaseSensitiveFilter = v,
+        public static readonly StyledProperty<bool> UseCaseSensitiveFilterProperty =
+            AvaloniaProperty.Register<FilterTextBox, bool>(nameof(UseCaseSensitiveFilter),
                 defaultBindingMode: BindingMode.TwoWay);
 
-        public static readonly DirectProperty<FilterTextBox, bool> UseWholeWordFilterProperty =
-            AvaloniaProperty.RegisterDirect<FilterTextBox, bool>(nameof(UseWholeWordFilter),
-                o => o.UseWholeWordFilter, (o, v) => o.UseWholeWordFilter = v,
+        public static readonly StyledProperty<bool> UseWholeWordFilterProperty =
+            AvaloniaProperty.Register<FilterTextBox, bool>(nameof(UseWholeWordFilter),
                 defaultBindingMode: BindingMode.TwoWay);
 
-        private bool _useRegexFilter, _useCaseSensitiveFilter, _useWholeWordFilter;
-
         public FilterTextBox()
         {
             Classes.Add("filter-text-box");
@@ -31,20 +26,20 @@ namespace Avalonia.Diagnostics.Controls
 
         public bool UseRegexFilter
         {
-            get => _useRegexFilter;
-            set => SetAndRaise(UseRegexFilterProperty, ref _useRegexFilter, value);
+            get => GetValue(UseRegexFilterProperty);
+            set => SetValue(UseRegexFilterProperty, value);
         }
 
         public bool UseCaseSensitiveFilter
         {
-            get => _useCaseSensitiveFilter;
-            set => SetAndRaise(UseCaseSensitiveFilterProperty, ref _useCaseSensitiveFilter, value);
+            get => GetValue(UseCaseSensitiveFilterProperty);
+            set => SetValue(UseCaseSensitiveFilterProperty,value);
         }
 
         public bool UseWholeWordFilter
         {
-            get => _useWholeWordFilter;
-            set => SetAndRaise(UseWholeWordFilterProperty, ref _useWholeWordFilter, value);
+            get => GetValue(UseWholeWordFilterProperty);
+            set => SetValue(UseWholeWordFilterProperty, value);
         }
 
         Type IStyleable.StyleKey => typeof(TextBox);
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/ConsoleView.xaml b/src/Avalonia.Diagnostics/Diagnostics/Views/ConsoleView.xaml
index 3bef23a160..dad87f72fd 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/ConsoleView.xaml
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/ConsoleView.xaml
@@ -40,7 +40,7 @@
              BorderBrush="{DynamicResource ThemeControlMidBrush}"
              BorderThickness="0,0,0,1"
              FontFamily="/Assets/Fonts/SourceSansPro-Regular.ttf"
-             Items="{Binding History}">
+             ItemsSource="{Binding History}">
       <ListBox.ItemTemplate>
         <DataTemplate>
           <StackPanel Orientation="Vertical">
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml b/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml
index 97f195c91b..c2e63da31c 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml
@@ -124,7 +124,7 @@
         </Grid>
 
         <ScrollViewer Grid.Row="1" HorizontalScrollBarVisibility="Disabled">
-          <ItemsControl Items="{Binding AppliedStyles}" >
+          <ItemsControl ItemsSource="{Binding AppliedStyles}" >
             <ItemsControl.ItemTemplate>
               <DataTemplate>
                 <Border BorderThickness="0,0,0,1" BorderBrush="#6C6C6C" Opacity="{Binding IsActive, Converter={StaticResource BoolToOpacity}}">
@@ -142,7 +142,7 @@
                       <TextBlock Grid.Row="0" Text="{Binding Name}" />
                     </Expander.Header>
 
-                    <ItemsControl Margin="20,0,0,0" Grid.Row="1" Items="{Binding Setters}">
+                    <ItemsControl Margin="20,0,0,0" Grid.Row="1" ItemsSource="{Binding Setters}">
                       
                       <ItemsControl.Styles>
                         <Style Selector="TextBlock.property-name">
@@ -253,7 +253,7 @@
         </ScrollViewer>
 
         <Expander Header="Pseudo Classes" Grid.Row="2">
-          <ItemsControl Items="{Binding PseudoClasses}">
+          <ItemsControl ItemsSource="{Binding PseudoClasses}">
             <ItemsControl.ItemsPanel>
               <ItemsPanelTemplate>
                 <WrapPanel />
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/EventsPageView.xaml b/src/Avalonia.Diagnostics/Diagnostics/Views/EventsPageView.xaml
index fabd05077a..54c2f06709 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/EventsPageView.xaml
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/EventsPageView.xaml
@@ -45,7 +45,7 @@
                               UseWholeWordFilter="{Binding UseWholeWordFilter}"
                               UseRegexFilter="{Binding UseRegexFilter}" />
 
-      <TreeView Grid.Row="1" Items="{Binding Nodes}" SelectedItem="{Binding SelectedNode, Mode=TwoWay}" >
+      <TreeView Grid.Row="1" ItemsSource="{Binding Nodes}" SelectedItem="{Binding SelectedNode, Mode=TwoWay}" >
         <TreeView.DataTemplates>
           <TreeDataTemplate DataType="vm:EventTreeNodeBase"
                             ItemsSource="{Binding Children}">
@@ -71,7 +71,7 @@
 
     <Grid RowDefinitions="*,4,2*,Auto" Grid.Column="2">
 
-      <ListBox Name="EventsList" Items="{Binding RecordedEvents}"
+      <ListBox Name="EventsList" ItemsSource="{Binding RecordedEvents}"
                SelectedItem="{Binding SelectedEvent, Mode=TwoWay}">
 
         <ListBox.ItemTemplate>
@@ -108,7 +108,7 @@
       <DockPanel Grid.Row="2" LastChildFill="True">
         <TextBlock DockPanel.Dock="Top" FontSize="16" Text="Event chain:" />
 
-        <ListBox Items="{Binding SelectedEvent.EventChain}">
+        <ListBox ItemsSource="{Binding SelectedEvent.EventChain}">
           <ListBox.ItemTemplate>
             <DataTemplate>
               <ListBoxItem Classes.handled="{Binding Handled}">
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/PropertyValueEditorView.cs b/src/Avalonia.Diagnostics/Diagnostics/Views/PropertyValueEditorView.cs
index 6e7729a350..6b52989f0b 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/PropertyValueEditorView.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/PropertyValueEditorView.cs
@@ -221,7 +221,7 @@ namespace Avalonia.Diagnostics.Views
                 return CreateControl<ComboBox>(
                     SelectingItemsControl.SelectedItemProperty, init: c =>
                     {
-                        c.Items = Enum.GetValues(propertyType);
+                        c.ItemsSource = Enum.GetValues(propertyType);
                     });
 
             var tb = CreateControl<CommitTextBox>(
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml b/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml
index 3ca3d0b60e..9ffc301dc1 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml
@@ -6,7 +6,7 @@
   <Grid ColumnDefinitions="0.35*,4,0.65*">
     <TreeView Name="tree"
               BorderThickness="0"
-              Items="{Binding Nodes}"
+              ItemsSource="{Binding Nodes}"
               SelectedItem="{Binding SelectedNode, Mode=TwoWay}">
       <TreeView.DataTemplates>
         <TreeDataTemplate DataType="vm:TreeNode"
diff --git a/src/Avalonia.FreeDesktop/Avalonia.FreeDesktop.csproj b/src/Avalonia.FreeDesktop/Avalonia.FreeDesktop.csproj
index 51af5862cf..da9add1fa4 100644
--- a/src/Avalonia.FreeDesktop/Avalonia.FreeDesktop.csproj
+++ b/src/Avalonia.FreeDesktop/Avalonia.FreeDesktop.csproj
@@ -12,8 +12,8 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Tmds.DBus.Protocol" Version="0.13.0" />
-    <PackageReference Include="Tmds.DBus.SourceGenerator" Version="0.0.2" />
+    <PackageReference Include="Tmds.DBus.Protocol" Version="0.14.0" />
+    <PackageReference Include="Tmds.DBus.SourceGenerator" Version="0.0.4" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/Avalonia.FreeDesktop/DBusMenuExporter.cs b/src/Avalonia.FreeDesktop/DBusMenuExporter.cs
index d08828f796..3073ea580c 100644
--- a/src/Avalonia.FreeDesktop/DBusMenuExporter.cs
+++ b/src/Avalonia.FreeDesktop/DBusMenuExporter.cs
@@ -60,38 +60,42 @@ namespace Avalonia.FreeDesktop
 
             public override string Path { get; }
 
-            protected override (uint revision, (int, Dictionary<string, DBusVariantItem>, DBusVariantItem[]) layout) OnGetLayout(int parentId, int recursionDepth, string[] propertyNames)
+            protected override ValueTask<(uint revision, (int, Dictionary<string, DBusVariantItem>, DBusVariantItem[]) layout)> OnGetLayoutAsync(int parentId, int recursionDepth, string[] propertyNames)
             {
                 var menu = GetMenu(parentId);
                 var layout = GetLayout(menu.item, menu.menu, recursionDepth, propertyNames);
                 if (!IsNativeMenuExported)
                 {
                     IsNativeMenuExported = true;
-                    Dispatcher.UIThread.Post(() => OnIsNativeMenuExportedChanged?.Invoke(this, EventArgs.Empty));
+                    OnIsNativeMenuExportedChanged?.Invoke(this, EventArgs.Empty);
                 }
 
-                return (_revision, layout);
+                return new ValueTask<(uint, (int, Dictionary<string, DBusVariantItem>, DBusVariantItem[]))>((_revision, layout));
             }
 
-            protected override (int, Dictionary<string, DBusVariantItem>)[] OnGetGroupProperties(int[] ids, string[] propertyNames) =>
-                ids.Select(id => (id, GetProperties(GetMenu(id), propertyNames))).ToArray();
+            protected override ValueTask<(int, Dictionary<string, DBusVariantItem>)[]> OnGetGroupPropertiesAsync(int[] ids, string[] propertyNames)
+                => new(ids.Select(id => (id, GetProperties(GetMenu(id), propertyNames))).ToArray());
 
-            protected override DBusVariantItem OnGetProperty(int id, string name) => GetProperty(GetMenu(id), name) ?? new DBusVariantItem("i", new DBusInt32Item(0));
+            protected override ValueTask<DBusVariantItem> OnGetPropertyAsync(int id, string name) =>
+                new(GetProperty(GetMenu(id), name) ?? new DBusVariantItem("i", new DBusInt32Item(0)));
 
-            protected override void OnEvent(int id, string eventId, DBusVariantItem data, uint timestamp) =>
-                Dispatcher.UIThread.Post(() => HandleEvent(id, eventId));
+            protected override ValueTask OnEventAsync(int id, string eventId, DBusVariantItem data, uint timestamp)
+            {
+                HandleEvent(id, eventId);
+                return new ValueTask();
+            }
 
-            protected override int[] OnEventGroup((int, string, DBusVariantItem, uint)[] events)
+            protected override ValueTask<int[]> OnEventGroupAsync((int, string, DBusVariantItem, uint)[] events)
             {
                 foreach (var e in events)
-                    Dispatcher.UIThread.Post(() => HandleEvent(e.Item1, e.Item2));
-                return Array.Empty<int>();
+                    HandleEvent(e.Item1, e.Item2);
+                return new ValueTask<int[]>(Array.Empty<int>());
             }
 
-            protected override bool OnAboutToShow(int id) => false;
+            protected override ValueTask<bool> OnAboutToShowAsync(int id) => new(false);
 
-            protected override (int[] updatesNeeded, int[] idErrors) OnAboutToShowGroup(int[] ids) =>
-                (Array.Empty<int>(), Array.Empty<int>());
+            protected override ValueTask<(int[] updatesNeeded, int[] idErrors)> OnAboutToShowGroupAsync(int[] ids) =>
+                new((Array.Empty<int>(), Array.Empty<int>()));
 
             private async Task InitializeAsync()
             {
diff --git a/src/Avalonia.FreeDesktop/DBusTrayIconImpl.cs b/src/Avalonia.FreeDesktop/DBusTrayIconImpl.cs
index afbee77067..fed8b87bc9 100644
--- a/src/Avalonia.FreeDesktop/DBusTrayIconImpl.cs
+++ b/src/Avalonia.FreeDesktop/DBusTrayIconImpl.cs
@@ -1,8 +1,10 @@
 using System;
 using System.Diagnostics;
+using System.Threading.Tasks;
 using Avalonia.Controls.Platform;
 using Avalonia.Logging;
 using Avalonia.Platform;
+using Avalonia.Threading;
 using Tmds.DBus.Protocol;
 using Tmds.DBus.SourceGenerator;
 
@@ -219,13 +221,6 @@ namespace Avalonia.FreeDesktop
             Connection = connection;
             BackingProperties.Menu = dbusMenuPath;
             BackingProperties.ToolTip = (string.Empty, Array.Empty<(int, int, byte[])>(), string.Empty, string.Empty);
-            BackingProperties.IconName = string.Empty;
-            BackingProperties.AttentionIconName = string.Empty;
-            BackingProperties.AttentionIconPixmap = new []{ DBusTrayIconImpl.EmptyPixmap };
-            BackingProperties.AttentionMovieName = string.Empty;
-            BackingProperties.IconThemePath = string.Empty;
-            BackingProperties.OverlayIconName = string.Empty;
-            BackingProperties.OverlayIconPixmap = new []{ DBusTrayIconImpl.EmptyPixmap };
             InvalidateAll();
         }
 
@@ -235,13 +230,17 @@ namespace Avalonia.FreeDesktop
 
         public event Action? ActivationDelegate;
 
-        protected override void OnContextMenu(int x, int y) { }
+        protected override ValueTask OnContextMenuAsync(int x, int y) => new();
 
-        protected override void OnActivate(int x, int y) => ActivationDelegate?.Invoke();
+        protected override ValueTask OnActivateAsync(int x, int y)
+        {
+            Dispatcher.UIThread.Post(() => ActivationDelegate?.Invoke());
+            return new ValueTask();
+        }
 
-        protected override void OnSecondaryActivate(int x, int y) { }
+        protected override ValueTask OnSecondaryActivateAsync(int x, int y) => new();
 
-        protected override void OnScroll(int delta, string orientation) { }
+        protected override ValueTask OnScrollAsync(int delta, string orientation) => new();
 
         public void InvalidateAll()
         {
diff --git a/src/Avalonia.Themes.Fluent/Controls/DataValidationErrors.xaml b/src/Avalonia.Themes.Fluent/Controls/DataValidationErrors.xaml
index 7d45d0444f..984a523471 100644
--- a/src/Avalonia.Themes.Fluent/Controls/DataValidationErrors.xaml
+++ b/src/Avalonia.Themes.Fluent/Controls/DataValidationErrors.xaml
@@ -50,7 +50,7 @@
       <DataTemplate>
         <ItemsControl x:DataType="DataValidationErrors"
                       Foreground="{DynamicResource SystemControlErrorTextForegroundBrush}"
-                      Items="{Binding}">
+                      ItemsSource="{Binding}">
           <ItemsControl.Styles>
             <Style Selector="TextBlock">
               <Setter Property="TextWrapping" Value="Wrap" />
@@ -98,7 +98,7 @@
             </Style>
           </Panel.Styles>
           <ToolTip.Tip>
-            <ItemsControl Items="{Binding}" x:DataType="collections:IEnumerable" />
+            <ItemsControl ItemsSource="{Binding}" x:DataType="collections:IEnumerable" />
           </ToolTip.Tip>
           <Path Width="14"
                 Height="14"
diff --git a/src/Avalonia.Themes.Fluent/Controls/DatePicker.xaml b/src/Avalonia.Themes.Fluent/Controls/DatePicker.xaml
index 28ec553660..e71e733eff 100644
--- a/src/Avalonia.Themes.Fluent/Controls/DatePicker.xaml
+++ b/src/Avalonia.Themes.Fluent/Controls/DatePicker.xaml
@@ -127,7 +127,7 @@
 
             <Popup Name="PART_Popup" WindowManagerAddShadowHint="False"
                    IsLightDismissEnabled="True" PlacementTarget="{TemplateBinding}"
-                   PlacementMode="Bottom">
+                   Placement="Bottom">
               <DatePickerPresenter Name="PART_PickerPresenter" />
             </Popup>
 
diff --git a/src/Avalonia.Themes.Fluent/Controls/ManagedFileChooser.xaml b/src/Avalonia.Themes.Fluent/Controls/ManagedFileChooser.xaml
index d2581caaf5..b3453569a4 100644
--- a/src/Avalonia.Themes.Fluent/Controls/ManagedFileChooser.xaml
+++ b/src/Avalonia.Themes.Fluent/Controls/ManagedFileChooser.xaml
@@ -136,7 +136,7 @@
             x:DataType="internal:ManagedFileChooserViewModel">
       <ControlTemplate>
         <DockPanel>
-          <ListBox x:Name="PART_QuickLinks" DockPanel.Dock="Left" Items="{Binding QuickLinks}" SelectedIndex="{Binding QuickLinksSelectedIndex}" Focusable="False">
+          <ListBox x:Name="PART_QuickLinks" DockPanel.Dock="Left" ItemsSource="{Binding QuickLinks}" SelectedIndex="{Binding QuickLinksSelectedIndex}" Focusable="False">
             <ListBox.ItemTemplate>
               <DataTemplate>
                 <StackPanel Spacing="4" Orientation="Horizontal" Background="Transparent">
@@ -173,7 +173,7 @@
               <DockPanel DockPanel.Dock="Top" Margin="0,0,0,4">
                 <ComboBox DockPanel.Dock="Right"
                     IsVisible="{Binding ShowFilters}"
-                    Items="{Binding Filters}"
+                    ItemsSource="{Binding Filters}"
                     SelectedItem="{Binding SelectedFilter}" />
                 <TextBox Text="{Binding FileName}" Watermark="File name" IsVisible="{Binding !SelectingFolder}" />
               </DockPanel>
@@ -220,7 +220,7 @@
               <TextBlock Grid.Column="8" Text="Size" />
             </Grid>
             <ListBox x:Name="PART_Files"
-                Items="{Binding Items}"
+                ItemsSource="{Binding Items}"
                 Margin="0 5"
                 SelectionMode="{Binding SelectionMode}"
                 SelectedItems="{Binding SelectedItems}"
diff --git a/src/Avalonia.Themes.Fluent/Controls/Menu.xaml b/src/Avalonia.Themes.Fluent/Controls/Menu.xaml
index 692bac958a..c234cfd68e 100644
--- a/src/Avalonia.Themes.Fluent/Controls/Menu.xaml
+++ b/src/Avalonia.Themes.Fluent/Controls/Menu.xaml
@@ -37,6 +37,7 @@
                    MinWidth="{Binding Bounds.Width, RelativeSource={RelativeSource TemplatedParent}}"
                    IsLightDismissEnabled="True"
                    IsOpen="{TemplateBinding IsSubMenuOpen, Mode=TwoWay}"
+                   Placement="BottomEdgeAlignedLeft"
                    OverlayInputPassThroughElement="{Binding $parent[Menu]}">
               <Border Background="{DynamicResource MenuFlyoutPresenterBackground}"
                       BorderBrush="{DynamicResource MenuFlyoutPresenterBorderBrush}"
diff --git a/src/Avalonia.Themes.Fluent/Controls/MenuItem.xaml b/src/Avalonia.Themes.Fluent/Controls/MenuItem.xaml
index 72a7797bc3..5a10c62860 100644
--- a/src/Avalonia.Themes.Fluent/Controls/MenuItem.xaml
+++ b/src/Avalonia.Themes.Fluent/Controls/MenuItem.xaml
@@ -118,7 +118,7 @@
           </Border>
           <Popup Name="PART_Popup"
                  WindowManagerAddShadowHint="False"
-                 PlacementMode="Right"
+                 Placement="Right"
                  HorizontalOffset="{DynamicResource MenuFlyoutSubItemPopupHorizontalOffset}"
                  IsLightDismissEnabled="False"
                  IsOpen="{TemplateBinding IsSubMenuOpen, Mode=TwoWay}">
diff --git a/src/Avalonia.Themes.Fluent/Controls/NativeMenuBar.xaml b/src/Avalonia.Themes.Fluent/Controls/NativeMenuBar.xaml
index d5c95ab46c..515a5a730b 100644
--- a/src/Avalonia.Themes.Fluent/Controls/NativeMenuBar.xaml
+++ b/src/Avalonia.Themes.Fluent/Controls/NativeMenuBar.xaml
@@ -7,13 +7,13 @@
       <ControlTemplate>
         <Menu
           IsVisible="{Binding !$parent[TopLevel].(NativeMenu.IsNativeMenuExported)}"
-          Items="{Binding $parent[TopLevel].(NativeMenu.Menu).Items}">
+          ItemsSource="{Binding $parent[TopLevel].(NativeMenu.Menu).Items}">
           <Menu.Styles>
             <Style Selector="MenuItem" x:DataType="NativeMenuItem">
               <Setter Property="Header" Value="{Binding Header}"/>
               <Setter Property="IsEnabled" Value="{Binding IsEnabled}"/>
               <Setter Property="InputGesture" Value="{Binding Gesture}"/>
-              <Setter Property="Items" Value="{Binding Menu.Items}"/>
+              <Setter Property="ItemsSource" Value="{Binding Menu.Items}"/>
               <Setter Property="Command" Value="{Binding Command}"/>
               <Setter Property="CommandParameter" Value="{Binding CommandParameter}"/>
               <Setter Property="(NativeMenuBar.EnableMenuItemClickForwarding)" Value="True"/>
diff --git a/src/Avalonia.Themes.Fluent/Controls/TimePicker.xaml b/src/Avalonia.Themes.Fluent/Controls/TimePicker.xaml
index 71ff0eaebc..39f7b0b224 100644
--- a/src/Avalonia.Themes.Fluent/Controls/TimePicker.xaml
+++ b/src/Avalonia.Themes.Fluent/Controls/TimePicker.xaml
@@ -151,7 +151,7 @@
                    WindowManagerAddShadowHint="False"
                    IsLightDismissEnabled="True"
                    PlacementTarget="{TemplateBinding}"
-                   PlacementMode="Bottom">
+                   Placement="Bottom">
               <TimePickerPresenter Name="PART_PickerPresenter" />
             </Popup>
 
diff --git a/src/Avalonia.Themes.Simple/Controls/DataValidationErrors.xaml b/src/Avalonia.Themes.Simple/Controls/DataValidationErrors.xaml
index ef8c6625bd..a4e5ab2d90 100644
--- a/src/Avalonia.Themes.Simple/Controls/DataValidationErrors.xaml
+++ b/src/Avalonia.Themes.Simple/Controls/DataValidationErrors.xaml
@@ -35,7 +35,7 @@
           </Canvas.Styles>
           <ToolTip.Tip>
             <ItemsControl x:DataType="DataValidationErrors"
-                          Items="{Binding}" />
+                          ItemsSource="{Binding}" />
           </ToolTip.Tip>
           <Path Data="M14,7 A7,7 0 0,0 0,7 M0,7 A7,7 0 1,0 14,7 M7,3l0,5 M7,9l0,2"
                 Stroke="{DynamicResource ErrorBrush}"
diff --git a/src/Avalonia.Themes.Simple/Controls/DatePicker.xaml b/src/Avalonia.Themes.Simple/Controls/DatePicker.xaml
index 5c57240aea..6cf352518a 100644
--- a/src/Avalonia.Themes.Simple/Controls/DatePicker.xaml
+++ b/src/Avalonia.Themes.Simple/Controls/DatePicker.xaml
@@ -142,7 +142,7 @@
 
             <Popup Name="PART_Popup"
                    IsLightDismissEnabled="True"
-                   PlacementMode="Bottom"
+                   Placement="Bottom"
                    PlacementTarget="{TemplateBinding}"
                    WindowManagerAddShadowHint="False">
               <DatePickerPresenter Name="PART_PickerPresenter" />
diff --git a/src/Avalonia.Themes.Simple/Controls/ManagedFileChooser.xaml b/src/Avalonia.Themes.Simple/Controls/ManagedFileChooser.xaml
index 2ef112f51c..a5b0649655 100644
--- a/src/Avalonia.Themes.Simple/Controls/ManagedFileChooser.xaml
+++ b/src/Avalonia.Themes.Simple/Controls/ManagedFileChooser.xaml
@@ -101,7 +101,7 @@
           <ComboBox Margin="0,5,0,0"
                     DockPanel.Dock="Bottom"
                     IsVisible="{Binding ShowFilters}"
-                    Items="{Binding Filters}"
+                    ItemsSource="{Binding Filters}"
                     SelectedItem="{Binding SelectedFilter}" />
 
           <TextBox DockPanel.Dock="Bottom"
@@ -114,7 +114,7 @@
                    BorderBrush="Transparent"
                    DockPanel.Dock="Left"
                    Focusable="False"
-                   Items="{Binding QuickLinks}"
+                   ItemsSource="{Binding QuickLinks}"
                    SelectedIndex="{Binding QuickLinksSelectedIndex}">
             <ListBox.ItemTemplate>
               <DataTemplate>
@@ -160,7 +160,7 @@
             </Grid>
             <ListBox x:Name="PART_Files"
                      Margin="0,5"
-                     Items="{Binding Items}"
+                     ItemsSource="{Binding Items}"
                      ScrollViewer.HorizontalScrollBarVisibility="Disabled"
                      SelectedItems="{Binding SelectedItems}"
                      SelectionMode="{Binding SelectionMode}">
diff --git a/src/Avalonia.Themes.Simple/Controls/Menu.xaml b/src/Avalonia.Themes.Simple/Controls/Menu.xaml
index 797aeedd23..0b3064412d 100644
--- a/src/Avalonia.Themes.Simple/Controls/Menu.xaml
+++ b/src/Avalonia.Themes.Simple/Controls/Menu.xaml
@@ -26,8 +26,8 @@
             </ContentPresenter>
             <Popup Name="PART_Popup"
                    IsLightDismissEnabled="True"
-                   IsOpen="{TemplateBinding IsSubMenuOpen,
-                                            Mode=TwoWay}"
+                   IsOpen="{TemplateBinding IsSubMenuOpen, Mode=TwoWay}"
+                   Placement="BottomEdgeAlignedLeft"
                    OverlayInputPassThroughElement="{Binding $parent[Menu]}">
               <Border Background="{DynamicResource ThemeBackgroundBrush}"
                       BorderBrush="{DynamicResource ThemeBorderMidBrush}"
diff --git a/src/Avalonia.Themes.Simple/Controls/MenuItem.xaml b/src/Avalonia.Themes.Simple/Controls/MenuItem.xaml
index 6056938938..7ec666eaf9 100644
--- a/src/Avalonia.Themes.Simple/Controls/MenuItem.xaml
+++ b/src/Avalonia.Themes.Simple/Controls/MenuItem.xaml
@@ -65,7 +65,7 @@
                    IsLightDismissEnabled="False"
                    IsOpen="{TemplateBinding IsSubMenuOpen,
                                             Mode=TwoWay}"
-                   PlacementMode="Right">
+                   Placement="Right">
               <Border Background="{DynamicResource ThemeBackgroundBrush}"
                       BorderBrush="{DynamicResource ThemeBorderMidBrush}"
                       BorderThickness="{TemplateBinding BorderThickness}">
diff --git a/src/Avalonia.Themes.Simple/Controls/NativeMenuBar.xaml b/src/Avalonia.Themes.Simple/Controls/NativeMenuBar.xaml
index 945622f22f..625bf71e66 100644
--- a/src/Avalonia.Themes.Simple/Controls/NativeMenuBar.xaml
+++ b/src/Avalonia.Themes.Simple/Controls/NativeMenuBar.xaml
@@ -7,13 +7,13 @@
     <Setter Property="Template">
       <ControlTemplate>
         <Menu IsVisible="{Binding !$parent[TopLevel].(NativeMenu.IsNativeMenuExported)}"
-              Items="{Binding $parent[TopLevel].(NativeMenu.Menu).Items}">
+              ItemsSource="{Binding $parent[TopLevel].(NativeMenu.Menu).Items}">
           <Menu.Styles>
             <Style Selector="MenuItem" x:DataType="NativeMenuItem">
               <Setter Property="Header" Value="{Binding Header}"/>
               <Setter Property="IsEnabled" Value="{Binding IsEnabled}"/>
               <Setter Property="InputGesture" Value="{Binding Gesture}"/>
-              <Setter Property="Items" Value="{Binding Menu.Items}"/>
+              <Setter Property="ItemsSource" Value="{Binding Menu.Items}"/>
               <Setter Property="Command" Value="{Binding Command}"/>
               <Setter Property="CommandParameter" Value="{Binding CommandParameter}"/>
               <Setter Property="(NativeMenuBar.EnableMenuItemClickForwarding)" Value="True"/>
diff --git a/src/Avalonia.Themes.Simple/Controls/TimePicker.xaml b/src/Avalonia.Themes.Simple/Controls/TimePicker.xaml
index 58066bb9a5..5acbc41a68 100644
--- a/src/Avalonia.Themes.Simple/Controls/TimePicker.xaml
+++ b/src/Avalonia.Themes.Simple/Controls/TimePicker.xaml
@@ -156,7 +156,7 @@
 
