Merge branch 'master' into improve-input-android

.github/PULL_REQUEST_TEMPLATE.md

@@ -21,7 +21,7 @@
 - [ ] Consider submitting a PR to https://github.com/AvaloniaUI/Documentation with user documentation
 
 ## Breaking changes
-<!--- List any breaking changes here. When the PR is merged please add an entry to https://github.com/AvaloniaUI/Avalonia/wiki/Breaking-Changes -->
+<!--- List any breaking changes here. -->
 
 ## Obsoletions / Deprecations
 <!--- Obsolete and Deprecated attributes on APIs MUST only be included when discussed with Core team. @grokys, @kekekeks & @danwalmsley -->

build/HarfBuzzSharp.props

@@ -1,7 +1,7 @@
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup>
-    <PackageReference Include="HarfBuzzSharp" Version="2.8.2" />
-    <PackageReference Condition="'$(IncludeLinuxSkia)' == 'true'" Include="HarfBuzzSharp.NativeAssets.Linux" Version="2.8.2" />
-    <PackageReference Condition="'$(IncludeWasmSkia)' == 'true'" Include="HarfBuzzSharp.NativeAssets.WebAssembly" Version="2.8.2" />
+    <PackageReference Include="HarfBuzzSharp" Version="2.8.2.1-preview.108" />
+    <PackageReference Condition="'$(IncludeLinuxSkia)' == 'true'" Include="HarfBuzzSharp.NativeAssets.Linux" Version="2.8.2.1-preview.108" />
+    <PackageReference Condition="'$(IncludeWasmSkia)' == 'true'" Include="HarfBuzzSharp.NativeAssets.WebAssembly" Version="2.8.2.1-preview.108" />
   </ItemGroup>
 </Project>

build/ReactiveUI.props

@@ -1,5 +1,5 @@
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup>
-    <PackageReference Include="ReactiveUI" Version="13.2.10" />
+    <PackageReference Include="ReactiveUI" Version="18.3.1" />
   </ItemGroup>
 </Project>

build/SkiaSharp.props

@@ -1,7 +1,7 @@
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup>
-    <PackageReference Include="SkiaSharp" Version="2.88.1-preview.1" />
-    <PackageReference Condition="'$(IncludeLinuxSkia)' == 'true'" Include="SkiaSharp.NativeAssets.Linux" Version="2.88.1-preview.1" />
-    <PackageReference Condition="'$(IncludeWasmSkia)' == 'true'" Include="SkiaSharp.NativeAssets.WebAssembly" Version="2.88.1-preview.1" />
+    <PackageReference Include="SkiaSharp" Version="2.88.1-preview.108" />
+    <PackageReference Condition="'$(IncludeLinuxSkia)' == 'true'" Include="SkiaSharp.NativeAssets.Linux" Version="2.88.1-preview.108" />
+    <PackageReference Condition="'$(IncludeWasmSkia)' == 'true'" Include="SkiaSharp.NativeAssets.WebAssembly" Version="2.88.1-preview.108" />
   </ItemGroup>
 </Project>

samples/ControlCatalog/DecoratedWindow.xaml

@@ -2,7 +2,7 @@
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         x:Class="ControlCatalog.DecoratedWindow"
         Title="Avalonia Control Gallery"
-        xmlns:local="clr-namespace:ControlCatalog" HasSystemDecorations="False" Name="Window">
+        xmlns:local="clr-namespace:ControlCatalog" SystemDecorations="None" Name="Window">
         <NativeMenu.Menu>
     <NativeMenu>
       <NativeMenuItem Header="Decorated">

samples/ControlCatalog/MainView.xaml.cs

@@ -22,8 +22,8 @@ namespace ControlCatalog
 
             if (AvaloniaLocator.Current?.GetService<IRuntimePlatform>()?.GetRuntimeInfo().IsDesktop == true)
             {
-                IList tabItems = ((IList)sideBar.Items);
-                tabItems.Add(new TabItem()
+                var tabItems = (sideBar.Items as IList);
+                tabItems?.Add(new TabItem()
                 {
                     Header = "Screens",
                     Content = new ScreenPage()
@@ -36,7 +36,7 @@ namespace ControlCatalog
             {
                 if (themes.SelectedItem is CatalogTheme theme)
                 {
-                    var themeStyle = Application.Current.Styles[0];
+                    var themeStyle = Application.Current!.Styles[0];
                     if (theme == CatalogTheme.FluentLight)
                     {
                         if (App.Fluent.Mode != FluentThemeMode.Light)

samples/ControlCatalog/MainWindow.xaml

@@ -18,15 +18,15 @@
     <NativeMenu>
       <NativeMenuItem Header="File">
         <NativeMenu>
-          <NativeMenuItem Icon="/Assets/test_icon.ico" Header="Open" Clicked="OnOpenClicked" Gesture="Ctrl+O"/>
-          <NativeMenuItemSeperator/><!-- Uses incorrect spelling to demonstrate backwards compatibility -->
+          <NativeMenuItem Icon="/Assets/test_icon.ico" Header="Open" Click="OnOpenClicked" Gesture="Ctrl+O"/>
+          <NativeMenuItemSeparator/>
           <NativeMenuItem Icon="/Assets/github_icon.png" Header="Recent">
             <NativeMenu/>
           </NativeMenuItem>
           <NativeMenuItemSeparator/>
           <NativeMenuItem Header="{x:Static local:MainWindow.MenuQuitHeader}"
                           Gesture="{x:Static local:MainWindow.MenuQuitGesture}"
-                          Clicked="OnCloseClicked" />
+                          Click="OnCloseClicked" />
         </NativeMenu>
       </NativeMenuItem>
       <NativeMenuItem Header="Edit">

samples/ControlCatalog/Models/Person.cs

@@ -85,7 +85,7 @@ namespace ControlCatalog.Models
             }
             else
             {
-                if (_errorLookup.TryGetValue(propertyName, out List<string> errorList))
+                if (_errorLookup.TryGetValue(propertyName, out var errorList))
                 {
                     errorList.Clear();
                     errorList.Add(error!);
@@ -114,12 +114,12 @@ namespace ControlCatalog.Models
             PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
         }
 
-        public IEnumerable? GetErrors(string propertyName)
+        public IEnumerable GetErrors(string? propertyName)
         {
-            if (_errorLookup.TryGetValue(propertyName, out List<string> errorList))
+            if (propertyName is { } && _errorLookup.TryGetValue(propertyName, out var errorList))
                 return errorList;
             else
-                return null;
+                return Array.Empty<object>();
         }
     }
 }

samples/ControlCatalog/Pages/AutoCompleteBoxPage.xaml

@@ -28,7 +28,7 @@
       </StackPanel>
       <StackPanel>
         <TextBlock Text="MinimumPopulateDelay: 1s" />
-        <AutoCompleteBox MinimumPopulateDelay="1" />
+        <AutoCompleteBox MinimumPopulateDelay="00:00:01" />
       </StackPanel>
       <StackPanel>
         <TextBlock Text="MaxDropDownHeight: 60" />

samples/ControlCatalog/Pages/AutoCompleteBoxPage.xaml.cs

@@ -1,8 +1,6 @@
 using Avalonia.Controls;
 using Avalonia.LogicalTree;
-using Avalonia.Markup;
 using Avalonia.Markup.Xaml;
-using Avalonia.Markup.Data;
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -161,23 +159,23 @@ namespace ControlCatalog.Pages
         private bool LastWordContains(string? searchText, string? item)
         {
             var words = searchText?.Split(' ') ?? Array.Empty<string>();
-            var options = Sentences.Select(x => x.First).ToArray();
+            var options = Sentences.Select(x => x.First)
+                .ToArray<LinkedListNode<string>?>();
             for (var i = 0; i < words.Length; ++i)
             {
                 var word = words[i];
                 for (var j = 0; word is { } && j < options.Length; ++j)
                 {
-                    var option = options[j];
-                    if (option == null)
-                        continue;
-
-                    if (i == words.Length - 1)
-                    {
-                        options[j] = option.Value.ToLower().Contains(word.ToLower()) ? option : null;
-                    }
-                    else
+                    if (options[i] is { } option)
                     {
-                        options[j] = option.Value.Equals(word, StringComparison.InvariantCultureIgnoreCase) ? option.Next : null;
+                        if (i == words.Length - 1)
+                        {
+                            options[j] = option.Value.ToLower().Contains(word.ToLower()) ? option : null;
+                        }
+                        else
+                        {
+                            options[j] = option.Value.Equals(word, StringComparison.InvariantCultureIgnoreCase) ? option.Next : null;
+                        }
                     }
                 }
             }

samples/ControlCatalog/Pages/ButtonSpinnerPage.xaml.cs

@@ -21,20 +21,23 @@ namespace ControlCatalog.Pages
         public void OnSpin(object sender, SpinEventArgs e)
         {
             var spinner = (ButtonSpinner)sender;
-            var txtBox = (TextBlock)spinner.Content;
 
-            int value = Array.IndexOf(_mountains, txtBox?.Text);
-            if (e.Direction == SpinDirection.Increase)
-                value++;
-            else
-                value--;
+            if (spinner.Content is TextBlock txtBox)
+            {
+                int value = Array.IndexOf(_mountains, txtBox.Text);
+                if (e.Direction == SpinDirection.Increase)
+                    value++;
+                else
+                    value--;
 
-            if (value < 0)
-                value = _mountains.Length - 1;
-            else if (value >= _mountains.Length)
-                value = 0;
+                if (value < 0)
+                    value = _mountains.Length - 1;
+                else if (value >= _mountains.Length)
+                    value = 0;
+
+                txtBox.Text = _mountains[value];
+            }
 
-            txtBox.Text = _mountains[value];
         }
 
         private readonly string[] _mountains = new[]

samples/ControlCatalog/Pages/ButtonsPage.xaml.cs

@@ -19,7 +19,7 @@ namespace ControlCatalog.Pages
             AvaloniaXamlLoader.Load(this);
         }
 
-        public void OnRepeatButtonClick(object sender, object args)
+        public void OnRepeatButtonClick(object? sender, object args)
         {
             repeatButtonClickCount++;
             var textBlock = this.Get<TextBlock>("RepeatButtonTextBlock");

samples/ControlCatalog/Pages/CarouselPage.xaml.cs

@@ -33,7 +33,7 @@ namespace ControlCatalog.Pages
 
         }
 
-        private void TransitionChanged(object sender, SelectionChangedEventArgs e)
+        private void TransitionChanged(object? sender, SelectionChangedEventArgs e)
         {
             switch (_transition.SelectedIndex)
             {

samples/ControlCatalog/Pages/ClipboardPage.xaml.cs

@@ -23,55 +23,79 @@ namespace ControlCatalog.Pages
             AvaloniaXamlLoader.Load(this);
         }
 
-        private async void CopyText(object sender, RoutedEventArgs args)
+        private async void CopyText(object? sender, RoutedEventArgs args)
         {
-            await Application.Current.Clipboard.SetTextAsync(ClipboardContent.Text);
+            if (Application.Current!.Clipboard is { } clipboard && ClipboardContent is { } clipboardContent)
+                await clipboard.SetTextAsync(clipboardContent.Text ?? String.Empty);
         }
 
-        private async void PasteText(object sender, RoutedEventArgs args)
+        private async void PasteText(object? sender, RoutedEventArgs args)
         {
-            ClipboardContent.Text = await Application.Current.Clipboard.GetTextAsync();
+            if(Application.Current!.Clipboard is { } clipboard)
+            {
+                ClipboardContent.Text = await clipboard.GetTextAsync();
+            }
         }
 
-        private async void CopyTextDataObject(object sender, RoutedEventArgs args)
+        private async void CopyTextDataObject(object? sender, RoutedEventArgs args)
         {
-            var dataObject = new DataObject();
-            dataObject.Set(DataFormats.Text, ClipboardContent.Text ?? string.Empty);
-            await Application.Current.Clipboard.SetDataObjectAsync(dataObject);
+            if (Application.Current!.Clipboard is { } clipboard)
+            {
+                var dataObject = new DataObject();
+                dataObject.Set(DataFormats.Text, ClipboardContent.Text ?? string.Empty);
+                await clipboard.SetDataObjectAsync(dataObject);
+            }
         }
 
-        private async void PasteTextDataObject(object sender, RoutedEventArgs args)
+        private async void PasteTextDataObject(object? sender, RoutedEventArgs args)
         {
-            ClipboardContent.Text = await Application.Current.Clipboard.GetDataAsync(DataFormats.Text) as string ?? string.Empty;
+            if (Application.Current!.Clipboard is { } clipboard)
+            {
+                ClipboardContent.Text = await clipboard.GetDataAsync(DataFormats.Text) as string ?? string.Empty;
+            }
         }
 
-        private async void CopyFilesDataObject(object sender, RoutedEventArgs args)
+        private async void CopyFilesDataObject(object? sender, RoutedEventArgs args)
         {
-            var files = ClipboardContent.Text.Split(new[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
-            if (files.Length == 0)
+            if (Application.Current!.Clipboard is { } clipboard)
             {
-                return;
+                var files = (ClipboardContent.Text ?? String.Empty)
+                .Split(new[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
+                if (files.Length == 0)
+                {
+                    return;
+                }
+                var dataObject = new DataObject();
+                dataObject.Set(DataFormats.FileNames, files);
+                await clipboard.SetDataObjectAsync(dataObject);
             }
-            var dataObject = new DataObject();
-            dataObject.Set(DataFormats.FileNames, files);
-            await Application.Current.Clipboard.SetDataObjectAsync(dataObject);
         }
 
-        private async void PasteFilesDataObject(object sender, RoutedEventArgs args)
+        private async void PasteFilesDataObject(object? sender, RoutedEventArgs args)
         {
-            var fiels = await Application.Current.Clipboard.GetDataAsync(DataFormats.FileNames) as IEnumerable<string>;
-            ClipboardContent.Text = fiels != null ? string.Join(Environment.NewLine, fiels) : string.Empty;
+            if (Application.Current!.Clipboard is { } clipboard)
+            {
+                var fiels = await clipboard.GetDataAsync(DataFormats.FileNames) as IEnumerable<string>;
+                ClipboardContent.Text = fiels != null ? string.Join(Environment.NewLine, fiels) : string.Empty;
+            }
         }
 
         private async void GetFormats(object sender, RoutedEventArgs args)
         {
-            var formats = await Application.Current.Clipboard.GetFormatsAsync();
-            ClipboardContent.Text = string.Join(Environment.NewLine, formats);
+            if (Application.Current!.Clipboard is { } clipboard)
+            {
+                var formats = await clipboard.GetFormatsAsync();
+                ClipboardContent.Text = string.Join(Environment.NewLine, formats);
+            }
         }
 
         private async void Clear(object sender, RoutedEventArgs args)
         {
-            await Application.Current.Clipboard.ClearAsync();
+            if (Application.Current!.Clipboard is { } clipboard)
+            {
+                await clipboard.ClearAsync();
+            }
+                
         }
     }
 }

samples/ControlCatalog/Pages/ComboBoxPage.xaml.cs

@@ -17,7 +17,7 @@ namespace ControlCatalog.Pages
         private void InitializeComponent()
         {
             AvaloniaXamlLoader.Load(this);
-            var fontComboBox = this.Find<ComboBox>("fontComboBox");
+            var fontComboBox = this.Get<ComboBox>("fontComboBox");
             fontComboBox.Items = FontManager.Current.GetInstalledFontFamilyNames().Select(x => new FontFamily(x));
             fontComboBox.SelectedIndex = 0;
         }

samples/ControlCatalog/Pages/CompositionPage.axaml.cs

@@ -1,14 +1,8 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Numerics;
-using System.Threading.Tasks;
 using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Controls.Primitives;
-using Avalonia.Interactivity;
 using Avalonia.Markup.Xaml;
-using Avalonia.Markup.Xaml.Templates;
 using Avalonia.Media;
 using Avalonia.Rendering.Composition;
 using Avalonia.Rendering.Composition.Animations;
@@ -18,7 +12,7 @@ namespace ControlCatalog.Pages;
 
 public partial class CompositionPage : UserControl
 {
-    private ImplicitAnimationCollection _implicitAnimations;
+    private ImplicitAnimationCollection? _implicitAnimations;
 
     public CompositionPage()
     {
@@ -28,7 +22,7 @@ public partial class CompositionPage : UserControl
     protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
     {
         base.OnAttachedToVisualTree(e);
-        this.FindControl<ItemsControl>("Items").Items = CreateColorItems();
+        this.Get<ItemsControl>("Items").Items = CreateColorItems();
     }
 
     private List<CompositionPageColorItem> CreateColorItems()
@@ -115,7 +109,6 @@ public partial class CompositionPage : UserControl
 
     public static void SetEnableAnimations(Border border, bool value)
     {
-        
         var page = border.FindAncestorOfType<CompositionPage>();
         if (page == null)
         {
@@ -127,8 +120,11 @@ public partial class CompositionPage : UserControl
             return;
 
         page.EnsureImplicitAnimations();
-        ElementComposition.GetElementVisual((Visual)border.GetVisualParent()).ImplicitAnimations =
-            page._implicitAnimations;
+        if (border.GetVisualParent() is Visual visualParent 
+            && ElementComposition.GetElementVisual(visualParent) is CompositionVisual compositionVisual)
+        {
+            compositionVisual.ImplicitAnimations = page._implicitAnimations;
+        }
     }
 }
 
@@ -150,4 +146,4 @@ public class CompositionPageColorItem
     {
         Color = color;
     }
-}
+}

samples/ControlCatalog/Pages/ContextFlyoutPage.xaml.cs

@@ -52,13 +52,13 @@ namespace ControlCatalog.Pages
             base.OnDataContextChanged(e);
         }
 
-        private void ContextFlyoutPage_Closing(object sender, CancelEventArgs e)
+        private void ContextFlyoutPage_Closing(object? sender, CancelEventArgs e)
         {
             var cancelCloseCheckBox = this.FindControl<CheckBox>("CancelCloseCheckBox");
             e.Cancel = cancelCloseCheckBox?.IsChecked ?? false;
         }
 
-        private void ContextFlyoutPage_Opening(object sender, EventArgs e)
+        private void ContextFlyoutPage_Opening(object? sender, EventArgs e)
         {
             if (e is CancelEventArgs cancelArgs)
             {
@@ -67,20 +67,20 @@ namespace ControlCatalog.Pages
             }
         }
 
-        private void CloseFlyout(object sender, RoutedEventArgs e)
+        private void CloseFlyout(object? sender, RoutedEventArgs e)
         {
             _textBox.ContextFlyout?.Hide();
         }
 
-        public void CustomContextRequested(object sender, ContextRequestedEventArgs e)
+        public void CustomContextRequested(object? sender, ContextRequestedEventArgs e)
         {
-            var border = (Border)sender;
-            var textBlock = (TextBlock)border.Child;
-
-            textBlock.Text = e.TryGetPosition(border, out var point)
-                ? $"Context was requested with pointer at: {point.X:N0}, {point.Y:N0}"
-                : "Context was requested without pointer";
-            e.Handled = true;
+            if (sender is Border border && border.Child is TextBlock textBlock)
+            {
+                textBlock.Text = e.TryGetPosition(border, out var point)
+                    ? $"Context was requested with pointer at: {point.X:N0}, {point.Y:N0}"
+                    : "Context was requested without pointer";
+                e.Handled = true;
+            }
         }
 
         private void InitializeComponent()

samples/ControlCatalog/Pages/ContextMenuPage.xaml.cs

@@ -35,30 +35,31 @@ namespace ControlCatalog.Pages
             base.OnDataContextChanged(e);
         }
 
-        private void ContextFlyoutPage_Closing(object sender, CancelEventArgs e)
+        private void ContextFlyoutPage_Closing(object? sender, CancelEventArgs e)
         {
             var cancelCloseCheckBox = this.FindControl<CheckBox>("CancelCloseCheckBox");
-            e.Cancel = cancelCloseCheckBox.IsChecked ?? false;
+            e.Cancel = cancelCloseCheckBox?.IsChecked ?? false;
         }
 
-        private void ContextFlyoutPage_Opening(object sender, EventArgs e)
+        private void ContextFlyoutPage_Opening(object? sender, EventArgs e)
         {
             if (e is CancelEventArgs cancelArgs)
             {
                 var cancelCloseCheckBox = this.FindControl<CheckBox>("CancelOpenCheckBox");
-                cancelArgs.Cancel = cancelCloseCheckBox.IsChecked ?? false;
+                cancelArgs.Cancel = cancelCloseCheckBox?.IsChecked ?? false;
             }
         }
 