             <Popup Name="PART_Popup"
                    IsLightDismissEnabled="True"
-                   PlacementMode="Bottom"
+                   Placement="Bottom"
                    PlacementTarget="{TemplateBinding}"
                    WindowManagerAddShadowHint="False">
               <TimePickerPresenter Name="PART_PickerPresenter" />
diff --git a/src/Avalonia.X11/X11Window.cs b/src/Avalonia.X11/X11Window.cs
index 6634ab4d7b..22748f6aa3 100644
--- a/src/Avalonia.X11/X11Window.cs
+++ b/src/Avalonia.X11/X11Window.cs
@@ -25,6 +25,9 @@ using Avalonia.X11.NativeDialogs;
 using static Avalonia.X11.XLib;
 // ReSharper disable IdentifierTypo
 // ReSharper disable StringLiteralTypo
+
+#nullable enable
+
 namespace Avalonia.X11
 {
     internal unsafe partial class X11Window : IWindowImpl, IPopupImpl, IXI2Client
@@ -35,11 +38,11 @@ namespace Avalonia.X11
         private XConfigureEvent? _configure;
         private PixelPoint? _configurePoint;
         private bool _triggeredExpose;
-        private IInputRoot _inputRoot;
+        private IInputRoot? _inputRoot;
         private readonly MouseDevice _mouse;
         private readonly TouchDevice _touch;
         private readonly IKeyboardDevice _keyboard;
-        private readonly ITopLevelNativeMenuExporter _nativeMenuExporter;
+        private readonly ITopLevelNativeMenuExporter? _nativeMenuExporter;
         private readonly IStorageProvider _storageProvider;
         private readonly X11NativeControlHost _nativeControlHost;
         private PixelPoint? _position;
@@ -54,8 +57,8 @@ namespace Avalonia.X11
         private bool _wasMappedAtLeastOnce = false;
         private double? _scalingOverride;
         private bool _disabled;
-        private TransparencyHelper _transparencyHelper;
-        private RawEventGrouper _rawEventGrouper;
+        private TransparencyHelper? _transparencyHelper;
+        private RawEventGrouper? _rawEventGrouper;
         private bool _useRenderWindow = false;
         private bool _usePositioningFlags = false;
 
@@ -66,7 +69,7 @@ namespace Avalonia.X11
             WaitPaint
         }
         
-        public X11Window(AvaloniaX11Platform platform, IWindowImpl popupParent)
+        public X11Window(AvaloniaX11Platform platform, IWindowImpl? popupParent)
         {
             _platform = platform;
             _popup = popupParent != null;
@@ -196,7 +199,7 @@ namespace Avalonia.X11
 
             XFlush(_x11.Display);
             if(_popup)
-                PopupPositioner = new ManagedPopupPositioner(new ManagedPopupPositionerPopupImplHelper(popupParent, MoveResize));
+                PopupPositioner = new ManagedPopupPositioner(new ManagedPopupPositionerPopupImplHelper(popupParent!, MoveResize));
             if (platform.Options.UseDBusMenu)
                 _nativeMenuExporter = DBusMenuExporter.TryCreateTopLevelNativeMenu(_handle);
             _nativeControlHost = new X11NativeControlHost(_platform, this);
@@ -214,7 +217,7 @@ namespace Avalonia.X11
 
             _storageProvider = new CompositeStorageProvider(new[]
             {
-                () => _platform.Options.UseDBusFilePicker ? DBusSystemDialog.TryCreateAsync(Handle) : Task.FromResult<IStorageProvider>(null),
+                () => _platform.Options.UseDBusFilePicker ? DBusSystemDialog.TryCreateAsync(Handle) : Task.FromResult<IStorageProvider?>(null),
                 () => GtkSystemDialog.TryCreate(this)
             });
         }
@@ -351,17 +354,17 @@ namespace Avalonia.X11
         public double DesktopScaling => RenderScaling;
 
         public IEnumerable<object> Surfaces { get; }
-        public Action<RawInputEventArgs> Input { get; set; }
-        public Action<Rect> Paint { get; set; }
-        public Action<Size, PlatformResizeReason> Resized { get; set; }
+        public Action<RawInputEventArgs>? Input { get; set; }
+        public Action<Rect>? Paint { get; set; }
+        public Action<Size, PlatformResizeReason>? Resized { get; set; }
         //TODO
-        public Action<double> ScalingChanged { get; set; }
-        public Action Deactivated { get; set; }
-        public Action Activated { get; set; }
-        public Func<WindowCloseReason, bool> Closing { get; set; }
-        public Action<WindowState> WindowStateChanged { get; set; }
+        public Action<double>? ScalingChanged { get; set; }
+        public Action? Deactivated { get; set; }
+        public Action? Activated { get; set; }
+        public Func<WindowCloseReason, bool>? Closing { get; set; }
+        public Action<WindowState>? WindowStateChanged { get; set; }
 
-        public Action<WindowTransparencyLevel> TransparencyLevelChanged
+        public Action<WindowTransparencyLevel>? TransparencyLevelChanged
         {
             get => _transparencyHelper?.TransparencyLevelChanged;
             set
@@ -371,7 +374,7 @@ namespace Avalonia.X11
             }
         }
 
-        public Action<bool> ExtendClientAreaToDecorationsChanged { get; set; }
+        public Action<bool>? ExtendClientAreaToDecorationsChanged { get; set; }
 
         public Thickness ExtendedMargins { get; } = new Thickness();
 
@@ -379,15 +382,18 @@ namespace Avalonia.X11
 
         public bool IsClientAreaExtendedToDecorations { get; }
 
-        public Action Closed { get; set; }
-        public Action<PixelPoint> PositionChanged { get; set; }
-        public Action LostFocus { get; set; }
+        public Action? Closed { get; set; }
+        public Action<PixelPoint>? PositionChanged { get; set; }
+        public Action? LostFocus { get; set; }
 
         public IRenderer CreateRenderer(IRenderRoot root) =>
             new CompositingRenderer(root, _platform.Compositor, () => Surfaces);
 
         private void OnEvent(ref XEvent ev)
         {
+            if (_inputRoot is null)
+                return;
+
             if (ev.type == XEventName.MapNotify)
             {
                 _mapped = true;
@@ -434,7 +440,8 @@ namespace Avalonia.X11
                             2 => RawPointerEventType.MiddleButtonDown,
                             3 => RawPointerEventType.RightButtonDown,
                             8 => RawPointerEventType.XButton1Down,
-                            9 => RawPointerEventType.XButton2Down
+                            9 => RawPointerEventType.XButton2Down,
+                            _ => throw new NotSupportedException("Unexepected RawPointerEventType.")
                         },
                         ref ev, ev.ButtonEvent.state);
                 else
@@ -462,7 +469,8 @@ namespace Avalonia.X11
                             2 => RawPointerEventType.MiddleButtonUp,
                             3 => RawPointerEventType.RightButtonUp,
                             8 => RawPointerEventType.XButton1Up,
-                            9 => RawPointerEventType.XButton2Up
+                            9 => RawPointerEventType.XButton2Up,
+                            _ => throw new NotSupportedException("Unexepected RawPointerEventType.")
                         },
                         ref ev, ev.ButtonEvent.state);
             }
@@ -618,7 +626,7 @@ namespace Avalonia.X11
             {
                 // Occurs once the window has been mapped, which is the earliest the extents
                 // can be retrieved, so invoke event to force update of TopLevel.FrameSize.
-                Resized.Invoke(ClientSize, PlatformResizeReason.Unspecified);
+                Resized?.Invoke(ClientSize, PlatformResizeReason.Unspecified);
             }
 
             if (atom == _x11.Atoms._NET_WM_STATE)
@@ -712,6 +720,8 @@ namespace Avalonia.X11
 
         private void DispatchInput(RawInputEventArgs args)
         {
+            if (_inputRoot is null)
+                return;
             Input?.Invoke(args);
             if (!args.Handled && args is RawKeyEventArgsWithText text && !string.IsNullOrEmpty(text.Text))
                 Input?.Invoke(new RawTextInputEventArgs(_keyboard, args.Timestamp, _inputRoot, text.Text));
@@ -744,11 +754,13 @@ namespace Avalonia.X11
             if (args is RawDragEvent drag)
                 drag.Location = drag.Location / RenderScaling;
             
-            _rawEventGrouper.HandleEvent(args);
+            _rawEventGrouper?.HandleEvent(args);
         }
 
         private void MouseEvent(RawPointerEventType type, ref XEvent ev, XModifierMask mods)
         {
+            if (_inputRoot is null)
+                return;
             var mev = new RawPointerEventArgs(
                 _mouse, (ulong)ev.ButtonEvent.time.ToInt64(), _inputRoot,
                 type, new Point(ev.ButtonEvent.x, ev.ButtonEvent.y), TranslateModifiers(mods));
@@ -783,7 +795,7 @@ namespace Avalonia.X11
 
         }
 
-        public IInputRoot InputRoot => _inputRoot;
+        public IInputRoot? InputRoot => _inputRoot;
         
         public void SetInputRoot(IInputRoot inputRoot)
         {
@@ -795,7 +807,7 @@ namespace Avalonia.X11
             Cleanup();            
         }
 
-        public virtual object TryGetFeature(Type featureType)
+        public virtual object? TryGetFeature(Type featureType)
         {
             if (featureType == typeof(ITopLevelNativeMenuExporter))
             {
@@ -953,7 +965,7 @@ namespace Avalonia.X11
             UpdateSizeHints(null);
         }
 
-        public void SetCursor(ICursorImpl cursor)
+        public void SetCursor(ICursorImpl? cursor)
         {
             if (cursor == null)
                 XDefineCursor(_x11.Display, _handle, _x11.DefaultCursor);
@@ -996,7 +1008,7 @@ namespace Avalonia.X11
         public IMouseDevice MouseDevice => _mouse;
         public TouchDevice TouchDevice => _touch;
 
-        public IPopupImpl CreatePopup() 
+        public IPopupImpl? CreatePopup() 
             => _platform.Options.OverlayPopups ? null : new X11Window(_platform, this);
 
         public void Activate()
@@ -1082,7 +1094,7 @@ namespace Avalonia.X11
             BeginMoveResize(side, e);
         }
 
-        public void SetTitle(string title)
+        public void SetTitle(string? title)
         {
             if (string.IsNullOrEmpty(title))
             {
@@ -1161,9 +1173,9 @@ namespace Avalonia.X11
         {
         }
 
-        public Action GotInputWhenDisabled { get; set; }
+        public Action? GotInputWhenDisabled { get; set; }
 
-        public void SetIcon(IWindowIconImpl icon)
+        public void SetIcon(IWindowIconImpl? icon)
         {
             if (icon != null)
             {
@@ -1218,7 +1230,7 @@ namespace Avalonia.X11
             );
         }
 
-        public IPopupPositioner PopupPositioner { get; }
+        public IPopupPositioner? PopupPositioner { get; }
 
         public void SetTransparencyLevelHint(WindowTransparencyLevel transparencyLevel) =>
             _transparencyHelper?.SetTransparencyRequest(transparencyLevel);
diff --git a/src/Browser/Avalonia.Browser/BrowserAppBuilder.cs b/src/Browser/Avalonia.Browser/BrowserAppBuilder.cs
index 32637b6d1b..9bb471005b 100644
--- a/src/Browser/Avalonia.Browser/BrowserAppBuilder.cs
+++ b/src/Browser/Avalonia.Browser/BrowserAppBuilder.cs
@@ -16,7 +16,7 @@ public class BrowserPlatformOptions
 public static class BrowserAppBuilder
 {
     /// <summary>
-    /// Configures browser backend, loads avalonia javascript modules and creates a single view lifetime from the passed <see cref="mainDivId"/> parameter.
+    /// Configures browser backend, loads avalonia javascript modules and creates a single view lifetime from the passed <see paramref="mainDivId"/> parameter.
     /// </summary>
     /// <param name="builder">Application builder.</param>
     /// <param name="mainDivId">ID of the html element where avalonia content should be rendered.</param>
diff --git a/src/Browser/Avalonia.Browser/Interop/GeneralHelpers.cs b/src/Browser/Avalonia.Browser/Interop/GeneralHelpers.cs
index 6e3b41c05b..67d1cfb776 100644
--- a/src/Browser/Avalonia.Browser/Interop/GeneralHelpers.cs
+++ b/src/Browser/Avalonia.Browser/Interop/GeneralHelpers.cs
@@ -1,4 +1,5 @@
 using System.Runtime.InteropServices.JavaScript;
+using System.Threading.Tasks;
 
 namespace Avalonia.Browser.Interop;
 
@@ -8,15 +9,22 @@ internal static partial class GeneralHelpers
     public static partial JSObject[] ItemsArrayAt(JSObject jsObject, string key);
     public static JSObject[] GetPropertyAsJSObjectArray(this JSObject jsObject, string key) => ItemsArrayAt(jsObject, key);
     
+    [JSImport("GeneralHelpers.itemAt", AvaloniaModule.MainModuleName)]
+    public static partial JSObject ItemAtInt(JSObject jsObject, int key);
+    public static JSObject GetArrayItem(this JSObject jsObject, int key) => ItemAtInt(jsObject, key);
+    
     [JSImport("GeneralHelpers.itemsArrayAt", AvaloniaModule.MainModuleName)]
     public static partial string[] ItemsArrayAtAsStrings(JSObject jsObject, string key);
     public static string[] GetPropertyAsStringArray(this JSObject jsObject, string key) => ItemsArrayAtAsStrings(jsObject, key);
     
     [JSImport("GeneralHelpers.callMethod", AvaloniaModule.MainModuleName)]
-    public static partial string IntCallMethodString(JSObject jsObject, string name);
+    public static partial string IntCallMethodStr(JSObject jsObject, string name);
+    [JSImport("GeneralHelpers.callMethod", AvaloniaModule.MainModuleName)]
+    public static partial string IntCallMethodStrStr(JSObject jsObject, string name, string arg1);
     [JSImport("GeneralHelpers.callMethod", AvaloniaModule.MainModuleName)]
-    public static partial string IntCallMethodStringString(JSObject jsObject, string name, string arg1);
+    public static partial Task<JSObject?> IntCallMethodPromiseObj(JSObject jsObject, string name);
 
-    public static string CallMethodString(this JSObject jsObject, string name) => IntCallMethodString(jsObject, name);
-    public static string CallMethodString(this JSObject jsObject, string name, string arg1) => IntCallMethodStringString(jsObject, name, arg1);
+    public static string CallMethodString(this JSObject jsObject, string name) => IntCallMethodStr(jsObject, name);
+    public static string CallMethodString(this JSObject jsObject, string name, string arg1) => IntCallMethodStrStr(jsObject, name, arg1);
+    public static Task<JSObject?> CallMethodObjectAsync(this JSObject jsObject, string name) => IntCallMethodPromiseObj(jsObject, name);
 }
diff --git a/src/Browser/Avalonia.Browser/Interop/StorageHelper.cs b/src/Browser/Avalonia.Browser/Interop/StorageHelper.cs
index 2d96ee8d1f..c56023c0f7 100644
--- a/src/Browser/Avalonia.Browser/Interop/StorageHelper.cs
+++ b/src/Browser/Avalonia.Browser/Interop/StorageHelper.cs
@@ -40,9 +40,9 @@ internal static partial class StorageHelper
     [JSImport("StorageItem.openRead", AvaloniaModule.StorageModuleName)]
     public static partial Task<JSObject> OpenRead(JSObject item);
 
-    [JSImport("StorageItem.getItems", AvaloniaModule.StorageModuleName)]
-    [return: JSMarshalAs<JSType.Promise<JSType.Object>>]
-    public static partial Task<JSObject?> GetItems(JSObject item);
+    [JSImport("StorageItem.getItemsIterator", AvaloniaModule.StorageModuleName)]
+    [return: JSMarshalAs<JSType.Object>]
+    public static partial JSObject? GetItemsIterator(JSObject item);
 
     [JSImport("StorageItems.itemsArray", AvaloniaModule.StorageModuleName)]
     public static partial JSObject[] ItemsArray(JSObject item);
@@ -52,4 +52,16 @@ internal static partial class StorageHelper
 
     [JSImport("StorageProvider.createAcceptType", AvaloniaModule.StorageModuleName)]
     public static partial JSObject CreateAcceptType(string description, string[] mimeTypes, string[]? extensions);
+
+    [JSImport("StorageProvider.deleteAsync", AvaloniaModule.StorageModuleName)]
+    public static partial Task DeleteAsync(JSObject fileHandle);
+    
+    [JSImport("StorageProvider.moveAsync", AvaloniaModule.StorageModuleName)]
+    public static partial Task<JSObject?> MoveAsync(JSObject fileHandle, JSObject destinationFolder);
+    
+    [JSImport("StorageProvider.createFile", AvaloniaModule.StorageModuleName)]
+    public static partial Task<JSObject?> CreateFile(JSObject folderHandle, string name);
+    
+    [JSImport("StorageProvider.createFolder", AvaloniaModule.StorageModuleName)]
+    public static partial Task<JSObject?> CreateFolder(JSObject folderHandle, string name);
 }
diff --git a/src/Browser/Avalonia.Browser/Storage/BrowserStorageProvider.cs b/src/Browser/Avalonia.Browser/Storage/BrowserStorageProvider.cs
index fc32b3b4f7..e6849f2fcc 100644
--- a/src/Browser/Avalonia.Browser/Storage/BrowserStorageProvider.cs
+++ b/src/Browser/Avalonia.Browser/Storage/BrowserStorageProvider.cs
@@ -199,6 +199,33 @@ internal abstract class JSStorageItem : IStorageBookmarkItem
         return Task.FromResult<IStorageFolder?>(null);
     }
 
+    public Task DeleteAsync()
+    {
+        return StorageHelper.DeleteAsync(FileHandle);
+    }
+
+    public async Task<IStorageItem?> MoveAsync(IStorageFolder destination)
+    {
+        if (destination is not JSStorageFolder folder)
+        {
+            throw new InvalidOperationException("Destination folder must be initialized the StorageProvider API.");
+        }
+
+        var storageItem = await StorageHelper.MoveAsync(FileHandle, folder.FileHandle);
+        if (storageItem is null)
+        {
+            return null;
+        }
+
+        var kind = storageItem.GetPropertyAsString("kind");
+        return kind switch
+        {
+            "directory" => new JSStorageFolder(storageItem),
+            "file" => new JSStorageFile(storageItem),
+            _ => this
+        };
+    }
+
     public Task ReleaseBookmarkAsync()
     {
         if (!CanBookmark)
@@ -258,24 +285,81 @@ internal class JSStorageFolder : JSStorageItem, IStorageBookmarkFolder
     {
     }
 
-    public async Task<IReadOnlyList<IStorageItem>> GetItemsAsync()
+    public async IAsyncEnumerable<IStorageItem> GetItemsAsync()
     {
-        using var items = await StorageHelper.GetItems(FileHandle);
-        if (items is null)
+        using var itemsIterator = StorageHelper.GetItemsIterator(FileHandle);
+        if (itemsIterator is null)
         {
-            return Array.Empty<IStorageItem>();
+            yield break;
         }
 
-        var itemsArray = StorageHelper.ItemsArray(items);
+        while (true)
+        {
+            var nextResult = await itemsIterator.CallMethodObjectAsync("next");
+            if (nextResult is null)
+            {
+                yield break;
+            }
+
+            var isDone = nextResult.GetPropertyAsBoolean("done");
+            if (isDone)
+            {
+                yield break;
+            }
 
-        return itemsArray
-            .Select(reference => reference.GetPropertyAsString("kind") switch
+            var valArray = nextResult.GetPropertyAsJSObject("value");
+            var storageItem = valArray?.GetArrayItem(1); // 0 - item name, 1 - item instance
+            if (storageItem is null)
             {
-                "directory" => (IStorageItem)new JSStorageFolder(reference),
-                "file" => new JSStorageFile(reference),
-                _ => null
-            })
-            .Where(i => i is not null)
-            .ToArray()!;
+                yield break;
+            }
+
+            var kind = storageItem.GetPropertyAsString("kind");
+            switch (kind)
+            {
+                case "directory":
+                    yield return new JSStorageFolder(storageItem);
+                    break;
+                case "file":
+                    yield return new JSStorageFile(storageItem);
+                    break;
+            }
+        }
+    }
+
+    public async Task<IStorageFile?> CreateFileAsync(string name)
+    {
+        try
+        {
+            var storageFile = await StorageHelper.CreateFile(FileHandle, name);
+            if (storageFile is null)
+            {
+                return null;
+            }
+
+            return new JSStorageFile(storageFile);
+        }
+        catch (JSException ex) when (ex.Message == BrowserStorageProvider.NoPermissionsMessage)
+        {
+            throw new UnauthorizedAccessException("User denied permissions to open the file", ex);
+        }
+    }
+
+    public async Task<IStorageFolder?> CreateFolderAsync(string name)
+    {
+        try
+        {
+            var storageFile = await StorageHelper.CreateFolder(FileHandle, name);
+            if (storageFile is null)
+            {
+                return null;
+            }
+
+            return new JSStorageFolder(storageFile);
+        }
+        catch (JSException ex) when (ex.Message == BrowserStorageProvider.NoPermissionsMessage)
+        {
+            throw new UnauthorizedAccessException("User denied permissions to open the file", ex);
+        }
     }
 }
diff --git a/src/Browser/Avalonia.Browser/webapp/modules/avalonia/generalHelpers.ts b/src/Browser/Avalonia.Browser/webapp/modules/avalonia/generalHelpers.ts
index fa001006ab..31d167e38d 100644
--- a/src/Browser/Avalonia.Browser/webapp/modules/avalonia/generalHelpers.ts
+++ b/src/Browser/Avalonia.Browser/webapp/modules/avalonia/generalHelpers.ts
@@ -1,5 +1,5 @@
 export class GeneralHelpers {
-    public static itemsArrayAt(instance: any, key: string): any[] {
+    public static itemsArrayAt(instance: any, key: any): any[] {
         const items = instance[key];
         if (!items) {
             return [];
@@ -12,6 +12,11 @@ export class GeneralHelpers {
         return retItems;
     }
 
+    public static itemAt(instance: any, key: any): any {
+        const item = instance[key];
+        return item;
+    }
+
     public static callMethod(instance: any, name: string /*, args */): any {
         const args = Array.prototype.slice.call(arguments, 2);
         return instance[name].apply(instance, args);
diff --git a/src/Browser/Avalonia.Browser/webapp/modules/storage/storageItem.ts b/src/Browser/Avalonia.Browser/webapp/modules/storage/storageItem.ts
index f444717094..56833e448c 100644
--- a/src/Browser/Avalonia.Browser/webapp/modules/storage/storageItem.ts
+++ b/src/Browser/Avalonia.Browser/webapp/modules/storage/storageItem.ts
@@ -89,16 +89,55 @@ export class StorageItem {
         }
     }
 
-    public static async getItems(item: StorageItem): Promise<StorageItems> {
+    public static getItemsIterator(item: StorageItem): any | null {
         if (item.kind !== "directory" || !item.handle) {
-            return new StorageItems([]);
+            return null;
         }
 