-        public void CustomContextRequested(object sender, ContextRequestedEventArgs e)
+        public void CustomContextRequested(object? sender, ContextRequestedEventArgs e)
         {
-            var border = (Border)sender;
-            var textBlock = (TextBlock)border.Child;
+            if (sender is Border border && border.Child is TextBlock textBlock)
+            {
+                textBlock.Text = e.TryGetPosition(border, out var point)
+                    ? $"Context was requested with pointer at: {point.X:N0}, {point.Y:N0}"
+                    : "Context was requested without pointer";
+                e.Handled = true;
+            }
 
-            textBlock.Text = e.TryGetPosition(border, out var point)
-                ? $"Context was requested with pointer at: {point.X:N0}, {point.Y:N0}"
-                : "Context was requested without pointer";
-            e.Handled = true;
         }
 
         private void InitializeComponent()

samples/ControlCatalog/Pages/DataGridPage.xaml.cs

@@ -62,7 +62,7 @@ namespace ControlCatalog.Pages
             addButton.Click += (a, b) => collectionView3.AddNew();
         }
 
-        private void Dg1_LoadingRow(object sender, DataGridRowEventArgs e)
+        private void Dg1_LoadingRow(object? sender, DataGridRowEventArgs e)
         {
             e.Row.Header = e.Row.GetIndex() + 1;
         }
@@ -74,7 +74,7 @@ namespace ControlCatalog.Pages
 
         private class ReversedStringComparer : IComparer<object>, IComparer
         {
-            public int Compare(object x, object y)
+            public int Compare(object? x, object? y)
             {
                 if (x is string left && y is string right)
                 {

samples/ControlCatalog/Pages/DialogsPage.xaml.cs

@@ -111,9 +111,16 @@ namespace ControlCatalog.Pages
                     Title = "Select folder",
                     Directory = lastSelectedDirectory?.TryGetUri(out var path) == true ? path.LocalPath : null
                 }.ShowAsync(GetWindow());
-                lastSelectedDirectory = new BclStorageFolder(new System.IO.DirectoryInfo(result));
-                results.Items = new [] { result };
-                resultsVisible.IsVisible = result != null;
+                if (string.IsNullOrEmpty(result))
+                {
+                    resultsVisible.IsVisible = false;
+                }
+                else
+                {
+                    lastSelectedDirectory = new BclStorageFolder(new System.IO.DirectoryInfo(result));
+                    results.Items = new[] { result };
+                    resultsVisible.IsVisible = true;
+                }
             };
             this.Get<Button>("OpenBoth").Click += async delegate
             {

samples/ControlCatalog/Pages/DragAndDropPage.xaml.cs

@@ -1,9 +1,9 @@
-using Avalonia.Controls;
-using Avalonia.Input;
-using Avalonia.Markup.Xaml;
-using System;
+using System;
 using System.Linq;
 using System.Reflection;
+using Avalonia.Controls;
+using Avalonia.Input;
+using Avalonia.Markup.Xaml;
 
 namespace ControlCatalog.Pages
 {
@@ -27,9 +27,9 @@ namespace ControlCatalog.Pages
         void SetupDnd(string suffix, Action<DataObject> factory, DragDropEffects effects)
         {
             var dragMe = this.Get<Border>("DragMe" + suffix);
-            var dragState = this.Get<TextBlock>("DragState"+suffix);
+            var dragState = this.Get<TextBlock>("DragState" + suffix);
 
-            async void DoDrag(object sender, Avalonia.Input.PointerPressedEventArgs e)
+            async void DoDrag(object? sender, Avalonia.Input.PointerPressedEventArgs e)
             {
                 var dragData = new DataObject();
                 factory(dragData);
@@ -55,7 +55,7 @@ namespace ControlCatalog.Pages
                 }
             }
 
-            void DragOver(object sender, DragEventArgs e)
+            void DragOver(object? sender, DragEventArgs e)
             {
                 if (e.Source is Control c && c.Name == "MoveTarget")
                 {
@@ -73,7 +73,7 @@ namespace ControlCatalog.Pages
                     e.DragEffects = DragDropEffects.None;
             }
 
-            void Drop(object sender, DragEventArgs e)
+            void Drop(object? sender, DragEventArgs e)
             {
                 if (e.Source is Control c && c.Name == "MoveTarget")
                 {
@@ -83,11 +83,11 @@ namespace ControlCatalog.Pages
                 {
                     e.DragEffects = e.DragEffects & (DragDropEffects.Copy);
                 }
-                
+
                 if (e.Data.Contains(DataFormats.Text))
                     _DropState.Text = e.Data.GetText();
                 else if (e.Data.Contains(DataFormats.FileNames))
-                    _DropState.Text = string.Join(Environment.NewLine, e.Data.GetFileNames());
+                    _DropState.Text = string.Join(Environment.NewLine, e.Data.GetFileNames() ?? Array.Empty<string>());
                 else if (e.Data.Contains(CustomFormat))
                     _DropState.Text = "Custom: " + e.Data.Get(CustomFormat);
             }

samples/ControlCatalog/Pages/FlyoutsPage.axaml.cs

@@ -20,7 +20,7 @@ namespace ControlCatalog.Pages
             SetXamlTexts();
         }
 
-        private void Afp_DoubleTapped(object sender, RoutedEventArgs e)
+        private void Afp_DoubleTapped(object? sender, RoutedEventArgs e)
         {
             if (sender is Panel p)
             {

samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml.cs

@@ -123,7 +123,7 @@ namespace ControlCatalog.Pages
             element.BringIntoView();
         }
 
-        private void RepeaterClick(object sender, PointerPressedEventArgs e)
+        private void RepeaterClick(object? sender, PointerPressedEventArgs e)
         {
             if ((e.Source as TextBlock)?.DataContext is ItemsRepeaterPageViewModel.Item item)
             {
@@ -132,7 +132,7 @@ namespace ControlCatalog.Pages
             }
         }
 
-        private void RepeaterOnKeyDown(object sender, KeyEventArgs e)
+        private void RepeaterOnKeyDown(object? sender, KeyEventArgs e)
         {
             if (e.Key == Key.F5)
             {
@@ -140,17 +140,17 @@ namespace ControlCatalog.Pages
             }
         }
 
-        private void scrollToLast_Click(object sender, Avalonia.Interactivity.RoutedEventArgs e)
+        private void scrollToLast_Click(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
         {
             ScrollTo(_viewModel.Items.Count - 1);
         }
 
-        private void scrollToRandom_Click(object sender, Avalonia.Interactivity.RoutedEventArgs e)
+        private void scrollToRandom_Click(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
         {
             ScrollTo(_random.Next(_viewModel.Items.Count - 1));
         }
 
-        private void scrollToSelected_Click(object sender, Avalonia.Interactivity.RoutedEventArgs e)
+        private void scrollToSelected_Click(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
         {
             ScrollTo(_selectedIndex);
         }

samples/ControlCatalog/Pages/NumericUpDownPage.xaml

@@ -54,11 +54,11 @@
       <Grid Grid.Row="0" Grid.Column="2" Margin="8" RowDefinitions="Auto,Auto,Auto,Auto,Auto" ColumnDefinitions="Auto, Auto">
         <TextBlock Grid.Row="0" Grid.Column="0" VerticalAlignment="Center" Margin="10,2,2,2">Minimum:</TextBlock>
         <NumericUpDown Grid.Row="0" Grid.Column="1" Value="{Binding #upDown.Minimum}"
-                       CultureInfo="{Binding #upDown.CultureInfo}" VerticalAlignment="Center" Margin="2" HorizontalAlignment="Center"/>
+                       NumberFormat="{Binding #upDown.NumberFormat}" VerticalAlignment="Center" Margin="2" HorizontalAlignment="Center"/>
 
         <TextBlock Grid.Row="1" Grid.Column="0" VerticalAlignment="Center" Margin="10,2,2,2">Maximum:</TextBlock>
         <NumericUpDown Grid.Row="1" Grid.Column="1" Value="{Binding #upDown.Maximum}"
-                       CultureInfo="{Binding #upDown.CultureInfo}" VerticalAlignment="Center" Margin="2" HorizontalAlignment="Center"/>
+                       NumberFormat="{Binding #upDown.NumberFormat}" VerticalAlignment="Center" Margin="2" HorizontalAlignment="Center"/>
 
         <TextBlock Grid.Row="2" Grid.Column="0" VerticalAlignment="Center" Margin="10,2,2,2">Increment:</TextBlock>
         <NumericUpDown Grid.Row="2" Grid.Column="1" Value="{Binding #upDown.Increment}" VerticalAlignment="Center"

samples/ControlCatalog/Pages/NumericUpDownPage.xaml.cs

@@ -2,9 +2,7 @@
 using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
-using Avalonia;
 using Avalonia.Controls;
-using Avalonia.Controls.Primitives;
 using Avalonia.Markup.Xaml;
 using MiniMvvm;
 
@@ -29,7 +27,7 @@ namespace ControlCatalog.Pages
     public class NumbersPageViewModel : ViewModelBase
     {
         private IList<FormatObject>? _formats;
-        private FormatObject _selectedFormat;
+        private FormatObject? _selectedFormat;
         private IList<Location>? _spinnerLocations;
 
         private double _doubleValue;
@@ -89,7 +87,7 @@ namespace ControlCatalog.Pages
             .Where(c => new[] { "en-US", "en-GB", "fr-FR", "ar-DZ", "zh-CH", "cs-CZ" }.Contains(c.Name))
             .ToArray();
 
-        public FormatObject SelectedFormat
+        public FormatObject? SelectedFormat
         {
             get { return _selectedFormat; }
             set { this.RaiseAndSetIfChanged(ref _selectedFormat, value); }

samples/ControlCatalog/Pages/OpenGlPage.xaml.cs

@@ -68,7 +68,7 @@ namespace ControlCatalog.Pages
             set => SetAndRaise(DiscoProperty, ref _disco, value);
         }
 
-        private string _info;
+        private string _info = string.Empty;
 
         public static readonly DirectProperty<OpenGlPageControl, string> InfoProperty =
             AvaloniaProperty.RegisterDirect<OpenGlPageControl, string>("Info", o => o.Info, (o, v) => o.Info = v);
@@ -205,7 +205,7 @@ namespace ControlCatalog.Pages
         public OpenGlPageControl()
         {
             var name = typeof(OpenGlPage).Assembly.GetManifestResourceNames().First(x => x.Contains("teapot.bin"));
-            using (var sr = new BinaryReader(typeof(OpenGlPage).Assembly.GetManifestResourceStream(name)))
+            using (var sr = new BinaryReader(typeof(OpenGlPage).Assembly.GetManifestResourceStream(name)!))
             {
                 var buf = new byte[sr.ReadInt32()];
                 sr.Read(buf, 0, buf.Length);
@@ -345,7 +345,7 @@ namespace ControlCatalog.Pages
                     0.01f, 1000);
 
 
-            var view = Matrix4x4.CreateLookAt(new Vector3(25, 25, 25), new Vector3(), new Vector3(0, -1, 0));
+            var view = Matrix4x4.CreateLookAt(new Vector3(25, 25, 25), new Vector3(), new Vector3(0, 1, 0));
             var model = Matrix4x4.CreateFromYawPitchRoll(_yaw, _pitch, _roll);
             var modelLoc = GL.GetUniformLocationString(_shaderProgram, "uModel");
             var viewLoc = GL.GetUniformLocationString(_shaderProgram, "uView");

samples/ControlCatalog/Pages/PointersPage.xaml.cs

@@ -1,8 +1,6 @@
 using System;
-using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Input;
-using Avalonia.Interactivity;
 using Avalonia.Markup.Xaml;
 
 namespace ControlCatalog.Pages;
@@ -31,28 +29,33 @@ public class PointersPage : UserControl
         border2.PointerExited += Border_PointerUpdated;
     }
 
-    private void Border_PointerUpdated(object sender, PointerEventArgs e)
+    private void Border_PointerUpdated(object? sender, PointerEventArgs e)
     {
-        var textBlock = (TextBlock)((Border)sender).Child;
-        var position = e.GetPosition((Border)sender);
-        textBlock.Text = @$"Type: {e.Pointer.Type}
+        if (sender is Border border && border.Child is TextBlock textBlock)
+        {
+            var position = e.GetPosition(border);
+            textBlock.Text = @$"Type: {e.Pointer.Type}
 Captured: {e.Pointer.Captured == sender}
 PointerId: {e.Pointer.Id}
 Position: {(int)position.X} {(int)position.Y}";
-        e.Handled = true;
+            e.Handled = true;
+        }
     }
 
-    private void Border_PointerCaptureLost(object sender, PointerCaptureLostEventArgs e)
+    private void Border_PointerCaptureLost(object? sender, PointerCaptureLostEventArgs e)
     {
-        var textBlock = (TextBlock)((Border)sender).Child;
-        textBlock.Text = @$"Type: {e.Pointer.Type}
+        if (sender is Border border && border.Child is TextBlock textBlock)
+        {
+            textBlock.Text = @$"Type: {e.Pointer.Type}
 Captured: {e.Pointer.Captured == sender}
 PointerId: {e.Pointer.Id}
 Position: ??? ???";
-        e.Handled = true;
+            e.Handled = true;
+
+        }
     }
 
-    private void Border_PointerReleased(object sender, PointerReleasedEventArgs e)
+    private void Border_PointerReleased(object? sender, PointerReleasedEventArgs e)
     {
         if (e.Pointer.Captured == sender)
         {
@@ -65,9 +68,9 @@ Position: ??? ???";
         }
     }
 
-    private void Border_PointerPressed(object sender, PointerPressedEventArgs e)
+    private void Border_PointerPressed(object? sender, PointerPressedEventArgs e)
     {
-        e.Pointer.Capture((Border)sender);
+        e.Pointer.Capture(sender as Border);
         e.Handled = true;
     }
 

samples/ControlCatalog/ViewModels/ContextPageViewModel.cs

@@ -53,14 +53,14 @@ namespace ControlCatalog.ViewModels
             var window = View?.GetVisualRoot() as Window;
             if (window == null)
                 return;
-            var dialog = new OpenFileDialog();
-            var result = await dialog.ShowAsync(window);
+
+            var result = await window.StorageProvider.OpenFilePickerAsync(new Avalonia.Platform.Storage.FilePickerOpenOptions() { AllowMultiple = true });
 
             if (result != null)
             {
-                foreach (var path in result)
+                foreach (var file in result)
                 {
-                    System.Diagnostics.Debug.WriteLine($"Opened: {path}");
+                    System.Diagnostics.Debug.WriteLine($"Opened: {file.Name}");
                 }
             }
         }

samples/ControlCatalog/ViewModels/MenuPageViewModel.cs

@@ -74,14 +74,13 @@ namespace ControlCatalog.ViewModels
             var window = View?.GetVisualRoot() as Window;
             if (window == null)
                 return;
-            var dialog = new OpenFileDialog();
-            var result = await dialog.ShowAsync(window);
+            var result = await window.StorageProvider.OpenFilePickerAsync(new Avalonia.Platform.Storage.FilePickerOpenOptions() { AllowMultiple = true });
 
             if (result != null)
             {
-                foreach (var path in result)
+                foreach (var file in result)
                 {
-                    System.Diagnostics.Debug.WriteLine($"Opened: {path}");
+                    System.Diagnostics.Debug.WriteLine($"Opened: {file.Name}");
                 }
             }
         }

samples/ControlCatalog/ViewModels/TransitioningContentControlPageViewModel.cs

@@ -117,9 +117,9 @@ namespace ControlCatalog.ViewModels
             PageTransitions[3].Transition = new PageSlide(TimeSpan.FromMilliseconds(Duration), PageSlide.SlideAxis.Vertical);
 
             var compositeTransition = new CompositePageTransition();
-            compositeTransition.PageTransitions.Add(PageTransitions[1].Transition);
-            compositeTransition.PageTransitions.Add(PageTransitions[2].Transition);
-            compositeTransition.PageTransitions.Add(PageTransitions[3].Transition);
+            compositeTransition.PageTransitions.Add(PageTransitions[1].Transition!);
+            compositeTransition.PageTransitions.Add(PageTransitions[2].Transition!);
+            compositeTransition.PageTransitions.Add(PageTransitions[3].Transition!);
             PageTransitions[4].Transition = compositeTransition;
 
             PageTransitions[5].Transition = new CustomTransition(TimeSpan.FromMilliseconds(Duration));

samples/IntegrationTestApp/MainWindow.axaml.cs

@@ -1,4 +1,3 @@
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using Avalonia;
@@ -31,20 +30,23 @@ namespace IntegrationTestApp
 
         private void InitializeViewMenu()
         {
-            var mainTabs = this.FindControl<TabControl>("MainTabs");
+            var mainTabs = this.Get<TabControl>("MainTabs");
             var viewMenu = (NativeMenuItem)NativeMenu.GetMenu(this).Items[1];
 
-            foreach (TabItem tabItem in mainTabs.Items)
+            if (mainTabs.Items is not null)
             {
-                var menuItem = new NativeMenuItem
+                foreach (TabItem tabItem in mainTabs.Items)
                 {
-                    Header = (string)tabItem.Header!,
-                    IsChecked = tabItem.IsSelected,
-                    ToggleType = NativeMenuItemToggleType.Radio,
-                };
-
-                menuItem.Click += (s, e) => tabItem.IsSelected = true;
-                viewMenu.Menu.Items.Add(menuItem);
+                    var menuItem = new NativeMenuItem
+                    {
+                        Header = (string)tabItem.Header!,
+                        IsChecked = tabItem.IsSelected,
+                        ToggleType = NativeMenuItemToggleType.Radio,
+                    };
+
+                    menuItem.Click += (s, e) => tabItem.IsSelected = true;
+                    viewMenu?.Menu?.Items.Add(menuItem);
+                }
             }
         }
 