-        const items: StorageItem[] = [];
-        for await (const [, value] of (item.handle as any).entries()) {
-            items.push(new StorageItem(value));
+        return (item.handle as any).entries();
+    }
+
+    public static async createFile(item: StorageItem, name: string): Promise<any | null> {
+        if (item.kind !== "directory" || !item.handle) {
+            throw new TypeError("Unable to create item in the requested directory");
         }
-        return new StorageItems(items);
+
+        await item.verityPermissions("readwrite");
+
+        return await ((item.handle as any).getFileHandle(name, { create: true }) as Promise<any>);
+    }
+
+    public static async createFolder(item: StorageItem, name: string): Promise<any | null> {
+        if (item.kind !== "directory" || !item.handle) {
+            throw new TypeError("Unable to create item in the requested directory");
+        }
+
+        await item.verityPermissions("readwrite");
+
+        return await ((item.handle as any).getDirectoryHandle(name, { create: true }) as Promise<any>);
+    }
+
+    public static async deleteAsync(item: StorageItem): Promise<any | null> {
+        if (!item.handle) {
+            return null;
+        }
+
+        await item.verityPermissions("readwrite");
+
+        return await ((item.handle as any).remove({ recursive: true }) as Promise<any>);
+    }
+
+    public static async moveAsync(item: StorageItem, destination: StorageItem): Promise<any | null> {
+        if (!item.handle) {
+            return null;
+        }
+        if (destination.kind !== "directory" || !destination.handle) {
+            throw new TypeError("Unable to move item to the requested directory");
+        }
+
+        await item.verityPermissions("readwrite");
+
+        return await ((item.handle as any).move(destination /*, newName */) as Promise<any>);
     }
 
     private async verityPermissions(mode: "read" | "readwrite"): Promise<void | never> {
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlDataContextTypeTransformer.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlDataContextTypeTransformer.cs
index a24d4eb6e9..681d2a38d4 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlDataContextTypeTransformer.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlDataContextTypeTransformer.cs
@@ -73,27 +73,32 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                     // Infer data type from collection binding on a control that displays items.
                     var property = context.ParentNodes().OfType<XamlPropertyAssignmentNode>().FirstOrDefault();
                     var attributeType = context.GetAvaloniaTypes().InheritDataTypeFromItemsAttribute;
-                    var attribute = property?.Property?.GetClrProperty().CustomAttributes
-                        .FirstOrDefault(a => a.Type == attributeType);
-    
-                    if (attribute is not null)
+                    var attributes = property?.Property?.GetClrProperty().CustomAttributes
+                        .Where(a => a.Type == attributeType).ToList();
+
+                    if (attributes?.Count > 0)
                     {
-                        var propertyName = (string)attribute.Parameters.First();
-                        XamlAstConstructableObjectNode parentObject;
-                        if (attribute.Properties.TryGetValue("AncestorType", out var type)
-                            && type is IXamlType xamlType)
-                        {
-                            parentObject = context.ParentNodes().OfType<XamlAstConstructableObjectNode>()
-                                .FirstOrDefault(n => n.Type.GetClrType().FullName == xamlType.FullName);
-                        }
-                        else
+                        foreach (var attribute in attributes)
                         {
-                            parentObject = context.ParentNodes().OfType<XamlAstConstructableObjectNode>().FirstOrDefault();
-                        }
-                            
-                        if (parentObject != null)
-                        {
-                            inferredDataContextTypeNode = InferDataContextOfPresentedItem(context, on, parentObject, propertyName);
+                            var propertyName = (string)attribute.Parameters.First();
+                            XamlAstConstructableObjectNode parentObject;
+                            if (attribute.Properties.TryGetValue("AncestorType", out var type)
+                                && type is IXamlType xamlType)
+                            {
+                                parentObject = context.ParentNodes().OfType<XamlAstConstructableObjectNode>()
+                                    .FirstOrDefault(n => n.Type.GetClrType().FullName == xamlType.FullName);
+                            }
+                            else
+                            {
+                                parentObject = context.ParentNodes().OfType<XamlAstConstructableObjectNode>().FirstOrDefault();
+                            }
+
+                            if (parentObject != null)
+                            {
+                                inferredDataContextTypeNode = InferDataContextOfPresentedItem(context, on, parentObject, propertyName);
+                                if (inferredDataContextTypeNode != null)
+                                    break;
+                            }
                         }
                     }
                     
diff --git a/src/Skia/Avalonia.Skia/DrawingContextImpl.cs b/src/Skia/Avalonia.Skia/DrawingContextImpl.cs
index e3e2f664c3..671e4d134c 100644
--- a/src/Skia/Avalonia.Skia/DrawingContextImpl.cs
+++ b/src/Skia/Avalonia.Skia/DrawingContextImpl.cs
@@ -375,7 +375,7 @@ namespace Avalonia.Skia
 
             foreach (var boxShadow in boxShadows)
             {
-                if (!boxShadow.IsDefault && !boxShadow.IsInset)
+                if (boxShadow != default && !boxShadow.IsInset)
                 {
                     using (var shadow = BoxShadowFilter.Create(_boxShadowPaint, boxShadow, _useOpacitySaveLayer ? 1 : _currentOpacity))
                     {
@@ -432,7 +432,7 @@ namespace Avalonia.Skia
 
             foreach (var boxShadow in boxShadows)
             {
-                if (!boxShadow.IsDefault && boxShadow.IsInset)
+                if (boxShadow != default && boxShadow.IsInset)
                 {
                     using (var shadow = BoxShadowFilter.Create(_boxShadowPaint, boxShadow, _useOpacitySaveLayer ? 1 : _currentOpacity))
                     {
diff --git a/src/Windows/Avalonia.Direct2D1/Media/DrawingContextImpl.cs b/src/Windows/Avalonia.Direct2D1/Media/DrawingContextImpl.cs
index 87fa963871..318b0fe9ae 100644
--- a/src/Windows/Avalonia.Direct2D1/Media/DrawingContextImpl.cs
+++ b/src/Windows/Avalonia.Direct2D1/Media/DrawingContextImpl.cs
@@ -29,7 +29,6 @@ namespace Avalonia.Direct2D1.Media
         /// <summary>
         /// Initializes a new instance of the <see cref="DrawingContextImpl"/> class.
         /// </summary>
-        /// <param name="visualBrushRenderer">The visual brush renderer.</param>
         /// <param name="renderTarget">The render target to draw to.</param>
         /// <param name="layerFactory">
         /// An object to use to create layers. May be null, in which case a
diff --git a/src/Windows/Avalonia.Win32/TrayIconImpl.cs b/src/Windows/Avalonia.Win32/TrayIconImpl.cs
index c19439c09e..05d9faa97b 100644
--- a/src/Windows/Avalonia.Win32/TrayIconImpl.cs
+++ b/src/Windows/Avalonia.Win32/TrayIconImpl.cs
@@ -150,7 +150,7 @@ namespace Avalonia.Win32
                 TransparencyLevelHint = WindowTransparencyLevel.Transparent,
                 Content = new TrayIconMenuFlyoutPresenter()
                 {
-                    Items = menuItems
+                    ItemsSource = menuItems
                 }
             };
 
diff --git a/src/Windows/Avalonia.Win32/Win32NativeToManagedMenuExporter.cs b/src/Windows/Avalonia.Win32/Win32NativeToManagedMenuExporter.cs
index 46cdf66653..ab4ec00b75 100644
--- a/src/Windows/Avalonia.Win32/Win32NativeToManagedMenuExporter.cs
+++ b/src/Windows/Avalonia.Win32/Win32NativeToManagedMenuExporter.cs
@@ -39,7 +39,7 @@ namespace Avalonia.Win32
 
                     if (item.Menu != null)
                     {
-                        newItem.Items = Populate(item.Menu);
+                        newItem.ItemsSource = Populate(item.Menu);
                     }
                     else if (item.HasClickHandlers && item is INativeMenuItemExporterEventsImplBridge bridge)
                     {
diff --git a/src/iOS/Avalonia.iOS/Storage/IOSStorageItem.cs b/src/iOS/Avalonia.iOS/Storage/IOSStorageItem.cs
index 27bd8faf64..7ab593e121 100644
--- a/src/iOS/Avalonia.iOS/Storage/IOSStorageItem.cs
+++ b/src/iOS/Avalonia.iOS/Storage/IOSStorageItem.cs
@@ -32,6 +32,7 @@ internal abstract class IOSStorageItem : IStorageBookmarkItem
     }
 
     internal NSUrl Url { get; }
+    internal string FilePath => _filePath;
 
     public bool CanBookmark => true;
 
@@ -54,6 +55,38 @@ internal abstract class IOSStorageItem : IStorageBookmarkItem
         return Task.FromResult<IStorageFolder?>(new IOSStorageFolder(Url.RemoveLastPathComponent()));
     }
 
+    public Task DeleteAsync()
+    {
+        return NSFileManager.DefaultManager.Remove(Url, out var error)
+            ? Task.CompletedTask
+            : Task.FromException(new NSErrorException(error));
+    }
+
+    public async Task<IStorageItem?> MoveAsync(IStorageFolder destination)
+    {
+        if (destination is not IOSStorageFolder folder)
+        {
+            throw new InvalidOperationException("Destination folder must be initialized the StorageProvider API.");
+        }
+
+        var isDir = this is IStorageFolder;
+        var newPath = new NSUrl(System.IO.Path.Combine(folder.FilePath, Name), isDir);
+
+        if (NSFileManager.DefaultManager.Move(folder.Url, newPath, out var error))
+        {
+            return isDir
+                ? new IOSStorageFolder(newPath)
+                : new IOSStorageFile(newPath);
+        }
+
+        if (error is not null)
+        {
+            throw new NSErrorException(error);
+        }
+
+        return null;
+    }
+
     public Task ReleaseBookmarkAsync()
     {
         // no-op
@@ -114,8 +147,9 @@ internal sealed class IOSStorageFolder : IOSStorageItem, IStorageBookmarkFolder
     {
     }
 
-    public async Task<IReadOnlyList<IStorageItem>> GetItemsAsync()
+    public async IAsyncEnumerable<IStorageItem> GetItemsAsync()
     {
+        // TODO: find out if it can be lazily enumerated.
         var tcs = new TaskCompletionSource<IReadOnlyList<IStorageItem>>();
 
         new NSFileCoordinator().CoordinateRead(Url,
@@ -142,6 +176,39 @@ internal sealed class IOSStorageFolder : IOSStorageItem, IStorageBookmarkFolder
             throw new NSErrorException(error);
         }
 
-        return await tcs.Task;
+        var items = await tcs.Task;
+        foreach (var item in items)
+        {
+            yield return item;
+        }
+    }
+
+    public Task<IStorageFile?> CreateFileAsync(string name)
+    {
+        var path = System.IO.Path.Combine(FilePath, name);
+        NSFileAttributes? attributes = null;
+        if (NSFileManager.DefaultManager.CreateFile(path, null, attributes))
+        {
+            return Task.FromResult<IStorageFile?>(new IOSStorageFile(new NSUrl(path, false)));
+        }
+
+        return Task.FromResult<IStorageFile?>(null);
+    }
+
+    public Task<IStorageFolder?> CreateFolderAsync(string name)
+    {
+        var path = System.IO.Path.Combine(FilePath, name);
+        NSFileAttributes? attributes = null;
+        if (NSFileManager.DefaultManager.CreateDirectory(path, false, attributes, out var error))
+        {
+            return Task.FromResult<IStorageFolder?>(new IOSStorageFolder(new NSUrl(path, true)));
+        }
+
+        if (error is not null)
+        {
+            throw new NSErrorException(error);
+        }
+        
+        return Task.FromResult<IStorageFolder?>(null);
     }
 }
diff --git a/src/tools/Avalonia.Generators/Avalonia.Generators.csproj b/src/tools/Avalonia.Generators/Avalonia.Generators.csproj
index 586caee605..4ebece583c 100644
--- a/src/tools/Avalonia.Generators/Avalonia.Generators.csproj
+++ b/src/tools/Avalonia.Generators/Avalonia.Generators.csproj
@@ -21,7 +21,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <None Include="Avalonia.Generators.props" Pack="true" PackagePath="buildTransitive/$(PackageId).props" />
     <None Include="$(OutputPath)\$(AssemblyName).dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false" />
   </ItemGroup>
 
diff --git a/tests/Avalonia.Base.UnitTests/AvaloniaPropertyTests.cs b/tests/Avalonia.Base.UnitTests/AvaloniaPropertyTests.cs
index 181596a681..bde750efdc 100644
--- a/tests/Avalonia.Base.UnitTests/AvaloniaPropertyTests.cs
+++ b/tests/Avalonia.Base.UnitTests/AvaloniaPropertyTests.cs
@@ -2,8 +2,6 @@ using System;
 using System.Collections.Generic;
 using Avalonia.Data;
 using Avalonia.PropertyStore;
-using Avalonia.Styling;
-using Avalonia.Utilities;
 using Xunit;
 
 namespace Avalonia.Base.UnitTests
@@ -29,7 +27,7 @@ namespace Avalonia.Base.UnitTests
         [Fact]
         public void GetMetadata_Returns_Supplied_Value()
         {
-            var metadata = new AvaloniaPropertyMetadata();
+            var metadata = new TestMetadata();
             var target = new TestProperty<string>("test", typeof(Class1), metadata);
 
             Assert.Same(metadata, target.GetMetadata<Class1>());
@@ -38,26 +36,30 @@ namespace Avalonia.Base.UnitTests
         [Fact]
         public void GetMetadata_Returns_Supplied_Value_For_Derived_Class()
         {
-            var metadata = new AvaloniaPropertyMetadata();
+            var metadata = new TestMetadata();
             var target = new TestProperty<string>("test", typeof(Class1), metadata);
 
             Assert.Same(metadata, target.GetMetadata<Class2>());
         }
 
         [Fact]
-        public void GetMetadata_Returns_Supplied_Value_For_Unrelated_Class()
+        public void GetMetadata_Returns_TypeSafe_Metadata_For_Unrelated_Class()
         {
-            var metadata = new AvaloniaPropertyMetadata();
+            var metadata = new TestMetadata(BindingMode.OneWayToSource, true, x => { _ = (StyledElement)x; });
             var target = new TestProperty<string>("test", typeof(Class3), metadata);
 
-            Assert.Same(metadata, target.GetMetadata<Class2>());
+            var targetMetadata = (TestMetadata)target.GetMetadata<Class2>();
+
+            Assert.Equal(metadata.DefaultBindingMode, targetMetadata.DefaultBindingMode);
+            Assert.Equal(metadata.EnableDataValidation, targetMetadata.EnableDataValidation);
+            Assert.Equal(null, targetMetadata.OwnerSpecificAction);
         }
 
         [Fact]
         public void GetMetadata_Returns_Overridden_Value()
         {
-            var metadata = new AvaloniaPropertyMetadata();
-            var overridden = new AvaloniaPropertyMetadata();
+            var metadata = new TestMetadata();
+            var overridden = new TestMetadata();
             var target = new TestProperty<string>("test", typeof(Class1), metadata);
 
             target.OverrideMetadata<Class2>(overridden);
@@ -68,9 +70,9 @@ namespace Avalonia.Base.UnitTests
         [Fact]
         public void OverrideMetadata_Should_Merge_Values()
         {
-            var metadata = new AvaloniaPropertyMetadata(BindingMode.TwoWay);
+            var metadata = new TestMetadata(BindingMode.TwoWay);
             var notify = (Action<AvaloniaObject, bool>)((a, b) => { });
-            var overridden = new AvaloniaPropertyMetadata();
+            var overridden = new TestMetadata();
             var target = new TestProperty<string>("test", typeof(Class1), metadata);
 
             target.OverrideMetadata<Class2>(overridden);
@@ -131,15 +133,31 @@ namespace Avalonia.Base.UnitTests
         [Fact]
         public void PropertyMetadata_BindingMode_Default_Returns_OneWay()
         {
-            var data = new AvaloniaPropertyMetadata(defaultBindingMode: BindingMode.Default);
+            var data = new TestMetadata(defaultBindingMode: BindingMode.Default);
 
             Assert.Equal(BindingMode.OneWay, data.DefaultBindingMode);
         }
 
+        private class TestMetadata : AvaloniaPropertyMetadata
+        {
+            public Action<AvaloniaObject> OwnerSpecificAction { get; }
+
+            public TestMetadata(BindingMode defaultBindingMode = BindingMode.Default, 
+                bool? enableDataValidation = null,
+                Action<AvaloniaObject> ownerSpecificAction = null) 
+                : base(defaultBindingMode, enableDataValidation)
+            {
+                OwnerSpecificAction = ownerSpecificAction;
+            }
+
+            public override AvaloniaPropertyMetadata GenerateTypeSafeMetadata() =>
+                new TestMetadata(DefaultBindingMode, EnableDataValidation, null);
+        }
+
         private class TestProperty<TValue> : AvaloniaProperty<TValue>
         {
-            public TestProperty(string name, Type ownerType, AvaloniaPropertyMetadata metadata = null)
-                : base(name, ownerType, metadata ?? new AvaloniaPropertyMetadata())
+            public TestProperty(string name, Type ownerType, TestMetadata metadata = null)
+                : base(name, ownerType, metadata ?? new TestMetadata())
             {
             }
 
diff --git a/tests/Avalonia.Base.UnitTests/Styling/SetterTests.cs b/tests/Avalonia.Base.UnitTests/Styling/SetterTests.cs
index 33023c4851..009a26ba18 100644
--- a/tests/Avalonia.Base.UnitTests/Styling/SetterTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Styling/SetterTests.cs
@@ -72,51 +72,51 @@ namespace Avalonia.Base.UnitTests.Styling
         [Fact]
         public void Can_Set_Direct_Property_In_Style_Without_Activator()
         {
-            var control = new TextBlock();
+            var control = new DirectPropertyClass();
             var target = new Setter();
-            var style = new Style(x => x.Is<TextBlock>())
+            var style = new Style(x => x.Is<DirectPropertyClass>())
             {
                 Setters =
                 {
-                    new Setter(TextBlock.TextProperty, "foo"),
+                    new Setter(DirectPropertyClass.FooProperty, "foo"),
                 }
             };
 
             Apply(style, control);
 
-            Assert.Equal("foo", control.Text);
+            Assert.Equal("foo", control.Foo);
         }
 
         [Fact]
         public void Can_Set_Direct_Property_Binding_In_Style_Without_Activator()
         {
-            var control = new TextBlock();
+            var control = new DirectPropertyClass();
             var target = new Setter();
             var source = new BehaviorSubject<object?>("foo");
-            var style = new Style(x => x.Is<TextBlock>())
+            var style = new Style(x => x.Is<DirectPropertyClass>())
             {
                 Setters =
                 {
-                    new Setter(TextBlock.TextProperty, source.ToBinding()),
+                    new Setter(DirectPropertyClass.FooProperty, source.ToBinding()),
                 }
             };
 
             Apply(style, control);
 
-            Assert.Equal("foo", control.Text);
+            Assert.Equal("foo", control.Foo);
         }
 
         [Fact]
         public void Cannot_Set_Direct_Property_Binding_In_Style_With_Activator()
         {
-            var control = new TextBlock();
+            var control = new DirectPropertyClass();
             var target = new Setter();
             var source = new BehaviorSubject<object?>("foo");
-            var style = new Style(x => x.Is<TextBlock>().Class("foo"))
+            var style = new Style(x => x.Is<DirectPropertyClass>().Class("foo"))
             {
                 Setters =
                 {
-                    new Setter(TextBlock.TextProperty, source.ToBinding()),
+                    new Setter(DirectPropertyClass.FooProperty, source.ToBinding()),
                 }
             };
 
@@ -126,13 +126,13 @@ namespace Avalonia.Base.UnitTests.Styling
         [Fact]
         public void Cannot_Set_Direct_Property_In_Style_With_Activator()
         {
-            var control = new TextBlock();
+            var control = new DirectPropertyClass();
             var target = new Setter();
-            var style = new Style(x => x.Is<TextBlock>().Class("foo"))
+            var style = new Style(x => x.Is<DirectPropertyClass>().Class("foo"))
             {
                 Setters =
                 {
-                    new Setter(TextBlock.TextProperty, "foo"),
+                    new Setter(DirectPropertyClass.FooProperty, "foo"),
                 }
             };
 
@@ -288,18 +288,18 @@ namespace Avalonia.Base.UnitTests.Styling
         {
             using var app = UnitTestApplication.Start(TestServices.MockThreadingInterface);
             var data = new Data { Foo = "foo" };
-            var control = new TextBox
+            var control = new DirectPropertyClass
             {
                 DataContext = data,
             };
 
-            var style = new Style(x => x.OfType<TextBox>())
+            var style = new Style(x => x.OfType<DirectPropertyClass>())
             {
                 Setters =
                 {
                     new Setter
                     {
-                        Property = TextBox.TextProperty,
+                        Property = DirectPropertyClass.FooProperty,
                         Value = new Binding
                         {
                             Path = "Foo",
@@ -310,9 +310,9 @@ namespace Avalonia.Base.UnitTests.Styling
             };
 
             Apply(style, control);
-            Assert.Equal("foo", control.Text);
+            Assert.Equal("foo", control.Foo);
 
-            control.Text = "bar";
+            control.Foo = "bar";
             Assert.Equal("bar", data.Foo);
         }
 
@@ -502,9 +502,9 @@ namespace Avalonia.Base.UnitTests.Styling
             Assert.Equal(Brushes.Blue, data.Bar);
         }
 
-        private void Apply(Style style, Control control)
+        private void Apply(Style style, StyledElement element)
         {
-            StyleHelpers.TryAttach(style, control);
+            StyleHelpers.TryAttach(style, element);
         }
 
         private void Apply(Setter setter, Control control)
@@ -535,5 +535,18 @@ namespace Avalonia.Base.UnitTests.Styling
                 throw new NotImplementedException();
             }
         }
+
+        private class DirectPropertyClass : StyledElement
+        {
+            public static readonly DirectProperty<DirectPropertyClass, string?> FooProperty = AvaloniaProperty.RegisterDirect<DirectPropertyClass, string?>(nameof(Foo),
+                x => x.Foo, (x, v) => x.Foo = v);
+            
+            private string? _foo;
+            public string? Foo
+            {
+                get => _foo;
+                set => SetAndRaise(FooProperty, ref _foo, value);
+            }
+        }
     }
 }
diff --git a/tests/Avalonia.Base.UnitTests/VisualTree/VisualExtensions_GetTransformedBounds.cs b/tests/Avalonia.Base.UnitTests/VisualTree/VisualExtensions_GetTransformedBounds.cs
new file mode 100644
index 0000000000..ba3c73e4c1
--- /dev/null
+++ b/tests/Avalonia.Base.UnitTests/VisualTree/VisualExtensions_GetTransformedBounds.cs
@@ -0,0 +1,153 @@
+using Avalonia.Controls;
+using Avalonia.Media;
+using Avalonia.VisualTree;
+using Xunit;
+
+namespace Avalonia.Base.UnitTests.VisualTree
+{
+    public class VisualExtensions_GetTransformedBounds
+    {
+        [Fact]
+        public void Root()
+        {
+            var root = new Border
+            {
+                Width = 100,
+                Height = 123,
+            };
+
+            Layout(root);
+
+            Assert.Equal(
+                new TransformedBounds(
+                    new Rect(0, 0, 100, 123),
+                    new Rect(0, 0, 100, 123),
+                    Matrix.Identity),
+                root.GetTransformedBounds());
+        }
+
+        [Fact]
+        public void Depth_1_No_Transform_Or_Clip()
+        {
+            Border target;
+            var root = new Border
+            {
+                Width = 1000,
+                Height = 1000,
+                Child = target = new Border
+                {
+                    Width = 500,
+                    Height = 500,
+                }
+            };
+
+            Layout(root);
+
+            Assert.Equal(
+                new TransformedBounds(
+                    new Rect(0, 0, 500, 500),
+                    new Rect(0, 0, 1000, 1000),
+                    Matrix.CreateTranslation(250, 250)),
+                target.GetTransformedBounds());
+        }
+
+        [Fact]
+        public void Depth_2_No_Transform_Or_Clip()
+        {
+            Border target;
+            var root = new Border
+            {
+                Width = 1000,
+                Height = 1000,
+                Child = new Border
+                {
+                    Width = 800,
+                    Height = 800,
+                    Child = target = new Border
+                    {
+                        Width = 500,
+                        Height = 500,
+                    }
+                }
+            };
+
+            Layout(root);
+
+            Assert.Equal(
+                new TransformedBounds(
+                    new Rect(0, 0, 500, 500),
+                    new Rect(0, 0, 1000, 1000),
+                    Matrix.CreateTranslation(250, 250)),
+                target.GetTransformedBounds());
+        }
+
+        [Fact]
+        public void Depth_2_No_Transform_With_Clip()
+        {
+            Border target;
+            var root = new Border
+            {
+                Width = 1000,
+                Height = 1000,
+                Child = new Border
+                {
+                    Width = 800,
+                    Height = 800,
+                    ClipToBounds = true,
+                    Child = target = new Border
+                    {
+                        Width = 500,
+                        Height = 500,
+                    }
+                }
+            };
+
+            Layout(root);
+
+            Assert.Equal(
+                new TransformedBounds(
+                    new Rect(0, 0, 500, 500),
+                    new Rect(100, 100, 800, 800),
+                    Matrix.CreateTranslation(250, 250)),
+                target.GetTransformedBounds());
+        }
+
+        [Fact]
+        public void Depth_2_Transformed_Clip()
+        {
+            Border target;
+            var root = new Border
+            {
+                Width = 1000,
+                Height = 1000,
+                Child = new Border
+                {
+                    Width = 800,
+                    Height = 800,
+                    ClipToBounds = true,
+                    RenderTransform = new MatrixTransform(Matrix.CreateTranslation(10, 20)),
+                    Child = target = new Border
+                    {
+                        Width = 500,
+                        Height = 500,
+                    }
+                }
+            };
+
+            Layout(root);
+
+            Assert.Equal(
+                new TransformedBounds(
+                    new Rect(0, 0, 500, 500),
+                    new Rect(110, 120, 800, 800),
+                    Matrix.CreateTranslation(260, 270)),
+                target.GetTransformedBounds());
+        }
+
+        private void Layout(Control c)
+        {
+            c.Measure(Size.Infinity);
+            c.Arrange(new Rect(c.DesiredSize));
+        }
+    }
+}
diff --git a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
index 2b043e0e48..c6237c2fa8 100644
--- a/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/CarouselTests.cs
@@ -23,7 +23,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new Carousel
             {
                 Template = CarouselTemplate(),
-                Items = new[]
+                ItemsSource = new[]
                 {
                     "Foo",
                     "Bar"
@@ -43,7 +43,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new Carousel
             {
                 Template = CarouselTemplate(),
-                Items = new[]
+                ItemsSource = new[]
                 {
                     "Foo",
                     "Bar"
@@ -73,7 +73,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new Carousel
             {
                 Template = CarouselTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             Prepare(target);
@@ -88,7 +88,7 @@ namespace Avalonia.Controls.UnitTests
             newItems.RemoveAt(0);
             Layout(target);
 
-            target.Items = newItems;
+            target.ItemsSource = newItems;
             Layout(target);
 
             child = GetContainerTextBlock(target.GetRealizedContainers().Single());
@@ -104,7 +104,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new Carousel
             {
                 Template = CarouselTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             Prepare(target);
@@ -133,7 +133,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new Carousel
             {
                 Template = CarouselTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             Prepare(target);
@@ -144,7 +144,7 @@ namespace Avalonia.Controls.UnitTests
 
             Assert.Equal("Foo", child.Text);
 
-            target.Items = null;
+            target.ItemsSource = null;
             Layout(target);
 
             var numChildren = target.GetRealizedContainers().Count();
@@ -166,7 +166,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new Carousel
             {
                 Template = CarouselTemplate(),
-                Items = items,
+                ItemsSource = items,
                 SelectedIndex = 2
             };
 
@@ -193,7 +193,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new Carousel
             {
                 Template = CarouselTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             Prepare(target);
@@ -225,7 +225,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new Carousel
             {
                 Template = CarouselTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             Prepare(target);
diff --git a/tests/Avalonia.Controls.UnitTests/ComboBoxTests.cs b/tests/Avalonia.Controls.UnitTests/ComboBoxTests.cs
index e206d809d3..9523d5db7f 100644
--- a/tests/Avalonia.Controls.UnitTests/ComboBoxTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ComboBoxTests.cs
@@ -23,7 +23,7 @@ namespace Avalonia.Controls.UnitTests
         {
             var target = new ComboBox
             {
-                Items = new[] { "Foo", "Bar" },
+                ItemsSource = new[] { "Foo", "Bar" },
             };
 
             _helper.Down(target);
@@ -43,7 +43,7 @@ namespace Avalonia.Controls.UnitTests
         {
             var target = new ComboBox
             {
-                Items = new[] { "Foo", "Bar" },
+                ItemsSource = new[] { "Foo", "Bar" },
             };
 
             _helper.Down(target);
@@ -66,15 +66,14 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.RealFocus))
             {
-                var items = new[]
-                {
-                    new ComboBoxItem() { Content = "bla" },
-                    new ComboBoxItem() { Content = "dd" },
-                    new ComboBoxItem() { Content = "sdf", IsEnabled = false }
-                };
                 var target = new ComboBox
                 {
-                    Items = items,
+                    Items =
+                    {
+                        new ComboBoxItem() { Content = "bla" },
+                        new ComboBoxItem() { Content = "dd" },
+                        new ComboBoxItem() { Content = "sdf", IsEnabled = false }
+                    },
                     Template = GetTemplate(),
                     WrapSelection = true
                 };
@@ -104,15 +103,14 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.RealFocus))
             {
-                var items = new[]
-                {
-                    new ComboBoxItem() { Content = "bla" },
-                    new ComboBoxItem() { Content = "dd", IsEnabled = false },
-                    new ComboBoxItem() { Content = "sdf" }
-                };
                 var target = new ComboBox
                 {
-                    Items = items,
+                    Items =
+                    {
+                        new ComboBoxItem() { Content = "bla" },
+                        new ComboBoxItem() { Content = "dd", IsEnabled = false },
+                        new ComboBoxItem() { Content = "sdf" }
+                    },
                     Template = GetTemplate()
                 };
                 var root = new TestRoot(target);
@@ -139,10 +137,9 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void SelectionBoxItem_Is_Rectangle_With_VisualBrush_When_Selection_Is_Control()
         {
-            var items = new[] { new Canvas() };
             var target = new ComboBox
             {
-                Items = items,
+                Items = { new Canvas() },
                 SelectedIndex = 0,
             };
             var root = new TestRoot(target);
@@ -152,7 +149,7 @@ namespace Avalonia.Controls.UnitTests
 
             var brush = rectangle.Fill as VisualBrush;
             Assert.NotNull(brush);
-            Assert.Same(items[0], brush.Visual);
+            Assert.Same(target.Items[0], brush.Visual);
         }
 