@@ -107,8 +109,8 @@ namespace IntegrationTestApp
 
         private void MenuClicked(object? sender, RoutedEventArgs e)
         {
-            var clickedMenuItemTextBlock = this.FindControl<TextBlock>("ClickedMenuItem");
-            clickedMenuItemTextBlock.Text = ((MenuItem)sender!).Header.ToString();
+            var clickedMenuItemTextBlock = this.Get<TextBlock>("ClickedMenuItem");
+            clickedMenuItemTextBlock.Text = (sender as MenuItem)?.Header?.ToString();
         }
 
         private void OnButtonClick(object? sender, RoutedEventArgs e)
@@ -116,13 +118,13 @@ namespace IntegrationTestApp
             var source = e.Source as Button;
 
             if (source?.Name == "ComboBoxSelectionClear")
-                this.FindControl<ComboBox>("BasicComboBox").SelectedIndex = -1;
+                this.Get<ComboBox>("BasicComboBox").SelectedIndex = -1;
             if (source?.Name == "ComboBoxSelectFirst")
-                this.FindControl<ComboBox>("BasicComboBox").SelectedIndex = 0;
+                this.Get<ComboBox>("BasicComboBox").SelectedIndex = 0;
             if (source?.Name == "ListBoxSelectionClear")
-                this.FindControl<ListBox>("BasicListBox").SelectedIndex = -1;
+                this.Get<ListBox>("BasicListBox").SelectedIndex = -1;
             if (source?.Name == "MenuClickedMenuItemReset")
-                this.FindControl<TextBlock>("ClickedMenuItem").Text = "None";
+                this.Get<TextBlock>("ClickedMenuItem").Text = "None";
             if (source?.Name == "ShowWindow")
                 ShowWindow();
             if (source?.Name == "SendToBack")

samples/RenderDemo/Pages/DrawingPage.xaml

@@ -1,134 +1,141 @@
-<UserControl 
-    xmlns="https://github.com/avaloniaui" 
+<UserControl
+    xmlns="https://github.com/avaloniaui"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     x:Class="RenderDemo.Pages.DrawingPage">
-    <UserControl.Styles>
-        <Style>
-            <Style.Resources>
-                <DrawingGroup x:Key="Bulb">
-                    <DrawingGroup.Transform>
-                        <MatrixTransform Matrix="1,0,0,1,0,-1028.4" />
-                    </DrawingGroup.Transform>
-                    <DrawingGroup>
-                        <DrawingGroup.Transform>
-                            <MatrixTransform Matrix="1,0,0,1.25,-10,1031.4" />
-                        </DrawingGroup.Transform>
-                        <GeometryDrawing Brush="#FF7F8C8D"
-                                         Geometry="F1 M24,14 A2,2,0,1,1,20,14 A2,2,0,1,1,24,14 z" />
-                    </DrawingGroup>
-                    <GeometryDrawing Brush="#FFF39C12"
-                                     Geometry="F1 M12,1030.4 C8.134,1030.4 5,1033.6 5,1037.6 5,1040.7 8.125,1043.5 9,1045.4 9.875,1047.2 9,1050.4 9,1050.4 L12,1049.9 15,1050.4 C15,1050.4 14.125,1047.2 15,1045.4 15.875,1043.5 19,1040.7 19,1037.6 19,1033.6 15.866,1030.4 12,1030.4 z" />
-                    <GeometryDrawing Brush="#FFF1C40F"
-                                     Geometry="F1 M12,1030.4 C15.866,1030.4 19,1033.6 19,1037.6 19,1040.7 15.875,1043.5 15,1045.4 14.125,1047.2 15,1050.4 15,1050.4 L12,1049.9 12,1030.4 z" />
-                    <GeometryDrawing Brush="#FFE67E22"
-                                     Geometry="F1 M9,1036.4 L8,1037.4 12,1049.4 16,1037.4 15,1036.4 14,1037.4 13,1036.4 12,1037.4 11,1036.4 10,1037.4 9,1036.4 z M9,1037.4 L10,1038.4 10.5,1037.9 11,1037.4 11.5,1037.9 12,1038.4 12.5,1037.9 13,1037.4 13.5,1037.9 14,1038.4 15,1037.4 15.438,1037.8 12,1048.1 8.5625,1037.8 9,1037.4 z" />
-                    <DrawingGroup>
-                        <DrawingGroup.Transform>
-                            <MatrixTransform Matrix="1,0,0,1,9,1045.4" />
-                        </DrawingGroup.Transform>
-                        <GeometryDrawing Brush="#FFBDC3C7">
-                            <GeometryDrawing.Geometry>
-                                <RectangleGeometry Rect="0,0,6,5" />
-                            </GeometryDrawing.Geometry>
-                        </GeometryDrawing>
-                    </DrawingGroup>
-                    <GeometryDrawing Brush="#FF95A5A6"
-                                     Geometry="F1 M9,1045.4 L9,1050.4 12,1050.4 12,1049.4 15,1049.4 15,1048.4 12,1048.4 12,1047.4 15,1047.4 15,1046.4 12,1046.4 12,1045.4 9,1045.4 z" />
-                    <GeometryDrawing Brush="#FF7F8C8D"
-                                     Geometry="F1 M9,1046.4 L9,1047.4 12,1047.4 12,1046.4 9,1046.4 z M9,1048.4 L9,1049.4 12,1049.4 12,1048.4 9,1048.4 z" />
-                </DrawingGroup>
-            </Style.Resources>
-        </Style>
-    </UserControl.Styles>
-    <Grid RowDefinitions="Auto,Auto,Auto"
-          ColumnDefinitions="Auto,Auto,Auto,Auto">
-        <TextBlock Text="None"
-                   Margin="3" />
-        <Border Grid.Column="0"
-                Grid.Row="1"
-                VerticalAlignment="Top"
-                HorizontalAlignment="Left"
-                BorderThickness="1"
-                BorderBrush="Gray"
-                Margin="5">
-            <DrawingPresenter Drawing="{DynamicResource Bulb}" />
-        </Border>
-        <TextBlock Text="Fill"
-                   Margin="3"
-                   Grid.Column="1" />
-        <Border Grid.Column="1"
-                Grid.Row="1"
-                VerticalAlignment="Top"
-                HorizontalAlignment="Left"
-                BorderThickness="1"
-                BorderBrush="Gray"
-                Margin="5">
-            <DrawingPresenter Drawing="{DynamicResource Bulb}"
-                              Width="100"
-                              Height="50"
-                              Stretch="Fill" />
-        </Border>
-        <TextBlock Text="Uniform"
-                   Margin="3"
-                   Grid.Column="2" />
-        <Border Grid.Column="2"
-                Grid.Row="1"
-                VerticalAlignment="Top"
-                HorizontalAlignment="Left"
-                BorderThickness="1"
-                BorderBrush="Gray"
-                Margin="5">
-            <DrawingPresenter Drawing="{DynamicResource Bulb}"
-                              Width="100"
-                              Height="50"
-                              Stretch="Uniform" />
-        </Border>
-        <TextBlock Text="UniformToFill"
-                   Margin="3"
-                   Grid.Column="3" />
-        <Border Grid.Column="3"
-                Grid.Row="1"
-                VerticalAlignment="Top"
-                HorizontalAlignment="Left"
-                BorderThickness="1"
-                BorderBrush="Gray"
-                Margin="5">
-            <DrawingPresenter Drawing="{DynamicResource Bulb}"
-                              Width="100"
-                              Height="50"
-                              Stretch="UniformToFill" />
-        </Border>
+  <UserControl.Styles>
+    <Style>
+      <Style.Resources>
+        <DrawingGroup x:Key="Bulb">
+          <DrawingGroup.Transform>
+            <MatrixTransform Matrix="1,0,0,1,0,-1028.4" />
+          </DrawingGroup.Transform>
+          <DrawingGroup>
+            <DrawingGroup.Transform>
+              <MatrixTransform Matrix="1,0,0,1.25,-10,1031.4" />
+            </DrawingGroup.Transform>
+            <GeometryDrawing Brush="#FF7F8C8D"
+                             Geometry="F1 M24,14 A2,2,0,1,1,20,14 A2,2,0,1,1,24,14 z" />
+          </DrawingGroup>
+          <GeometryDrawing Brush="#FFF39C12"
+                           Geometry="F1 M12,1030.4 C8.134,1030.4 5,1033.6 5,1037.6 5,1040.7 8.125,1043.5 9,1045.4 9.875,1047.2 9,1050.4 9,1050.4 L12,1049.9 15,1050.4 C15,1050.4 14.125,1047.2 15,1045.4 15.875,1043.5 19,1040.7 19,1037.6 19,1033.6 15.866,1030.4 12,1030.4 z" />
+          <GeometryDrawing Brush="#FFF1C40F"
+                           Geometry="F1 M12,1030.4 C15.866,1030.4 19,1033.6 19,1037.6 19,1040.7 15.875,1043.5 15,1045.4 14.125,1047.2 15,1050.4 15,1050.4 L12,1049.9 12,1030.4 z" />
+          <GeometryDrawing Brush="#FFE67E22"
+                           Geometry="F1 M9,1036.4 L8,1037.4 12,1049.4 16,1037.4 15,1036.4 14,1037.4 13,1036.4 12,1037.4 11,1036.4 10,1037.4 9,1036.4 z M9,1037.4 L10,1038.4 10.5,1037.9 11,1037.4 11.5,1037.9 12,1038.4 12.5,1037.9 13,1037.4 13.5,1037.9 14,1038.4 15,1037.4 15.438,1037.8 12,1048.1 8.5625,1037.8 9,1037.4 z" />
+          <DrawingGroup>
+            <DrawingGroup.Transform>
+              <MatrixTransform Matrix="1,0,0,1,9,1045.4" />
+            </DrawingGroup.Transform>
+            <GeometryDrawing Brush="#FFBDC3C7">
+              <GeometryDrawing.Geometry>
+                <RectangleGeometry Rect="0,0,6,5" />
+              </GeometryDrawing.Geometry>
+            </GeometryDrawing>
+          </DrawingGroup>
+          <GeometryDrawing Brush="#FF95A5A6"
+                           Geometry="F1 M9,1045.4 L9,1050.4 12,1050.4 12,1049.4 15,1049.4 15,1048.4 12,1048.4 12,1047.4 15,1047.4 15,1046.4 12,1046.4 12,1045.4 9,1045.4 z" />
+          <GeometryDrawing Brush="#FF7F8C8D"
+                           Geometry="F1 M9,1046.4 L9,1047.4 12,1047.4 12,1046.4 9,1046.4 z M9,1048.4 L9,1049.4 12,1049.4 12,1048.4 9,1048.4 z" />
+        </DrawingGroup>
+      </Style.Resources>
+    </Style>
+  </UserControl.Styles>
+  <Grid RowDefinitions="Auto,Auto,Auto"
+        ColumnDefinitions="Auto,Auto,Auto,Auto">
+    <TextBlock Text="None"
+               Margin="3" />
+    <Border Grid.Column="0"
+            Grid.Row="1"
+            VerticalAlignment="Top"
+            HorizontalAlignment="Left"
+            BorderThickness="1"
+            BorderBrush="Gray"
+            Margin="5">
+      <Image>
+        <Image.Source>
+          <DrawingImage Drawing="{DynamicResource Bulb}" />
+        </Image.Source>
+      </Image>
+    </Border>
+    <TextBlock Text="Fill"
+               Margin="3"
+               Grid.Column="1" />
+    <Border Grid.Column="1"
+            Grid.Row="1"
+            VerticalAlignment="Top"
+            HorizontalAlignment="Left"
+            BorderThickness="1"
+            BorderBrush="Gray"
+            Margin="5">
+      <Image Width="100" Height="50" Stretch="Fill">
+        <Image.Source>
+          <DrawingImage Drawing="{DynamicResource Bulb}" />
+        </Image.Source>
+      </Image>
+    </Border>
+    <TextBlock Text="Uniform"
+               Margin="3"
+               Grid.Column="2" />
+    <Border Grid.Column="2"
+            Grid.Row="1"
+            VerticalAlignment="Top"
+            HorizontalAlignment="Left"
+            BorderThickness="1"
+            BorderBrush="Gray"
+            Margin="5">
+      <Image Width="100" Height="50" Stretch="Uniform">
+        <Image.Source>
+          <DrawingImage Drawing="{DynamicResource Bulb}" />
+        </Image.Source>
+      </Image>
+    </Border>
+    <TextBlock Text="UniformToFill"
+               Margin="3"
+               Grid.Column="3" />
+    <Border Grid.Column="3"
+            Grid.Row="1"
+            VerticalAlignment="Top"
+            HorizontalAlignment="Left"
+            BorderThickness="1"
+            BorderBrush="Gray"
+            Margin="5">
+      <Image Width="100" Height="50" Stretch="UniformToFill">
+        <Image.Source>
+          <DrawingImage Drawing="{DynamicResource Bulb}" />
+        </Image.Source>
+      </Image>
+    </Border>
 
-        <!-- For comparison -->
+    <!-- For comparison -->
 
-        <Ellipse Grid.Row="2"
-                 Grid.Column="0"
-                 Width="100"
-                 Height="50"
-                 Stretch="None"
-                 Fill="Blue"
-                 Margin="5"/>
-        <Ellipse Grid.Row="2"
-                 Grid.Column="1"
-                 Width="100"
-                 Height="50"
-                 Stretch="Fill"
-                 Fill="Blue"
-                 Margin="5" />
-        <Ellipse Grid.Row="2"
-                 Grid.Column="2"
-                 Width="100"
-                 Height="50"
-                 Stretch="Uniform"
-                 Fill="Blue"
-                 Margin="5" />
-        <Ellipse Grid.Row="2"
-                 Grid.Column="3"
-                 Width="100"
-                 Height="50"
-                 Stretch="UniformToFill"
-                 Fill="Blue"
-                 Margin="5" />
+    <Ellipse Grid.Row="2"
+             Grid.Column="0"
+             Width="100"
+             Height="50"
+             Stretch="None"
+             Fill="Blue"
+             Margin="5"/>
+    <Ellipse Grid.Row="2"
+             Grid.Column="1"
+             Width="100"
+             Height="50"
+             Stretch="Fill"
+             Fill="Blue"
+             Margin="5" />
+    <Ellipse Grid.Row="2"
+             Grid.Column="2"
+             Width="100"
+             Height="50"
+             Stretch="Uniform"
+             Fill="Blue"
+             Margin="5" />
+    <Ellipse Grid.Row="2"
+             Grid.Column="3"
+             Width="100"
+             Height="50"
+             Stretch="UniformToFill"
+             Fill="Blue"
+             Margin="5" />
 
-    </Grid>
-</UserControl>
+  </Grid>
+</UserControl>

samples/RenderDemo/Pages/TextFormatterPage.axaml.cs

@@ -78,7 +78,7 @@ namespace RenderDemo.Pages
                 _defaultProperties = defaultProperties;
             }
             
-            public TextRun? GetTextRun(int textSourceIndex)
+            public TextRun GetTextRun(int textSourceIndex)
             {
                 if (textSourceIndex >= _text.Length * 2 + TextRun.DefaultTextSourceLength)
                 {
@@ -107,7 +107,7 @@ namespace RenderDemo.Pages
             public Control Control => _control;
             public override Size Size => _control.DesiredSize;
             public override double Baseline => 0;
-            public override TextRunProperties? Properties { get; }
+            public override TextRunProperties Properties { get; }
 
             public override void Draw(DrawingContext drawingContext, Point origin)
             {

src/Android/Avalonia.Android/AndroidThreadingInterface.cs

@@ -27,46 +27,33 @@ namespace Avalonia.Android
         {
             if (interval.TotalMilliseconds < 10)
                 interval = TimeSpan.FromMilliseconds(10);
-            object l = new object();
+
             var stopped = false;
             Timer timer = null;
-            var scheduled = false;
             timer = new Timer(_ =>
             {
-                lock (l)
+                if (stopped)
+                    return;
+
+                EnsureInvokeOnMainThread(() =>
                 {
-                    if (stopped)
+                    try
                     {
-                        timer.Dispose();
-                        return;
+                        tick();
                     }
-                    if (scheduled)
-                        return;
-                    scheduled = true;
-                    EnsureInvokeOnMainThread(() =>
+                    finally
                     {
-                        try
-                        {
-                            tick();
-                        }
-                        finally
-                        {
-                            lock (l)
-                            {
-                                scheduled = false;
-                            }
-                        }
-                    });
-                }
-            }, null, TimeSpan.Zero, interval);
+                        if (!stopped)
+                            timer.Change(interval, Timeout.InfiniteTimeSpan);
+                    }
+                });
+            },
+            null, interval, Timeout.InfiniteTimeSpan);
 
             return Disposable.Create(() =>
             {
-                lock (l)
-                {
-                    stopped = true;
-                    timer.Dispose();
-                }
+                stopped = true;
+                timer.Dispose();
             });
         }
 

src/Avalonia.Base/Animation/Animation.cs

@@ -172,23 +172,6 @@ namespace Avalonia.Animation
             set { SetAndRaise(SpeedRatioProperty, ref _speedRatio, value); }
         }
 
-        /// <summary>
-        /// Obsolete: Do not use this property, use <see cref="IterationCount"/> instead.
-        /// </summary>
-        /// <value></value>
-        [Obsolete("This property has been superceded by IterationCount.")]
-        public string RepeatCount
-        {
-            get { return IterationCount.ToString(); }
-            set
-            {
-                var val = value.ToUpper();
-                val = val.Replace("LOOP", "INFINITE");
-                val = val.Replace("NONE", "1");
-                IterationCount = IterationCount.Parse(val);
-            }
-        }
-
         /// <summary>
         /// Gets the children of the <see cref="Animation"/>.
         /// </summary>

src/Avalonia.Base/Animation/Animators/SolidColorBrushAnimator.cs

@@ -37,17 +37,4 @@ namespace Avalonia.Animation.Animators
         }
     }
     
-    [Obsolete("Use ISolidColorBrushAnimator instead")]
-    public class SolidColorBrushAnimator : Animator<SolidColorBrush?>
-    {    
-        public override SolidColorBrush? Interpolate(double progress, SolidColorBrush? oldValue, SolidColorBrush? newValue)
-        {
-            if (oldValue is null || newValue is null)
-            {
-                return progress >= 0.5 ? newValue : oldValue;
-            }
-
-            return new SolidColorBrush(ColorAnimator.InterpolateCore(progress, oldValue.Color, newValue.Color));
-        }
-    }
 }

src/Avalonia.Base/AvaloniaObjectExtensions.cs

@@ -468,41 +468,6 @@ namespace Avalonia
             });
         }
 
-        /// <summary>
-        /// Subscribes to a property changed notifications for changes that originate from a
-        /// <typeparamref name="TTarget"/>.
-        /// </summary>
-        /// <typeparam name="TTarget">The type of the property change sender.</typeparam>
-        /// <param name="observable">The property changed observable.</param>
-        /// <param name="handler">Given a TTarget, returns the handler.</param>
-        /// <returns>A disposable that can be used to terminate the subscription.</returns>
-        [Obsolete("Use overload taking Action<TTarget, AvaloniaPropertyChangedEventArgs>.")]
-        public static IDisposable AddClassHandler<TTarget>(
-            this IObservable<AvaloniaPropertyChangedEventArgs> observable,
-            Func<TTarget, Action<AvaloniaPropertyChangedEventArgs>> handler)
-            where TTarget : class
-        {
-            return observable.Subscribe(e => SubscribeAdapter(e, handler));
-        }
-
-        /// <summary>
-        /// Observer method for <see cref="AddClassHandler{TTarget}(IObservable{AvaloniaPropertyChangedEventArgs},
-        /// Func{TTarget, Action{AvaloniaPropertyChangedEventArgs}})"/>.
-        /// </summary>
-        /// <typeparam name="TTarget">The sender type to accept.</typeparam>
-        /// <param name="e">The event args.</param>
-        /// <param name="handler">Given a TTarget, returns the handler.</param>
-        private static void SubscribeAdapter<TTarget>(
-            AvaloniaPropertyChangedEventArgs e,
-            Func<TTarget, Action<AvaloniaPropertyChangedEventArgs>> handler)
-            where TTarget : class
-        {
-            if (e.Sender is TTarget target)
-            {
-                handler(target)(e);
-            }
-        }
-
         private class BindingAdaptor : IBinding
         {
             private IObservable<object?> _source;

src/Avalonia.Base/AvaloniaProperty`1.cs

@@ -30,21 +30,6 @@ namespace Avalonia
             _changed = new Subject<AvaloniaPropertyChangedEventArgs<TValue>>();
         }
 
-        /// <summary>
-        /// Initializes a new instance of the <see cref="AvaloniaProperty{TValue}"/> class.
-        /// </summary>
-        /// <param name="source">The property to copy.</param>
-        /// <param name="ownerType">The new owner type.</param>
-        /// <param name="metadata">Optional overridden metadata.</param>
-        [Obsolete("Use constructor with AvaloniaProperty<TValue> instead.", true)]
-        protected AvaloniaProperty(
-            AvaloniaProperty source,
-            Type ownerType,
-            AvaloniaPropertyMetadata? metadata)
-            : this(source as AvaloniaProperty<TValue> ?? throw new InvalidOperationException(), ownerType, metadata)
-        {
-        }
-
         /// <summary>
         /// Initializes a new instance of the <see cref="AvaloniaProperty{TValue}"/> class.
         /// </summary>

src/Avalonia.Base/Collections/AvaloniaListExtensions.cs

@@ -140,21 +140,6 @@ namespace Avalonia.Collections
             }
         }
 
-        [Obsolete("Causes memory leaks. Use DynamicData or similar instead.")]
-        public static IAvaloniaReadOnlyList<TDerived> CreateDerivedList<TSource, TDerived>(
-            this IAvaloniaReadOnlyList<TSource> collection,
-            Func<TSource, TDerived> select)
-        {
-            var result = new AvaloniaList<TDerived>();
-
-            collection.ForEachItem(
-                (i, item) => result.Insert(i, select(item)),
-                (i, item) => result.RemoveAt(i),
-                () => result.Clear());
-
-            return result;
-        }
-
         /// <summary>
         /// Listens for property changed events from all items in a collection.
         /// </summary>

src/Avalonia.Base/DirectPropertyBase.cs

@@ -29,21 +29,6 @@ namespace Avalonia
         {
         }
 
-        /// <summary>
-        /// Initializes a new instance of the <see cref="DirectPropertyBase{TValue}"/> class.
-        /// </summary>
-        /// <param name="source">The property to copy.</param>
-        /// <param name="ownerType">The new owner type.</param>
-        /// <param name="metadata">Optional overridden metadata.</param>
-        [Obsolete("Use constructor with DirectPropertyBase<TValue> instead.", true)]
-        protected DirectPropertyBase(
-            AvaloniaProperty source,
-            Type ownerType,
-            AvaloniaPropertyMetadata metadata)
-            : this(source as DirectPropertyBase<TValue> ?? throw new InvalidOperationException(), ownerType, metadata)
-        {
-        }
-
         /// <summary>
         /// Initializes a new instance of the <see cref="DirectPropertyBase{TValue}"/> class.
         /// </summary>

src/Avalonia.Base/EnumExtensions.cs

@@ -8,10 +8,6 @@ namespace Avalonia
     /// </summary>
     public static class EnumExtensions
     {
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        [Obsolete("This method is obsolete. Use HasAllFlags instead.")]
-        public static bool HasFlagCustom<T>(this T value, T flag) where T : unmanaged, Enum
-            => value.HasAllFlags(flag);
             