         [Fact]
@@ -160,7 +157,7 @@ namespace Avalonia.Controls.UnitTests
         {
             var target = new ComboBox
             {
-                Items = new[] { new Canvas() },
+                Items = { new Canvas() },
                 SelectedIndex = 0,
                 Template = GetTemplate(),
             };
@@ -218,7 +215,7 @@ namespace Avalonia.Controls.UnitTests
             {
                 var target = new ComboBox
                 {
-                    Items = new[] { new Canvas() },
+                    Items = { new Canvas() },
                     SelectedIndex = 0,
                     Template = GetTemplate(),
                 };
@@ -257,7 +254,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ComboBox
                 {
                     Template = GetTemplate(),                    
-                    Items = items.Select(x => new ComboBoxItem { Content = x })
+                    ItemsSource = items.Select(x => new ComboBoxItem { Content = x })
                 };
 
                 target.ApplyTemplate();
@@ -326,7 +323,7 @@ namespace Avalonia.Controls.UnitTests
 
                 var target = new ComboBox
                 {
-                    Items = new[] { new Canvas() },
+                    Items = { new Canvas() },
                     SelectedIndex = 0,
                     Template = GetTemplate(),
                 };
@@ -363,17 +360,16 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void FlowDirection_Of_RectangleContent_Shuold_Be_LeftToRight()
         {
-            var items = new[]
-            {
-                new ComboBoxItem()
-                { 
-                    Content = new Control()
-                }
-            };
             var target = new ComboBox
             {
                 FlowDirection = FlowDirection.RightToLeft,
-                Items = items,
+                Items =
+                {
+                    new ComboBoxItem()
+                    {
+                        Content = new Control()
+                    }
+                },
                 Template = GetTemplate()
             };
 
@@ -393,16 +389,15 @@ namespace Avalonia.Controls.UnitTests
             {
                 Child = new Control()
             };
-            var items = new[]
-            { 
-                new ComboBoxItem()
-                {
-                    Content = parentContent.Child
-                }
-            };
             var target = new ComboBox
             {
-                Items = items,
+                Items = 
+                {
+                    new ComboBoxItem()
+                    {
+                        Content = parentContent.Child
+                    }
+                },
                 Template = GetTemplate()
             };
 
@@ -428,17 +423,16 @@ namespace Avalonia.Controls.UnitTests
                 {
                     Child = new Control()
                 };
-                var items = new[]
-                { 
-                    new ComboBoxItem()
-                    {
-                        Content = parentContent.Child
-                    }
-                };
                 var target = new ComboBox
                 {
                     FlowDirection = FlowDirection.RightToLeft,
-                    Items = items,
+                    Items =
+                    {
+                        new ComboBoxItem()
+                        {
+                            Content = parentContent.Child
+                        }
+                    },
                     Template = GetTemplate()
                 };
 
diff --git a/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs b/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
index d99c90cb77..803cc793fd 100644
--- a/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
@@ -303,7 +303,7 @@ namespace Avalonia.Controls.UnitTests
                 window.Show();
 
                 var c = new ContextMenu();
-                c.PlacementMode = PlacementMode.Bottom;
+                c.Placement = PlacementMode.Bottom;
                 c.Open(button);
 
                 var overlay = LightDismissOverlayLayer.GetLightDismissOverlayLayer(window);
diff --git a/tests/Avalonia.Controls.UnitTests/ItemsControlTests.cs b/tests/Avalonia.Controls.UnitTests/ItemsControlTests.cs
index 7b5aa83b46..41aaa7b670 100644
--- a/tests/Avalonia.Controls.UnitTests/ItemsControlTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ItemsControlTests.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Collections.Specialized;
 using System.Linq;
@@ -16,6 +17,46 @@ namespace Avalonia.Controls.UnitTests
 {
     public class ItemsControlTests
     {
+        [Fact]
+        public void Setting_ItemsSource_Should_Populate_Items()
+        {
+            var target = new ItemsControl
+            {
+                Template = GetTemplate(),
+                ItemTemplate = new FuncDataTemplate<string>((_, __) => new Canvas()),
+                ItemsSource = new[] { "foo", "bar" },
+            };
+
+            Assert.NotSame(target.ItemsSource, target.Items);
+            Assert.Equal(target.ItemsSource, target.Items);
+        }
+
+        [Fact]
+        public void Cannot_Set_ItemsSource_With_Items_Present()
+        {
+            var target = new ItemsControl
+            {
+                Template = GetTemplate(),
+                ItemTemplate = new FuncDataTemplate<string>((_, __) => new Canvas()),
+                Items = { "foo", "bar" },
+            };
+
+            Assert.Throws<InvalidOperationException>(() => target.ItemsSource = new[] { "baz" });
+        }
+
+        [Fact]
+        public void Cannot_Modify_Items_When_ItemsSource_Set()
+        {
+            var target = new ItemsControl
+            {
+                Template = GetTemplate(),
+                ItemTemplate = new FuncDataTemplate<string>((_, __) => new Canvas()),
+                ItemsSource = Array.Empty<string>(),
+            };
+
+            Assert.Throws<InvalidOperationException>(() => target.Items.Add("foo"));
+        }
+
         [Fact]
         public void Should_Use_ItemTemplate_To_Create_Control()
         {
@@ -25,7 +66,7 @@ namespace Avalonia.Controls.UnitTests
                 ItemTemplate = new FuncDataTemplate<string>((_, __) => new Canvas()),
             };
 
-            target.Items = new[] { "Foo" };
+            target.ItemsSource = new[] { "Foo" };
             target.ApplyTemplate();
             target.Presenter.ApplyTemplate();
 
@@ -44,7 +85,7 @@ namespace Avalonia.Controls.UnitTests
                 ItemTemplate = new FuncDataTemplate<string>((_, __) => new Canvas()),
             };
 
-            target.Items = new[] { "Foo" };
+            target.ItemsSource = new[] { "Foo" };
             target.ApplyTemplate();
             target.Presenter.ApplyTemplate();
 
@@ -66,7 +107,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl();
 
             target.Template = GetTemplate();
-            target.Items = new[] { "Foo" };
+            target.ItemsSource = new[] { "Foo" };
             target.ApplyTemplate();
             target.Presenter.ApplyTemplate();
 
@@ -79,7 +120,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl();
 
             target.Template = GetTemplate();
-            target.Items = new[] { "Foo" };
+            target.ItemsSource = new[] { "Foo" };
             target.ApplyTemplate();
             target.Presenter!.ApplyTemplate();
 
@@ -92,7 +133,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl();
 
             target.Template = GetTemplate();
-            target.Items = new[] { "Foo" };
+            target.ItemsSource = new[] { "Foo" };
             target.ApplyTemplate();
             target.Presenter.ApplyTemplate();
 
@@ -111,7 +152,7 @@ namespace Avalonia.Controls.UnitTests
             };
 
             target.Template = GetTemplate();
-            target.Items = new[] { "Foo" };
+            target.ItemsSource = new[] { "Foo" };
             target.ApplyTemplate();
             target.Presenter.ApplyTemplate();
 
@@ -134,7 +175,7 @@ namespace Avalonia.Controls.UnitTests
                 target.TemplatedParent = templatedParent;
                 target.Template = GetTemplate();
 
-                target.Items = new[] { "Foo" };
+                target.ItemsSource = new[] { "Foo" };
 
                 root.ApplyTemplate();
                 target.ApplyTemplate();
@@ -153,7 +194,7 @@ namespace Avalonia.Controls.UnitTests
             var child = new Control();
 
             target.Template = GetTemplate();
-            target.Items = new[] { child };
+            target.Items.Add(child);
 
             Assert.Equal(child.Parent, target);
             Assert.Equal(child.GetLogicalParent(), target);
@@ -171,7 +212,7 @@ namespace Avalonia.Controls.UnitTests
             var child = new Control();
 
             target.Template = GetTemplate();
-            target.Items = new[] { child };
+            target.Items.Add(child);
             root.LayoutManager.ExecuteInitialLayoutPass();
 
             Assert.Equal(target, child.Parent);
@@ -188,7 +229,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl
             {
                 Template = GetTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             var root = new TestRoot(true, target);
@@ -206,11 +247,13 @@ namespace Avalonia.Controls.UnitTests
         {
             var target = new ItemsControl();
             var child = new Control();
-            var items = new AvaloniaList<Control>(child);
 
             target.Template = GetTemplate();
-            target.Items = items;
-            items.RemoveAt(0);
+            target.Items.Add(child);
+
+            Assert.Single(target.GetLogicalChildren());
+
+            target.Items.RemoveAt(0);
 
             Assert.Null(child.Parent);
             Assert.Null(child.GetLogicalParent());
@@ -224,151 +267,127 @@ namespace Avalonia.Controls.UnitTests
             var child = new Control();
 
             target.Template = GetTemplate();
-            target.Items = new[] { child };
-            target.Items = null;
-
-            Assert.Null(child.Parent);
-            Assert.Null(((ILogical)child).LogicalParent);
-        }
+            target.Items.Add(child);
 
-        [Fact]
-        public void Clearing_Items_Should_Clear_Child_Controls_Parent()
-        {
-            var target = new ItemsControl();
-            var child = new Control();
+            Assert.Single(target.GetLogicalChildren());
 
-            target.Template = GetTemplate();
-            target.Items = new[] { child };
-            target.ApplyTemplate();
-            target.Items = null;
+            target.Items.Clear();
 
             Assert.Null(child.Parent);
             Assert.Null(((ILogical)child).LogicalParent);
         }
 
         [Fact]
-        public void Adding_Control_Item_Should_Make_Control_Appear_In_LogicalChildren()
+        public void Assigning_ItemsSource_Should_Not_Fire_LogicalChildren_CollectionChanged_Before_ApplyTemplate()
         {
             var target = new ItemsControl();
             var child = new Control();
+            var called = false;
 
-            target.Template = GetTemplate();
-            target.Items = new[] { child };
-
-            // Should appear both before and after applying template.
-            Assert.Equal(new ILogical[] { child }, target.GetLogicalChildren());
+            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) => called = true;
 
-            target.ApplyTemplate();
+            var list = new AvaloniaList<Control>(new[] { child });
+            target.ItemsSource = list;
 
-            Assert.Equal(new ILogical[] { child }, target.GetLogicalChildren());
+            Assert.False(called);
         }
 
         [Fact]
-        public void Adding_String_Item_Should_Make_ContentPresenter_Appear_In_LogicalChildren()
+        public void Changing_ItemsSource_Should_Not_Fire_LogicalChildren_CollectionChanged_Before_ApplyTemplate()
         {
             var target = new ItemsControl();
             var child = new Control();
+            var called = false;
 
-            target.Template = GetTemplate();
-            target.Items = new[] { "Foo" };
-            target.ApplyTemplate();
-            target.Presenter.ApplyTemplate();
+            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) => called = true;
 
-            var logical = (ILogical)target;
-            Assert.Equal(1, logical.LogicalChildren.Count);
-            Assert.IsType<ContentPresenter>(logical.LogicalChildren[0]);
+            var list = new AvaloniaList<Control>();
+            target.ItemsSource = list;
+            list.Add(child);
+
+            Assert.False(called);
         }
 
         [Fact]
-        public void Setting_Items_To_Null_Should_Remove_LogicalChildren()
+        public void Clearing_Items_Should_Clear_Child_Controls_Parent()
         {
             var target = new ItemsControl();
             var child = new Control();
 
             target.Template = GetTemplate();
-            target.Items = new[] { "Foo" };
+            target.Items.Add(child);
             target.ApplyTemplate();
-            target.Presenter.ApplyTemplate();
-
-            Assert.NotEmpty(target.GetLogicalChildren());
-
-            target.Items = null;
+            target.Items.Clear();
 
-            Assert.Equal(new ILogical[0], target.GetLogicalChildren());
+            Assert.Null(child.Parent);
+            Assert.Null(((ILogical)child).LogicalParent);
         }
 
-
         [Fact]
-        public void Setting_Items_Should_Fire_LogicalChildren_CollectionChanged()
+        public void Adding_Control_Item_Should_Make_Control_Appear_In_LogicalChildren()
         {
             var target = new ItemsControl();
             var child = new Control();
-            var called = false;
 
             target.Template = GetTemplate();
-            target.ApplyTemplate();
+            target.Items.Add(child);
 
-            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) =>
-                called = e.Action == NotifyCollectionChangedAction.Add;
+            // Should appear both before and after applying template.
+            Assert.Equal(new ILogical[] { child }, target.GetLogicalChildren());
 
-            target.Items = new[] { child };
+            target.ApplyTemplate();
 
-            Assert.True(called);
+            Assert.Equal(new ILogical[] { child }, target.GetLogicalChildren());
         }
 
         [Fact]
-        public void Setting_Items_To_Null_Should_Fire_LogicalChildren_CollectionChanged()
+        public void Adding_String_Item_Should_Make_ContentPresenter_Appear_In_LogicalChildren()
         {
             var target = new ItemsControl();
-            var child = new Control();
-            var called = false;
 
             target.Template = GetTemplate();
-            target.Items = new[] { child };
+            target.ItemsSource = new[] { "Foo" };
             target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
 
-            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) =>
-                called = e.Action == NotifyCollectionChangedAction.Remove;
-
-            target.Items = null;
-
-            Assert.True(called);
+            var logical = (ILogical)target;
+            Assert.Equal(1, logical.LogicalChildren.Count);
+            Assert.IsType<ContentPresenter>(logical.LogicalChildren[0]);
         }
 
         [Fact]
-        public void Changing_Items_Should_Fire_LogicalChildren_CollectionChanged()
+        public void Adding_Items_Should_Fire_LogicalChildren_CollectionChanged()
         {
             var target = new ItemsControl();
             var child = new Control();
             var called = false;
 
             target.Template = GetTemplate();
-            target.Items = new[] { child };
             target.ApplyTemplate();
 
-            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) => called = true;
+            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) =>
+                called = e.Action == NotifyCollectionChangedAction.Add;
 
-            target.Items = new[] { "Foo" };
+            target.Items.Add(child);
 
             Assert.True(called);
         }
 
         [Fact]
-        public void Adding_Items_Should_Fire_LogicalChildren_CollectionChanged()
+        public void Clearing_Items_Should_Fire_LogicalChildren_CollectionChanged()
         {
             var target = new ItemsControl();
-            var items = new AvaloniaList<string> { "Foo" };
+            var child = new Control();
             var called = false;
 
             target.Template = GetTemplate();
-            target.Items = items;
+            target.Items.Add(child);
             target.ApplyTemplate();
-            target.Presenter.ApplyTemplate();
 
             ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) =>
-                called = e.Action == NotifyCollectionChangedAction.Add;
+                called = e.Action == NotifyCollectionChangedAction.Remove;
 
-            items.Add("Bar");
+            target.Items.Clear();
 
             Assert.True(called);
         }
@@ -381,16 +400,13 @@ namespace Avalonia.Controls.UnitTests
             var called = false;
 
             target.Template = GetTemplate();
-            target.Items = items;
-            target.ApplyTemplate();
-            target.Presenter.ApplyTemplate();
+            target.ItemsSource = items;
 
-            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) =>
-                called = e.Action == NotifyCollectionChangedAction.Remove;
+            ((ILogical)target).LogicalChildren.CollectionChanged += (s, e) => called = true;
 
             items.Remove("Bar");
 
-            Assert.True(called);
+            Assert.False(called);
         }
 
         [Fact]
@@ -418,7 +434,7 @@ namespace Avalonia.Controls.UnitTests
         {
             var target = new ItemsControl
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = GetTemplate(),
             };
 
@@ -451,7 +467,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl()
             {
                 Template = GetTemplate(),
-                Items = new[] { 1, 2, 3 },
+                ItemsSource = new[] { 1, 2, 3 },
             };
 
             Assert.DoesNotContain(":empty", target.Classes);
@@ -474,10 +490,10 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl()
             {
                 Template = GetTemplate(),
-                Items = new[] { 1, 2, 3 },
+                ItemsSource = new[] { 1, 2, 3 },
             };
 
-            target.Items = new int[0];
+            target.ItemsSource = new int[0];
 
             Assert.Contains(":empty", target.Classes);
         }
@@ -488,7 +504,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl()
             {
                 Template = GetTemplate(),
-                Items = new[] { 1, 2, 3 },
+                ItemsSource = new[] { 1, 2, 3 },
             };
 
             Assert.Equal(3, target.ItemCount);
@@ -502,7 +518,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl()
             {
                 Template = GetTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             items.Add(4);
@@ -522,7 +538,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl()
             {
                 Template = GetTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             items.Clear();
@@ -538,7 +554,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl()
             {
                 Template = GetTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             items.Add(1);
@@ -547,14 +563,14 @@ namespace Avalonia.Controls.UnitTests
         }
 
         [Fact]
-        public void Single_Item_Class_Should_Be_Set_When_Items_Collection_Count_Increases_To_One()
+        public void Single_Item_Class_Should_Be_Set_When_ItemsSource_Collection_Count_Increases_To_One()
         {
             var items = new ObservableCollection<int>() { };
 
             var target = new ItemsControl()
             {
                 Template = GetTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             items.Add(1);
@@ -570,7 +586,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl()
             {
                 Template = GetTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             items.Clear();
@@ -586,7 +602,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl()
             {
                 Template = GetTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             items.Add(2);
@@ -613,7 +629,7 @@ namespace Avalonia.Controls.UnitTests
                 {
                     new FuncDataTemplate<Item>((x, __) => new Button { Content = x })
                 },
-                Items = items,
+                ItemsSource = items,
             };
 
             target.ApplyTemplate();
@@ -641,7 +657,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl
             {
                 Template = GetTemplate(),
-                Items = items,
+                ItemsSource = items,
             };
 
             target.ApplyTemplate();
@@ -665,7 +681,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ItemsControl
                 {
                     Template = GetTemplate(),
-                    Items = items,
+                    ItemsSource = items,
                 };
 
                 var root = new TestRoot { Child = target };
@@ -701,7 +717,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ItemsControl
                 {
                     Template = GetTemplate(),
-                    Items = items,
+                    ItemsSource = items,
                 };
 
                 var root = new TestRoot { Child = target };
@@ -729,7 +745,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ItemsControl
             {
                 Template = GetTemplate(),
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 ItemTemplate = new FuncDataTemplate<string>((_, __) => new Canvas()),
             };
 
@@ -755,7 +771,7 @@ namespace Avalonia.Controls.UnitTests
                 DisplayMemberBinding = new Binding("Length")
             };
 
-            target.Items = new[] { "Foo" };
+            target.ItemsSource = new[] { "Foo" };
             target.ApplyTemplate();
             target.Presenter.ApplyTemplate();
 
@@ -774,7 +790,7 @@ namespace Avalonia.Controls.UnitTests
                 DisplayMemberBinding = new Binding("Value")
             };
 
-            target.Items = new[] { new Item("Foo", "Bar") };
+            target.ItemsSource = new[] { new Item("Foo", "Bar") };
             target.ApplyTemplate();
             target.Presenter.ApplyTemplate();
 
@@ -816,6 +832,135 @@ namespace Avalonia.Controls.UnitTests
             Assert.Throws<InvalidOperationException>(() => target.DisplayMemberBinding = new Binding("Length"));
         }
 
+        [Fact]
+        public void ContainerPrepared_Is_Raised_For_Each_Item_Container_On_Layout()
+        {
+            var target = new ItemsControl
+            {
+                Template = GetTemplate(),
+                Items = { "Foo", "Bar", "Baz" },
+            };
+
+            var result = new List<Control>();
+            var index = 0;
+
+            target.ContainerPrepared += (s, e) =>
+            {
+                Assert.Equal(index++, e.Index);
+                result.Add(e.Container);
+            };
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            Assert.Equal(3, result.Count);
+            Assert.Equal(target.GetRealizedContainers(), result);
+        }
+
+        [Fact]
+        public void ContainerPrepared_Is_Raised_For_Each_ItemsSource_Container_On_Layout()
+        {
+            var target = new ItemsControl
+            {
+                Template = GetTemplate(),
+                ItemsSource = new[] { "Foo", "Bar", "Baz" },
+            };
+
+            var result = new List<Control>();
+            var index = 0;
+
+            target.ContainerPrepared += (s, e) =>
+            {
+                Assert.Equal(index++, e.Index);
+                result.Add(e.Container);
+            };
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            Assert.Equal(3, result.Count);
+            Assert.Equal(target.GetRealizedContainers(), result);
+        }
+
+        [Fact]
+        public void ContainerPrepared_Is_Raised_For_Added_Item()
+        {
+            var target = new ItemsControl
+            {
+                Template = GetTemplate(),
+                Items = { "Foo", "Bar", "Baz" },
+            };
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            var result = new List<Control>();
+
+            target.ContainerPrepared += (s, e) =>
+            {
+                Assert.Equal(3, e.Index);
+                result.Add(e.Container);
+            };
+
+            target.Items.Add("Qux");
+
+            Assert.Equal(1, result.Count);
+        }
+
+        [Fact]
+        public void ContainerIndexChanged_Is_Raised_When_Item_Added()
+        {
+            var target = new ItemsControl
+            {
+                Template = GetTemplate(),
+                Items = { "Foo", "Bar", "Baz" },
+            };
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            var result = new List<Control>();
+            var index = 1;
+
+            target.ContainerIndexChanged += (s, e) =>
+            {
+                Assert.Equal(index++, e.OldIndex);
+                Assert.Equal(index, e.NewIndex);
+                result.Add(e.Container);
+            };
+
+            target.Items.Insert(1, "Qux");
+
+            Assert.Equal(2, result.Count);
+            Assert.Equal(target.GetRealizedContainers().Skip(2), result);
+        }
+
+        [Fact]
+        public void ContainerClearing_Is_Raised_When_Item_Removed()
+        {
+            var target = new ItemsControl
+            {
+                Template = GetTemplate(),
+                Items = { "Foo", "Bar", "Baz" },
+            };
+
+            target.ApplyTemplate();
+            target.Presenter.ApplyTemplate();
+
+            var expected = target.ContainerFromIndex(1);
+            var raised = 0;
+
+            target.ContainerClearing += (s, e) =>
+            {
+                Assert.Same(expected, e.Container);
+                ++raised;
+            };
+
+            target.Items.RemoveAt(1);
+
+            Assert.Equal(1, raised);
+        }
+
         private class Item
         {
             public Item(string value)
diff --git a/tests/Avalonia.Controls.UnitTests/ItemsSourceViewTests.cs b/tests/Avalonia.Controls.UnitTests/ItemsSourceViewTests.cs
index df842b21a7..faa143bb8e 100644
--- a/tests/Avalonia.Controls.UnitTests/ItemsSourceViewTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ItemsSourceViewTests.cs
@@ -38,6 +38,35 @@ namespace Avalonia.Controls.UnitTests
             Assert.Throws<ArgumentException>(() => ItemsSourceView.GetOrCreate(source));
         }
 
+        [Fact]
+        public void Reassigning_Source_Unsubscribes_From_Previous_Source()
+        {
+            var source = new AvaloniaList<string>();
+            var target = new ReassignableItemsSourceView(source);
+            var debug = (INotifyCollectionChangedDebug)source;
+
+            target.CollectionChanged += (s, e) => { };
+
+            Assert.Equal(1, debug.GetCollectionChangedSubscribers().Length);
+
+            target.SetSource(new string[0]);
+
+            Assert.Null(debug.GetCollectionChangedSubscribers());
+        }
+
+        [Fact]
+        public void Reassigning_Source_Subscribes_To_New_Source()
+        {
+            var source = new AvaloniaList<string>();
+            var target = new ReassignableItemsSourceView(new string[0]);
+            var debug = (INotifyCollectionChangedDebug)source;
+
+            target.CollectionChanged += (s, e) => { };
+            target.SetSource(source);
+
+            Assert.Equal(1, debug.GetCollectionChangedSubscribers().Length);
+        }
+
         private class InvalidCollection : INotifyCollectionChanged, IEnumerable<string>
         {
             public event NotifyCollectionChangedEventHandler CollectionChanged { add { } remove { } }
@@ -52,5 +81,15 @@ namespace Avalonia.Controls.UnitTests
                 yield break;
             }
         }
+
+        private class ReassignableItemsSourceView : ItemsSourceView
+        {
+            public ReassignableItemsSourceView(IEnumerable source)
+                : base(source)
+            {
+            }
+
+            public new void SetSource(IEnumerable source) => base.SetSource(source);
+        }
     }
 }
diff --git a/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs b/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs
index 8170545f68..f42185a59c 100644
--- a/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ListBoxTests.cs
@@ -29,7 +29,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ListBox
             {
                 Template = ListBoxTemplate(),
-                Items = new[] { "Foo" },
+                ItemsSource = new[] { "Foo" },
                 ItemTemplate = new FuncDataTemplate<string>((_, __) => new Canvas()),
             };
 
@@ -81,7 +81,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = ListBoxTemplate(),
-                    Items = items,
+                    ItemsSource = items,
                 };
 
                 Prepare(target);
@@ -107,7 +107,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = ListBoxTemplate(),
-                    Items = items,
+                    ItemsSource = items,
                     ItemContainerTheme = theme,
                 };
 
@@ -124,12 +124,11 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface))
             {
-                var items = new[] { "Foo", "Bar", "Baz " };
                 var theme = new ControlTheme(typeof(ListBoxItem));
                 var target = new ListBox
                 {
                     Template = ListBoxTemplate(),
-                    Items = new[] { new ListBoxItem() },
+                    Items = { new ListBoxItem() },
                     ItemContainerTheme = theme,
                 };
 
@@ -149,7 +148,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = ListBoxTemplate(),
-                    Items = new[] { "Foo", "Bar", "Baz " },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz " },
                 };
 
                 Prepare(target);
@@ -184,7 +183,7 @@ namespace Avalonia.Controls.UnitTests
                     {
                         new FuncDataTemplate<Item>((x, _) => new Button { Content = x })
                     },
-                    Items = items,
+                    ItemsSource = items,
                 };
 
                 Prepare(target);
@@ -208,7 +207,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = ListBoxTemplate(),
-                    Items = Enumerable.Range(0, 20).Select(x => $"Item {x}").ToList(),
+                    ItemsSource = Enumerable.Range(0, 20).Select(x => $"Item {x}").ToList(),
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Height = 10 }),
                     SelectedIndex = 0,
                 };
@@ -236,7 +235,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = ListBoxTemplate(),
-                    Items = Enumerable.Range(0, 20).Select(x => $"Item {x}").ToList(),
+                    ItemsSource = Enumerable.Range(0, 20).Select(x => $"Item {x}").ToList(),
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Width = 20, Height = 10 }),
                     SelectedIndex = 0,
                 };
@@ -258,7 +257,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = ListBoxTemplate(),
-                    Items = items,
+                    ItemsSource = items,
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Width = 20, Height = 10 }),
                     SelectedIndex = 0,
                 };
@@ -272,7 +271,7 @@ namespace Avalonia.Controls.UnitTests
                 items.Remove("Item 2");
                 Layout(target);
 
-                var actual = target.Presenter.Panel.Children.Cast<ListBoxItem>().Select(x => (string)x.Content).ToList();
+                var actual = target.GetRealizedContainers().Cast<ListBoxItem>().Select(x => (string)x.Content).ToList();
                 Assert.Equal(items.OrderBy(x => x), actual.OrderBy(x => x));
             }
         }
@@ -286,7 +285,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = ListBoxTemplate(),
-                    Items = items,
+                    ItemsSource = items,
                     SelectionMode = SelectionMode.Toggle,
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Height = 10 })
                 };
@@ -318,7 +317,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = ListBoxTemplate(),
-                    Items = items,
+                    ItemsSource = items,
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Height = 10 })
                 };
 
@@ -364,7 +363,7 @@ namespace Avalonia.Controls.UnitTests
 
                 lm.ExecuteInitialLayoutPass();
 
-                target.Items = items;
+                target.ItemsSource = items;
 
                 lm.ExecuteLayoutPass();
 
@@ -415,7 +414,7 @@ namespace Avalonia.Controls.UnitTests
                     Height = 100,
                     Width = 50,
                     ItemTemplate = new FuncDataTemplate<object>((c, _) => new Border() { Height = 10 }),
-                    Items = items,
+                    ItemsSource = items,
                 };
                 wnd.Content = target;
 
@@ -450,7 +449,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = ListBoxTemplate(),
-                    Items = items,
+                    ItemsSource = items,
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Height = 10 }),
                     SelectionMode = SelectionMode.AlwaysSelected,
                 };
@@ -497,7 +496,7 @@ namespace Avalonia.Controls.UnitTests
                     AutoScrollToSelectedItem = true,
                     Width = 50,
                     ItemTemplate = new FuncDataTemplate<object>((c, _) => new Border() { Height = 10 }),
-                    Items = items,
+                    ItemsSource = items,
                 };
                 wnd.Content = target;
 
@@ -533,7 +532,7 @@ namespace Avalonia.Controls.UnitTests
         {
             var target = new ListBox
             {
-                [!ListBox.ItemsProperty] = new Binding("Items"),
+                [!ListBox.ItemsSourceProperty] = new Binding("Items"),
                 [!ListBox.SelectedItemsProperty] = new Binding("SelectedItems"),
             };
 
@@ -650,7 +649,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ListBox
             {
                 Template = ListBoxTemplate(),
-                Items = new[] { "Foo" },
+                ItemsSource = new[] { "Foo" },
                 ItemTemplate = new FuncDataTemplate<string>((_, __) => new Canvas()),
                 SelectionMode = SelectionMode.AlwaysSelected,
             };
@@ -672,7 +671,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ListBox
             {
                 Template = ListBoxTemplate(),
-                Items = items,
+                ItemsSource = items,
                 ItemTemplate = new FuncDataTemplate<string>((_, __) => new Canvas { Height = 10 }),
             };
 
@@ -703,7 +702,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ListBox
             {
                 Template = ListBoxTemplate(),
-                Items = items,
+                ItemsSource = items,
                 ItemTemplate = new FuncDataTemplate<string>((_, __) => new Canvas { Height = 10 }),
                 AutoScrollToSelectedItem = true,
                 SelectedIndex = 1,
@@ -749,7 +748,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = ListBoxTemplate(),
-                    Items = items,
+                    ItemsSource = items,
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Height = 10 }),
                     WrapSelection = true
                 };
@@ -786,6 +785,146 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
+        [Fact]
+        public void ContainerPrepared_Is_Raised_For_Each_Item_Container_On_Layout()
+        {
+            using var app = UnitTestApplication.Start(TestServices.MockPlatformRenderInterface);
+
+            var target = new ListBox
+            {
+                Template = ListBoxTemplate(),
+                Items = { "Foo", "Bar", "Baz" },
+            };
+
+            var result = new List<Control>();
+            var index = 0;
+
+            target.ContainerPrepared += (s, e) =>
+            {
+                Assert.Equal(index++, e.Index);
+                result.Add(e.Container);
+            };
+
+            Prepare(target);
+
+            Assert.Equal(3, result.Count);
+            Assert.Equal(target.GetRealizedContainers(), result);
+        }
+
+        [Fact]
+        public void ContainerPrepared_Is_Raised_For_Each_ItemsSource_Container_On_Layout()
+        {
+            using var app = UnitTestApplication.Start(TestServices.MockPlatformRenderInterface);
+
+            var target = new ListBox
+            {
+                Template = ListBoxTemplate(),
+                ItemsSource = new[] { "Foo", "Bar", "Baz" },
+            };
+
+            var result = new List<Control>();
+            var index = 0;
+
+            target.ContainerPrepared += (s, e) =>
+            {
+                Assert.Equal(index++, e.Index);
+                result.Add(e.Container);
+            };
+
+            Prepare(target);
+
+            Assert.Equal(3, result.Count);
+            Assert.Equal(target.GetRealizedContainers(), result);
+        }
+
+        [Fact]
+        public void ContainerPrepared_Is_Raised_For_Added_Item()
+        {
+            using var app = UnitTestApplication.Start(TestServices.MockPlatformRenderInterface);
+
+            var data = new AvaloniaList<string> { "Foo", "Bar", "Baz" };
+            var target = new ListBox
+            {
+                Template = ListBoxTemplate(),
+                ItemsSource = data,
+            };
+
+            Prepare(target);
+
+            var result = new List<Control>();
+
+            target.ContainerPrepared += (s, e) =>
+            {
+                Assert.Equal(3, e.Index);
+                result.Add(e.Container);
+            };
+
+            data.Add("Qux");
+            Layout(target);
+
+            Assert.Equal(1, result.Count);
+        }
+
+        [Fact]
+        public void ContainerIndexChanged_Is_Raised_When_Item_Added()
+        {
+            using var app = UnitTestApplication.Start(TestServices.MockPlatformRenderInterface);
+
+            var data = new AvaloniaList<string> { "Foo", "Bar", "Baz" };
+            var target = new ListBox
+            {
+                Template = ListBoxTemplate(),
+                ItemsSource = data,
+            };
+
+            Prepare(target);
+
+            var result = new List<Control>();
+            var index = 1;
+
+            target.ContainerIndexChanged += (s, e) =>
+            {
+                Assert.Equal(index++, e.OldIndex);
+                Assert.Equal(index, e.NewIndex);
+                result.Add(e.Container);
+            };
+
+            data.Insert(1, "Qux");
+            Layout(target);
+
+            Assert.Equal(2, result.Count);
+            Assert.Equal(target.GetRealizedContainers().Skip(2), result);
+        }
+
+        [Fact]
+        public void ContainerClearing_Is_Raised_When_Item_Removed()
+        {
+            using var app = UnitTestApplication.Start(TestServices.MockPlatformRenderInterface);
+
+            var data = new AvaloniaList<string> { "Foo", "Bar", "Baz" };
+            var target = new ListBox
+            {
+                Template = ListBoxTemplate(),
+                ItemsSource = data,
+            };
+
+            Prepare(target);
+
+            var expected = target.ContainerFromIndex(1);
+            var raised = 0;
+
+            target.ContainerClearing += (s, e) =>
+            {
+                Assert.Same(expected, e.Container);
+                ++raised;
+            };
+
+            data.RemoveAt(1);
+            Layout(target);
+
+            Assert.Equal(1, raised);
+        }
+
         private class ResettingCollection : List<string>, INotifyCollectionChanged
         {
             public ResettingCollection(int itemCount)
diff --git a/tests/Avalonia.Controls.UnitTests/ListBoxTests_Multiple.cs b/tests/Avalonia.Controls.UnitTests/ListBoxTests_Multiple.cs
index 942eb8bf5b..7a724b070e 100644
--- a/tests/Avalonia.Controls.UnitTests/ListBoxTests_Multiple.cs
+++ b/tests/Avalonia.Controls.UnitTests/ListBoxTests_Multiple.cs
@@ -18,7 +18,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ListBox
             {
                 Template = new FuncControlTemplate(CreateListBoxTemplate),
-                Items = new[] { "Foo", "Bar", "Baz " },
+                ItemsSource = new[] { "Foo", "Bar", "Baz " },
                 SelectionMode = SelectionMode.Multiple
             };
 
@@ -41,7 +41,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ListBox
             {
                 Template = new FuncControlTemplate(CreateListBoxTemplate),
-                Items = new[] { "Foo", "Bar", "Baz " },
+                ItemsSource = new[] { "Foo", "Bar", "Baz " },
                 SelectionMode = SelectionMode.Multiple
             };
 
@@ -64,7 +64,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ListBox
             {
                 Template = new FuncControlTemplate(CreateListBoxTemplate),
-                Items = new[] { "Foo", "Bar", "Baz " },
+                ItemsSource = new[] { "Foo", "Bar", "Baz " },
                 SelectionMode = SelectionMode.Multiple
             };
 
diff --git a/tests/Avalonia.Controls.UnitTests/ListBoxTests_Single.cs b/tests/Avalonia.Controls.UnitTests/ListBoxTests_Single.cs
index 131642fc4e..5551d1c7df 100644
--- a/tests/Avalonia.Controls.UnitTests/ListBoxTests_Single.cs
+++ b/tests/Avalonia.Controls.UnitTests/ListBoxTests_Single.cs
@@ -26,7 +26,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ListBox
             {
                 Template = new FuncControlTemplate(CreateListBoxTemplate),
-                Items = new[] { "Foo", "Bar", "Baz " },
+                ItemsSource = new[] { "Foo", "Bar", "Baz " },
             };
 
             ApplyTemplate(target);
@@ -45,7 +45,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ListBox
             {
                 Template = new FuncControlTemplate(CreateListBoxTemplate),
-                Items = new[] { "Foo", "Bar", "Baz " },
+                ItemsSource = new[] { "Foo", "Bar", "Baz " },
             };
 
             ApplyTemplate(target);
@@ -64,7 +64,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ListBox
             {
                 Template = new FuncControlTemplate(CreateListBoxTemplate),
-                Items = new[] { "Foo", "Bar", "Baz " },
+                ItemsSource = new[] { "Foo", "Bar", "Baz " },
             };
 
             ApplyTemplate(target);
@@ -86,7 +86,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = new FuncControlTemplate(CreateListBoxTemplate),
-                    Items = new[] { "Foo", "Bar", "Baz " },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz " },
                 };
                 AvaloniaLocator.CurrentMutable.Bind<PlatformHotkeyConfiguration>().ToConstant(new Mock<PlatformHotkeyConfiguration>().Object);
                 ApplyTemplate(target);
@@ -116,7 +116,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = new FuncControlTemplate(CreateListBoxTemplate),
-                    Items = new[] { "Foo", "Bar", "Baz " },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz " },
                 };
                 AvaloniaLocator.CurrentMutable.Bind<PlatformHotkeyConfiguration>().ToConstant(new Mock<PlatformHotkeyConfiguration>().Object);
                 ApplyTemplate(target);
@@ -134,7 +134,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = new FuncControlTemplate(CreateListBoxTemplate),
-                    Items = new[] { "Foo", "Bar", "Baz " },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz " },
                 };
                 AvaloniaLocator.CurrentMutable.Bind<PlatformHotkeyConfiguration>().ToConstant(new Mock<PlatformHotkeyConfiguration>().Object);
                 ApplyTemplate(target);
@@ -154,7 +154,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = new FuncControlTemplate(CreateListBoxTemplate),
-                    Items = new[] { "Foo", "Bar", "Baz " },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz " },
                     SelectionMode = SelectionMode.Single | SelectionMode.Toggle,
                 };
                 AvaloniaLocator.CurrentMutable.Bind<PlatformHotkeyConfiguration>().ToConstant(new Mock<PlatformHotkeyConfiguration>().Object);
@@ -174,7 +174,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = new FuncControlTemplate(CreateListBoxTemplate),
-                    Items = new[] { "Foo", "Bar", "Baz " },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz " },
                     SelectionMode = SelectionMode.Toggle,
                 };
 
@@ -196,7 +196,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = new FuncControlTemplate(CreateListBoxTemplate),
-                    Items = new[] { "Foo", "Bar", "Baz " },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz " },
                     SelectionMode = SelectionMode.Toggle | SelectionMode.AlwaysSelected,
                 };
                 AvaloniaLocator.CurrentMutable.Bind<PlatformHotkeyConfiguration>().ToConstant(new Mock<PlatformHotkeyConfiguration>().Object);
@@ -217,7 +217,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new ListBox
                 {
                     Template = new FuncControlTemplate(CreateListBoxTemplate),
-                    Items = new[] { "Foo", "Bar", "Baz " },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz " },
                     SelectionMode = SelectionMode.Single | SelectionMode.Toggle,
                 };
                 AvaloniaLocator.CurrentMutable.Bind<PlatformHotkeyConfiguration>().ToConstant(new Mock<PlatformHotkeyConfiguration>().Object);
@@ -236,7 +236,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new ListBox
             {
                 Template = new FuncControlTemplate(CreateListBoxTemplate),
-                Items = new[] { "Foo", "Bar", "Baz " },
+                ItemsSource = new[] { "Foo", "Bar", "Baz " },
             };
 
             ApplyTemplate(target);
@@ -259,7 +259,7 @@ namespace Avalonia.Controls.UnitTests
             {
                 Template = new FuncControlTemplate(CreateListBoxTemplate),
                 DataContext = viewModel,
-                Items = viewModel.Items
+                ItemsSource = viewModel.Items
             };
 
             target.Bind(ListBox.SelectedItemProperty,
diff --git a/tests/Avalonia.Controls.UnitTests/MenuItemTests.cs b/tests/Avalonia.Controls.UnitTests/MenuItemTests.cs
index e80ca17993..1049ff2678 100644
--- a/tests/Avalonia.Controls.UnitTests/MenuItemTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/MenuItemTests.cs
@@ -191,7 +191,7 @@ namespace Avalonia.Controls.UnitTests
                     return true;
                 });
                 var target = new MenuItem();
-                var contextMenu = new ContextMenu { Items = new AvaloniaList<MenuItem> { target } };
+                var contextMenu = new ContextMenu { Items = { target } };
                 var window = new Window { Content = new Panel { ContextMenu = contextMenu } };
                 window.ApplyStyling();
                 window.ApplyTemplate();
@@ -270,8 +270,8 @@ namespace Avalonia.Controls.UnitTests
                     return true;
                 });
                 var target = new MenuItem();
-                var parentMenuItem = new MenuItem { Items = new AvaloniaList<MenuItem> { target } };
-                var contextMenu = new ContextMenu { Items = new AvaloniaList<MenuItem> { parentMenuItem } };
+                var parentMenuItem = new MenuItem { Items = { target } };
+                var contextMenu = new ContextMenu { Items = { parentMenuItem } };
                 var window = new Window { Content = new Panel { ContextMenu = contextMenu } };
                 window.ApplyStyling();
                 window.ApplyTemplate();
@@ -317,12 +317,12 @@ namespace Avalonia.Controls.UnitTests
                 MenuItem childMenu2;
                 var menu = new Menu
                 {
-                    Items = new[]
+                    Items =
                     {
                         (topLevelMenu = new MenuItem
                         {
                             Header = "Foo",
-                            Items = new[]
+                            Items =
                             {
                                 (childMenu1 = new MenuItem { Header = "Bar" }),
                                 (childMenu2 = new MenuItem { Header = "Baz" }),
diff --git a/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests.cs b/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests.cs
index 573ce5834d..ca98991c4b 100644
--- a/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests.cs
@@ -114,7 +114,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
                 var panel = Assert.IsType<StackPanel>(target.Panel);
 
                 var newItems = new[] { "qux", "quux", "corge" };
-                itemsControl.Items = newItems;
+                itemsControl.ItemsSource = newItems;
                 root.LayoutManager.ExecuteLayoutPass();
 
                 AssertContainers(panel, newItems);
@@ -139,7 +139,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
             var itemsControl = new ItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = new FuncControlTemplate<ItemsControl>((_, _) => result)
             };
 
diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/PopupRootTests.cs b/tests/Avalonia.Controls.UnitTests/Primitives/PopupRootTests.cs
index 788e6a48bb..fb88c98343 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/PopupRootTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/PopupRootTests.cs
@@ -67,7 +67,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
                 var window = new Window();
-                var target = new Popup {PlacementMode = PlacementMode.Pointer};
+                var target = new Popup {Placement = PlacementMode.Pointer};
                 var child = new Control();
 
                 window.Content = target;
diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs b/tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs
index bc1225e0e8..1e22aa9129 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs
@@ -207,7 +207,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             using (CreateServices())
             {
-                var target = new Popup() {PlacementMode = PlacementMode.Pointer};
+                var target = new Popup() {Placement = PlacementMode.Pointer};
                 var root = PreparedWindow(target);
 
                 target.Open();
@@ -226,7 +226,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             using (CreateServices())
             {
                 var window = PreparedWindow();
-                var target = new Popup() {PlacementMode = PlacementMode.Pointer};
+                var target = new Popup() {Placement = PlacementMode.Pointer};
 
                 window.Content = target;
 
@@ -249,7 +249,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             using (CreateServices())
             {
                 var window = PreparedWindow();
-                var target = new Popup() {PlacementMode = PlacementMode.Pointer};
+                var target = new Popup() {Placement = PlacementMode.Pointer};
 
                 window.Content = target;
                 window.ApplyTemplate();
@@ -274,7 +274,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             using (CreateServices())
             {
                 var window = PreparedWindow();
-                var target = new Popup() { PlacementMode = PlacementMode.Pointer };
+                var target = new Popup() { Placement = PlacementMode.Pointer };
 
                 window.Content = target;
                 window.ApplyTemplate();
@@ -395,7 +395,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var item = new Border();
                 var root = PreparedWindow(target = new PopupItemsControl
                 {
-                    Items = new[] { item },
+                    Items = { item },
                     Template = new FuncControlTemplate<PopupItemsControl>(PopupItemsControlTemplate),
                 }); ;
                 root.Show();
@@ -490,7 +490,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var item = new Border();
                 var root = PreparedWindow(target = new PopupItemsControl
                 {
-                    Items = new[] { item },
+                    Items = { item },
                     Template = new FuncControlTemplate<PopupItemsControl>(PopupItemsControlTemplate),
                 });
                 root.Show();
@@ -742,7 +742,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 {
                     Width = 400,
                     Height = 200,
-                    PlacementMode = PlacementMode.Pointer
+                    Placement = PlacementMode.Pointer
                 };
                 var window = PreparedWindow(popup);
                 window.Show();
@@ -791,7 +791,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var popup = new Popup()
                 {
                     PlacementTarget = placementTarget,
-                    PlacementMode = PlacementMode.Bottom,
+                    Placement = PlacementMode.Bottom,
                     Width = 10,
                     Height = 10
                 };
@@ -852,7 +852,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var popup = new Popup()
                 {
                     PlacementTarget = placementTarget,
-                    PlacementMode = PlacementMode.Pointer,
+                    Placement = PlacementMode.Pointer,
                     Width = 10,
                     Height = 10
                 };
@@ -907,7 +907,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var popup = new Popup()
                 {
                     PlacementTarget = placementTarget,
-                    PlacementMode = PlacementMode.Bottom,
+                    Placement = PlacementMode.Bottom,
                     Width = 10,
                     Height = 10
                 };
@@ -967,7 +967,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var popup = new Popup()
                 {
                     PlacementTarget = placementTarget,
-                    PlacementMode = PlacementMode.Pointer,
+                    Placement = PlacementMode.Pointer,
                     Width = 10,
                     Height = 10
                 };
@@ -1020,7 +1020,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                     Width = 20,
                     Height = 20,
                     PlacementTarget = parentPopup, 
-                    PlacementMode = PlacementMode.AnchorAndGravity,
+                    Placement = PlacementMode.AnchorAndGravity,
                     PlacementAnchor = PopupAnchor.TopLeft,
                     PlacementGravity = PopupGravity.BottomRight
                 };
diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs
index 7d129d987e..3fa2bb515d 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs
@@ -43,7 +43,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -61,7 +61,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -82,7 +82,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -105,7 +105,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -127,7 +127,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new ListBox();
             target.BeginInit();
-            target.Items = items;
+            target.ItemsSource = items;
             target.Template = Template();
             target.EndInit();
 
@@ -144,7 +144,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             };
 
             var target = new ListBox();
-            target.Items = items;
+            target.ItemsSource = items;
             target.Template = Template();
             target.DataContext = new object();
 
@@ -163,7 +163,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox();
             target.BeginInit();
             target.SelectionMode = SelectionMode.Single | SelectionMode.AlwaysSelected;
-            target.Items = items;
+            target.ItemsSource = items;
             target.Template = Template();
             target.EndInit();
 
@@ -184,7 +184,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             listBox.SelectedIndex = 1;
             var items = new AvaloniaList<string>();
-            listBox.Items = items;
+            listBox.ItemsSource = items;
             items.Add("A");
             items.Add("B");
             items.Add("C");
@@ -202,7 +202,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var listBox = new ListBox
             {
                 SelectionMode = SelectionMode.Single,
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
                 SelectedIndex = 1
             };
 
@@ -220,7 +220,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var listBox = new ListBox
             {
                 SelectionMode = SelectionMode.Single,
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
                 SelectedIndex = 2
             };
 
@@ -240,7 +240,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var listBox = new ListBox
             {
                 SelectionMode = SelectionMode.Single,
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
                 SelectedItem = "bar"
             };
 
@@ -259,7 +259,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var listBox = new ListBox
             {
                 SelectionMode = SelectionMode.Multiple,
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
             };
 
             var selected = new[] { "foo", "bar" };
@@ -282,7 +282,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var listBox = new ListBox
             {
                 SelectionMode = SelectionMode.Multiple,
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
             };
 
             var selected = new[] { "foo", "bar" };
@@ -308,7 +308,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             {
                 SelectionMode = SelectionMode.Single | SelectionMode.AlwaysSelected,
 
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
                 SelectedIndex = 1
             };
 
@@ -331,7 +331,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -353,7 +353,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -376,7 +376,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -403,7 +403,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -430,7 +430,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -451,7 +451,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -487,7 +487,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -509,7 +509,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -519,7 +519,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             Assert.Equal(items[1], target.SelectedItem);
             Assert.Equal(1, target.SelectedIndex);
 
-            target.Items = null;
+            target.ItemsSource = null;
 
             Assert.Null(target.SelectedItem);
             Assert.Equal(-1, target.SelectedIndex);
@@ -536,7 +536,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -575,7 +575,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
                 SelectionMode = SelectionMode.AlwaysSelected,
             };
@@ -611,7 +611,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl();
             target.BeginInit();
-            target.Items = items;
+            target.ItemsSource = items;
             target.Template = Template();
             target.EndInit();
 
@@ -648,7 +648,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -684,7 +684,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -722,7 +722,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -749,7 +749,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -779,7 +779,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -807,7 +807,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -839,7 +839,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -868,7 +868,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
                 SelectedIndex = 1,
             };
@@ -896,7 +896,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -932,7 +932,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -968,7 +968,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
                 SelectionMode = SelectionMode.AlwaysSelected,
             };
@@ -1004,7 +1004,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
                 SelectionMode = SelectionMode.AlwaysSelected,
             };
@@ -1041,7 +1041,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -1078,7 +1078,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             ((ISupportInitialize)target).BeginInit();
             target.SelectedIndex = 1;
-            target.Items = items;
+            target.ItemsSource = items;
             ((ISupportInitialize)target).EndInit();
 
             Prepare(target);
@@ -1096,7 +1096,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             ((ISupportInitialize)target).BeginInit();
             target.SelectedItem = "Bar";
-            target.Items = items;
+            target.ItemsSource = items;
             ((ISupportInitialize)target).EndInit();
 
             Prepare(target);
@@ -1127,7 +1127,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var itemsBinding = new Binding("Child.Items");
             var selectedBinding = new Binding("Child.SelectedItem");
 
-            target.Bind(SelectingItemsControl.ItemsProperty, itemsBinding);
+            target.Bind(SelectingItemsControl.ItemsSourceProperty, itemsBinding);
             target.Bind(SelectingItemsControl.SelectedItemProperty, selectedBinding);
 
             Assert.Equal(1, target.SelectedIndex);
@@ -1163,13 +1163,13 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var root = new SelectingItemsControl
             {
                 Template = Template(),
-                Items = new Control[]
+                ItemsSource = new Control[]
                 {
                     new Border(),
                     nested = new ListBox
                     {
                         Template = Template(),
-                        Items = new[] { "foo", "bar" },
+                        ItemsSource = new[] { "foo", "bar" },
                         SelectedIndex = 1,
                     }
                 },
@@ -1197,7 +1197,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz " },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz " },
                 };
                 AvaloniaLocator.CurrentMutable.Bind<PlatformHotkeyConfiguration>().ToConstant(new Mock<PlatformHotkeyConfiguration>().Object);
                 Prepare(target);
@@ -1221,7 +1221,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = items,
+                    ItemsSource = items,
                 };
                 AvaloniaLocator.CurrentMutable.Bind<PlatformHotkeyConfiguration>().ToConstant(new Mock<PlatformHotkeyConfiguration>().Object);
                 Prepare(target);
@@ -1245,7 +1245,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             itemsMock.Object.AddRange(new[] { "Foo", "Bar", "Baz" });
             var target = new SelectingItemsControl
             {
-                Items = itemsMock.Object
+                ItemsSource = itemsMock.Object
             };
 
             target.SelectedIndex = 1;
@@ -1268,7 +1268,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             target.BeginInit();
             root.Child = target;
 
-            DelayedBinding.Add(target, ItemsControl.ItemsProperty, new Binding(nameof(RootWithItems.Items)));
+            DelayedBinding.Add(target, ItemsControl.ItemsSourceProperty, new Binding(nameof(RootWithItems.Items)));
             DelayedBinding.Add(target, ListBox.SelectedItemProperty, new Binding(nameof(RootWithItems.Selected)));
             target.EndInit();
             root.EndInit();
@@ -1299,7 +1299,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var itemsBinding = new Binding("Child.Items");
             var selectedIndBinding = new Binding("Child.SelectedIndex");
 
-            target.Bind(SelectingItemsControl.ItemsProperty, itemsBinding);
+            target.Bind(SelectingItemsControl.ItemsSourceProperty, itemsBinding);
             target.Bind(SelectingItemsControl.SelectedIndexProperty, selectedIndBinding);
 
             Assert.Equal(1, target.SelectedIndex);
@@ -1318,7 +1318,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
                 };
                 AvaloniaLocator.CurrentMutable.Bind<PlatformHotkeyConfiguration>().ToConstant(new Mock<PlatformHotkeyConfiguration>().Object);
                 Prepare(target);
@@ -1336,7 +1336,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
                 };
                 AvaloniaLocator.CurrentMutable.Bind<PlatformHotkeyConfiguration>().ToConstant(new Mock<PlatformHotkeyConfiguration>().Object);
                 Prepare(target);
@@ -1359,7 +1359,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 SelectedIndex = 1,
             };
 
@@ -1384,7 +1384,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 SelectedIndex = 1,
             };
 
@@ -1405,14 +1405,14 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var other = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 SelectionMode = SelectionMode.AlwaysSelected,
             };
 
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 [!ListBox.SelectedIndexProperty] = other[!ListBox.SelectedIndexProperty],
             };
 
@@ -1434,14 +1434,14 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var other = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 SelectionMode = SelectionMode.AlwaysSelected,
             };
 
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 [!ListBox.SelectedItemProperty] = other[!ListBox.SelectedItemProperty],
             };
 
@@ -1468,7 +1468,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 SelectedIndex = 1,
             };
 
@@ -1493,7 +1493,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
             };
 
             var raised = false;
@@ -1518,7 +1518,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
             };
 
             var raised = false;
@@ -1540,7 +1540,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
                 var target = new ListBox
                 {
-                    Items = items,
+                    ItemsSource = items,
                     ItemTemplate = new FuncDataTemplate<string>((x, _) =>
                         new TextBlock
                         {
@@ -1582,7 +1582,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 SelectedIndex = 2,
             };
 
@@ -1614,7 +1614,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 SelectedIndex = 2,
             };
 
@@ -1645,7 +1645,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 AutoScrollToSelectedItem = false,
             };
 