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static unsafe bool HasAllFlags<T>(this T value, T flags) where T : unmanaged, Enum

src/Avalonia.Base/Input/PointerOverPreProcessor.cs

@@ -158,6 +158,8 @@ namespace Avalonia.Input
                     ClearPointerOver(pointer, root, timestamp, position, properties, inputModifiers);
                 }
             }
+
+            _lastPointer = (pointer, root.PointToScreen(position));
         }
 
         private void SetPointerOverToElement(IPointer pointer, IInputRoot root, IInputElement element,
@@ -195,7 +197,6 @@ namespace Avalonia.Input
             }
 
             el = root.PointerOverElement = element;
-            _lastPointer = (pointer, root.PointToScreen(position));
 
             e.RoutedEvent = InputElement.PointerEnteredEvent;
 

src/Avalonia.Base/Interactivity/RoutedEvent.cs

@@ -113,24 +113,6 @@ namespace Avalonia.Interactivity
         {
         }
 
-        [Obsolete("Use overload taking Action<TTarget, TEventArgs>.")]
-        public IDisposable AddClassHandler<TTarget>(
-            Func<TTarget, Action<TEventArgs>> handler,
-            RoutingStrategies routes = RoutingStrategies.Direct | RoutingStrategies.Bubble,
-            bool handledEventsToo = false)
-            where TTarget : class, IInteractive
-        {
-            void Adapter(object? sender, RoutedEventArgs e)
-            {
-                if (sender is TTarget target && e is TEventArgs args)
-                {
-                    handler(target)(args);
-                }
-            }
-
-            return AddClassHandler(typeof(TTarget), Adapter, routes, handledEventsToo);
-        }
-
         public IDisposable AddClassHandler<TTarget>(
             Action<TTarget, TEventArgs> handler,
             RoutingStrategies routes = RoutingStrategies.Direct | RoutingStrategies.Bubble,

src/Avalonia.Base/Layout/ILayoutManager.cs

@@ -44,17 +44,6 @@ namespace Avalonia.Layout
         /// </remarks>
         void ExecuteInitialLayoutPass();
 
-        /// <summary>
-        /// Executes the initial layout pass on a layout root.
-        /// </summary>
-        /// <param name="root">The control to lay out.</param>
-        /// <remarks>
-        /// You should not usually need to call this method explictly, the layout root will call
-        /// it to carry out the initial layout of the control.
-        /// </remarks>
-        [Obsolete("Call ExecuteInitialLayoutPass without parameter")]
-        void ExecuteInitialLayoutPass(ILayoutRoot root);
-
         /// <summary>
         /// Registers a control as wanting to receive effective viewport notifications.
         /// </summary>

src/Avalonia.Base/Layout/LayoutManager.cs

@@ -196,17 +196,6 @@ namespace Avalonia.Layout
             ExecuteLayoutPass();
         }
 
-        [Obsolete("Call ExecuteInitialLayoutPass without parameter")]
-        public void ExecuteInitialLayoutPass(ILayoutRoot root)
-        {
-            if (root != _owner)
-            {
-                throw new ArgumentException("ExecuteInitialLayoutPass called with incorrect root.");
-            }
-
-            ExecuteInitialLayoutPass();
-        }
-
         public void Dispose()
         {
             _disposed = true;

src/Avalonia.Base/Layout/Layoutable.cs

@@ -460,20 +460,6 @@ namespace Avalonia.Layout
             _effectiveViewportChanged?.Invoke(this, e);
         }
 
-        /// <summary>
-        /// Marks a property as affecting the control's measurement.
-        /// </summary>
-        /// <param name="properties">The properties.</param>
-        /// <remarks>
-        /// After a call to this method in a control's static constructor, any change to the
-        /// property will cause <see cref="InvalidateMeasure"/> to be called on the element.
-        /// </remarks>
-        [Obsolete("Use AffectsMeasure<T> and specify the control type.")]
-        protected static void AffectsMeasure(params AvaloniaProperty[] properties)
-        {
-            AffectsMeasure<Layoutable>(properties);
-        }
-
         /// <summary>
         /// Marks a property as affecting the control's measurement.
         /// </summary>
@@ -497,20 +483,6 @@ namespace Avalonia.Layout
             }
         }
 
-        /// <summary>
-        /// Marks a property as affecting the control's arrangement.
-        /// </summary>
-        /// <param name="properties">The properties.</param>
-        /// <remarks>
-        /// After a call to this method in a control's static constructor, any change to the
-        /// property will cause <see cref="InvalidateArrange"/> to be called on the element.
-        /// </remarks>
-        [Obsolete("Use AffectsArrange<T> and specify the control type.")]
-        protected static void AffectsArrange(params AvaloniaProperty[] properties)
-        {
-            AffectsArrange<Layoutable>(properties);
-        }
-
         /// <summary>
         /// Marks a property as affecting the control's arrangement.
         /// </summary>

src/Avalonia.Base/Media/Imaging/Bitmap.cs

@@ -89,22 +89,6 @@ namespace Avalonia.Media.Imaging
             PlatformImpl.Dispose();
         }
 
-        /// <summary>
-        /// Initializes a new instance of the <see cref="Bitmap"/> class.
-        /// </summary>
-        /// <param name="format">The pixel format.</param>
-        /// <param name="data">The pointer to the source bytes.</param>
-        /// <param name="size">The size of the bitmap in device pixels.</param>
-        /// <param name="dpi">The DPI of the bitmap.</param>
-        /// <param name="stride">The number of bytes per row.</param>
-        [Obsolete("Use overload taking an AlphaFormat.")]
-        public Bitmap(PixelFormat format, IntPtr data, PixelSize size, Vector dpi, int stride)
-        {
-            var ri = GetFactory();
-            PlatformImpl = RefCountable.Create(ri
-                .LoadBitmap(format, ri.DefaultAlphaFormat, data, size, dpi, stride));
-        }
-
         /// <summary>
         /// Initializes a new instance of the <see cref="Bitmap"/> class.
         /// </summary>

src/Avalonia.Base/Media/Imaging/WriteableBitmap.cs

@@ -9,18 +9,6 @@ namespace Avalonia.Media.Imaging
     /// </summary>
     public class WriteableBitmap : Bitmap
     {
-        /// <summary>
-        /// Initializes a new instance of the <see cref="WriteableBitmap"/> class.
-        /// </summary>
-        /// <param name="size">The size of the bitmap in device pixels.</param>
-        /// <param name="dpi">The DPI of the bitmap.</param>
-        /// <param name="format">The pixel format (optional).</param>
-        /// <returns>An <see cref="IWriteableBitmapImpl"/>.</returns>
-        [Obsolete("Use overload taking an AlphaFormat.")]
-        public WriteableBitmap(PixelSize size, Vector dpi, PixelFormat? format = null)
-            : base(CreatePlatformImpl(size, dpi, format, null))
-        {
-        }
 
         /// <summary>
         /// Initializes a new instance of the <see cref="WriteableBitmap"/> class.
@@ -30,7 +18,7 @@ namespace Avalonia.Media.Imaging
         /// <param name="format">The pixel format (optional).</param>
         /// <param name="alphaFormat">The alpha format (optional).</param>
         /// <returns>An <see cref="IWriteableBitmapImpl"/>.</returns>
-        public WriteableBitmap(PixelSize size, Vector dpi, PixelFormat format, AlphaFormat alphaFormat) 
+        public WriteableBitmap(PixelSize size, Vector dpi, PixelFormat? format = null, AlphaFormat? alphaFormat = null) 
             : base(CreatePlatformImpl(size, dpi, format, alphaFormat))
         {
         }

src/Avalonia.Base/Platform/Storage/FileIO/BclStorageFile.cs

@@ -12,6 +12,11 @@ public class BclStorageFile : IStorageBookmarkFile
 {
     private readonly FileInfo _fileInfo;
 
+    public BclStorageFile(string fileName)
+    {
+        _fileInfo = new FileInfo(fileName);
+    }
+
     public BclStorageFile(FileInfo fileInfo)
     {
         _fileInfo = fileInfo ?? throw new ArgumentNullException(nameof(fileInfo));
@@ -27,15 +32,14 @@ public class BclStorageFile : IStorageBookmarkFile
 
     public Task<StorageItemProperties> GetBasicPropertiesAsync()
     {
-        var props = new StorageItemProperties();
         if (_fileInfo.Exists)
         {
-            props = new StorageItemProperties(
+            return Task.FromResult(new StorageItemProperties(
                 (ulong)_fileInfo.Length,
                 _fileInfo.CreationTimeUtc,
-                _fileInfo.LastAccessTimeUtc);
+                _fileInfo.LastAccessTimeUtc));
         }
-        return Task.FromResult(props);
+        return Task.FromResult(new StorageItemProperties());
     }
 
     public Task<IStorageFolder?> GetParentAsync()

src/Avalonia.Base/Platform/Storage/FileIO/BclStorageFolder.cs

@@ -14,6 +14,15 @@ public class BclStorageFolder : IStorageBookmarkFolder
 {
     private readonly DirectoryInfo _directoryInfo;
 
+    public BclStorageFolder(string path)
+    {
+        _directoryInfo = new DirectoryInfo(path);
+        if (!_directoryInfo.Exists)
+        {
+            throw new ArgumentException("Directory must exist");
+        }
+    }
+
     public BclStorageFolder(DirectoryInfo directoryInfo)
     {
         _directoryInfo = directoryInfo ?? throw new ArgumentNullException(nameof(directoryInfo));

src/Avalonia.Base/Utilities/MathUtilities.cs

@@ -324,6 +324,41 @@ namespace Avalonia.Utilities
             return angle * 2 * Math.PI;
         }
 
+        /// <summary>
+        /// Calculates the point of an angle on an ellipse.
+        /// </summary>
+        /// <param name="centre">The centre point of the ellipse.</param>
+        /// <param name="radiusX">The x radius of the ellipse.</param>
+        /// <param name="radiusY">The y radius of the ellipse.</param>
+        /// <param name="angle">The angle in radians.</param>
+        /// <returns>A point on the ellipse.</returns>
+        public static Point GetEllipsePoint(Point centre, double radiusX, double radiusY, double angle)
+        {
+            return new Point(radiusX * Math.Cos(angle) + centre.X, radiusY * Math.Sin(angle) + centre.Y);
+        }
+
+        /// <summary>
+        /// Gets the minimum and maximum from the specified numbers.
+        /// </summary>
+        /// <param name="a">The first number.</param>
+        /// <param name="b">The second number.</param>
+        /// <returns>A tuple containing the minimum and maximum of the two specified numbers.</returns>
+        public static (double min, double max) GetMinMax(double a, double b)
+        {
+            return a < b ? (a, b) : (b, a);
+        }
+
+        /// <summary>
+        /// Gets the minimum and maximum from the specified number and the difference with that number.
+        /// </summary>
+        /// <param name="initialValue">The initial value to use.</param>
+        /// <param name="delta">The difference for <paramref name="initialValue"/>.</param>
+        /// <returns>A tuple containing the minimum and maximum of the specified number and the difference with that number.</returns>
+        public static (double min, double max) GetMinMaxFromDelta(double initialValue, double delta)
+        {
+            return GetMinMax(initialValue, initialValue + delta);
+        }
+
         private static void ThrowCannotBeGreaterThanException<T>(T min, T max)
         {
             throw new ArgumentException($"{min} cannot be greater than {max}.");

src/Avalonia.Base/Utilities/WeakObservable.cs

@@ -9,31 +9,6 @@ namespace Avalonia.Utilities
     /// </summary>
     public static class WeakObservable
     {
-        /// <summary>
-        /// Converts a .NET event conforming to the standard .NET event pattern into an observable
-        /// sequence, subscribing weakly.
-        /// </summary>
-        /// <typeparam name="TTarget">The type of target.</typeparam>
-        /// <typeparam name="TEventArgs">The type of the event args.</typeparam>
-        /// <param name="target">Object instance that exposes the event to convert.</param>
-        /// <param name="eventName">Name of the event to convert.</param>
-        /// <returns></returns>
-        [Obsolete("Use WeakEvent-based overload")]
-        public static IObservable<EventPattern<object, TEventArgs>> FromEventPattern<TTarget, TEventArgs>(
-            TTarget target, 
-            string eventName)
-            where TEventArgs : EventArgs
-        {
-            _ = target ?? throw new ArgumentNullException(nameof(target));
-            _ = eventName ?? throw new ArgumentNullException(nameof(eventName));
-
-            return Observable.Create<EventPattern<object, TEventArgs>>(observer =>
-            {
-                var handler = new Handler<TEventArgs>(observer);
-                WeakSubscriptionManager.Subscribe(target, eventName, handler);
-                return () => WeakSubscriptionManager.Unsubscribe(target, eventName, handler);
-            }).Publish().RefCount();
-        }
 
         private class Handler<TEventArgs> 
             : IWeakSubscriber<TEventArgs>,

src/Avalonia.Base/Utilities/WeakSubscriptionManager.cs

@@ -1,193 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Reflection;
-using System.Runtime.CompilerServices;
-
-namespace Avalonia.Utilities
-{
-    /// <summary>
-    /// Manages subscriptions to events using weak listeners.
-    /// </summary>
-    public static class WeakSubscriptionManager
-    {
-        /// <summary>
-        /// Subscribes to an event on an object using a weak subscription.
-        /// </summary>
-        /// <typeparam name="TTarget">The type of the target.</typeparam>
-        /// <typeparam name="TEventArgs">The type of the event arguments.</typeparam>
-        /// <param name="target">The event source.</param>
-        /// <param name="eventName">The name of the event.</param>
-        /// <param name="subscriber">The subscriber.</param>
-        [Obsolete("Use WeakEvent")]
-        public static void Subscribe<TTarget, TEventArgs>(TTarget target, string eventName, IWeakSubscriber<TEventArgs> subscriber)
-            where TEventArgs : EventArgs
-        {
-            _ = target ?? throw new ArgumentNullException(nameof(target));
-
-            var dic = SubscriptionTypeStorage<TEventArgs>.Subscribers.GetOrCreateValue(target);
-
-            if (!dic.TryGetValue(eventName, out var sub))
-            {
-                dic[eventName] = sub = new Subscription<TEventArgs>(dic, typeof(TTarget), target, eventName);
-            }
-
-            sub.Add(new WeakReference<IWeakSubscriber<TEventArgs>>(subscriber));
-        }
-
-        /// <summary>
-        /// Unsubscribes from an event.
-        /// </summary>
-        /// <typeparam name="T">The type of the event arguments.</typeparam>
-        /// <param name="target">The event source.</param>
-        /// <param name="eventName">The name of the event.</param>
-        /// <param name="subscriber">The subscriber.</param>
-        public static void Unsubscribe<T>(object target, string eventName, IWeakSubscriber<T> subscriber)
-            where T : EventArgs
-        {
-            if (SubscriptionTypeStorage<T>.Subscribers.TryGetValue(target, out var dic))
-            {
-                if (dic.TryGetValue(eventName, out var sub))
-                {
-                    sub.Remove(subscriber);
-                }
-            }
-        }
-
-        private static class SubscriptionTypeStorage<T>
-            where T : EventArgs
-        {
-            public static readonly ConditionalWeakTable<object, SubscriptionDic<T>> Subscribers
-                = new ConditionalWeakTable<object, SubscriptionDic<T>>();
-        }
-
-        private class SubscriptionDic<T> : Dictionary<string, Subscription<T>>
-            where T : EventArgs
-        {
-        }
-
-        private static readonly Dictionary<Type, Dictionary<string, EventInfo>> Accessors
-            = new Dictionary<Type, Dictionary<string, EventInfo>>();
-
-        private class Subscription<T> where T : EventArgs
-        {
-            private readonly EventInfo _info;
-            private readonly SubscriptionDic<T> _sdic;
-            private readonly object _target;
-            private readonly string _eventName;
-            private readonly Delegate _delegate;
-
-            private WeakReference<IWeakSubscriber<T>>?[] _data = new WeakReference<IWeakSubscriber<T>>?[16];
-            private int _count = 0;
-
-            public Subscription(SubscriptionDic<T> sdic, Type targetType, object target, string eventName)
-            {
-                _sdic = sdic;
-                _target = target;
-                _eventName = eventName;
-                if (!Accessors.TryGetValue(targetType, out var evDic))
-                    Accessors[targetType] = evDic = new Dictionary<string, EventInfo>();
-
-                if (evDic.TryGetValue(eventName, out var info))
-                {
-                    _info = info;
-                }
-                else
-                {
-                    var ev = targetType.GetRuntimeEvents().FirstOrDefault(x => x.Name == eventName);
-
-                    if (ev == null)
-                    {
-                        throw new ArgumentException(
-                            $"The event {eventName} was not found on {target.GetType()}.");
-                    }
-
-                    evDic[eventName] = _info = ev;
-                }
-
-                var del = new Action<object, T>(OnEvent);
-                _delegate = del.GetMethodInfo().CreateDelegate(_info.EventHandlerType!, del.Target);
-                _info.AddMethod!.Invoke(target, new[] { _delegate });
-            }
-
-            void Destroy()
-            {
-                _info.RemoveMethod!.Invoke(_target, new[] { _delegate });
-                _sdic.Remove(_eventName);
-            }
-
-            public void Add(WeakReference<IWeakSubscriber<T>> s)
-            {
-                if (_count == _data.Length)
-                {
-                    //Extend capacity
-                    var ndata = new WeakReference<IWeakSubscriber<T>>?[_data.Length*2];
-                    Array.Copy(_data, ndata, _data.Length);
-                    _data = ndata;
-                }
-                _data[_count] = s!;
-                _count++;
-            }
-
-            public void Remove(IWeakSubscriber<T> s)
-            {
-                var removed = false;
-
-                for (int c = 0; c < _count; ++c)
-                {
-                    var reference = _data[c];
-                    IWeakSubscriber<T>? instance;
-
-                    if (reference != null && reference.TryGetTarget(out instance) && instance == s)
-                    {
-                        _data[c] = null;
-                        removed = true;
-                    }
-                }
-
-                if (removed)
-                {
-                    Compact();
-                }
-            }
-
-            void Compact()
-            {
-                int empty = -1;
-                for (int c = 0; c < _count; c++)
-                {
-                    var r = _data[c];
-                    //Mark current index as first empty
-                    if (r == null && empty == -1)
-                        empty = c;
-                    //If current element isn't null and we have an empty one
-                    if (r != null && empty != -1)
-                    {
-                        _data[c] = null;
-                        _data[empty] = r;
-                        empty++;
-                    }
-                }
-                if (empty != -1)
-                    _count = empty;
-                if (_count == 0)
-                    Destroy();
-            }
-
-            void OnEvent(object sender, T eventArgs)
-            {
-                var needCompact = false;
-                for(var c=0; c<_count; c++)
-                {
-                    var r = _data[c];
-                    if (r?.TryGetTarget(out var sub) == true)
-                        sub!.OnEvent(sender, eventArgs);
-                    else
-                        needCompact = true;
-                }
-                if (needCompact)
-                    Compact();
-            }
-        }
-    }
-}

src/Avalonia.Base/Visual.cs

@@ -338,22 +338,6 @@ namespace Avalonia
             Contract.Requires<ArgumentNullException>(context != null);
         }
 
-        /// <summary>
-        /// Indicates that a property change should cause <see cref="InvalidateVisual"/> to be
-        /// called.
-        /// </summary>
-        /// <param name="properties">The properties.</param>
-        /// <remarks>
-        /// This method should be called in a control's static constructor with each property
-        /// on the control which when changed should cause a redraw. This is similar to WPF's
-        /// FrameworkPropertyMetadata.AffectsRender flag.
-        /// </remarks>
-        [Obsolete("Use AffectsRender<T> and specify the control type.")]
-        protected static void AffectsRender(params AvaloniaProperty[] properties)
-        {
-            AffectsRender<Visual>(properties);
-        }
-
         /// <summary>
         /// Indicates that a property change should cause <see cref="InvalidateVisual"/> to be
         /// called.