@@ -1671,7 +1671,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             target.BeginInit();
             target.Template = Template();
-            target.Items = new[] { "Foo", "Bar", "Baz" };
+            target.ItemsSource = new[] { "Foo", "Bar", "Baz" };
             target.SelectedItems = selectedItems;
             target.SelectedItem = "Bar";
             target.EndInit();
@@ -1691,7 +1691,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new TestSelector
             {
                 Template = Template(),
-                Items = new[]
+                Items =
                 {
                     new ListBoxItem { Focusable = false },
                     new ListBoxItem { Focusable = false },
@@ -1713,7 +1713,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new TestSelector
             {
                 Template = Template(),
-                Items = new[]
+                Items =
                 {
                     new ListBoxItem(),
                     new ListBoxItem { Focusable = false },
@@ -1733,7 +1733,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new TestSelector
             {
                 Template = Template(),
-                Items = new[]
+                Items =
                 {
                     new ListBoxItem { Focusable = false },
                     new ListBoxItem(),
@@ -1753,7 +1753,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new TestSelector
             {
                 Template = Template(),
-                Items = new[]
+                Items =
                 {
                     new ListBoxItem { Focusable = false },
                     new ListBoxItem { Focusable = false },
@@ -1776,7 +1776,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new TestSelector
             {
                 Template = Template(),
-                Items = new[]
+                Items =
                 {
                     new ListBoxItem { Focusable = false },
                     new ListBoxItem { Focusable = false },
@@ -1800,7 +1800,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new TestSelector
             {
                 Template = Template(),
-                Items = new[]
+                Items =
                 {
                     new ListBoxItem(),
                     new ListBoxItem { IsEnabled = false },
@@ -1831,7 +1831,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 second
             };
 
-            target.Items = items;
+            target.ItemsSource = items;
 
             Prepare(target);
 
@@ -1878,7 +1878,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new ListBox
             {
-                [!ListBox.ItemsProperty] = new Binding("Items"),
+                [!ListBox.ItemsSourceProperty] = new Binding("Items"),
                 [!ListBox.SelectedIndexProperty] = new Binding("SelectedIndex"),
                 DataContext = vm,
             };
@@ -1906,7 +1906,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new ListBox
             {
-                [!ListBox.ItemsProperty] = new Binding("Items"),
+                [!ListBox.ItemsSourceProperty] = new Binding("Items"),
                 [!ListBox.SelectedItemsProperty] = new Binding("SelectedItems"),
                 DataContext = vm,
             };
@@ -1926,7 +1926,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             using var app = Start();
             var target = new SelectingItemsControl
             {
-                Items = new[] { "foo", "bar", "baz"},
+                ItemsSource = new[] { "foo", "bar", "baz"},
                 SelectedItem = "bar",
             };
 
@@ -1935,7 +1935,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             Assert.Equal(1, target.SelectedIndex);
             Assert.Equal("bar", target.SelectedItem);
 
-            target.Items = new[] { "qux", "foo", "bar" };
+            target.ItemsSource = new[] { "qux", "foo", "bar" };
 
             Assert.Equal(2, target.SelectedIndex);
             Assert.Equal("bar", target.SelectedItem);
@@ -1947,7 +1947,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             using var app = Start();
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
             };
 
             var raised = 0;
@@ -1976,7 +1976,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             using var app = Start();
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
             };
 
             var raised = 0;
@@ -2007,13 +2007,13 @@ namespace Avalonia.Controls.UnitTests.Primitives
             // Simulates problem with TabStrip and Carousel with bound SelectedIndex.
             var tabStrip = new TestSelector 
             { 
-                Items = items, 
+                ItemsSource = items, 
                 SelectionMode = SelectionMode.AlwaysSelected,
             };
 
             var carousel = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 [!Carousel.SelectedIndexProperty] = tabStrip[!TabStrip.SelectedIndexProperty],
             };
 
@@ -2048,13 +2048,13 @@ namespace Avalonia.Controls.UnitTests.Primitives
             // Simulates problem with TabStrip and Carousel with bound SelectedItem.
             var tabStrip = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 SelectionMode = SelectionMode.AlwaysSelected,
             };
 
             var carousel = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 [!Carousel.SelectedItemProperty] = tabStrip[!TabStrip.SelectedItemProperty],
             };
 
@@ -2100,7 +2100,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
                 var target = new SelectingItemsControl
                 {
-                    Items = items, 
+                    ItemsSource = items, 
                     Template = Template(), 
                     IsTextSearchEnabled = false
                 };
diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_AutoSelect.cs b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_AutoSelect.cs
index c3e37666f7..71bd0933a1 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_AutoSelect.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_AutoSelect.cs
@@ -16,7 +16,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -32,7 +32,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var items = new AvaloniaList<string>();
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -50,7 +50,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var items = new ResetOnAdd();
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -68,7 +68,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -87,7 +87,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
@@ -106,7 +106,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var items = new AvaloniaList<string>(new[] { "foo", "bar" });
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
             };
 
diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_Multiple.cs b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_Multiple.cs
index 0b72baf336..1108780d9a 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_Multiple.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_Multiple.cs
@@ -27,7 +27,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -42,7 +42,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -57,7 +57,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -75,7 +75,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
                 Template = Template(),
             };
 
@@ -94,7 +94,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             // Issue #2565.
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
                 Template = Template(),
             };
 
@@ -112,7 +112,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -129,7 +129,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -157,7 +157,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -179,7 +179,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -200,26 +200,23 @@ namespace Avalonia.Controls.UnitTests.Primitives
         [Fact]
         public void Adding_SelectedItems_Should_Set_Item_IsSelected()
         {
-            var items = new[]
-            {
-                new ListBoxItem(),
-                new ListBoxItem(),
-                new ListBoxItem(),
-            };
-
             var target = new TestSelector
             {
-                Items = items,
+                Items = 
+                {
+                    new ListBoxItem(),
+                    new ListBoxItem(),
+                    new ListBoxItem(),
+                },
                 Template = Template(),
             };
 
             target.ApplyTemplate();
             target.Presenter.ApplyTemplate();
-            target.SelectedItems.Add(items[0]);
-            target.SelectedItems.Add(items[1]);
-
-            var foo = target.Presenter.Panel.Children[0];
+            target.SelectedItems.Add(target.Items[0]);
+            target.SelectedItems.Add(target.Items[1]);
 
+            var items = target.Items.Cast<ListBoxItem>().ToList();
             Assert.True(items[0].IsSelected);
             Assert.True(items[1].IsSelected);
             Assert.False(items[2].IsSelected);
@@ -228,23 +225,22 @@ namespace Avalonia.Controls.UnitTests.Primitives
         [Fact]
         public void Assigning_SelectedItems_Should_Set_Item_IsSelected()
         {
-            var items = new[]
-            {
-                new ListBoxItem(),
-                new ListBoxItem(),
-                new ListBoxItem(),
-            };
-
             var target = new TestSelector
             {
-                Items = items,
+                Items =
+                {
+                    new ListBoxItem(),
+                    new ListBoxItem(),
+                    new ListBoxItem(),
+                },
                 Template = Template(),
             };
 
             target.ApplyTemplate();
             target.Presenter.ApplyTemplate();
-            target.SelectedItems = new AvaloniaList<object> { items[0], items[1] };
+            target.SelectedItems = new AvaloniaList<object> { target.Items[0], target.Items[1] };
 
+            var items = target.Items.Cast<ListBoxItem>().ToList();
             Assert.True(items[0].IsSelected);
             Assert.True(items[1].IsSelected);
             Assert.False(items[2].IsSelected);
@@ -253,25 +249,24 @@ namespace Avalonia.Controls.UnitTests.Primitives
         [Fact]
         public void Removing_SelectedItems_Should_Clear_Item_IsSelected()
         {
-            var items = new[]
-            {
-                new ListBoxItem(),
-                new ListBoxItem(),
-                new ListBoxItem(),
-            };
-
             var target = new TestSelector
             {
-                Items = items,
+                Items =
+                {
+                    new ListBoxItem(),
+                    new ListBoxItem(),
+                    new ListBoxItem(),
+                },
                 Template = Template(),
             };
 
             target.ApplyTemplate();
             target.Presenter.ApplyTemplate();
-            target.SelectedItems.Add(items[0]);
-            target.SelectedItems.Add(items[1]);
-            target.SelectedItems.Remove(items[1]);
+            target.SelectedItems.Add(target.Items[0]);
+            target.SelectedItems.Add(target.Items[1]);
+            target.SelectedItems.Remove(target.Items[1]);
 
+            var items = target.Items.Cast<ListBoxItem>().ToList();
             Assert.True(items[0].IsSelected);
             Assert.False(items[1].IsSelected);
         }
@@ -279,25 +274,24 @@ namespace Avalonia.Controls.UnitTests.Primitives
         [Fact]
         public void Reassigning_SelectedItems_Should_Clear_Item_IsSelected()
         {
-            var items = new[]
-            {
-                new ListBoxItem(),
-                new ListBoxItem(),
-                new ListBoxItem(),
-            };
-
             var target = new TestSelector
             {
-                Items = items,
+                Items = 
+                {
+                    new ListBoxItem(),
+                    new ListBoxItem(),
+                    new ListBoxItem(),
+                },
                 Template = Template(),
             };
 
             target.ApplyTemplate();
-            target.SelectedItems.Add(items[0]);
-            target.SelectedItems.Add(items[1]);
+            target.SelectedItems.Add(target.Items[0]);
+            target.SelectedItems.Add(target.Items[1]);
 
-            target.SelectedItems = new AvaloniaList<object> { items[0], items[1] };
+            target.SelectedItems = new AvaloniaList<object> { target.Items[0], target.Items[1] };
 
+            var items = target.Items.Cast<ListBoxItem>().ToList();
             Assert.False(items[0].IsSelected);
             Assert.False(items[1].IsSelected);
         }
@@ -307,7 +301,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
                 Template = Template(),
             };
 
@@ -329,7 +323,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[]
+                ItemsSource = new[]
                 {
                     "foo",
                     "bar",
@@ -353,7 +347,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[]
+                ItemsSource = new[]
                 {
                     "foo",
                     "bar",
@@ -378,7 +372,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[]
+                ItemsSource = new[]
                 {
                     "foo",
                     "bar",
@@ -404,7 +398,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar", "baz", "qux" },
+                ItemsSource = new[] { "foo", "bar", "baz", "qux" },
                 Template = Template(),
                 SelectedIndex = 0,
                 SelectionMode = SelectionMode.Multiple,
@@ -427,7 +421,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar", "baz", "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz", "foo", "bar", "baz" },
                 Template = Template(),
                 SelectedIndex = 0,
                 SelectionMode = SelectionMode.Multiple,
@@ -450,7 +444,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
                 Template = Template(),
             };
 
@@ -471,7 +465,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
                 Template = Template(),
             };
 
@@ -536,8 +530,8 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 Mode = BindingMode.OneWay,
             };
 
-            // Bind Items and SelectedItems to the VM.
-            target.Bind(TestSelector.ItemsProperty, itemsBinding);
+            // Bind ItemsSource and SelectedItems to the VM.
+            target.Bind(TestSelector.ItemsSourceProperty, itemsBinding);
             target.Bind(TestSelector.SelectedItemsProperty, selectedItemsBinding);
 
             // Set DataContext and SelectedIndex
@@ -576,8 +570,8 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 Mode = BindingMode.OneWay,
             };
 
-            // Bind Items and Selection to the VM.
-            target.Bind(TestSelector.ItemsProperty, itemsBinding);
+            // Bind ItemsSource and Selection to the VM.
+            target.Bind(TestSelector.ItemsSourceProperty, itemsBinding);
             target.Bind(TestSelector.SelectionProperty, selectionBinding);
 
             // Set DataContext and SelectedIndex
@@ -610,9 +604,9 @@ namespace Avalonia.Controls.UnitTests.Primitives
             };
 
             var itemsBinding = new Binding { Path = "Items" };
-            target.Bind(TestSelector.ItemsProperty, itemsBinding);
+            target.Bind(TestSelector.ItemsSourceProperty, itemsBinding);
 
-            Assert.Same(data.Items, target.Items);
+            Assert.Same(data.Items, target.ItemsSource);
 
             target.SelectedItems.Add("bar");
             target.DataContext = null;
@@ -629,7 +623,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             {
                 DataContext = items,
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
             };
 
             var called = false;
@@ -653,7 +647,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
                 SelectedItem = "bar",
             };
@@ -679,7 +673,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
                 SelectedItem = "bar",
             };
@@ -708,7 +702,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz" },
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
                     Height = 100,
@@ -733,7 +727,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz", "Qux" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz", "Qux" },
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
                     Height = 100,
@@ -791,7 +785,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz", "Qux" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz", "Qux" },
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
                     Height = 100,
@@ -825,7 +819,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz" },
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
                     Height = 100,
@@ -856,7 +850,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
                     Height = 100,
@@ -884,7 +878,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
                     Height = 100,
@@ -912,7 +906,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
                     Height = 100,
@@ -940,7 +934,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz", "Qux" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz", "Qux" },
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
                     Height = 100,
@@ -992,7 +986,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
                     Height = 100,
@@ -1026,7 +1020,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new TestSelector
             {
                 Template = Template(),
-                Items = new[] { "Foo", "Bar", "Baz" },
+                ItemsSource = new[] { "Foo", "Bar", "Baz" },
                 SelectionMode = SelectionMode.Multiple,
             };
 
@@ -1045,7 +1039,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new TestSelector
             {
                 Template = Template(),
-                Items = new[] { "Foo", "Bar", "Baz" },
+                ItemsSource = new[] { "Foo", "Bar", "Baz" },
                 SelectionMode = SelectionMode.Multiple,
             };
 
@@ -1059,7 +1053,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             target.SelectAll();
 
             Assert.NotNull(receivedArgs);
-            Assert.Equal(target.Items, receivedArgs.AddedItems);
+            Assert.Equal(target.ItemsSource, receivedArgs.AddedItems);
             Assert.Empty(receivedArgs.RemovedItems);
         }
 
@@ -1069,7 +1063,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new TestSelector
             {
                 Template = Template(),
-                Items = new[] { "Foo", "Bar", "Baz" },
+                ItemsSource = new[] { "Foo", "Bar", "Baz" },
                 SelectionMode = SelectionMode.Multiple,
                 SelectedIndex = 0,
             };
@@ -1089,7 +1083,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new TestSelector
             {
                 Template = Template(),
-                Items = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
+                ItemsSource = new[] { "Foo", "Bar", "Baz", "Foo", "Bar", "Baz" },
                 SelectionMode = SelectionMode.Multiple,
             };
 
@@ -1113,7 +1107,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 SelectionMode = SelectionMode.Multiple,
                 Width = 100,
                 Height = 100,
@@ -1145,7 +1139,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new TestSelector
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 SelectionMode = SelectionMode.Multiple,
             };
 
@@ -1178,7 +1172,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 SelectionMode = SelectionMode.Multiple,
                 Width = 100,
                 Height = 100,
@@ -1209,7 +1203,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var target = new ListBox
             {
                 Template = Template(),
-                Items = items,
+                ItemsSource = items,
                 SelectionMode = SelectionMode.Multiple,
                 Width = 100,
                 Height = 100,
@@ -1232,7 +1226,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz" },
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Width = 20, Height = 10 }),
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
@@ -1262,7 +1256,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz" },
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Width = 20, Height = 10 }),
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
@@ -1290,7 +1284,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz" },
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Width = 20, Height = 10 }),
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
@@ -1315,27 +1309,25 @@ namespace Avalonia.Controls.UnitTests.Primitives
         [Fact]
         public void Adding_Selected_ItemContainers_Should_Update_Selection()
         {
-            var items = new AvaloniaList<ItemContainer>(new[]
-            {
-                new ItemContainer(),
-                new ItemContainer(),
-            });
-
             var target = new TestSelector
             {
-                Items = items,
+                Items =
+                {
+                    new ItemContainer(),
+                    new ItemContainer(),
+                },
                 SelectionMode = SelectionMode.Multiple,
                 Template = Template(),
             };
 
             target.ApplyTemplate();
             target.Presenter.ApplyTemplate();
-            items.Add(new ItemContainer { IsSelected = true });
-            items.Add(new ItemContainer { IsSelected = true });
+            target.Items.Add(new ItemContainer { IsSelected = true });
+            target.Items.Add(new ItemContainer { IsSelected = true });
 
             Assert.Equal(2, target.SelectedIndex);
-            Assert.Equal(items[2], target.SelectedItem);
-            Assert.Equal(new[] { items[2], items[3] }, target.SelectedItems);
+            Assert.Equal(target.Items[2], target.SelectedItem);
+            Assert.Equal(new[] { target.Items[2], target.Items[3] }, target.SelectedItems);
         }
 
         [Fact]
@@ -1346,7 +1338,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz" },
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Width = 20, Height = 10 }),
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
@@ -1373,7 +1365,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var target = new ListBox
                 {
                     Template = Template(),
-                    Items = new[] { "Foo", "Bar", "Baz" },
+                    ItemsSource = new[] { "Foo", "Bar", "Baz" },
                     ItemTemplate = new FuncDataTemplate<string>((x, _) => new TextBlock { Width = 20, Height = 10 }),
                     SelectionMode = SelectionMode.Multiple,
                     Width = 100,
@@ -1397,7 +1389,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -1412,7 +1404,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -1429,7 +1421,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -1442,14 +1434,14 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
             var selection = new SelectionModel<string>();
             target.Selection = selection;
 
-            Assert.Same(target.Items, selection.Source);
+            Assert.Same(target.ItemsSource, selection.Source);
         }
 
         [Fact]
@@ -1457,7 +1449,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -1478,7 +1470,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar", "baz" },
+                ItemsSource = new[] { "foo", "bar", "baz" },
                 Template = Template(),
             };
 
@@ -1499,7 +1491,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
         {
             var target = new TestSelector
             {
-                Items = new[] { "foo", "bar" },
+                ItemsSource = new[] { "foo", "bar" },
                 Template = Template(),
             };
 
@@ -1514,16 +1506,14 @@ namespace Avalonia.Controls.UnitTests.Primitives
         [Fact]
         public void Assigning_Selection_Should_Set_Item_IsSelected()
         {
-            var items = new[]
-            {
-                new ListBoxItem(),
-                new ListBoxItem(),
-                new ListBoxItem(),
-            };
-
             var target = new TestSelector
             {
-                Items = items,
+                Items =
+                {
+                    new ListBoxItem(),
+                    new ListBoxItem(),
+                    new ListBoxItem(),
+                },
                 Template = Template(),
             };
 
@@ -1534,6 +1524,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             selection.SelectRange(0, 1);
             target.Selection = selection;
 
+            var items = target.Items.Cast<ListBoxItem>().ToList();
             Assert.True(items[0].IsSelected);
             Assert.True(items[1].IsSelected);
             Assert.False(items[2].IsSelected);
@@ -1546,7 +1537,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
             var target = new TestSelector
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
                 SelectedItem = "bar",
             };
diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_SelectedValue.cs b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_SelectedValue.cs
index df81b1faae..e9b8895174 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_SelectedValue.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_SelectedValue.cs
@@ -21,7 +21,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var items = TestClass.GetItems();
             var sic = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 SelectedValueBinding = new Binding("Name"),
                 Template = Template()
             };
@@ -37,7 +37,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var items = TestClass.GetItems();
             var sic = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 SelectedValueBinding = new Binding("Name"),
                 Template = Template()
             };
@@ -53,7 +53,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var items = TestClass.GetItems();
             var sic = new ListBox
             {
-                Items = items,
+                ItemsSource = items,
                 SelectedValueBinding = new Binding("Name"),
                 Template = Template()
             };
@@ -78,7 +78,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var items = TestClass.GetItems();
                 var sic = new SelectingItemsControl
                 {
-                    Items = items,
+                    ItemsSource = items,
                     SelectedValueBinding = new Binding("Name"),
                     Template = Template()
                 };
@@ -99,7 +99,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var items = TestClass.GetItems();
                 var sic = new SelectingItemsControl
                 {
-                    Items = items,
+                    ItemsSource = items,
                     SelectedValueBinding = new Binding("Name"),
                     Template = Template()
                 };
@@ -120,7 +120,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var items = TestClass.GetItems();
                 var sic = new SelectingItemsControl
                 {
-                    Items = items,
+                    ItemsSource = items,
                     SelectedValueBinding = new Binding("Name"),
                     Template = Template()
                 };
@@ -143,7 +143,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var items = TestClass.GetItems();
             var sic = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template()
             };
 
@@ -158,7 +158,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var items = TestClass.GetItems();
             var sic = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
                 SelectedValueBinding = new Binding("Name"),
                 SelectedValue = "Item2"
@@ -176,7 +176,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var items = TestClass.GetItems();
             var sic = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
                 SelectedValueBinding = new Binding("Name"),
                 SelectedValue = "Item2"
@@ -197,7 +197,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var items = TestClass.GetItems();
                 var sic = new SelectingItemsControl
                 {
-                    Items = items,
+                    ItemsSource = items,
                     Template = Template(),
                     SelectedValueBinding = new Binding("Name"),
                     SelectedValue = "Item2"
@@ -205,7 +205,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
                 Prepare(sic);
 
-                sic.Items = new List<TestClass>
+                sic.ItemsSource = new List<TestClass>
                 {
                     new TestClass("NewItem", string.Empty)
                 };
@@ -224,7 +224,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var items = TestClass.GetItems();
                 var sic = new SelectingItemsControl
                 {
-                    Items = items,
+                    ItemsSource = items,
                     Template = Template(),
                     SelectedValueBinding = new Binding("Name"),
                 };
@@ -250,7 +250,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
             var items = TestClass.GetItems();
             var sic = new SelectingItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = Template(),
                 SelectedValueBinding = new Binding("Name"),
                 SelectedValue = "Item2"
diff --git a/tests/Avalonia.Controls.UnitTests/Primitives/TabStripTests.cs b/tests/Avalonia.Controls.UnitTests/Primitives/TabStripTests.cs
index 05183fe787..d50f6e1d0d 100644
--- a/tests/Avalonia.Controls.UnitTests/Primitives/TabStripTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/TabStripTests.cs
@@ -14,90 +14,84 @@ namespace Avalonia.Controls.UnitTests.Primitives
         [Fact]
         public void First_Tab_Should_Be_Selected_By_Default()
         {
-            var items = new[]
-            {
-                new TabItem
-                {
-                    Name = "first"
-                },
-                new TabItem
-                {
-                    Name = "second"
-                },
-            };
-
             var target = new TabStrip
             {
                 Template = new FuncControlTemplate<TabStrip>(CreateTabStripTemplate),
-                Items = items,
+                Items =
+                {
+                    new TabItem
+                    {
+                        Name = "first"
+                    },
+                    new TabItem
+                    {
+                        Name = "second"
+                    },
+                }
             };
 
             target.ApplyTemplate();
 
             Assert.Equal(0, target.SelectedIndex);
-            Assert.Same(items[0], target.SelectedItem);
+            Assert.Same(target.Items[0], target.SelectedItem);
         }
 
         [Fact]
         public void Setting_SelectedItem_Should_Set_Selection()
         {
-            var items = new[]
-            {
-                new TabItem
-                {
-                    Name = "first"
-                },
-                new TabItem
-                {
-                    Name = "second"
-                },
-            };
-
             var target = new TabStrip
             {
                 Template = new FuncControlTemplate<TabStrip>(CreateTabStripTemplate),
-                Items = items,
-                SelectedItem = items[1],
+                Items =
+                {
+                    new TabItem
+                    {
+                        Name = "first"
+                    },
+                    new TabItem
+                    {
+                        Name = "second"
+                    },
+                },             
             };
 
+            target.SelectedItem = target.Items[1];
             target.ApplyTemplate();
 
             Assert.Equal(1, target.SelectedIndex);
-            Assert.Same(items[1], target.SelectedItem);
+            Assert.Same(target.Items[1], target.SelectedItem);
         }
 
         [Fact]
         public void Removing_Selected_Should_Select_First()
         {
-            var items = new ObservableCollection<TabItem>()
-            {
-                new TabItem
-                {
-                    Name = "first"
-                },
-                new TabItem
-                {
-                    Name = "second"
-                },
-                new TabItem
-                {
-                    Name = "3rd"
-                },
-            };
-
             var target = new TabStrip
             {
                 Template = new FuncControlTemplate<TabStrip>(CreateTabStripTemplate),
-                Items = items
+                Items =
+                {
+                    new TabItem
+                    {
+                        Name = "first"
+                    },
+                    new TabItem
+                    {
+                        Name = "second"
+                    },
+                    new TabItem
+                    {
+                        Name = "3rd"
+                    },
+                }
             };
 
             target.ApplyTemplate();
-            target.SelectedItem = items[1];
-            Assert.Same(items[1], target.SelectedItem);
-            items.RemoveAt(1);
+            target.SelectedItem = target.Items[1];
+            Assert.Same(target.Items[1], target.SelectedItem);
+            target.Items.RemoveAt(1);
 
             Assert.Equal(0, target.SelectedIndex);
-            Assert.Same(items[0], target.SelectedItem);
+            Assert.Same(target.Items[0], target.SelectedItem);
             Assert.Same("first", ((TabItem)target.SelectedItem).Name);
         }
 
diff --git a/tests/Avalonia.Controls.UnitTests/TabControlTests.cs b/tests/Avalonia.Controls.UnitTests/TabControlTests.cs
index 0f72b2101a..7440ee4858 100644
--- a/tests/Avalonia.Controls.UnitTests/TabControlTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/TabControlTests.cs
@@ -24,7 +24,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TabControl
             {
                 Template = TabControlTemplate(),
-                Items = new[]
+                Items =
                 {
                     (selected = new TabItem
                     {
@@ -48,21 +48,17 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Pre_Selecting_TabItem_Should_Set_SelectedContent_After_It_Was_Added()
         {
+            const string secondContent = "Second";
             var target = new TabControl
             {
                 Template = TabControlTemplate(),
+                Items =
+                {
+                    new TabItem { Header = "First"},
+                    new TabItem { Header = "Second", Content = secondContent, IsSelected = true }
+                },
             };
 
-            const string secondContent = "Second";
-
-            var items = new AvaloniaList<object>
-            {
-                new TabItem { Header = "First"},
-                new TabItem { Header = "Second", Content = secondContent, IsSelected = true }
-            };
-
-            target.Items = items;
-
             ApplyTemplate(target);
 
             Assert.Equal(secondContent, target.SelectedContent);
@@ -71,107 +67,105 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Logical_Children_Should_Be_TabItems()
         {
-            var items = new[]
-            {
-                new TabItem
-                {
-                    Content = "foo"
-                },
-                new TabItem
-                {
-                    Content = "bar"
-                },
-            };
-
             var target = new TabControl
             {
                 Template = TabControlTemplate(),
-                Items = items,
+                Items =
+                {
+                    new TabItem
+                    {
+                        Content = "foo"
+                    },
+                    new TabItem
+                    {
+                        Content = "bar"
+                    },
+                }
             };
 
-            Assert.Equal(items, target.GetLogicalChildren());
+            Assert.Equal(target.Items, target.GetLogicalChildren().ToList());
             target.ApplyTemplate();
-            Assert.Equal(items, target.GetLogicalChildren());
+            Assert.Equal(target.Items, target.GetLogicalChildren().ToList());
         }
 
         [Fact]
         public void Removal_Should_Set_First_Tab()
         {
-            var collection = new ObservableCollection<TabItem>()
-            {
-                new TabItem
-                {
-                    Name = "first",
-                    Content = "foo",
-                },
-                new TabItem
-                {
-                    Name = "second",
-                    Content = "bar",
-                },
-                new TabItem
-                {
-                    Name = "3rd",
-                    Content = "barf",
-                },
-            };
-
             var target = new TabControl
             {
                 Template = TabControlTemplate(),
-                Items = collection,
+                Items =
+                {
+                    new TabItem
+                    {
+                        Name = "first",
+                        Content = "foo",
+                    },
+                    new TabItem
+                    {
+                        Name = "second",
+                        Content = "bar",
+                    },
+                    new TabItem
+                    {
+                        Name = "3rd",
+                        Content = "barf",
+                    },
+                }
             };
 
             Prepare(target);
-            target.SelectedItem = collection[1];
+            target.SelectedItem = target.Items[1];
 
-            Assert.Same(collection[1], target.SelectedItem);
-            Assert.Equal(collection[1].Content, target.SelectedContent);
+            var item = Assert.IsType<TabItem>(target.Items[1]);
+            Assert.Same(item, target.SelectedItem);
+            Assert.Equal(item.Content, target.SelectedContent);
 
-            collection.RemoveAt(1);
+            target.Items.RemoveAt(1);
 
-            Assert.Same(collection[0], target.SelectedItem);
-            Assert.Equal(collection[0].Content, target.SelectedContent);
+            item = Assert.IsType<TabItem>(target.Items[0]);
+            Assert.Same(item, target.SelectedItem);
+            Assert.Equal(item.Content, target.SelectedContent);
         }
 
         [Fact]
         public void Removal_Should_Set_New_Item0_When_Item0_Selected()
         {
-            var collection = new ObservableCollection<TabItem>()
-            {
-                new TabItem
-                {
-                    Name = "first",
-                    Content = "foo",
-                },
-                new TabItem
-                {
-                    Name = "second",
-                    Content = "bar",
-                },
-                new TabItem
-                {
-                    Name = "3rd",
-                    Content = "barf",
-                },
-            };
-
             var target = new TabControl
             {
                 Template = TabControlTemplate(),
-                Items = collection,
+                Items =
+                {
+                    new TabItem
+                    {
+                        Name = "first",
+                        Content = "foo",
+                    },
+                    new TabItem
+                    {
+                        Name = "second",
+                        Content = "bar",
+                    },
+                    new TabItem
+                    {
+                        Name = "3rd",
+                        Content = "barf",
+                    },
+                }
             };
 
             Prepare(target);
-            target.SelectedItem = collection[0];
+            target.SelectedItem = target.Items[0];
 
-            Assert.Same(collection[0], target.SelectedItem);
-            Assert.Equal(collection[0].Content, target.SelectedContent);
+            var item = Assert.IsType<TabItem>(target.Items[0]);
+            Assert.Same(item, target.SelectedItem);
+            Assert.Equal(item.Content, target.SelectedContent);
 
-            collection.RemoveAt(0);
+            target.Items.RemoveAt(0);
 
-            Assert.Same(collection[0], target.SelectedItem);
-            Assert.Equal(collection[0].Content, target.SelectedContent);
+            item = Assert.IsType<TabItem>(target.Items[0]);
+            Assert.Same(item, target.SelectedItem);
+            Assert.Equal(item.Content, target.SelectedContent);
         }
 
         [Fact]
@@ -189,7 +183,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TabControl
             {
                 Template = TabControlTemplate(),
-                Items = collection,
+                ItemsSource = collection,
             };
 
             Prepare(target);
@@ -207,26 +201,8 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void TabItem_Templates_Should_Be_Set_Before_TabItem_ApplyTemplate()
         {
-            var collection = new[]
-            {
-                new TabItem
-                {
-                    Name = "first",
-                    Content = "foo",
-                },
-                new TabItem
-                {
-                    Name = "second",
-                    Content = "bar",
-                },
-                new TabItem
-                {
-                    Name = "3rd",
-                    Content = "barf",
-                },
-            };
-
             var template = new FuncControlTemplate<TabItem>((x, __) => new Decorator());
+            TabControl target;
             var root = new TestRoot
             {
                 Styles =
@@ -239,13 +215,31 @@ namespace Avalonia.Controls.UnitTests
                         }
                     }
                 },
-                Child = new TabControl
+                Child = (target = new TabControl
                 {
                     Template = TabControlTemplate(),
-                    Items = collection,
-                }
+                    Items = 
+                    {
+                        new TabItem
+                        {
+                            Name = "first",
+                            Content = "foo",
+                        },
+                        new TabItem
+                        {
+                            Name = "second",
+                            Content = "bar",
+                        },
+                        new TabItem
+                        {
+                            Name = "3rd",
+                            Content = "barf",
+                        },
+                    },
+                })
             };
 
+            var collection = target.Items.Cast<TabItem>().ToList();
             Assert.Same(collection[0].Template, template);
             Assert.Same(collection[1].Template, template);
             Assert.Same(collection[2].Template, template);
@@ -271,7 +265,7 @@ namespace Avalonia.Controls.UnitTests
                 {
                     new FuncDataTemplate<Item>((x, __) => new Button { Content = x })
                 },
-                Items = items,
+                ItemsSource = items,
             };
 
             ApplyTemplate(target);
@@ -313,16 +307,14 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Non_IHeadered_Control_Items_Should_Be_Ignored()
         {
-            var items = new[]
-            {
-                new TextBlock { Text = "foo" },
-                new TextBlock { Text = "bar" },
-            };
-
             var target = new TabControl
             {
                 Template = TabControlTemplate(),
-                Items = items,
+                Items =
+                {
+                    new TextBlock { Text = "foo" },
+                    new TextBlock { Text = "bar" },
+                },
             };
 
             ApplyTemplate(target);
@@ -343,7 +335,7 @@ namespace Avalonia.Controls.UnitTests
             TabControl target = new TabControl
             {
                 Template = TabControlTemplate(),
-                Items = new[]
+                Items =
                 {
                     new TabItem { Header = "Foo" },
                     new TabItem { Header = "Foo", Content = new Decorator() },
@@ -368,7 +360,7 @@ namespace Avalonia.Controls.UnitTests
                 Template = TabControlTemplate(),
                 ContentTemplate = new FuncDataTemplate<string>((x, _) =>
                     new TextBlock { Tag = "bar", Text = x }),
-                Items = new[] { "Foo" },
+                ItemsSource = new[] { "Foo" },
             };
             var root = new TestRoot(target);
 
@@ -392,7 +384,7 @@ namespace Avalonia.Controls.UnitTests
             {
                 Template = TabControlTemplate(),
                 DataContext = dataContext,
-                Items = new AvaloniaList<object> { tabItem }
+                Items = { tabItem }
             };
 
             ApplyTemplate(target);
@@ -409,7 +401,7 @@ namespace Avalonia.Controls.UnitTests
 <Window xmlns='https://github.com/avaloniaui'
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
         xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.Xaml;assembly=Avalonia.Markup.Xaml.UnitTests'>
-    <TabControl Name='tabs' Items='{Binding Tabs}'/>
+    <TabControl Name='tabs' ItemsSource='{Binding Tabs}'/>
 </Window>";
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var tabControl = window.FindControl<TabControl>("tabs");
@@ -417,7 +409,7 @@ namespace Avalonia.Controls.UnitTests
                 tabControl.DataContext = new { Tabs = new List<string>() };
                 window.ApplyTemplate();
 
-                Assert.Equal(0, tabControl.Items.Count());
+                Assert.Equal(0, tabControl.ItemsSource.Count());
             }
         }
 
diff --git a/tests/Avalonia.Controls.UnitTests/TextBlockTests.cs b/tests/Avalonia.Controls.UnitTests/TextBlockTests.cs
index de5e5a8ea3..d8da198f5b 100644
--- a/tests/Avalonia.Controls.UnitTests/TextBlockTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/TextBlockTests.cs
@@ -192,7 +192,7 @@ namespace Avalonia.Controls.UnitTests
 
                 target.Inlines.Add(new Run("Hello World"));
 
-                Assert.Equal("Hello World", target.Text);
+                Assert.Equal(null, target.Text);
 
                 Assert.Equal(1, target.Inlines.Count);
 
diff --git a/tests/Avalonia.Controls.UnitTests/TreeViewTests.cs b/tests/Avalonia.Controls.UnitTests/TreeViewTests.cs
index eee6e49617..4f533c2f78 100644
--- a/tests/Avalonia.Controls.UnitTests/TreeViewTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/TreeViewTests.cs
@@ -31,7 +31,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = CreateTestTreeData(),
+                ItemsSource = CreateTestTreeData(),
             };
 
             var root = new TestRoot(target);
@@ -54,7 +54,7 @@ namespace Avalonia.Controls.UnitTests
                 Child = target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = CreateTestTreeData(),
+                    ItemsSource = CreateTestTreeData(),
                     ItemTemplate = new FuncTreeDataTemplate<Node>(
                         (_, __) => new Canvas(),
                         x => x.Children),
@@ -82,7 +82,7 @@ namespace Avalonia.Controls.UnitTests
                 Child = target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = CreateTestTreeData(),
+                    ItemsSource = CreateTestTreeData(),
                     ItemContainerTheme = theme,
                     ItemTemplate = new FuncTreeDataTemplate<Node>(
                         (_, __) => new Canvas(),
@@ -112,7 +112,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = CreateTestTreeData(),
+                ItemsSource = CreateTestTreeData(),
             };
 
             var root = new TestRoot(target);
@@ -131,7 +131,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = CreateTestTreeData(),
+                ItemsSource = CreateTestTreeData(),
             };
 
             var root = new TestRoot(target);
@@ -151,7 +151,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = tree,
+                ItemsSource = tree,
             };
 
             // For TreeViewItem to find its parent TreeView, OnAttachedToLogicalTree needs
@@ -181,7 +181,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -212,7 +212,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree
+                    ItemsSource = tree
                 };
 
                 var visualRoot = new TestRoot();
@@ -247,7 +247,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree
+                    ItemsSource = tree
                 };
 
                 var visualRoot = new TestRoot();
@@ -287,7 +287,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                     SelectionMode = SelectionMode.Multiple
                 };
 
@@ -330,7 +330,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                     SelectionMode = SelectionMode.Multiple
                 };
 
@@ -367,7 +367,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                     SelectionMode = SelectionMode.Multiple
                 };
 
@@ -404,7 +404,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                     SelectionMode = SelectionMode.Multiple
                 };
 
@@ -455,7 +455,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -488,7 +488,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -521,7 +521,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -554,7 +554,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -591,7 +591,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -649,7 +649,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -686,7 +686,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -744,7 +744,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -781,7 +781,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -839,7 +839,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -876,7 +876,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -934,7 +934,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -985,7 +985,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -1036,7 +1036,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -1066,7 +1066,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                 };
 
                 var visualRoot = new TestRoot();
@@ -1105,7 +1105,7 @@ namespace Avalonia.Controls.UnitTests
                     DataContext = dataContext
                 };
 
-                target.Bind(TreeView.ItemsProperty, new Binding("Items"));
+                target.Bind(TreeView.ItemsSourceProperty, new Binding("Items"));
                 target.Bind(TreeView.SelectedItemProperty, new Binding("SelectedItem"));
 
                 var visualRoot = new TestRoot();
@@ -1137,7 +1137,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = new[] { "Foo", "Bar", "Baz " },
+                ItemsSource = new[] { "Foo", "Bar", "Baz " },
             };
 
             ApplyTemplates(target);
@@ -1171,7 +1171,7 @@ namespace Avalonia.Controls.UnitTests
                 {
                     new FuncDataTemplate<Node>((x, _) => new Button { Content = x })
                 },
-                Items = items,
+                ItemsSource = items,
             };
 
             ApplyTemplates(target);
@@ -1189,15 +1189,13 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Control_Item_Should_Not_Be_NameScope()
         {
-            var items = new object[]
-            {
-                new TreeViewItem(),
-            };
-
             var target = new TreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = items,
+                Items =
+                {
+                    new TreeViewItem(),
+                }
             };
 
             target.ApplyTemplate();
@@ -1215,7 +1213,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = data,
+                ItemsSource = data,
             };
 
             var root = new TestRoot(target);
@@ -1256,7 +1254,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = data,
+                    ItemsSource = data,
                 };
 
                 var button = new Button();
@@ -1302,7 +1300,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = data,
+                    ItemsSource = data,
                     SelectedItem = selectedNode
                 };
 
@@ -1341,7 +1339,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                     SelectionMode = SelectionMode.Multiple
                 };
 
@@ -1379,7 +1377,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                     SelectionMode = SelectionMode.Multiple
                 };
 
@@ -1426,7 +1424,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                     SelectionMode = SelectionMode.Multiple
                 };
 
@@ -1473,7 +1471,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                     SelectionMode = SelectionMode.Multiple,
                 };
                 AvaloniaLocator.CurrentMutable.Bind<PlatformHotkeyConfiguration>().ToConstant(new Mock<PlatformHotkeyConfiguration>().Object);
@@ -1503,7 +1501,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                     SelectionMode = SelectionMode.Multiple,
                 };
 
@@ -1542,7 +1540,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                     SelectionMode = SelectionMode.Multiple,
                 };
 
@@ -1575,7 +1573,7 @@ namespace Avalonia.Controls.UnitTests
                 var target = new TreeView
                 {
                     Template = CreateTreeViewTemplate(),
-                    Items = tree,
+                    ItemsSource = tree,
                     SelectionMode = SelectionMode.Multiple,
                 };
 
@@ -1606,7 +1604,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = tree,
+                ItemsSource = tree,
             };
 
             var visualRoot = new TestRoot();
@@ -1630,7 +1628,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new DerivedTreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = tree,
+                ItemsSource = tree,
             };
 
             var visualRoot = new TestRoot();
@@ -1655,7 +1653,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = tree,
+                ItemsSource = tree,
             };
 
             var visualRoot = new TestRoot();
@@ -1688,11 +1686,11 @@ namespace Avalonia.Controls.UnitTests
                 {
                     Template = CreateTreeViewTemplate(),
                     SelectionMode = SelectionMode.Multiple,
-                    Items = new List<Node>
-                {
-                    new Node { Value = "Root1", },
-                    new Node { Value = "Root2", },
-                },
+                    ItemsSource = new List<Node>
+                    {
+                        new Node { Value = "Root1", },
+                        new Node { Value = "Root2", },
+                    },
                 };
 
                 var visualRoot = new TestRoot
@@ -1726,7 +1724,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = tree,
+                ItemsSource = tree,
             };
 
             var root = new TestRoot();
@@ -1760,7 +1758,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new TreeView
             {
                 Template = CreateTreeViewTemplate(),
-                Items = tree,
+                ItemsSource = tree,
             };
 
             var root = new TestRoot();
@@ -1788,7 +1786,7 @@ namespace Avalonia.Controls.UnitTests
             var target = new DerivedTreeViewWithDerivedTreeViewItems
             {
                 Template = CreateTreeViewTemplate(),
-                Items = tree,
+                ItemsSource = tree,
             };
 
             ApplyTemplates(target);
@@ -1825,14 +1823,14 @@ namespace Avalonia.Controls.UnitTests
 
             foreach (var index in indexes)
             {
-                var item = ((IList)c.Items)[index];
+                var item = c.ItemsView[index];
                 c = (ItemsControl)target.TreeContainerFromItem(item);
             }
 
             return (TreeViewItem)c;
         }
 
-        private IList<Node> CreateTestTreeData()
+        private AvaloniaList<Node> CreateTestTreeData()
         {
             return new AvaloniaList<Node>
             {
diff --git a/tests/Avalonia.Controls.UnitTests/Utils/HotKeyManagerTests.cs b/tests/Avalonia.Controls.UnitTests/Utils/HotKeyManagerTests.cs
index 336aad79da..75a1baad6e 100644
--- a/tests/Avalonia.Controls.UnitTests/Utils/HotKeyManagerTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Utils/HotKeyManagerTests.cs
@@ -263,7 +263,7 @@ namespace Avalonia.Controls.UnitTests.Utils
             };
             var rootMenu = new Menu();
 
-            rootMenu.Items = new[] { menuitem };
+            rootMenu.Items.Add(menuitem);
 
             root.Content = rootMenu;
             return menuitem;
@@ -288,7 +288,7 @@ namespace Avalonia.Controls.UnitTests.Utils
             };
             var rootMenu = new Menu();
 
-            rootMenu.Items = new[] { menuitem };
+            rootMenu.Items.Add(menuitem);
 
             root.Content = rootMenu;
             return menuitem;
diff --git a/tests/Avalonia.Controls.UnitTests/VirtualizingCarouselPanelTests.cs b/tests/Avalonia.Controls.UnitTests/VirtualizingCarouselPanelTests.cs
index ea6b9367cf..721e8bde68 100644
--- a/tests/Avalonia.Controls.UnitTests/VirtualizingCarouselPanelTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/VirtualizingCarouselPanelTests.cs
@@ -218,7 +218,7 @@ namespace Avalonia.Controls.UnitTests
         {
             var carousel = new Carousel
             {
-                Items = items,
+                ItemsSource = items,
                 Template = CarouselTemplate(),
                 PageTransition = transition,
             };
diff --git a/tests/Avalonia.Controls.UnitTests/VirtualizingStackPanelTests.cs b/tests/Avalonia.Controls.UnitTests/VirtualizingStackPanelTests.cs
index ba8e7242a1..42b419bbcc 100644
--- a/tests/Avalonia.Controls.UnitTests/VirtualizingStackPanelTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/VirtualizingStackPanelTests.cs
@@ -9,15 +9,12 @@ using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Templates;
 using Avalonia.Data;
 using Avalonia.Layout;
-using Avalonia.LogicalTree;
 using Avalonia.Media;
 using Avalonia.Styling;
 using Avalonia.UnitTests;
 using Avalonia.VisualTree;
 using Xunit;
 
-#nullable enable
-
 namespace Avalonia.Controls.UnitTests
 {
     public class VirtualizingStackPanelTests
@@ -53,7 +50,7 @@ namespace Avalonia.Controls.UnitTests
 
             Assert.Empty(itemsControl.GetRealizedContainers());
 
-            itemsControl.Items = new[] { "foo", "bar" };
+            itemsControl.ItemsSource = new[] { "foo", "bar" };
             Layout(target);
 
             AssertRealizedItems(target, itemsControl, 0, 2);
@@ -99,7 +96,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using var app = App();
             var (target, _, itemsControl) = CreateTarget();
-            var items = (IList)itemsControl.Items!;
+            var items = (IList)itemsControl.ItemsSource!;
 
             Assert.Equal(10, target.GetRealizedElements().Count);
 
@@ -131,7 +128,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using var app = App();
             var (target, _, itemsControl) = CreateTarget();
-            var items = (IList)itemsControl.Items!;
+            var items = (IList)itemsControl.ItemsSource!;
 
             Assert.Equal(10, target.GetRealizedElements().Count);
 
@@ -161,7 +158,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using var app = App();
             var (target, _, itemsControl) = CreateTarget();
-            var items = (ObservableCollection<string>)itemsControl.Items!;
+            var items = (ObservableCollection<string>)itemsControl.ItemsSource!;
 
             Assert.Equal(10, target.GetRealizedElements().Count);
 
@@ -190,7 +187,7 @@ namespace Avalonia.Controls.UnitTests
         {
             using var app = App();
             var (target, _, itemsControl) = CreateTarget();
-            var items = (ObservableCollection<string>)itemsControl.Items!;
+            var items = (ObservableCollection<string>)itemsControl.ItemsSource!;
 
             Assert.Equal(10, target.GetRealizedElements().Count);
 
@@ -409,6 +406,36 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
+        [Fact]
+        public void ContainerPrepared_Is_Raised_When_Scrolling()
+        {
+            using var app = App();
+            var (target, scroll, itemsControl) = CreateTarget();
+            var raised = 0;
+
+            itemsControl.ContainerPrepared += (s, e) => ++raised;
+
+            scroll.Offset = new Vector(0, 200);
+            Layout(target);
+
+            Assert.Equal(10, raised);
+        }
+
+        [Fact]
+        public void ContainerClearing_Is_Raised_When_Scrolling()
+        {
+            using var app = App();
+            var (target, scroll, itemsControl) = CreateTarget();
+            var raised = 0;
+
+            itemsControl.ContainerClearing += (s, e) => ++raised;
+
+            scroll.Offset = new Vector(0, 200);
+            Layout(target);
+
+            Assert.Equal(10, raised);
+        }
+
         private static IReadOnlyList<int> GetRealizedIndexes(VirtualizingStackPanel target, ItemsControl itemsControl)
         {
             return target.GetRealizedElements()
@@ -473,7 +500,7 @@ namespace Avalonia.Controls.UnitTests
 
             var itemsControl = new ItemsControl
             {
-                Items = items,
+                ItemsSource = items,
                 Template = new FuncControlTemplate<ItemsControl>((_, _) => scroll),
                 ItemsPanel = new FuncTemplate<Panel>(() => target),
             };
diff --git a/tests/Avalonia.IntegrationTests.Appium/ElementExtensions.cs b/tests/Avalonia.IntegrationTests.Appium/ElementExtensions.cs
index 2184c5c155..99c30085d6 100644
--- a/tests/Avalonia.IntegrationTests.Appium/ElementExtensions.cs
+++ b/tests/Avalonia.IntegrationTests.Appium/ElementExtensions.cs
@@ -11,19 +11,26 @@ using Xunit;
 
 namespace Avalonia.IntegrationTests.Appium
 {
+    public record class WindowChrome(
+        AppiumWebElement? Close,
+        AppiumWebElement? Minimize,
+        AppiumWebElement? Maximize,
+        AppiumWebElement? FullScreen);
+
     internal static class ElementExtensions
     {
         public static IReadOnlyList<AppiumWebElement> GetChildren(this AppiumWebElement element) =>
             element.FindElementsByXPath("*/*");
 
-        public static (AppiumWebElement close, AppiumWebElement minimize, AppiumWebElement maximize) GetChromeButtons(this AppiumWebElement window)
+        public static WindowChrome GetChromeButtons(this AppiumWebElement window)
         {
             if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
             {
-                var closeButton = window.FindElementByXPath("//XCUIElementTypeButton[1]");
-                var fullscreenButton = window.FindElementByXPath("//XCUIElementTypeButton[2]");
-                var minimizeButton = window.FindElementByXPath("//XCUIElementTypeButton[3]");
-                return (closeButton, minimizeButton, fullscreenButton);
+                var closeButton = window.FindElementsByAccessibilityId("_XCUI:CloseWindow").FirstOrDefault();
+                var fullscreenButton = window.FindElementsByAccessibilityId("_XCUI:FullScreenWindow").FirstOrDefault();
+                var minimizeButton = window.FindElementsByAccessibilityId("_XCUI:MinimizeWindow").FirstOrDefault();
+                var zoomButton = window.FindElementsByAccessibilityId("_XCUI:ZoomWindow").FirstOrDefault();
+                return new(closeButton, minimizeButton, zoomButton, fullscreenButton);
             }
 
             throw new NotSupportedException("GetChromeButtons not supported on this platform.");
@@ -138,7 +145,7 @@ namespace Avalonia.IntegrationTests.Appium
                     var text = windows.Select(x => x.Text).ToList();
                     var newWindow = session.FindElements(By.XPath("/XCUIElementTypeApplication/XCUIElementTypeWindow"))
                         .First(x => x.Text == newWindowTitle);
-                    var (close, _, _) = ((AppiumWebElement)newWindow).GetChromeButtons();
+                    var close = ((AppiumWebElement)newWindow).FindElementByAccessibilityId("_XCUI:CloseWindow");
                     close!.Click();
                     Thread.Sleep(1000);
                 });
diff --git a/tests/Avalonia.IntegrationTests.Appium/PlatformFactAttribute.cs b/tests/Avalonia.IntegrationTests.Appium/PlatformFactAttribute.cs
index 3acf9fd5e2..17c42216e9 100644
--- a/tests/Avalonia.IntegrationTests.Appium/PlatformFactAttribute.cs
+++ b/tests/Avalonia.IntegrationTests.Appium/PlatformFactAttribute.cs
@@ -17,6 +17,7 @@ namespace Avalonia
     internal class PlatformFactAttribute : FactAttribute
     {
         private readonly string? _reason;
+        private string? _skip;
 
         public PlatformFactAttribute(TestPlatforms platforms, string? reason = null)
         {
@@ -28,8 +29,16 @@ namespace Avalonia
 
         public override string? Skip
         {
-            get => IsSupported() ? null : $"Ignored on {RuntimeInformation.OSDescription}" + (_reason is not null ? $" reason: \"{_reason}\"" : "");
-            set => throw new NotSupportedException();
+            get
+            {
+                if (_skip is not null)
+                    return _skip;
+                if (!IsSupported())
+                    return $"Ignored on {RuntimeInformation.OSDescription}" +
+                           (_reason is not null ? $" reason: '{_reason}'" : "");
+                return null;
+            }
+            set => _skip = value;
         }
 
         private bool IsSupported()
diff --git a/tests/Avalonia.IntegrationTests.Appium/PlatformTheoryAttribute.cs b/tests/Avalonia.IntegrationTests.Appium/PlatformTheoryAttribute.cs
index 7ac30ee11b..46a8e1af98 100644
--- a/tests/Avalonia.IntegrationTests.Appium/PlatformTheoryAttribute.cs
+++ b/tests/Avalonia.IntegrationTests.Appium/PlatformTheoryAttribute.cs
@@ -7,14 +7,21 @@ namespace Avalonia.IntegrationTests.Appium
 {
     internal class PlatformTheoryAttribute : TheoryAttribute
     {
+        private string? _skip;
+
         public PlatformTheoryAttribute(TestPlatforms platforms = TestPlatforms.All) => Platforms = platforms;
 
         public TestPlatforms Platforms { get; }
 
         public override string? Skip
         {
-            get => IsSupported() ? null : $"Ignored on {RuntimeInformation.OSDescription}";
-            set => throw new NotSupportedException();
+            get
+            {
+                if (_skip is not null)
+                    return _skip;
+                return !IsSupported() ? $"Ignored on {RuntimeInformation.OSDescription}" : null;
+            }
+            set => _skip = value;
         }
 
         private bool IsSupported()
diff --git a/tests/Avalonia.IntegrationTests.Appium/ScrollBarTests.cs b/tests/Avalonia.IntegrationTests.Appium/ScrollBarTests.cs
new file mode 100644
index 0000000000..e9d0a5d3a4
--- /dev/null
+++ b/tests/Avalonia.IntegrationTests.Appium/ScrollBarTests.cs
@@ -0,0 +1,33 @@
+using OpenQA.Selenium.Appium;
+using Xunit;
+
+namespace Avalonia.IntegrationTests.Appium
+{
+    [Collection("Default")]
+    public class ScrollBarTests
+    {
+        private readonly AppiumDriver<AppiumWebElement> _session;
+
+        public ScrollBarTests(DefaultAppFixture fixture)
+        {
+            _session = fixture.Session;
+
+            var tabs = _session.FindElementByAccessibilityId("MainTabs");
+            var tab = tabs.FindElementByName("ScrollBarTab");
+            tab.Click();
+        }
+
+        [Fact]
+        public void ScrollBar_Increases_Value_By_LargeChange_When_IncreaseButton_Is_Clicked()
+        {
+            var button = _session.FindElementByAccessibilityId("MyScrollBar");
+            Assert.True(double.Parse(button.Text) == 20);
+
+            button.Click();
+
+            // Default LargeChange value is 10 so when clicking the IncreaseButton
+            // ScrollBar value should be increased by 10.
+            Assert.Equal(30, double.Parse(button.Text));
+        }
+    }
+}
diff --git a/tests/Avalonia.IntegrationTests.Appium/WindowTests_MacOS.cs b/tests/Avalonia.IntegrationTests.Appium/WindowTests_MacOS.cs
index 039d30bbc1..68a31c7ccb 100644
--- a/tests/Avalonia.IntegrationTests.Appium/WindowTests_MacOS.cs
+++ b/tests/Avalonia.IntegrationTests.Appium/WindowTests_MacOS.cs
@@ -83,9 +83,9 @@ namespace Avalonia.IntegrationTests.Appium
         public void WindowOrder_Modal_Dialog_Stays_InFront_Of_Parent_When_In_Fullscreen()
         {
             var mainWindow = GetWindow("MainWindow");
-            var buttons = mainWindow.GetChromeButtons();
+            var fullScreen = mainWindow.FindElementByAccessibilityId("_XCUI:FullScreenWindow");
 