src/Avalonia.Base/VisualTree/IVisualTreeHost.cs

@@ -1,19 +0,0 @@
-using System;
-
-namespace Avalonia.VisualTree
-{
-    /// <summary>
-    /// Interface for controls that host their own separate visual tree, such as popups.
-    /// </summary>
-    [Obsolete]
-    public interface IVisualTreeHost
-    {
-        /// <summary>
-        /// Gets the root of the hosted visual tree.
-        /// </summary>
-        /// <value>
-        /// The root of the hosted visual tree.
-        /// </value>
-        IVisual? Root { get; }
-    }
-}

src/Avalonia.Controls.ColorPicker/Themes/Fluent/Fluent.xaml

@@ -11,15 +11,20 @@
                    Stretch="Uniform"
                    DestinationRect="0,0,8,8">
         <VisualBrush.Visual>
-          <DrawingPresenter Width="8"
-                            Height="8">
-            <DrawingGroup>
-              <GeometryDrawing Geometry="M0,0 L2,0 2,2, 0,2Z"
-                               Brush="Transparent" />
-              <GeometryDrawing Geometry="M0,1 L2,1 2,2, 1,2 1,0 0,0Z"
-                               Brush="#19808080" />
-            </DrawingGroup>
-          </DrawingPresenter>
+          <Image Width="8" Height="8">
+            <Image.Source>
+              <DrawingImage>
+                <DrawingImage.Drawing>
+                    <DrawingGroup>
+                      <GeometryDrawing Geometry="M0,0 L2,0 2,2, 0,2Z"
+                                       Brush="Transparent" />
+                      <GeometryDrawing Geometry="M0,1 L2,1 2,2, 1,2 1,0 0,0Z"
+                                       Brush="#19808080" />
+                    </DrawingGroup>
+                </DrawingImage.Drawing>
+              </DrawingImage>
+            </Image.Source>
+          </Image>
         </VisualBrush.Visual>
       </VisualBrush>
 

src/Avalonia.Controls.ColorPicker/Themes/Simple/Simple.xaml

@@ -11,15 +11,20 @@
                    Stretch="Uniform"
                    DestinationRect="0,0,8,8">
         <VisualBrush.Visual>
-          <DrawingPresenter Width="8"
-                            Height="8">
-            <DrawingGroup>
-              <GeometryDrawing Geometry="M0,0 L2,0 2,2, 0,2Z"
-                               Brush="Transparent" />
-              <GeometryDrawing Geometry="M0,1 L2,1 2,2, 1,2 1,0 0,0Z"
-                               Brush="#19808080" />
-            </DrawingGroup>
-          </DrawingPresenter>
+          <Image Width="8" Height="8">
+            <Image.Source>
+              <DrawingImage>
+                <DrawingImage.Drawing>
+                  <DrawingGroup>
+                    <GeometryDrawing Geometry="M0,0 L2,0 2,2, 0,2Z"
+                                     Brush="Transparent" />
+                    <GeometryDrawing Geometry="M0,1 L2,1 2,2, 1,2 1,0 0,0Z"
+                                     Brush="#19808080" />
+                  </DrawingGroup>
+                </DrawingImage.Drawing>
+              </DrawingImage>
+            </Image.Source>
+          </Image>
         </VisualBrush.Visual>
       </VisualBrush>
 

src/Avalonia.Controls.DataGrid/DataGrid.cs

@@ -2167,7 +2167,23 @@ namespace Avalonia.Controls
 
             return desiredSize;
         }
+        
+        /// <inheritdoc/>
+        protected override void OnDataContextBeginUpdate()
+        {
+            base.OnDataContextBeginUpdate();
 
+            NotifyDataContextPropertyForAllRowCells(GetAllRows(), true);
+        }
+
+        /// <inheritdoc/>
+        protected override void OnDataContextEndUpdate()
+        {
+            base.OnDataContextEndUpdate();
+
+            NotifyDataContextPropertyForAllRowCells(GetAllRows(), false);
+        }
+        
         /// <summary>
         /// Raises the BeginningEdit event.
         /// </summary>
@@ -3165,6 +3181,20 @@ namespace Avalonia.Controls
             }
         }
 
+        private static void NotifyDataContextPropertyForAllRowCells(IEnumerable<DataGridRow> rowSource, bool arg2)
+        {
+            foreach (DataGridRow row in rowSource)
+            {
+                foreach (DataGridCell cell in row.Cells)
+                {
+                    if (cell.Content is StyledElement cellContent)
+                    {
+                        DataContextProperty.Notifying?.Invoke(cellContent, arg2);
+                    }
+                }
+            }
+        }
+
         private void UpdateRowDetailsVisibilityMode(DataGridRowDetailsVisibilityMode newDetailsMode)
         {
             int itemCount = DataConnection.Count;

src/Avalonia.Controls/AutoCompleteBox.cs

@@ -392,6 +392,8 @@ namespace Avalonia.Controls
         private AutoCompleteSelector<object>? _itemSelector;
         private AutoCompleteSelector<string?>? _textSelector;
 
+        private readonly EventHandler _populateDropDownHandler;
+
         public static readonly RoutedEvent<SelectionChangedEventArgs> SelectionChangedEvent =
             RoutedEvent.Register<SelectionChangedEventArgs>(nameof(SelectionChanged), RoutingStrategies.Bubble, typeof(AutoCompleteBox));
 
@@ -668,6 +670,7 @@ namespace Avalonia.Controls
 
                 if (newValue == TimeSpan.Zero)
                 {
+                    _delayTimer.Tick -= _populateDropDownHandler;
                     _delayTimer = null;
                 }
             }
@@ -678,7 +681,7 @@ namespace Avalonia.Controls
                 if (_delayTimer == null)
                 {
                     _delayTimer = new DispatcherTimer();
-                    _delayTimer.Tick += PopulateDropDown;
+                    _delayTimer.Tick += _populateDropDownHandler;
                 }
 
                 // Set the new tick interval
@@ -864,6 +867,7 @@ namespace Avalonia.Controls
         /// </summary>
         public AutoCompleteBox()
         {
+            _populateDropDownHandler = PopulateDropDown;
             ClearView();
         }
 
@@ -1771,10 +1775,7 @@ namespace Avalonia.Controls
         /// <param name="e">The event arguments.</param>
         private void PopulateDropDown(object? sender, EventArgs e)
         {
-            if (_delayTimer != null)
-            {
-                _delayTimer.Stop();
-            }
+            _delayTimer?.Stop();
 
             // Update the prefix/search text.
             SearchText = Text;

src/Avalonia.Controls/Calendar/Calendar.cs

@@ -224,7 +224,7 @@ namespace Avalonia.Controls
     /// </para>
     /// </remarks>
     [TemplatePart(PART_ElementMonth, typeof(CalendarItem))]
-    [TemplatePart(PART_ElementRoot,  typeof(Panel))]
+    [TemplatePart(PART_ElementRoot, typeof(Panel))]
     public class Calendar : TemplatedControl
     {
         internal const int RowsPerMonth = 7;
@@ -338,14 +338,11 @@ namespace Avalonia.Controls
         /// <param name="e">The DependencyPropertyChangedEventArgs.</param>
         private void OnIsTodayHighlightedChanged(AvaloniaPropertyChangedEventArgs e)
         {
-            if (DisplayDate != null)
-            {
-                int i = DateTimeHelper.CompareYearMonth(DisplayDateInternal, DateTime.Today);
+            int i = DateTimeHelper.CompareYearMonth(DisplayDateInternal, DateTime.Today);
 
-                if (i > -2 && i < 2)
-                {
-                    UpdateMonths();
-                }
+            if (i > -2 && i < 2)
+            {
+                UpdateMonths();
             }
         }
 
@@ -655,7 +652,7 @@ namespace Avalonia.Controls
                 SelectedDatesChanged?.Invoke(this, e);
             }
         }
-        
+
         internal Collection<DateTime> RemovedItems { get; set; }
         internal DateTime? LastSelectedDateInternal { get; set; }
         internal DateTime? LastSelectedDate
@@ -914,7 +911,7 @@ namespace Avalonia.Controls
                 o => o.DisplayDateEnd,
                 (o, v) => o.DisplayDateEnd = v,
                 defaultBindingMode: BindingMode.TwoWay);
-        
+
         /// <summary>
         /// Gets or sets the last date to be displayed.
         /// </summary>
@@ -1242,7 +1239,7 @@ namespace Avalonia.Controls
                                     {
                                         b.IsSelected = false;
                                     }
-                                } 
+                                }
                             }
                         }
                     }
@@ -1278,7 +1275,7 @@ namespace Avalonia.Controls
 
         internal void OnPreviousClick()
         {
-            if (DisplayMode == CalendarMode.Month && DisplayDate != null)
+            if (DisplayMode == CalendarMode.Month)
             {
                 DateTime? d = DateTimeHelper.AddMonths(DateTimeHelper.DiscardDayTime(DisplayDate), -1);
                 if (d.HasValue)
@@ -1326,7 +1323,7 @@ namespace Avalonia.Controls
         }
         internal void OnNextClick()
         {
-            if (DisplayMode == CalendarMode.Month && DisplayDate != null)
+            if (DisplayMode == CalendarMode.Month)
             {
                 DateTime? d = DateTimeHelper.AddMonths(DateTimeHelper.DiscardDayTime(DisplayDate), 1);
                 if (d.HasValue)
@@ -1645,7 +1642,7 @@ namespace Avalonia.Controls
         {
             if (DisplayMode == CalendarMode.Month)
             {
-                if (LastSelectedDate.HasValue && DisplayDateInternal != null)
+                if (LastSelectedDate.HasValue)
                 {
                     // If a blackout day is inactive, when clicked on it, the
                     // previous inactive day which is not a blackout day can get
@@ -1897,24 +1894,21 @@ namespace Avalonia.Controls
             {
                 case CalendarMode.Month:
                     {
-                        if (DisplayDate != null)
-                        {
-                            DateTime? selectedDate = new DateTime(DisplayDateInternal.Year, DisplayDateInternal.Month, 1);
+                        DateTime? selectedDate = new DateTime(DisplayDateInternal.Year, DisplayDateInternal.Month, 1);
 
-                            if (DateTimeHelper.CompareYearMonth(DateTime.MaxValue, selectedDate.Value) > 0)
-                            {
-                                // since DisplayDate is not equal to
-                                // DateTime.MaxValue we are sure selectedDate is\
-                                // not null
-                                selectedDate = DateTimeHelper.AddMonths(selectedDate.Value, 1)!.Value;
-                                selectedDate = DateTimeHelper.AddDays(selectedDate.Value, -1)!.Value;
-                            }
-                            else
-                            {
-                                selectedDate = DateTime.MaxValue;
-                            }
-                            ProcessSelection(shift, selectedDate, null);
+                        if (DateTimeHelper.CompareYearMonth(DateTime.MaxValue, selectedDate.Value) > 0)
+                        {
+                            // since DisplayDate is not equal to
+                            // DateTime.MaxValue we are sure selectedDate is\
+                            // not null
+                            selectedDate = DateTimeHelper.AddMonths(selectedDate.Value, 1)!.Value;
+                            selectedDate = DateTimeHelper.AddDays(selectedDate.Value, -1)!.Value;
                         }
+                        else
+                        {
+                            selectedDate = DateTime.MaxValue;
+                        }
+                        ProcessSelection(shift, selectedDate, null);
                         break;
                     }
                 case CalendarMode.Year:
@@ -2026,7 +2020,6 @@ namespace Avalonia.Controls
                             focusDate = DisplayDate;
                             LastSelectedDate = DisplayDate;
                         }
-                        Debug.Assert(focusDate != null, "focusDate should not be null!");
                         FocusButton = FindDayButtonFromDay(focusDate);
 
                         if (FocusButton != null)
@@ -2091,17 +2084,17 @@ namespace Avalonia.Controls
 
         static Calendar()
         {
-            IsEnabledProperty.Changed.AddClassHandler<Calendar>((x,e) => x.OnIsEnabledChanged(e));
-            FirstDayOfWeekProperty.Changed.AddClassHandler<Calendar>((x,e) => x.OnFirstDayOfWeekChanged(e));
-            IsTodayHighlightedProperty.Changed.AddClassHandler<Calendar>((x,e) => x.OnIsTodayHighlightedChanged(e));
-            DisplayModeProperty.Changed.AddClassHandler<Calendar>((x,e) => x.OnDisplayModePropertyChanged(e));
-            SelectionModeProperty.Changed.AddClassHandler<Calendar>((x,e) => x.OnSelectionModeChanged(e));
-            SelectedDateProperty.Changed.AddClassHandler<Calendar>((x,e) => x.OnSelectedDateChanged(e));
-            DisplayDateProperty.Changed.AddClassHandler<Calendar>((x,e) => x.OnDisplayDateChanged(e));
-            DisplayDateStartProperty.Changed.AddClassHandler<Calendar>((x,e) => x.OnDisplayDateStartChanged(e));
-            DisplayDateEndProperty.Changed.AddClassHandler<Calendar>((x,e) => x.OnDisplayDateEndChanged(e));
-            KeyDownEvent.AddClassHandler<Calendar>((x,e) => x.Calendar_KeyDown(e));
-            KeyUpEvent.AddClassHandler<Calendar>((x,e) => x.Calendar_KeyUp(e));
+            IsEnabledProperty.Changed.AddClassHandler<Calendar>((x, e) => x.OnIsEnabledChanged(e));
+            FirstDayOfWeekProperty.Changed.AddClassHandler<Calendar>((x, e) => x.OnFirstDayOfWeekChanged(e));
+            IsTodayHighlightedProperty.Changed.AddClassHandler<Calendar>((x, e) => x.OnIsTodayHighlightedChanged(e));
+            DisplayModeProperty.Changed.AddClassHandler<Calendar>((x, e) => x.OnDisplayModePropertyChanged(e));
+            SelectionModeProperty.Changed.AddClassHandler<Calendar>((x, e) => x.OnSelectionModeChanged(e));
+            SelectedDateProperty.Changed.AddClassHandler<Calendar>((x, e) => x.OnSelectedDateChanged(e));
+            DisplayDateProperty.Changed.AddClassHandler<Calendar>((x, e) => x.OnDisplayDateChanged(e));
+            DisplayDateStartProperty.Changed.AddClassHandler<Calendar>((x, e) => x.OnDisplayDateStartChanged(e));
+            DisplayDateEndProperty.Changed.AddClassHandler<Calendar>((x, e) => x.OnDisplayDateEndChanged(e));
+            KeyDownEvent.AddClassHandler<Calendar>((x, e) => x.Calendar_KeyDown(e));
+            KeyUpEvent.AddClassHandler<Calendar>((x, e) => x.Calendar_KeyUp(e));
         }
 
         /// <summary>

src/Avalonia.Controls/Calendar/CalendarItem.cs

@@ -4,7 +4,6 @@
 // All other rights reserved.
 
 using System;
-using System.Collections.Generic;
 using System.Diagnostics;
 using System.Globalization;
 using Avalonia.Collections.Pooled;
@@ -353,7 +352,6 @@ namespace Avalonia.Controls.Primitives
         {
             if (Owner != null)
             {
-                Debug.Assert(Owner.DisplayDate != null, "The Owner Calendar's DisplayDate should not be null!");
                 _currentMonth = Owner.DisplayDateInternal;
             }
             else
@@ -361,17 +359,14 @@ namespace Avalonia.Controls.Primitives
                 _currentMonth = DateTime.Today;
             }
 
-            if (_currentMonth != null)
-            {
-                SetMonthModeHeaderButton();
-                SetMonthModePreviousButton(_currentMonth);
-                SetMonthModeNextButton(_currentMonth);
+            SetMonthModeHeaderButton();
+            SetMonthModePreviousButton(_currentMonth);
+            SetMonthModeNextButton(_currentMonth);
 
-                if (MonthView != null)
-                {
-                    SetDayTitles();
-                    SetCalendarDayButtons(_currentMonth);
-                }
+            if (MonthView != null)
+            {
+                SetDayTitles();
+                SetCalendarDayButtons(_currentMonth);
             }
         }
         private void SetMonthModeHeaderButton()
@@ -592,7 +587,6 @@ namespace Avalonia.Controls.Primitives
         {
             if (Owner != null)
             {
-                Debug.Assert(Owner.SelectedMonth != null, "The Owner Calendar's SelectedMonth should not be null!");
                 _currentMonth = (DateTime)Owner.SelectedMonth;
             }
             else
@@ -600,16 +594,13 @@ namespace Avalonia.Controls.Primitives
                 _currentMonth = DateTime.Today;
             }
 
-            if (_currentMonth != null)
-            {
-                SetYearModeHeaderButton();
-                SetYearModePreviousButton();
-                SetYearModeNextButton();
+            SetYearModeHeaderButton();
+            SetYearModePreviousButton();
+            SetYearModeNextButton();
 
-                if (YearView != null)
-                {
-                    SetMonthButtonsForYearMode();
-                }
+            if (YearView != null)
+            {
+                SetMonthButtonsForYearMode();
             }
         }
         private void SetYearModeHeaderButton()
@@ -660,7 +651,6 @@ namespace Avalonia.Controls.Primitives
                         childButton.IsCalendarButtonFocused = false;
                     }
 
-                    Debug.Assert(Owner.DisplayDateInternal != null, "The Owner Calendar's DisplayDateInternal should not be null!");
                     childButton.IsSelected = (DateTimeHelper.CompareYearMonth(day, Owner.DisplayDateInternal) == 0);
 
                     if (DateTimeHelper.CompareYearMonth(day, Owner.DisplayDateRangeStart) < 0 || DateTimeHelper.CompareYearMonth(day, Owner.DisplayDateRangeEnd) > 0)
@@ -685,7 +675,6 @@ namespace Avalonia.Controls.Primitives
 
             if (Owner != null)
             {
-                Debug.Assert(Owner.SelectedYear != null, "The owning Calendar's selected year should not be null!");
                 selectedYear = Owner.SelectedYear;
                 _currentMonth = (DateTime)Owner.SelectedMonth;
             }
@@ -695,19 +684,16 @@ namespace Avalonia.Controls.Primitives
                 selectedYear = DateTime.Today;
             }
 
-            if (_currentMonth != null)
-            {
-                int decade = DateTimeHelper.DecadeOfDate(selectedYear);
-                int decadeEnd = DateTimeHelper.EndOfDecade(selectedYear);
+            int decade = DateTimeHelper.DecadeOfDate(selectedYear);
+            int decadeEnd = DateTimeHelper.EndOfDecade(selectedYear);
 
-                SetDecadeModeHeaderButton(decade, decadeEnd);
-                SetDecadeModePreviousButton(decade);
-                SetDecadeModeNextButton(decadeEnd);
+            SetDecadeModeHeaderButton(decade, decadeEnd);
+            SetDecadeModePreviousButton(decade);
+            SetDecadeModeNextButton(decadeEnd);
 