-            buttons.maximize.Click();
+            fullScreen.Click();
 
             Thread.Sleep(500);
 
@@ -239,17 +239,18 @@ namespace Avalonia.IntegrationTests.Appium
         public void Parent_Window_Has_Disabled_ChromeButtons_When_Modal_Dialog_Shown()
         {
             var window = GetWindow("MainWindow");
-            var (closeButton, miniaturizeButton, zoomButton) = window.GetChromeButtons();
+            var windowChrome = window.GetChromeButtons();
 
-            Assert.True(closeButton.Enabled);
-            Assert.True(zoomButton.Enabled);
-            Assert.True(miniaturizeButton.Enabled);
+            Assert.True(windowChrome.Close!.Enabled);
+            Assert.True(windowChrome.FullScreen!.Enabled);
+            Assert.True(windowChrome.Minimize!.Enabled);
+            Assert.Null(windowChrome.Maximize);
 
             using (OpenWindow(new PixelSize(200, 100), ShowWindowMode.Modal, WindowStartupLocation.CenterOwner))
             {
-                Assert.False(closeButton.Enabled);
-                Assert.False(zoomButton.Enabled);
-                Assert.False(miniaturizeButton.Enabled);
+                Assert.False(windowChrome.Close!.Enabled);
+                Assert.False(windowChrome.FullScreen!.Enabled);
+                Assert.False(windowChrome.Minimize!.Enabled);
             }
         }
 
@@ -259,11 +260,11 @@ namespace Avalonia.IntegrationTests.Appium
             using (OpenWindow(new PixelSize(200, 100), ShowWindowMode.Modal, WindowStartupLocation.CenterOwner))
             {
                 var secondaryWindow = GetWindow("SecondaryWindow");
-                var (closeButton, miniaturizeButton, zoomButton) = secondaryWindow.GetChromeButtons();
+                var windowChrome = secondaryWindow.GetChromeButtons();
 
-                Assert.True(closeButton.Enabled);
-                Assert.True(zoomButton.Enabled);
-                Assert.False(miniaturizeButton.Enabled);
+                Assert.True(windowChrome.Close!.Enabled);
+                Assert.True(windowChrome.Maximize!.Enabled);
+                Assert.False(windowChrome.Minimize!.Enabled);
             }
         }
         
@@ -274,7 +275,7 @@ namespace Avalonia.IntegrationTests.Appium
             using (OpenWindow(new PixelSize(200, 100), mode, WindowStartupLocation.Manual))
             {
                 var secondaryWindow = GetWindow("SecondaryWindow");
-                var (_, miniaturizeButton, _) = secondaryWindow.GetChromeButtons();
+                var miniaturizeButton = secondaryWindow.FindElementByAccessibilityId("_XCUI:MinimizeWindow");
 
                 Assert.False(miniaturizeButton.Enabled);
             }
@@ -288,7 +289,7 @@ namespace Avalonia.IntegrationTests.Appium
             using (OpenWindow(new PixelSize(200, 100), mode, WindowStartupLocation.Manual))
             {
                 var secondaryWindow = GetWindow("SecondaryWindow");
-                var (_, miniaturizeButton, _) = secondaryWindow.GetChromeButtons();
+                var miniaturizeButton = secondaryWindow.FindElementByAccessibilityId("_XCUI:MinimizeWindow");
 
                 miniaturizeButton.Click();
                 Thread.Sleep(1000);
@@ -332,7 +333,7 @@ namespace Avalonia.IntegrationTests.Appium
 
             // Close the window manually.
             secondaryWindow = GetWindow("SecondaryWindow");
-            secondaryWindow.GetChromeButtons().close.Click();
+            secondaryWindow.FindElementByAccessibilityId("_XCUI:CloseWindow").Click();
         }
 
         [PlatformTheory(TestPlatforms.MacOS)]
@@ -344,22 +345,92 @@ namespace Avalonia.IntegrationTests.Appium
             using (OpenWindow(null, mode, WindowStartupLocation.Manual, canResize: false))
             {
                 var secondaryWindow = GetWindow("SecondaryWindow");
-                var (_, _, zoomButton) = secondaryWindow.GetChromeButtons();
+                var zoomButton = mode == ShowWindowMode.NonOwned ?
+                    secondaryWindow.FindElementByAccessibilityId("_XCUI:FullScreenWindow") :
+                    secondaryWindow.FindElementByAccessibilityId("_XCUI:ZoomWindow");
                 Assert.False(zoomButton.Enabled);
             }
         }
-        
+
+        [PlatformFact(TestPlatforms.MacOS)]
+        public void Toggling_SystemDecorations_Should_Preserve_ExtendClientArea()
+        {
+            // #10650
+            using (OpenWindow(extendClientArea: true))
+            {
+                var secondaryWindow = GetWindow("SecondaryWindow");
+                
+                // The XPath of the title bar text _should_ be "XCUIElementTypeStaticText"
+                // but Appium seems to put a fake node between the window and the title bar
+                // https://stackoverflow.com/a/71914227/6448
+                var titleBar = secondaryWindow.FindElementsByXPath("/*/XCUIElementTypeStaticText").Count;
+                
+                Assert.Equal(0, titleBar);
+
+                secondaryWindow.FindElementByAccessibilityId("CurrentSystemDecorations").Click();
+                _session.FindElementByAccessibilityId("SystemDecorationsNone").SendClick();
+                secondaryWindow.FindElementByAccessibilityId("CurrentSystemDecorations").Click();
+                _session.FindElementByAccessibilityId("SystemDecorationsFull").SendClick();
+
+                titleBar = secondaryWindow.FindElementsByXPath("/*/XCUIElementTypeStaticText").Count;
+                Assert.Equal(0, titleBar);
+            }
+        }
+
+        [PlatformTheory(TestPlatforms.MacOS)]
+        [InlineData(SystemDecorations.None)]
+        [InlineData(SystemDecorations.BorderOnly)]
+        [InlineData(SystemDecorations.Full)]
+        public void ExtendClientArea_SystemDecorations_Shows_Correct_Buttons(SystemDecorations decorations)
+        {
+            // #10650
+            using (OpenWindow(extendClientArea: true, systemDecorations: decorations))
+            {
+                var secondaryWindow = GetWindow("SecondaryWindow");
+
+                try
+                {
+                    var chrome = secondaryWindow.GetChromeButtons();
+                
+                    if (decorations == SystemDecorations.Full)
+                    {
+                        Assert.NotNull(chrome.Close);
+                        Assert.NotNull(chrome.Minimize);
+                        Assert.NotNull(chrome.FullScreen);
+                    }
+                    else
+                    {
+                        Assert.Null(chrome.Close);
+                        Assert.Null(chrome.Minimize);
+                        Assert.Null(chrome.FullScreen);
+                    }
+                }
+                finally
+                {
+                    if (decorations != SystemDecorations.Full)
+                    {
+                        secondaryWindow.FindElementByAccessibilityId("CurrentSystemDecorations").Click();
+                        _session.FindElementByAccessibilityId("SystemDecorationsFull").SendClick();
+                    }
+                }
+            }
+        }
+
         private IDisposable OpenWindow(
-            PixelSize? size,
-            ShowWindowMode mode,
-            WindowStartupLocation location,
-            bool canResize = true)
+            PixelSize? size = null,
+            ShowWindowMode mode = ShowWindowMode.NonOwned,
+            WindowStartupLocation location = WindowStartupLocation.Manual,
+            bool canResize = true,
+            SystemDecorations systemDecorations = SystemDecorations.Full,
+            bool extendClientArea = false)
         {
             var sizeTextBox = _session.FindElementByAccessibilityId("ShowWindowSize");
             var modeComboBox = _session.FindElementByAccessibilityId("ShowWindowMode");
             var locationComboBox = _session.FindElementByAccessibilityId("ShowWindowLocation");
             var canResizeCheckBox = _session.FindElementByAccessibilityId("ShowWindowCanResize");
             var showButton = _session.FindElementByAccessibilityId("ShowWindow");
+            var systemDecorationsComboBox = _session.FindElementByAccessibilityId("ShowWindowSystemDecorations");
+            var extendClientAreaCheckBox = _session.FindElementByAccessibilityId("ShowWindowExtendClientAreaToDecorationsHint");
 
             if (size.HasValue)
                 sizeTextBox.SendKeys($"{size.Value.Width}, {size.Value.Height}");
@@ -379,6 +450,15 @@ namespace Avalonia.IntegrationTests.Appium
             if (canResizeCheckBox.GetIsChecked() != canResize)
                 canResizeCheckBox.Click();
 
+            if (systemDecorationsComboBox.GetComboBoxValue() != systemDecorations.ToString())
+            {
+                systemDecorationsComboBox.Click();
+                _session.FindElementByName(systemDecorations.ToString()).SendClick();
+            }
+            
+            if (extendClientAreaCheckBox.GetIsChecked() != extendClientArea)
+                extendClientAreaCheckBox.Click();
+            
             return showButton.OpenWindowWithClick();
         }
 
diff --git a/tests/Avalonia.LeakTests/ControlTests.cs b/tests/Avalonia.LeakTests/ControlTests.cs
index c9f79871c9..1320d34f39 100644
--- a/tests/Avalonia.LeakTests/ControlTests.cs
+++ b/tests/Avalonia.LeakTests/ControlTests.cs
@@ -353,7 +353,7 @@ namespace Avalonia.LeakTests
                                     (x, _) => new TextBlock { Text = x.Name },
                                     x => x.Children)
                             },
-                            Items = nodes
+                            ItemsSource = nodes
                         }
                     };
 
@@ -428,7 +428,7 @@ namespace Avalonia.LeakTests
                     {
                         Content = new TabControl
                         {
-                            Items = new[] { new TabItem() }
+                            ItemsSource = new[] { new TabItem() }
                         }
                     };
 
@@ -440,7 +440,7 @@ namespace Avalonia.LeakTests
                     Assert.IsType<TabItem>(tabControl.Presenter.Panel.Children[0]);
 
                     // Clear the items and ensure the TabItem is removed.
-                    tabControl.Items = null;
+                    tabControl.ItemsSource = null;
                     window.LayoutManager.ExecuteLayoutPass();
                     Assert.Empty(tabControl.Presenter.Panel.Children);
 
@@ -545,7 +545,7 @@ namespace Avalonia.LeakTests
                 {
                     var contextMenu = new ContextMenu
                     {
-                        Items = new[]
+                        Items =
                         {
                             new MenuItem { Header = "Foo" },
                             new MenuItem { Header = "Foo" },
@@ -594,7 +594,7 @@ namespace Avalonia.LeakTests
                 {
                     var contextMenu = new ContextMenu
                     {
-                        Items = new[]
+                        Items =
                         {
                             new MenuItem { Header = "Foo" },
                             new MenuItem { Header = "Foo" },
@@ -740,7 +740,7 @@ namespace Avalonia.LeakTests
                             }),
                             (lb = new ListBox
                             {
-                                Items = items,
+                                ItemsSource = items,
                                 ItemTemplate = new FuncDataTemplate<int>((_, _) =>
                                     new Canvas
                                     {
@@ -858,7 +858,7 @@ namespace Avalonia.LeakTests
                     // Add the listbox and render it
                     tl.Content = listBox;
                     lm.ExecuteInitialLayoutPass();
-                    listBox.Items = keyGestures;
+                    listBox.ItemsSource = keyGestures;
                     lm.ExecuteLayoutPass();
 
                     // Let the button detach when clearing the source items
diff --git a/tests/Avalonia.Markup.UnitTests/Data/MultiBindingTests.cs b/tests/Avalonia.Markup.UnitTests/Data/MultiBindingTests.cs
index bf9631760a..f6a4437a9e 100644
--- a/tests/Avalonia.Markup.UnitTests/Data/MultiBindingTests.cs
+++ b/tests/Avalonia.Markup.UnitTests/Data/MultiBindingTests.cs
@@ -173,11 +173,11 @@ namespace Avalonia.Markup.UnitTests.Data
                 },
             };
 
-            target.Bind(ItemsControl.ItemsProperty, binding);
+            target.Bind(ItemsControl.ItemsSourceProperty, binding);
             Assert.Equal(target.ItemCount, 3);
-            Assert.Equal(target.Items.ElementAt(0), source.A);
-            Assert.Equal(target.Items.ElementAt(1), source.B);
-            Assert.Equal(target.Items.ElementAt(2), source.C);
+            Assert.Equal(target.ItemsView[0], source.A);
+            Assert.Equal(target.ItemsView[1], source.B);
+            Assert.Equal(target.ItemsView[2], source.C);
         }
 
         private class ConcatConverter : IMultiValueConverter
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs
index 27634b457b..57d6a8902a 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs
@@ -122,7 +122,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
         xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'
         x:DataType='local:TestDataContext'>
-    <ItemsControl Name='itemsControl' Items='{CompiledBinding Path=ListProperty}'>
+    <ItemsControl Name='itemsControl' ItemsSource='{CompiledBinding Path=ListProperty}'>
 	    <ItemsControl.ItemTemplate>
 		    <DataTemplate>
 			    <TextBlock />
@@ -143,7 +143,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 window.DataContext = dataContext;
 
-                Assert.Equal(dataContext.ListProperty, textBlock.Items);
+                Assert.Equal(dataContext.ListProperty, textBlock.ItemsSource);
             }
         }
         
@@ -528,7 +528,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
         xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'
         x:DataType='local:TestDataContext'>
-    <ItemsControl Items='{CompiledBinding ListProperty}' Name='target'>
+    <ItemsControl ItemsSource='{CompiledBinding ListProperty}' Name='target'>
         <ItemsControl.ItemTemplate>
             <DataTemplate>
                 <TextBlock Text='{CompiledBinding}' Name='textBlock' />
@@ -1782,7 +1782,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
         xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'
         x:DataType='local:TestDataContext'
         x:CompileBindings='True'>
-    <ComboBox x:Name='comboBox' Items='{Binding GenericProperty}' SelectedItem='{Binding GenericProperty.CurrentItem}' />
+    <ComboBox x:Name='comboBox' ItemsSource='{Binding GenericProperty}' SelectedItem='{Binding GenericProperty.CurrentItem}' />
 </Window>";
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var comboBox = window.FindControl<ComboBox>("comboBox");
@@ -1991,7 +1991,10 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
     public class DataGridLikeControl : Control
     {
         public static readonly DirectProperty<DataGridLikeControl, IEnumerable?> ItemsProperty =
-            ItemsControl.ItemsProperty.AddOwner<DataGridLikeControl>(o => o.Items, (o, v) => o.Items = v);
+            AvaloniaProperty.RegisterDirect<DataGridLikeControl, IEnumerable?>(
+                nameof(Items),
+                x => x.Items,
+                (x, v) => x.Items = v);
 
         private IEnumerable _items;
         public IEnumerable Items
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BasicTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BasicTests.cs
index 1b795a304c..5d55c831a3 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BasicTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BasicTests.cs
@@ -505,7 +505,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
             {
                 var xaml = @"
 <Window xmlns='https://github.com/avaloniaui'>
-    <ItemsControl Name='itemsControl' Items='{Binding}'>
+    <ItemsControl Name='itemsControl' ItemsSource='{Binding}'>
     </ItemsControl>
 </Window>
 ";
@@ -522,7 +522,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
 
                 target.DataContext = items;
 
-                Assert.Equal(items, itemsControl.Items);
+                Assert.Equal(items, itemsControl.ItemsSource);
             }
         }
 
@@ -760,7 +760,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
             {
                 var xaml = @"
 <Window xmlns='https://github.com/avaloniaui'>
-    <ListBox Items='{Binding Items}' SelectedItems='{Binding SelectedItems}'/>
+    <ListBox ItemsSource='{Binding Items}' SelectedItems='{Binding SelectedItems}'/>
 </Window>";
 
                 var window = AvaloniaRuntimeXamlLoader.Parse<Window>(xaml);
@@ -773,7 +773,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
 
                 window.DataContext = vm;
 
-                Assert.Equal(vm.Items, listBox.Items);
+                Assert.Equal(vm.Items, listBox.ItemsSource);
 
                 Assert.Equal(vm.SelectedItems, listBox.SelectedItems);
             }
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/DataTemplateTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/DataTemplateTests.cs
index 70146bb0c1..05e81dc0ba 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/DataTemplateTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/DataTemplateTests.cs
@@ -74,7 +74,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
 <Window xmlns='https://github.com/avaloniaui'
         xmlns:sys='clr-namespace:System;assembly=mscorlib'
         xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
-    <ItemsControl Name='itemsControl' Items='{Binding}'>
+    <ItemsControl Name='itemsControl' ItemsSource='{Binding}'>
         <ItemsControl.ItemTemplate>
             <DataTemplate>
                 <UserControl Name='foo'/>
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/StyleTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/StyleTests.cs
index 933958b3a0..114b9d6064 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/StyleTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/StyleTests.cs
@@ -377,7 +377,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
                 };
 
                 var list = window.FindControl<ListBox>("list");
-                list.Items = collection;
+                list.ItemsSource = collection;
 
                 window.Show();
 
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/XamlIlTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/XamlIlTests.cs
index 09ed78accb..3154da8ecf 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/XamlIlTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/XamlIlTests.cs
@@ -391,7 +391,7 @@ namespace Avalonia.Markup.Xaml.UnitTests
   </ItemsControl>
 </Window>
 ", typeof(XamlIlBugTestsEventHandlerCodeBehind).Assembly, this);
-            ((ItemsControl)Content).Items = new[] {"123"};
+            ((ItemsControl)Content).ItemsSource = new[] {"123"};
         }
     }
     
diff --git a/tests/Avalonia.ReactiveUI.UnitTests/AutoDataTemplateBindingHookTest.cs b/tests/Avalonia.ReactiveUI.UnitTests/AutoDataTemplateBindingHookTest.cs
index c00303f4f8..9f49d94801 100644
--- a/tests/Avalonia.ReactiveUI.UnitTests/AutoDataTemplateBindingHookTest.cs
+++ b/tests/Avalonia.ReactiveUI.UnitTests/AutoDataTemplateBindingHookTest.cs
@@ -41,7 +41,7 @@ namespace Avalonia.ReactiveUI.UnitTests
                 
                 Content = List;
                 ViewModel = new ExampleViewModel();
-                this.OneWayBind(ViewModel, x => x.Items, x => x.List.Items);
+                this.OneWayBind(ViewModel, x => x.Items, x => x.List.ItemsSource);
             }
         }
 
diff --git a/tests/Avalonia.Skia.UnitTests/Media/CustomFontManagerImpl.cs b/tests/Avalonia.Skia.UnitTests/Media/CustomFontManagerImpl.cs
index e18344580b..4b91209e5b 100644
--- a/tests/Avalonia.Skia.UnitTests/Media/CustomFontManagerImpl.cs
+++ b/tests/Avalonia.Skia.UnitTests/Media/CustomFontManagerImpl.cs
@@ -68,66 +68,6 @@ namespace Avalonia.Skia.UnitTests.Media
             return true;
         }
 
-        public IGlyphTypeface CreateGlyphTypeface(Typeface typeface)
-        {
-            SKTypeface skTypeface;
-
-            Uri source = null;
-
-            switch (typeface.FontFamily.Name)
-            {
-                case "Twitter Color Emoji":
-                    {
-                        source = _emojiTypeface.FontFamily.Key.Source;
-                        break;
-                    }
-                case "Noto Sans":
-                    {
-                        source = _italicTypeface.FontFamily.Key.Source;
-                        break;
-                    }
-                case "Noto Sans Arabic":
-                    {
-                        source = _arabicTypeface.FontFamily.Key.Source;
-                        break;
-                    }
-                case "Noto Sans Hebrew":
-                    {
-                        source = _hebrewTypeface.FontFamily.Key.Source;
-                        break;
-                    }
-                case FontFamily.DefaultFontFamilyName:
-                case "Noto Mono":
-                    {
-                        source = _defaultTypeface.FontFamily.Key.Source;
-                        break;
-                    }
-                default:
-                    {
-
-                        break;
-                    }
-            }
-
-            if (source is null)
-            {
-                skTypeface = SKTypeface.FromFamilyName(typeface.FontFamily.Name,
-                           (SKFontStyleWeight)typeface.Weight, SKFontStyleWidth.Normal, (SKFontStyleSlant)typeface.Style);
-            }
-            else
-            {
-                var assetLoader = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();
-
-                var assetUri = FontFamilyLoader.LoadFontAssets(source).First();
-
-                var stream = assetLoader.Open(assetUri);
-
-                skTypeface = SKTypeface.FromStream(stream);
-            }
-
-            return new GlyphTypefaceImpl(skTypeface, FontSimulations.None);
-        }
-
         public bool TryCreateGlyphTypeface(string familyName, FontStyle style, FontWeight weight,
             FontStretch stretch, [NotNullWhen(true)] out IGlyphTypeface glyphTypeface)
         {
@@ -137,54 +77,40 @@ namespace Avalonia.Skia.UnitTests.Media
 
             switch (familyName)
             {
-                case "Twitter Color Emoji":
+                case "TWITTER COLOR EMOJI":
                     {
                         source = _emojiTypeface.FontFamily.Key.Source;
                         break;
                     }
-                case "Noto Sans":
+                case "NOTO SANS":
                     {
                         source = _italicTypeface.FontFamily.Key.Source;
                         break;
                     }
-                case "Noto Sans Arabic":
+                case "NOTO SANS ARABIC":
                     {
                         source = _arabicTypeface.FontFamily.Key.Source;
                         break;
                     }
-                case "Noto Sans Hebrew":
+                case "NOTO SANS HEBREW":
                     {
                         source = _hebrewTypeface.FontFamily.Key.Source;
                         break;
                     }
-                case FontFamily.DefaultFontFamilyName:
-                case "Noto Mono":
-                    {
-                        source = _defaultTypeface.FontFamily.Key.Source;
-                        break;
-                    }
                 default:
                     {
-
+                        source = _defaultTypeface.FontFamily.Key.Source;
                         break;
                     }
             }
 
-            if (source is null)
-            {
-                skTypeface = SKTypeface.FromFamilyName(familyName,
-                           (SKFontStyleWeight)weight, SKFontStyleWidth.Normal, (SKFontStyleSlant)style);
-            }
-            else
-            {
-                var assetLoader = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();
+            var assetLoader = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();
 
-                var assetUri = FontFamilyLoader.LoadFontAssets(source).First();
+            var assetUri = FontFamilyLoader.LoadFontAssets(source).First();
 
-                var stream = assetLoader.Open(assetUri);
+            var stream = assetLoader.Open(assetUri);
 
-                skTypeface = SKTypeface.FromStream(stream);
-            }
+            skTypeface = SKTypeface.FromStream(stream);
 
             glyphTypeface = new GlyphTypefaceImpl(skTypeface, FontSimulations.None);
 
diff --git a/tests/Avalonia.Skia.UnitTests/Media/FontManagerImplTests.cs b/tests/Avalonia.Skia.UnitTests/Media/FontManagerTests.cs
similarity index 72%
rename from tests/Avalonia.Skia.UnitTests/Media/FontManagerImplTests.cs
rename to tests/Avalonia.Skia.UnitTests/Media/FontManagerTests.cs
index 859726e871..37f275484a 100644
--- a/tests/Avalonia.Skia.UnitTests/Media/FontManagerImplTests.cs
+++ b/tests/Avalonia.Skia.UnitTests/Media/FontManagerTests.cs
@@ -1,5 +1,4 @@
 using System;
-using System.Linq;
 using Avalonia.Media;
 using Avalonia.UnitTests;
 using SkiaSharp;
@@ -7,7 +6,7 @@ using Xunit;
 
 namespace Avalonia.Skia.UnitTests.Media
 {
-    public class FontManagerImplTests
+    public class FontManagerTests
     {
         private static string s_fontUri = "resm:Avalonia.Skia.UnitTests.Assets?assembly=Avalonia.Skia.UnitTests#Noto Mono";
 
@@ -87,5 +86,36 @@ namespace Avalonia.Skia.UnitTests.Media
                 Assert.False(result);
             }
         }
+
+        [Fact]
+        public void Should_Load_Embedded_Font_With_Wrong_CharacterCasing()
+        {
+            using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface.With(fontManagerImpl: new FontManagerImpl())))
+            {
+                var result = FontManager.Current.TryGetGlyphTypeface(new Typeface("resm:Avalonia.Skia.UnitTests.Assets?assembly=Avalonia.Skia.UnitTests#noto mOnO"), out var glyphTypeface);
+
+                Assert.True(result);
+
+                Assert.Equal("Noto Mono", glyphTypeface.FamilyName);
+            }
+        }
+
+        [Fact]
+        public void Should_Load_Embedded_DefaultFontFamily()
+        {
+            using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface.With(fontManagerImpl: new FontManagerImpl())))
+            {
+                using (AvaloniaLocator.EnterScope())
+                {
+                    AvaloniaLocator.CurrentMutable.BindToSelf(new FontManagerOptions { DefaultFamilyName = s_fontUri });
+
+                    var result = FontManager.Current.TryGetGlyphTypeface(new Typeface(FontFamily.DefaultFontFamilyName), out var glyphTypeface);
+
+                    Assert.True(result);
+
+                    Assert.Equal("Noto Mono", glyphTypeface.FamilyName);
+                }
+            }
+        }
     }
 }
diff --git a/tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextFormatterTests.cs b/tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextFormatterTests.cs
index 540c05f0da..cdcaadeff8 100644
--- a/tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextFormatterTests.cs
+++ b/tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextFormatterTests.cs
@@ -416,14 +416,14 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
         }
 
         [InlineData("Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor",
-            new[] { "Lorem ipsum ", "dolor sit amet, ", "consectetur ", "adipisicing elit, ", "sed do eiusmod " })]
+            new[] { "Lorem ipsum ", "dolor sit ", "amet, ", "consectetur ", "adipisicing ", "elit, sed do ", "eiusmod tempor" })]
 
         [Theory]
         public void Should_Produce_Wrapped_And_Trimmed_Lines(string text, string[] expectedLines)
         {
             using (Start())
             {
-                var typeface = new Typeface("Verdana");
+                var typeface = Typeface.Default;
 
                 var defaultProperties = new GenericTextRunProperties(typeface, 32, foregroundBrush: Brushes.Black);
 
@@ -432,9 +432,9 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                     new ValueSpan<TextRunProperties>(0, 5,
                         new GenericTextRunProperties(typeface, 48)),
                     new ValueSpan<TextRunProperties>(6, 11,
-                        new GenericTextRunProperties(new Typeface("Verdana", weight: FontWeight.Bold), 32)),
+                        new GenericTextRunProperties(new Typeface(FontFamily.Default, weight: FontWeight.Bold), 32)),
                     new ValueSpan<TextRunProperties>(28, 28,
-                        new GenericTextRunProperties(new Typeface("Verdana", FontStyle.Italic),32))
+                        new GenericTextRunProperties(new Typeface(FontFamily.Default, FontStyle.Italic),32))
                 };
 
                 var textSource = new FormattedTextSource(text, defaultProperties, styleSpans);