-                if (YearView != null)
-                {
-                    SetYearButtons(decade, decadeEnd);
-                }
+            if (YearView != null)
+            {
+                SetYearButtons(decade, decadeEnd);
             }
         }
         internal void UpdateYearViewSelection(CalendarButton calendarButton)
@@ -822,22 +808,15 @@ namespace Avalonia.Controls.Primitives
                 {
                     if (Owner.DisplayMode == CalendarMode.Month)
                     {
-                        if (Owner.DisplayDate != null)
-                        {
-                            d = Owner.DisplayDateInternal;
-                            Owner.SelectedMonth = new DateTime(d.Year, d.Month, 1);
-                        }
+                        d = Owner.DisplayDateInternal;
+                        Owner.SelectedMonth = new DateTime(d.Year, d.Month, 1);
                         Owner.DisplayMode = CalendarMode.Year;
                     }
                     else
                     {
                         Debug.Assert(Owner.DisplayMode == CalendarMode.Year, "The Owner Calendar's DisplayMode should be Year!");
-
-                        if (Owner.SelectedMonth != null)
-                        {
-                            d = Owner.SelectedMonth;
-                            Owner.SelectedYear = new DateTime(d.Year, d.Month, 1);
-                        }
+                        d = Owner.SelectedMonth;
+                        Owner.SelectedYear = new DateTime(d.Year, d.Month, 1);
                         Owner.DisplayMode = CalendarMode.Decade;
                     }
                 }

src/Avalonia.Controls/Calendar/SelectedDatesCollection.cs

@@ -297,7 +297,7 @@ namespace Avalonia.Controls.Primitives
                 }
                 else
                 {
-                    if (item != null && DateTime.Compare(this[index], item) != 0 && Calendar.IsValidDateSelection(_owner, item))
+                    if (DateTime.Compare(this[index], item) != 0 && Calendar.IsValidDateSelection(_owner, item))
                     {
                         removedItems.Add(this[index]);
                         base.SetItem(index, item);

src/Avalonia.Controls/Control.cs

@@ -8,6 +8,7 @@ using Avalonia.Controls.Templates;
 using Avalonia.Input;
 using Avalonia.Input.Platform;
 using Avalonia.Interactivity;
+using Avalonia.LogicalTree;
 using Avalonia.Media;
 using Avalonia.Rendering;
 using Avalonia.Styling;
@@ -104,7 +105,6 @@ namespace Avalonia.Controls
         private static readonly HashSet<Control> _loadedQueue = new HashSet<Control>();
         private static readonly HashSet<Control> _loadedProcessingQueue = new HashSet<Control>();
 
-        private bool _isAttachedToVisualTree = false;
         private bool _isLoaded = false;
         private DataTemplates? _dataTemplates;
         private IControl? _focusAdorner;
@@ -347,7 +347,7 @@ namespace Avalonia.Controls
         internal void OnLoadedCore()
         {
             if (_isLoaded == false &&
-                _isAttachedToVisualTree)
+                ((ILogical)this).IsAttachedToLogicalTree)
             {
                 _isLoaded = true;
                 OnLoaded();
@@ -395,7 +395,6 @@ namespace Avalonia.Controls
         protected sealed override void OnAttachedToVisualTreeCore(VisualTreeAttachmentEventArgs e)
         {
             base.OnAttachedToVisualTreeCore(e);
-            _isAttachedToVisualTree = true;
 
             InitializeIfNeeded();
 
@@ -406,7 +405,6 @@ namespace Avalonia.Controls
         protected sealed override void OnDetachedFromVisualTreeCore(VisualTreeAttachmentEventArgs e)
         {
             base.OnDetachedFromVisualTreeCore(e);
-            _isAttachedToVisualTree = false;
 
             OnUnloadedCore();
         }

src/Avalonia.Controls/DesktopApplicationExtensions.cs

@@ -8,8 +8,6 @@ namespace Avalonia.Controls
 {
     public static class DesktopApplicationExtensions
     {
-        [Obsolete("Running application without a cancellation token and a lifetime is no longer supported, see https://github.com/AvaloniaUI/Avalonia/wiki/Application-lifetimes for details", true)]
-        public static void Run(this Application app) => throw new NotSupportedException();
 
         /// <summary>
         /// On desktop-style platforms runs the application's main loop until closable is closed

src/Avalonia.Controls/DrawingPresenter.cs

@@ -1,61 +0,0 @@
-using System;
-using Avalonia.Controls.Shapes;
-using Avalonia.Media;
-using Avalonia.Metadata;
-
-namespace Avalonia.Controls
-{
-    [Obsolete("Use Image control with DrawingImage source")]
-    public class DrawingPresenter : Control
-    {
-        static DrawingPresenter()
-        {
-            AffectsMeasure<DrawingPresenter>(DrawingProperty);
-            AffectsRender<DrawingPresenter>(DrawingProperty);
-        }
-
-        public static readonly StyledProperty<Drawing> DrawingProperty =
-            AvaloniaProperty.Register<DrawingPresenter, Drawing>(nameof(Drawing));
-
-        public static readonly StyledProperty<Stretch> StretchProperty =
-            AvaloniaProperty.Register<DrawingPresenter, Stretch>(nameof(Stretch), Stretch.Uniform);
-
-        [Content]
-        public Drawing Drawing
-        {
-            get => GetValue(DrawingProperty);
-            set => SetValue(DrawingProperty, value);
-        }
-
-        public Stretch Stretch
-        {
-            get => GetValue(StretchProperty);
-            set => SetValue(StretchProperty, value);
-        }
-
-        private Matrix _transform = Matrix.Identity;
-
-        protected override Size MeasureOverride(Size availableSize)
-        {
-            if (Drawing == null) return new Size();
-
-            var (size, transform) = Shape.CalculateSizeAndTransform(availableSize, Drawing.GetBounds(), Stretch);
-
-            _transform = transform;
-
-            return size;
-        }
-
-        public override void Render(DrawingContext context)
-        {
-            if (Drawing != null)
-            {
-                using (context.PushPreTransform(_transform))
-                using (context.PushClip(new Rect(Bounds.Size)))
-                {
-                    Drawing.Draw(context);
-                }
-            }
-        }
-    }
-}

src/Avalonia.Controls/GridLength.cs

@@ -180,7 +180,7 @@ namespace Avalonia.Controls
                 return "Auto";
             }
 
-            string s = _value.ToString();
+            string s = _value.ToString(CultureInfo.InvariantCulture);
             return IsStar ? s + "*" : s;
         }
 

src/Avalonia.Controls/LoggingExtensions.cs

@@ -1,21 +1,10 @@
-using System;
-using Avalonia.Controls;
+using Avalonia.Controls;
 using Avalonia.Logging;
 
 namespace Avalonia
 {
     public static class LoggingExtensions
     {
-        [Obsolete("Use LogToTrace")]
-        public static T LogToDebug<T>(
-            this T builder,
-            LogEventLevel level = LogEventLevel.Warning,
-            params string[] areas)
-                where T : AppBuilderBase<T>, new()
-        {
-            return LogToTrace(builder, level, areas);
-        }
-
         /// <summary>
         /// Logs Avalonia events to the <see cref="System.Diagnostics.Trace"/> sink.
         /// </summary>

src/Avalonia.Controls/NativeMenuItem.cs

@@ -186,13 +186,6 @@ namespace Avalonia.Controls
         /// </summary>
         public event EventHandler? Click;
 
-        [Obsolete("Use Click event.")]
-        public event EventHandler Clicked
-        {
-            add => Click += value;
-            remove => Click -= value;
-        }
-
         void INativeMenuItemExporterEventsImplBridge.RaiseClicked()
         {
             Click?.Invoke(this, new EventArgs());

src/Avalonia.Controls/NativeMenuItemSeparator.cs

@@ -1,16 +1,7 @@
-using System;
-
-namespace Avalonia.Controls
+namespace Avalonia.Controls
 {
-
-    [Obsolete("This class exists to maintain backwards compatibility with existing code. Use NativeMenuItemSeparator instead")]
-    public class NativeMenuItemSeperator : NativeMenuItemSeparator 
-    {
-    }
-
     public class NativeMenuItemSeparator : NativeMenuItemBase
     {
-        [Obsolete("This is a temporary hack to make our MenuItem recognize this as a separator, don't use", true)]
-        public string Header => "-";
+
     }
 }

src/Avalonia.Controls/Notifications/WindowNotificationManager.cs

@@ -102,15 +102,12 @@ namespace Avalonia.Controls.Notifications
                 Content = content
             };
 
-            if (notification != null)
+            notificationControl.NotificationClosed += (sender, args) =>
             {
-                notificationControl.NotificationClosed += (sender, args) =>
-                {
-                    notification.OnClose?.Invoke();
+                notification?.OnClose?.Invoke();
 
-                    _items?.Remove(sender);
-                };
-            }
+                _items?.Remove(sender);
+            };
 
             notificationControl.PointerPressed += (sender, args) =>
             {

src/Avalonia.Controls/NumericUpDown/NumericUpDown.cs

@@ -45,14 +45,6 @@ namespace Avalonia.Controls
             AvaloniaProperty.RegisterDirect<NumericUpDown, bool>(nameof(ClipValueToMinMax),
                 updown => updown.ClipValueToMinMax, (updown, b) => updown.ClipValueToMinMax = b);
 
-        /// <summary>
-        /// Defines the <see cref="CultureInfo"/> property.
-        /// </summary>
-        [Obsolete]
-        public static readonly DirectProperty<NumericUpDown, CultureInfo?> CultureInfoProperty =
-            AvaloniaProperty.RegisterDirect<NumericUpDown, CultureInfo?>(nameof(CultureInfo), o => o.CultureInfo,
-                (o, v) => o.CultureInfo = v, CultureInfo.CurrentCulture);
-
         /// <summary>
         /// Defines the <see cref="NumberFormat"/> property.
         /// </summary>
@@ -187,21 +179,6 @@ namespace Avalonia.Controls
             set { SetAndRaise(ClipValueToMinMaxProperty, ref _clipValueToMinMax, value); }
         }
 
-        /// <summary>
-        /// Gets or sets the current CultureInfo.
-        /// </summary>
-        [Obsolete("CultureInfo is obsolete, please use NumberFormat instead.")]
-        public CultureInfo? CultureInfo
-        {
-            get { return _cultureInfo; }
-            set
-            {
-                SetAndRaise(CultureInfoProperty, ref _cultureInfo, value);
-                //Set and Raise the NumberFormatProperty when CultureInfo is changed.
-                SetAndRaise(NumberFormatProperty, ref _numberFormat, value?.NumberFormat);
-            }
-        }
-
         /// <summary>
         /// Gets or sets the current NumberFormatInfo
         /// </summary>
@@ -335,9 +312,6 @@ namespace Avalonia.Controls
         /// </summary>
         static NumericUpDown()
         {
-#pragma warning disable CS0612 // Type or member is obsolete
-            CultureInfoProperty.Changed.Subscribe(OnCultureInfoChanged);
-#pragma warning restore CS0612 // Type or member is obsolete
             NumberFormatProperty.Changed.Subscribe(OnNumberFormatChanged);
             FormatStringProperty.Changed.Subscribe(FormatStringChanged);
             IncrementProperty.Changed.Subscribe(IncrementChanged);
@@ -416,19 +390,6 @@ namespace Avalonia.Controls
             }
         }
 
-        /// <summary>
-        /// Called when the <see cref="CultureInfo"/> property value changed.
-        /// </summary>
-        /// <param name="oldValue">The old value.</param>
-        /// <param name="newValue">The new value.</param>
-        protected virtual void OnCultureInfoChanged(CultureInfo? oldValue, CultureInfo? newValue)
-        {
-            if (IsInitialized)
-            {
-                SyncTextAndValueProperties(false, null);
-            }
-        }
-
         /// <summary>
         /// Called when the <see cref="NumberFormat"/> property value changed.
         /// </summary>
@@ -729,20 +690,6 @@ namespace Avalonia.Controls
             }
         }
 
-        /// <summary>
-        /// Called when the <see cref="CultureInfo"/> property value changed.
-        /// </summary>
-        /// <param name="e">The event args.</param>
-        private static void OnCultureInfoChanged(AvaloniaPropertyChangedEventArgs e)
-        {
-            if (e.Sender is NumericUpDown upDown)
-            {
-                var oldValue = (CultureInfo?)e.OldValue;
-                var newValue = (CultureInfo?)e.NewValue;
-                upDown.OnCultureInfoChanged(oldValue, newValue);
-            }
-        }
-
         /// <summary>
         /// Called when the <see cref="NumberFormat"/> property value changed.
         /// </summary>

src/Avalonia.Controls/Platform/InternalPlatformThreadingInterface.cs

@@ -43,7 +43,7 @@ namespace Avalonia.Controls.Platform
                 _priority = priority;
                 _interval = interval;
                 _tick = tick;
-                _timer = new Timer(OnTimer, null, interval, TimeSpan.FromMilliseconds(-1));
+                _timer = new Timer(OnTimer, null, interval, Timeout.InfiniteTimeSpan);
                 _handle = GCHandle.Alloc(_timer);
             }
 
@@ -57,7 +57,7 @@ namespace Avalonia.Controls.Platform
                     if (_timer == null)
                         return;
                     _tick();
-                    _timer?.Change(_interval, TimeSpan.FromMilliseconds(-1));
+                    _timer?.Change(_interval, Timeout.InfiniteTimeSpan);
                 });
             }
 

src/Avalonia.Controls/Primitives/Popup.cs

@@ -22,9 +22,7 @@ namespace Avalonia.Controls.Primitives
     /// <summary>
     /// Displays a popup window.
     /// </summary>
-#pragma warning disable CS0612 // Type or member is obsolete
-    public class Popup : Control, IVisualTreeHost, IPopupHostProvider
-#pragma warning restore CS0612 // Type or member is obsolete
+    public class Popup : Control, IPopupHostProvider
     {
         public static readonly StyledProperty<bool> WindowManagerAddShadowHintProperty =
             AvaloniaProperty.Register<Popup, bool>(nameof(WindowManagerAddShadowHint), false);
@@ -90,14 +88,6 @@ namespace Avalonia.Controls.Primitives
         public static readonly StyledProperty<Control?> PlacementTargetProperty =
             AvaloniaProperty.Register<Popup, Control?>(nameof(PlacementTarget));
 
-#pragma warning disable 618
-        /// <summary>
-        /// Defines the <see cref="ObeyScreenEdges"/> property.
-        /// </summary>
-        public static readonly StyledProperty<bool> ObeyScreenEdgesProperty =
-            AvaloniaProperty.Register<Popup, bool>(nameof(ObeyScreenEdges), true);
-#pragma warning restore 618
-
         public static readonly StyledProperty<bool> OverlayDismissEventPassThroughProperty =
             AvaloniaProperty.Register<Popup, bool>(nameof(OverlayDismissEventPassThrough));
 
@@ -125,17 +115,6 @@ namespace Avalonia.Controls.Primitives
         public static readonly StyledProperty<double> VerticalOffsetProperty =
             AvaloniaProperty.Register<Popup, double>(nameof(VerticalOffset));
 
-        /// <summary>
-        /// Defines the <see cref="StaysOpen"/> property.
-        /// </summary>
-        [Obsolete("Use IsLightDismissEnabledProperty")]
-        public static readonly DirectProperty<Popup, bool> StaysOpenProperty =
-            AvaloniaProperty.RegisterDirect<Popup, bool>(
-                nameof(StaysOpen),
-                o => o.StaysOpen,
-                (o, v) => o.StaysOpen = v,
-                true);
-
         /// <summary>
         /// Defines the <see cref="Topmost"/> property.
         /// </summary>
@@ -301,13 +280,6 @@ namespace Avalonia.Controls.Primitives
             set { SetValue(PlacementTargetProperty, value); }
         }
 
-        [Obsolete("This property has no effect")]
-        public bool ObeyScreenEdges
-        {
-            get => GetValue(ObeyScreenEdgesProperty);
-            set => SetValue(ObeyScreenEdgesProperty, value);
-        }
-
         /// <summary>
         /// Gets or sets a value indicating whether the event that closes the popup is passed
         /// through to the parent window.
@@ -352,17 +324,6 @@ namespace Avalonia.Controls.Primitives
             set { SetValue(VerticalOffsetProperty, value); }
         }
 
-        /// <summary>
-        /// Gets or sets a value indicating whether the popup should stay open when the popup is
-        /// pressed or loses focus.
-        /// </summary>
-        [Obsolete("Use IsLightDismissEnabled")]
-        public bool StaysOpen
-        {
-            get => !IsLightDismissEnabled;
-            set => IsLightDismissEnabled = !value;
-        }
-
         /// <summary>
         /// Gets or sets whether this popup appears on top of all other windows
         /// </summary>
@@ -372,11 +333,6 @@ namespace Avalonia.Controls.Primitives
             set { SetValue(TopmostProperty, value); }
         }
 
-        /// <summary>
-        /// Gets the root of the popup window.
-        /// </summary>
-        IVisual? IVisualTreeHost.Root => _openState?.PopupHost.HostedVisualTreeRoot;
-
         IPopupHost? IPopupHostProvider.PopupHost => Host;
 
         event Action<IPopupHost?>? IPopupHostProvider.PopupHostChanged 

src/Avalonia.Controls/Primitives/TemplatedControl.cs

@@ -297,9 +297,6 @@ namespace Avalonia.Controls.Primitives
 
                     var e = new TemplateAppliedEventArgs(nameScope);
                     OnApplyTemplate(e);
-#pragma warning disable CS0618 // Type or member is obsolete
-                    OnTemplateApplied(e);
-#pragma warning restore CS0618 // Type or member is obsolete
                     RaiseEvent(e);
                 }
 
@@ -378,15 +375,6 @@ namespace Avalonia.Controls.Primitives
             }
         }
 
-        /// <summary>
-        /// Called when the control's template is applied.
-        /// </summary>
-        /// <param name="e">The event args.</param>
-        [Obsolete("Use OnApplyTemplate")]
-        protected virtual void OnTemplateApplied(TemplateAppliedEventArgs e)
-        {
-        }
-
         /// <summary>
         /// Called when the <see cref="Template"/> property changes.
         /// </summary>

src/Avalonia.Controls/ProgressBar.cs

@@ -251,11 +251,9 @@ namespace Avalonia.Controls
                     TemplateProperties.Container2AnimationEndPosition = barIndicatorWidth2 * 1.66; // Position at 166%
 
 
-#pragma warning disable CS0618 // Type or member is obsolete
                     // Remove these properties when we switch to fluent as default and removed the old one.
                     IndeterminateStartingOffset = -dim;
                     IndeterminateEndingOffset = dim;
-#pragma warning restore CS0618 // Type or member is obsolete
 
                     var padding = Padding;
                     var rectangle = new RectangleGeometry(

src/Avalonia.Controls/Remote/RemoteWidget.cs

@@ -77,10 +77,8 @@ namespace Avalonia.Controls.Remote
                     _bitmap.PixelSize.Height != _lastFrame.Height)
                 {
                     _bitmap?.Dispose();
-#pragma warning disable CS0618 // Type or member is obsolete
                     _bitmap = new WriteableBitmap(new PixelSize(_lastFrame.Width, _lastFrame.Height),
                         new Vector(96, 96), fmt);
-#pragma warning restore CS0618 // Type or member is obsolete
                 }
                 using (var l = _bitmap.Lock())
                 {

src/Avalonia.Controls/RichTextBlock.cs

@@ -381,9 +381,7 @@ namespace Avalonia.Controls
                 var hit = TextLayout.HitTestPoint(point);
                 var index = hit.TextPosition;
 
-#pragma warning disable CS0618 // Type or member is obsolete
                 switch (e.ClickCount)
-#pragma warning restore CS0618 // Type or member is obsolete
                 {
                     case 1:
                         if (clickToSelect)

src/Avalonia.Controls/Shapes/Arc.cs

@@ -1,8 +1,12 @@
 using System;
 using Avalonia.Media;
+using Avalonia.Utilities;
 
 namespace Avalonia.Controls.Shapes
 {
+    /// <summary>
+    /// Represents a circular or elliptical arc (a segment of a curve).
+    /// </summary>
     public class Arc : Shape
     {
         /// <summary>
@@ -19,8 +23,12 @@ namespace Avalonia.Controls.Shapes
 
         static Arc()
         {
-            StrokeThicknessProperty.OverrideDefaultValue<Arc>(1);
-            AffectsGeometry<Arc>(BoundsProperty, StrokeThicknessProperty, StartAngleProperty, SweepAngleProperty);
+            StrokeThicknessProperty.OverrideDefaultValue<Arc>(1.0d);
+            AffectsGeometry<Arc>(
+                BoundsProperty,
+                StrokeThicknessProperty,
+                StartAngleProperty,
+                SweepAngleProperty);
         }
 
         /// <summary>
@@ -42,10 +50,11 @@ namespace Avalonia.Controls.Shapes
             set => SetValue(SweepAngleProperty, value);
         }
 
+        /// <inheritdoc/>
         protected override Geometry CreateDefiningGeometry()
         {
-            var angle1 = DegreesToRad(StartAngle);
-            var angle2 = angle1 + DegreesToRad(SweepAngle);
+            var angle1 = MathUtilities.Deg2Rad(StartAngle);
+            var angle2 = angle1 + MathUtilities.Deg2Rad(SweepAngle);
 
             var startAngle = Math.Min(angle1, angle2);
             var sweepAngle = Math.Max(angle1, angle2);
@@ -80,24 +89,25 @@ namespace Avalonia.Controls.Shapes
 
                 var arcGeometry = new StreamGeometry();
 
-                using (var ctx = arcGeometry.Open())
+                using (StreamGeometryContext context = arcGeometry.Open())
                 {
-                    ctx.BeginFigure(startPoint, false);
-                    ctx.ArcTo(endPoint, new Size(radiusX, radiusY), angleGap, angleGap >= Math.PI,
+                    context.BeginFigure(startPoint, false);
+                    context.ArcTo(
+                        endPoint,
+                        new Size(radiusX, radiusY),
+                        rotationAngle: angleGap,
+                        isLargeArc: angleGap >= Math.PI,
                         SweepDirection.Clockwise);
-                    ctx.EndFigure(false);
+                    context.EndFigure(false);
                 }
 
                 return arcGeometry;
             }
         }
 
-        static double DegreesToRad(double inAngle) =>
-            inAngle * Math.PI / 180;
+        private static double RadToNormRad(double inAngle) => ((inAngle % (Math.PI * 2)) + (Math.PI * 2)) % (Math.PI * 2);
 
-        static double RadToNormRad(double inAngle) => ((inAngle % (Math.PI * 2)) + (Math.PI * 2)) % (Math.PI * 2);
-
-        static Point GetRingPoint(double radiusX, double radiusY, double centerX, double centerY, double angle) =>
+        private static Point GetRingPoint(double radiusX, double radiusY, double centerX, double centerY, double angle) =>
             new Point((radiusX * Math.Cos(angle)) + centerX, (radiusY * Math.Sin(angle)) + centerY);
     }
 }

src/Avalonia.Controls/Shapes/Sector.cs

@@ -0,0 +1,97 @@
+using System;
+using Avalonia.Media;
+using Avalonia.Utilities;
+
+namespace Avalonia.Controls.Shapes
+{
+    /// <summary>
+    /// Represents a circular or elliptical sector (a pie-shaped closed region of a circle or ellipse).
+    /// </summary>
+    public class Sector : Shape
+    {
+        /// <summary>
+        /// Defines the <see cref="StartAngle"/> property.
+        /// </summary>
+        public static readonly StyledProperty<double> StartAngleProperty =
+            AvaloniaProperty.Register<Sector, double>(nameof(StartAngle), 0.0d);
+
+        /// <summary>
+        /// Defines the <see cref="SweepAngle"/> property.
+        /// </summary>
+        public static readonly StyledProperty<double> SweepAngleProperty =
+            AvaloniaProperty.Register<Sector, double>(nameof(SweepAngle), 0.0d);
+
+        /// <summary>
+        /// Gets or sets the angle at which the sector's arc starts, in degrees.
+        /// </summary>
+        public double StartAngle
+        {
+            get => GetValue(StartAngleProperty);
+            set => SetValue(StartAngleProperty, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the angle, in degrees, added to the <see cref="StartAngle"/> defining where the sector's arc ends.
+        /// A positive value is clockwise, negative is counter-clockwise.
+        /// </summary>
+        public double SweepAngle
+        {
+            get => GetValue(SweepAngleProperty);
+            set => SetValue(SweepAngleProperty, value);
+        }
+
+        static Sector()
+        {
+            StrokeThicknessProperty.OverrideDefaultValue<Sector>(1.0d);
+            AffectsGeometry<Sector>(
+                BoundsProperty,
+                StrokeThicknessProperty,
+                StartAngleProperty,
+                SweepAngleProperty);
+        }
+
+        /// <inheritdoc/>
+        protected override Geometry? CreateDefiningGeometry()
+        {
+            Rect rect = new Rect(Bounds.Size);
+            Rect deflatedRect = rect.Deflate(StrokeThickness * 0.5d);
+
+            if (SweepAngle >= 360.0d || SweepAngle <= -360.0d)
+            {
+                return new EllipseGeometry(deflatedRect);
+            }
+
+            if (SweepAngle == 0.0d)
+            {
+                return new StreamGeometry();
+            }
+
+            (double startAngle, double endAngle) = MathUtilities.GetMinMaxFromDelta(
+                MathUtilities.Deg2Rad(StartAngle),
+                MathUtilities.Deg2Rad(SweepAngle));
+
+            Point centre = new Point(rect.Width * 0.5d, rect.Height * 0.5d);
+            double radiusX = deflatedRect.Width * 0.5d;
+            double radiusY = deflatedRect.Height * 0.5d;
+            Point startCurvePoint = MathUtilities.GetEllipsePoint(centre, radiusX, radiusY, startAngle);
+            Point endCurvePoint = MathUtilities.GetEllipsePoint(centre, radiusX, radiusY, endAngle);
+            Size size = new Size(radiusX, radiusY);
+
+            var streamGeometry = new StreamGeometry();
+            using (StreamGeometryContext context = streamGeometry.Open())
+            {
+                context.BeginFigure(startCurvePoint, false);
+                context.ArcTo(
+                    endCurvePoint,
+                    size,
+                    rotationAngle: 0.0d,
+                    isLargeArc: Math.Abs(SweepAngle) > 180.0d,
+                    SweepDirection.Clockwise);
+                context.LineTo(centre);
+                context.EndFigure(true);
+            }
+
+            return streamGeometry;
+        }
+    }
+}

src/Avalonia.Controls/SystemDialog.cs

@@ -32,13 +32,6 @@ namespace Avalonia.Controls
     [Obsolete("Use Window.StorageProvider API or TopLevel.StorageProvider API")]
     public abstract class FileSystemDialog : SystemDialog
     {
-        [Obsolete("Use Directory")]
-        public string? InitialDirectory
-        {
-            get => Directory;
-            set => Directory = value;
-        }
-
         /// <summary>
         /// Gets or sets the initial directory that will be displayed when the file system dialog
         /// is opened.
@@ -87,7 +80,7 @@ namespace Avalonia.Controls
                 DefaultExtension = DefaultExtension,
                 FileTypeChoices = Filters?.Select(f => new FilePickerFileType(f.Name!) { Patterns = f.Extensions.Select(e => $"*.{e}").ToArray() }).ToArray(),
                 Title = Title,
-                SuggestedStartLocation = InitialDirectory is { } directory
+                SuggestedStartLocation = Directory is { } directory
                         ? new BclStorageFolder(new System.IO.DirectoryInfo(directory))
                         : null,
                 ShowOverwritePrompt = ShowOverwritePrompt
@@ -129,7 +122,7 @@ namespace Avalonia.Controls
                 AllowMultiple = AllowMultiple,
                 FileTypeFilter = Filters?.Select(f => new FilePickerFileType(f.Name!) { Patterns = f.Extensions.Select(e => $"*.{e}").ToArray() }).ToArray(),
                 Title = Title,
-                SuggestedStartLocation = InitialDirectory is { } directory
+                SuggestedStartLocation = Directory is { } directory
                     ? new BclStorageFolder(new System.IO.DirectoryInfo(directory))
                     : null
             };
@@ -142,13 +135,6 @@ namespace Avalonia.Controls
     [Obsolete("Use Window.StorageProvider API or TopLevel.StorageProvider API")]
     public class OpenFolderDialog : FileSystemDialog
     {
-        [Obsolete("Use Directory")]
-        public string? DefaultDirectory
-        {
-            get => Directory;
-            set => Directory = value;
-        }
-
         /// <summary>
         /// Shows the open folder dialog.
         /// </summary>
@@ -170,7 +156,7 @@ namespace Avalonia.Controls
             return new FolderPickerOpenOptions
             {
                 Title = Title,
-                SuggestedStartLocation = InitialDirectory is { } directory
+                SuggestedStartLocation = Directory is { } directory
                     ? new BclStorageFolder(new System.IO.DirectoryInfo(directory))
                     : null
             };

src/Avalonia.Controls/TextBox.cs

@@ -1165,9 +1165,7 @@ namespace Avalonia.Controls
 
                 SetAndRaise(CaretIndexProperty, ref _caretIndex, index);
 
-#pragma warning disable CS0618 // Type or member is obsolete
                 switch (e.ClickCount)
-#pragma warning restore CS0618 // Type or member is obsolete
                 {
                     case 1:
                         if (clickToSelect)

src/Avalonia.Controls/TopLevel.cs

@@ -404,9 +404,6 @@ namespace Avalonia.Controls
             LayoutManager?.Dispose();
         }
 
-        [Obsolete("Use HandleResized(Size, PlatformResizeReason)")]
-        protected virtual void HandleResized(Size clientSize) => HandleResized(clientSize, PlatformResizeReason.Unspecified);
-
         /// <summary>
         /// Handles a resize notification from <see cref="ITopLevelImpl.Resized"/>.
         /// </summary>

src/Avalonia.Controls/Window.cs

@@ -79,16 +79,6 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<SizeToContent> SizeToContentProperty =
             AvaloniaProperty.Register<Window, SizeToContent>(nameof(SizeToContent));
 
-        /// <summary>
-        /// Enables or disables system window decorations (title bar, buttons, etc)
-        /// </summary>
-        [Obsolete("Use SystemDecorationsProperty instead")]
-        public static readonly DirectProperty<Window, bool> HasSystemDecorationsProperty =
-            AvaloniaProperty.RegisterDirect<Window, bool>(
-                nameof(HasSystemDecorations),
-                o => o.HasSystemDecorations,
-                (o, v) => o.HasSystemDecorations = v);
-
         /// <summary>
         /// Defines the <see cref="ExtendClientAreaToDecorationsHint"/> property.
         /// </summary>
@@ -289,25 +279,6 @@ namespace Avalonia.Controls
             set { SetValue(TitleProperty, value); }
         }
 
-        /// <summary>
-        /// Enables or disables system window decorations (title bar, buttons, etc)
-        /// </summary>
-        [Obsolete("Use SystemDecorations instead")]
-        public bool HasSystemDecorations
-        {
-            get => SystemDecorations == SystemDecorations.Full;
-            set
-            {
-                var oldValue = HasSystemDecorations;
-
-                if (oldValue != value)
-                {
-                    SystemDecorations = value ? SystemDecorations.Full : SystemDecorations.None;
-                    RaisePropertyChanged(HasSystemDecorationsProperty, oldValue, value);
-                }
-            }
-        }
-
         /// <summary>
         /// Gets or sets if the ClientArea is Extended into the Window Decorations (chrome or border).
         /// </summary>
@@ -985,9 +956,6 @@ namespace Avalonia.Controls
             Owner = null;
         }
 
-        [Obsolete("Use HandleResized(Size, PlatformResizeReason)")]
-        protected sealed override void HandleResized(Size clientSize) => HandleResized(clientSize, PlatformResizeReason.Unspecified);
-
         /// <inheritdoc/>
         protected sealed override void HandleResized(Size clientSize, PlatformResizeReason reason)
         {
@@ -1033,19 +1001,9 @@ namespace Avalonia.Controls
             base.OnPropertyChanged(change);
             if (change.Property == SystemDecorationsProperty)
             {
-                var (typedOldValue, typedNewValue) = change.GetOldAndNewValue<SystemDecorations>();
+                var (_, typedNewValue) = change.GetOldAndNewValue<SystemDecorations>();
 
                 PlatformImpl?.SetSystemDecorations(typedNewValue);
-
-                var o = typedOldValue == SystemDecorations.Full;
-                var n = typedNewValue == SystemDecorations.Full;
-
-                if (o != n)
-                {
-#pragma warning disable CS0618 // Type or member is obsolete
-                    RaisePropertyChanged(HasSystemDecorationsProperty, o, n);
-#pragma warning restore CS0618 // Type or member is obsolete
-                }
             }
         }
 

src/Avalonia.Controls/WindowBase.cs

@@ -94,9 +94,6 @@ namespace Avalonia.Controls
         
         public Screens Screens { get; private set; }
 
-        [Obsolete("No longer used. Always returns false.")]
-        protected bool AutoSizing => false;
-
         /// <summary>
         /// Gets or sets the owner of the window.
         /// </summary>
@@ -169,9 +166,6 @@ namespace Avalonia.Controls
             }
         }
 
-        [Obsolete("No longer used. Has no effect.")]
-        protected IDisposable BeginAutoSizing() => Disposable.Empty;
-
         /// <summary>
         /// Ensures that the window is initialized.
         /// </summary>
@@ -226,9 +220,6 @@ namespace Avalonia.Controls
             }
         }
 
-        [Obsolete("Use HandleResized(Size, PlatformResizeReason)")]
-        protected override void HandleResized(Size clientSize) => HandleResized(clientSize, PlatformResizeReason.Unspecified);
-
         /// <summary>
         /// Handles a resize notification from <see cref="ITopLevelImpl.Resized"/>.
         /// </summary>

src/Avalonia.Diagnostics/Diagnostics/Screenshots/FilePickerHandler.cs

@@ -3,6 +3,8 @@ using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using Avalonia.Controls;
+using Avalonia.Platform.Storage;
+using Avalonia.Platform.Storage.FileIO;
 using Lifetimes = Avalonia.Controls.ApplicationLifetimes;
 
 namespace Avalonia.Diagnostics.Screenshots
@@ -59,24 +61,25 @@ namespace Avalonia.Diagnostics.Screenshots
         protected async override Task<Stream?> GetStream(IControl control)
         {
             Stream? output = default;
-            var result = await new SaveFileDialog()
+            var result = await GetWindow(control).StorageProvider.SaveFilePickerAsync(new FilePickerSaveOptions
             {
+                SuggestedStartLocation = new BclStorageFolder(new DirectoryInfo(ScreenshotsRoot)),
                 Title = Title,
-                Filters = new() { new FileDialogFilter() { Name = "PNG", Extensions = new() { "png" } } },
-                Directory = ScreenshotsRoot,
-            }.ShowAsync(GetWindow(control));
-            if (!string.IsNullOrWhiteSpace(result))
+                FileTypeChoices = new FilePickerFileType[] { new FilePickerFileType("PNG") { Patterns = new string[] { "*.png" } } }
+            });
+
+            if (result!=null && !string.IsNullOrWhiteSpace(result.Name))
             {
-                var foldler = Path.GetDirectoryName(result);
+                var folder = Path.GetDirectoryName(result.Name);
                 // Directory information for path, or null if path denotes a root directory or is
                 // null. Returns System.String.Empty if path does not contain directory information.
-                if (!string.IsNullOrWhiteSpace(foldler))
+                if (!string.IsNullOrWhiteSpace(folder))
                 {
-                    if (!Directory.Exists(foldler))
+                    if (!Directory.Exists(folder))
                     {
-                        Directory.CreateDirectory(foldler);
+                        Directory.CreateDirectory(folder);
                     }
-                    output = new FileStream(result, FileMode.Create);
+                    output = new FileStream(result.Name, FileMode.Create);
                 }
             }
             return output;

src/Avalonia.Dialogs/AboutAvaloniaDialog.xaml

@@ -76,7 +76,11 @@
     </Canvas>
     <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Top" Margin="18">
       <Border Height="70" Width="70">
-        <DrawingPresenter Drawing="{DynamicResource AvaloniaLogo}" />
+        <Image>
+          <Image.Source>
+            <DrawingImage Drawing="{DynamicResource AvaloniaLogo}"/>
+          </Image.Source>
+        </Image>
       </Border>
       <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" Margin="10,-10,0,0">
         <TextBlock Text="{Binding Version, StringFormat=Avalonia {0}}" FontSize="40" Foreground="White" />

src/Avalonia.Headless/HeadlessPlatformThreadingInterface.cs

@@ -36,35 +36,35 @@ namespace Avalonia.Headless
 
         public IDisposable StartTimer(DispatcherPriority priority, TimeSpan interval, Action tick)
         {
-            var cancelled = false;
-            var enqueued = false;
-            var l = new object();
-            var timer = new Timer(_ =>
+            if (interval.TotalMilliseconds < 10)
+                interval = TimeSpan.FromMilliseconds(10);
+
+            var stopped = false;
+            Timer timer = null;
+            timer = new Timer(_ =>
             {
-                lock (l)
+                if (stopped)
+                    return;
+
+                Dispatcher.UIThread.Post(() =>
                 {
-                    if (cancelled || enqueued)
-                        return;
-                    enqueued = true;
-                    Dispatcher.UIThread.Post(() =>
+                    try
                     {
-                        lock (l)
-                        {
-                            enqueued = false;
-                            if (cancelled)
-                                return;
-                            tick();
-                        }
-                    }, priority);
-                }
-            }, null, interval, interval);
+                        tick();
+                    }
+                    finally
+                    {
+                        if (!stopped)
+                            timer.Change(interval, Timeout.InfiniteTimeSpan);
+                    }
+                });
+            },
+            null, interval, Timeout.InfiniteTimeSpan);
+
             return Disposable.Create(() =>
             {
-                lock (l)
-                {
-                    timer.Dispose();
-                    cancelled = true;
-                }
+                stopped = true;
+                timer.Dispose();
             });
         }
 

src/Avalonia.OpenGL/Controls/OpenGlControlBase.cs

@@ -34,7 +34,7 @@ namespace Avalonia.OpenGL.Controls
                 _attachment.Present();
             }
 
-            context.DrawImage(_bitmap, new Rect(_bitmap.Size), Bounds);
+            context.DrawImage(_bitmap, new Rect(_bitmap.Size), new Rect(Bounds.Size));
             base.Render(context);
         }
         
@@ -84,6 +84,7 @@ namespace Avalonia.OpenGL.Controls
                 using (_context.MakeCurrent())
                 {
                     var gl = _context.GlInterface;
+                    gl.ActiveTexture(GL_TEXTURE0);
                     gl.BindTexture(GL_TEXTURE_2D, 0);
                     gl.BindFramebuffer(GL_FRAMEBUFFER, 0);
                     gl.DeleteFramebuffer(_fb);

src/Avalonia.ReactiveUI/AvaloniaActivationForViewFetcher.cs

@@ -2,6 +2,7 @@ using System;
 using System.Reactive.Linq;
 using Avalonia.VisualTree;
 using Avalonia.Controls;
+using Avalonia.Interactivity;
 using ReactiveUI;
 
 namespace Avalonia.ReactiveUI
@@ -25,27 +26,28 @@ namespace Avalonia.ReactiveUI
         public IObservable<bool> GetActivationForView(IActivatableView view)
         {
             if (!(view is IVisual visual)) return Observable.Return(false);
-            if (view is WindowBase window) return GetActivationForWindowBase(window);
+            if (view is Control control) return GetActivationForControl(control);
             return GetActivationForVisual(visual);
         }
 
         /// <summary>
-        /// Listens to Opened and Closed events for Avalonia windows.
+        /// Listens to Loaded and Unloaded 
+        /// events for Avalonia Control.
         /// </summary>
-        private IObservable<bool> GetActivationForWindowBase(WindowBase window) 
+        private IObservable<bool> GetActivationForControl(Control control) 
         {
-            var windowLoaded = Observable
-                .FromEventPattern(
-                    x => window.Opened += x,
-                    x => window.Opened -= x)
+            var controlLoaded = Observable
+                .FromEventPattern<RoutedEventArgs>(
+                    x => control.Loaded += x,
+                    x => control.Loaded -= x)
                 .Select(args => true);
-            var windowUnloaded = Observable
-                .FromEventPattern(
-                    x => window.Closed += x,
-                    x => window.Closed -= x)
+            var controlUnloaded = Observable
+                .FromEventPattern<RoutedEventArgs>(
+                    x => control.Unloaded += x,
+                    x => control.Unloaded -= x)
                 .Select(args => false);
-            return windowLoaded
-                .Merge(windowUnloaded)
+            return controlLoaded
+                .Merge(controlUnloaded)
                 .DistinctUntilChanged();
         }
 

src/Avalonia.ReactiveUI/RoutedViewHost.cs

@@ -50,7 +50,7 @@ namespace Avalonia.ReactiveUI
     /// ReactiveUI routing documentation website</see> for more info.
     /// </para>
     /// </remarks>
-    public class RoutedViewHost : TransitioningContentControl, IActivatableView, IEnableLogger
+    public class RoutedViewHost : TransitioningContentControl, IActivatableView, IEnableLogger, IStyleable
     {
         /// <summary>
         /// <see cref="AvaloniaProperty"/> for the <see cref="Router"/> property.
@@ -126,6 +126,8 @@ namespace Avalonia.ReactiveUI
         /// </summary>
         public IViewLocator? ViewLocator { get; set; }
 
+        Type IStyleable.StyleKey => typeof(TransitioningContentControl);
+        
         /// <summary>
         /// Invoked when ReactiveUI router navigates to a view model.
         /// </summary>

src/Avalonia.ReactiveUI/ViewModelViewHost.cs

@@ -2,7 +2,7 @@ using System;
 using System.Reactive.Disposables;
 
 using Avalonia.Controls;
-
+using Avalonia.Styling;
 using ReactiveUI;
 using Splat;
 
@@ -13,7 +13,7 @@ namespace Avalonia.ReactiveUI
     /// the ViewModel property and display it. This control is very useful
     /// inside a DataTemplate to display the View associated with a ViewModel.
     /// </summary>
-    public class ViewModelViewHost : TransitioningContentControl, IViewFor, IEnableLogger
+    public class ViewModelViewHost : TransitioningContentControl, IViewFor, IEnableLogger, IStyleable
     {
         /// <summary>
         /// <see cref="AvaloniaProperty"/> for the <see cref="ViewModel"/> property.
@@ -78,6 +78,8 @@ namespace Avalonia.ReactiveUI
         /// </summary>
         public IViewLocator? ViewLocator { get; set; }
 
+        Type IStyleable.StyleKey => typeof(TransitioningContentControl);
+
         /// <summary>
         /// Invoked when ReactiveUI router navigates to a view model.
         /// </summary>

src/Avalonia.Themes.Fluent/Controls/ManagedFileChooser.xaml

@@ -138,7 +138,11 @@
             <ListBox.ItemTemplate>
               <DataTemplate>
                 <StackPanel Spacing="4" Orientation="Horizontal" Background="Transparent">
-                  <DrawingPresenter Width="16" Height="16" Drawing="{Binding IconKey, Converter={StaticResource Icons}}"/>
+                  <Image Width="16" Height="16">
+                    <Image.Source>
+                      <DrawingImage Drawing="{Binding IconKey, Converter={StaticResource Icons}}"/>
+                    </Image.Source>
+                  </Image>
                   <TextBlock Text="{Binding DisplayName}"/>
                 </StackPanel>
               </DataTemplate>
@@ -231,7 +235,11 @@
                       <ColumnDefinition SharedSizeGroup="Splitter" />
                       <ColumnDefinition SharedSizeGroup="Size" />
                     </Grid.ColumnDefinitions>
-                    <DrawingPresenter Width="16" Height="16" Drawing="{Binding IconKey, Converter={StaticResource Icons}}"/>
+                    <Image Width="16" Height="16">
+                      <Image.Source>
+                        <DrawingImage Drawing="{Binding IconKey, Converter={StaticResource Icons}}"/>
+                      </Image.Source>
+                    </Image>
                     <TextBlock Grid.Column="2" Text="{Binding DisplayName}"/>
                     <TextBlock Grid.Column="4" Text="{Binding Modified}" />
                     <TextBlock Grid.Column="6" Text="{Binding Type}" />

src/Avalonia.Themes.Simple/Controls/CalendarDatePicker.xaml

@@ -118,7 +118,7 @@
 
           <Popup Name="PART_Popup"
                  PlacementTarget="{TemplateBinding}"
-                 StaysOpen="False">
+                 IsLightDismissEnabled="False">
             <Calendar Name="PART_Calendar"
                       DisplayDate="{TemplateBinding DisplayDate}"
                       DisplayDateEnd="{TemplateBinding DisplayDateEnd}"

src/Avalonia.X11/X11IconLoader.cs

@@ -68,9 +68,7 @@ namespace Avalonia.X11
         public void Save(Stream outputStream)
         {
             using (var wr =
-#pragma warning disable CS0618 // Type or member is obsolete
                 new WriteableBitmap(new PixelSize(_width, _height), new Vector(96, 96), PixelFormat.Bgra8888))
-#pragma warning restore CS0618 // Type or member is obsolete
             {
                 using (var fb = wr.Lock())
                 {

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlDeferredResourceTransformer.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using XamlX.Ast;
 using XamlX.Emit;
@@ -47,7 +48,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
             return !node.Type.GetClrType().IsValueType;
         }
         
-        class AdderSetter : IXamlPropertySetter, IXamlEmitablePropertySetter<IXamlILEmitter>
+        class AdderSetter : IXamlILOptimizedEmitablePropertySetter, IEquatable<AdderSetter>
         {
             private readonly IXamlMethod _getter;
             private readonly IXamlMethod _adder;
@@ -58,16 +59,22 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                 _adder = adder;
                 TargetType = getter.DeclaringType;
                 Parameters = adder.ParametersWithThis().Skip(1).ToList();
+
+                bool allowNull = Parameters.Last().AcceptsNull();
+                BinderParameters = new PropertySetterBinderParameters
+                {
+                    AllowMultiple = true,
+                    AllowXNull = allowNull,
+                    AllowRuntimeNull = allowNull
+                };
             }
 
             public IXamlType TargetType { get; }
 
-            public PropertySetterBinderParameters BinderParameters { get; } = new PropertySetterBinderParameters
-            {
-                AllowMultiple = true
-            };
+            public PropertySetterBinderParameters BinderParameters { get; }
 
             public IReadOnlyList<IXamlType> Parameters { get; }
+
             public void Emit(IXamlILEmitter emitter)
             {
                 var locals = new Stack<XamlLocalsPool.PooledLocal>();
@@ -80,11 +87,40 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                 }
 
                 emitter.EmitCall(_getter);
-                while (locals.Count > 0)
+                while (locals.Count>0)
                     using (var loc = locals.Pop())
                         emitter.Ldloc(loc.Local);
                 emitter.EmitCall(_adder, true);
             }
+
+            public void EmitWithArguments(
+                XamlEmitContextWithLocals<IXamlILEmitter, XamlILNodeEmitResult> context,
+                IXamlILEmitter emitter,
+                IReadOnlyList<IXamlAstValueNode> arguments)
+            {
+                emitter.EmitCall(_getter);
+
+                for (var i = 0; i < arguments.Count; ++i)
+                    context.Emit(arguments[i], emitter, Parameters[i]);
+
+                emitter.EmitCall(_adder, true);
+            }
+
+            public bool Equals(AdderSetter other)
+            {
+                if (ReferenceEquals(null, other))
+                    return false;
+                if (ReferenceEquals(this, other))
+                    return true;
+
+                return _getter.Equals(other._getter) && _adder.Equals(other._adder);
+            }
+
+            public override bool Equals(object obj)
+                => Equals(obj as AdderSetter);
+
+            public override int GetHashCode()
+                => (_getter.GetHashCode() * 397) ^ _adder.GetHashCode();
         }
     }
 }

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlSetterTransformer.cs

@@ -75,17 +75,17 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
             {
                 Getter = setterType.Methods.First(m => m.Name == "get_Value");
                 var method = setterType.Methods.First(m => m.Name == "set_Value");
-                Setters.Add(new XamlIlDirectCallPropertySetter(method, types.IBinding));
-                Setters.Add(new XamlIlDirectCallPropertySetter(method, types.UnsetValueType));
-                Setters.Add(new XamlIlDirectCallPropertySetter(method, targetType));
+                Setters.Add(new XamlIlDirectCallPropertySetter(method, types.IBinding, false));
+                Setters.Add(new XamlIlDirectCallPropertySetter(method, types.UnsetValueType, false));
+                Setters.Add(new XamlIlDirectCallPropertySetter(method, targetType, targetType.AcceptsNull()));
             }
             
-            class XamlIlDirectCallPropertySetter : IXamlPropertySetter, IXamlEmitablePropertySetter<IXamlILEmitter>
+            sealed class XamlIlDirectCallPropertySetter : IXamlPropertySetter, IXamlEmitablePropertySetter<IXamlILEmitter>
             {
                 private readonly IXamlMethod _method;
                 private readonly IXamlType _type;
                 public IXamlType TargetType { get; }
-                public PropertySetterBinderParameters BinderParameters { get; } = new PropertySetterBinderParameters();
+                public PropertySetterBinderParameters BinderParameters { get; }
                 public IReadOnlyList<IXamlType> Parameters { get; }
                 public void Emit(IXamlILEmitter codegen)
                 {
@@ -94,13 +94,27 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                     codegen.EmitCall(_method, true);
                 }
 
-                public XamlIlDirectCallPropertySetter(IXamlMethod method, IXamlType type)
+                public XamlIlDirectCallPropertySetter(IXamlMethod method, IXamlType type, bool allowNull)
                 {
                     _method = method;
                     _type = type;
                     Parameters = new[] {type};
                     TargetType = method.ThisOrFirstParameter();
+                    BinderParameters = new PropertySetterBinderParameters
+                    {
+                        AllowXNull = allowNull,
+                        AllowRuntimeNull = allowNull
+                    };
                 }
+
+                private bool Equals(XamlIlDirectCallPropertySetter other) 
+                    => Equals(_method, other._method) && Equals(_type, other._type);
+
+                public override bool Equals(object obj) 
+                    => Equals(obj as XamlIlDirectCallPropertySetter);
+
+                public override int GetHashCode() 
+                    => (_method.GetHashCode() * 397) ^ _type.GetHashCode();
             }
         }
     }

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/XamlIlAvaloniaPropertyHelper.cs

@@ -206,38 +206,64 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
             Setters.Insert(0, new UnsetValueSetter(types, original.DeclaringType, field));
         }
 
-        abstract class AvaloniaPropertyCustomSetter : IXamlPropertySetter, IXamlEmitablePropertySetter<IXamlILEmitter>
+        abstract class AvaloniaPropertyCustomSetter : IXamlILOptimizedEmitablePropertySetter, IEquatable<AvaloniaPropertyCustomSetter>
         {
-            protected AvaloniaXamlIlWellKnownTypes Types;
-            protected IXamlField AvaloniaProperty;
+            protected readonly AvaloniaXamlIlWellKnownTypes Types;
+            protected readonly IXamlField AvaloniaProperty;
 
-            public AvaloniaPropertyCustomSetter(AvaloniaXamlIlWellKnownTypes types,
+            protected AvaloniaPropertyCustomSetter(
+                AvaloniaXamlIlWellKnownTypes types,
                 IXamlType declaringType,
-                IXamlField avaloniaProperty)
+                IXamlField avaloniaProperty,
+                bool allowNull)
             {
                 Types = types;
                 AvaloniaProperty = avaloniaProperty;
                 TargetType = declaringType;
+                BinderParameters = new PropertySetterBinderParameters
+                {
+                    AllowXNull = allowNull,
+                    AllowRuntimeNull = allowNull
+                };
             }
 
             public IXamlType TargetType { get; }
 
-            public PropertySetterBinderParameters BinderParameters { get; } = new PropertySetterBinderParameters
-            {
-                AllowXNull = false
-            };
+            public PropertySetterBinderParameters BinderParameters { get; }
 
             public IReadOnlyList<IXamlType> Parameters { get; set; }
-            public abstract void Emit(IXamlILEmitter codegen);
+
+            public abstract void Emit(IXamlILEmitter emitter);
+
+            public abstract void EmitWithArguments(
+                XamlEmitContextWithLocals<IXamlILEmitter, XamlILNodeEmitResult> context,
+                IXamlILEmitter emitter,
+                IReadOnlyList<IXamlAstValueNode> arguments);
+
+            public bool Equals(AvaloniaPropertyCustomSetter other)
+            {
+                if (ReferenceEquals(null, other))
+                    return false;
+                if (ReferenceEquals(this, other))
+                    return true;
+
+                return GetType() == other.GetType() && AvaloniaProperty.Equals(other.AvaloniaProperty);
+            }
+
+            public override bool Equals(object obj)
+                => Equals(obj as AvaloniaPropertyCustomSetter);
+
+            public override int GetHashCode() 
+                => AvaloniaProperty.GetHashCode();
         }
 
         class BindingSetter : AvaloniaPropertyCustomSetter
         {
             public BindingSetter(AvaloniaXamlIlWellKnownTypes types,
                 IXamlType declaringType,
-                IXamlField avaloniaProperty) : base(types, declaringType, avaloniaProperty)
+                IXamlField avaloniaProperty) : base(types, declaringType, avaloniaProperty, false)
             {
-                Parameters = new[] {types.IBinding};
+                Parameters = new[] { types.IBinding };
             }
 
             public override void Emit(IXamlILEmitter emitter)
@@ -246,10 +272,25 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
                     emitter
                         .Stloc(bloc.Local)
                         .Ldsfld(AvaloniaProperty)
-                        .Ldloc(bloc.Local)
-                        // TODO: provide anchor?
-                        .Ldnull();
-                emitter.EmitCall(Types.AvaloniaObjectBindMethod, true);
+                        .Ldloc(bloc.Local);
+                EmitAnchorAndBind(emitter);
+            }
+
+            public override void EmitWithArguments(
+                XamlEmitContextWithLocals<IXamlILEmitter, XamlILNodeEmitResult> context,
+                IXamlILEmitter emitter,
+                IReadOnlyList<IXamlAstValueNode> arguments)
+            {
+                emitter.Ldsfld(AvaloniaProperty);
+                context.Emit(arguments[0], emitter, Parameters[0]);
+                EmitAnchorAndBind(emitter);
+            }
+
+            private void EmitAnchorAndBind(IXamlILEmitter emitter)
+            {
+                emitter
+                    .Ldnull() // TODO: provide anchor?
+                    .EmitCall(Types.AvaloniaObjectBindMethod, true);
             }
         }
 
@@ -257,7 +298,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
         {
             public BindingWithPrioritySetter(AvaloniaXamlIlWellKnownTypes types,
                 IXamlType declaringType,
-                IXamlField avaloniaProperty) : base(types, declaringType, avaloniaProperty)
+                IXamlField avaloniaProperty) : base(types, declaringType, avaloniaProperty, false)
             {
                 Parameters = new[] { types.BindingPriority, types.IBinding };
             }
@@ -265,15 +306,29 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
             public override void Emit(IXamlILEmitter emitter)
             {
                 using (var bloc = emitter.LocalsPool.GetLocal(Types.IBinding))
-                using (var priorityLocal = emitter.LocalsPool.GetLocal(Types.Int))
                     emitter
                         .Stloc(bloc.Local)
-                        .Stloc(priorityLocal.Local)
+                        .Pop() // ignore priority
                         .Ldsfld(AvaloniaProperty)
-                        .Ldloc(bloc.Local)
-                        // TODO: provide anchor?
-                        .Ldnull();
-                emitter.EmitCall(Types.AvaloniaObjectBindMethod, true);
+                        .Ldloc(bloc.Local);
+                EmitAnchorAndBind(emitter);
+            }
+
+            public override void EmitWithArguments(
+                XamlEmitContextWithLocals<IXamlILEmitter, XamlILNodeEmitResult> context,
+                IXamlILEmitter emitter,
+                IReadOnlyList<IXamlAstValueNode> arguments)
+            {
+                emitter.Ldsfld(AvaloniaProperty);
+                context.Emit(arguments[1], emitter, Parameters[1]);
+                EmitAnchorAndBind(emitter);
+            }
+
+            private void EmitAnchorAndBind(IXamlILEmitter emitter)
+            {
+                emitter
+                    .Ldnull() // TODO: provide anchor?
+                    .EmitCall(Types.AvaloniaObjectBindMethod, true);
             }
         }
 
@@ -281,7 +336,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
         {
             public SetValueWithPrioritySetter(AvaloniaXamlIlWellKnownTypes types, IXamlType declaringType, IXamlField avaloniaProperty,
                 IXamlType propertyType)
-                : base(types, declaringType, avaloniaProperty)
+                : base(types, declaringType, avaloniaProperty, propertyType.AcceptsNull())
             {
                 Parameters = new[] { types.BindingPriority, propertyType };
             }
@@ -295,9 +350,6 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
                    - value
                 */
 
-                var method = Types.AvaloniaObjectSetStyledPropertyValue
-                    .MakeGenericMethod(new[] { Parameters[1] });
-
                 using (var valueLocal = emitter.LocalsPool.GetLocal(Parameters[1]))
                 using (var priorityLocal = emitter.LocalsPool.GetLocal(Types.Int))
                     emitter
@@ -305,25 +357,57 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
                         .Stloc(priorityLocal.Local)
                         .Ldsfld(AvaloniaProperty)
                         .Ldloc(valueLocal.Local)
-                        .Ldloc(priorityLocal.Local)
-                        .EmitCall(method, true);
+                        .Ldloc(priorityLocal.Local);
+
+                EmitSetStyledPropertyValue(emitter);
+            }
+
+            public override void EmitWithArguments(
+                XamlEmitContextWithLocals<IXamlILEmitter, XamlILNodeEmitResult> context,
+                IXamlILEmitter emitter,
+                IReadOnlyList<IXamlAstValueNode> arguments)
+            {
+                emitter.Ldsfld(AvaloniaProperty);
+                context.Emit(arguments[1], emitter, Parameters[1]);
+                context.Emit(arguments[0], emitter, Parameters[0]);
+                EmitSetStyledPropertyValue(emitter);
+            }
+
+            private void EmitSetStyledPropertyValue(IXamlILEmitter emitter)
+            {
+                var method = Types.AvaloniaObjectSetStyledPropertyValue.MakeGenericMethod(new[] { Parameters[1] });
+                emitter.EmitCall(method, true);
             }
         }
 
         class UnsetValueSetter : AvaloniaPropertyCustomSetter
         {
             public UnsetValueSetter(AvaloniaXamlIlWellKnownTypes types, IXamlType declaringType, IXamlField avaloniaProperty) 
-                : base(types, declaringType, avaloniaProperty)
+                : base(types, declaringType, avaloniaProperty, false)
             {
-                Parameters = new[] {types.UnsetValueType};
+                Parameters = new[] { types.UnsetValueType };
             }
 
             public override void Emit(IXamlILEmitter codegen)
             {
+                codegen.Pop();
+                EmitSetValue(codegen);
+            }
+
+            public override void EmitWithArguments(
+                XamlEmitContextWithLocals<IXamlILEmitter, XamlILNodeEmitResult> context,
+                IXamlILEmitter emitter,
+                IReadOnlyList<IXamlAstValueNode> arguments)
+            {
+                EmitSetValue(emitter);
+            }
+
+            private void EmitSetValue(IXamlILEmitter emitter)
+            {
+                // Ignore the instance and load one from the static field to avoid extra local variable
                 var unsetValue = Types.AvaloniaProperty.Fields.First(f => f.Name == "UnsetValue");
-                codegen
-                    // Ignore the instance and load one from the static field to avoid extra local variable
-                    .Pop()
+
+                emitter
                     .Ldsfld(AvaloniaProperty)
                     .Ldsfld(unsetValue)
                     .Ldc_I4(0)

src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github

@@ -1 +1 @@
-Subproject commit a4e6be2d1407abec4f35fcb208848830ce513ead
+Subproject commit c1c0594ec2c35b08988183b1a5b3e34dfa19179d

src/Skia/Avalonia.Skia/Gpu/OpenGl/OpenGlBitmapImpl.cs

@@ -41,7 +41,7 @@ namespace Avalonia.Skia
                         new GRGlTextureInfo(
                             GlConsts.GL_TEXTURE_2D, (uint)_surface.GetTextureId(),
                             (uint)_surface.InternalFormat)))
-                    using (var surface = SKSurface.Create(context.GrContext, backendTexture, GRSurfaceOrigin.TopLeft,
+                    using (var surface = SKSurface.Create(context.GrContext, backendTexture, GRSurfaceOrigin.BottomLeft,
                         SKColorType.Rgba8888))
                     {
                         // Again, silently ignore, if something went wrong it's not our fault
@@ -118,7 +118,7 @@ namespace Avalonia.Skia
                 {
                     var gl = _context.GlInterface;
                     
-                    var textures = new int[2];
+                    Span<int> textures = stackalloc int[2];
                     fixed (int* ptex = textures)
                         gl.GenTextures(2, ptex);
                     _texture = textures[0];
@@ -139,7 +139,6 @@ namespace Avalonia.Skia
 
                     gl.FramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, _texture, 0);
                     gl.BindTexture(GL_TEXTURE_2D, oldTexture);
-                    
                 }
             }
         }
@@ -161,15 +160,15 @@ namespace Avalonia.Skia
                     gl.GetIntegerv(GL_ACTIVE_TEXTURE, out var oldActive);
                     
                     gl.BindFramebuffer(GL_FRAMEBUFFER, _fbo);
-                    gl.BindTexture(GL_TEXTURE_2D, _frontBuffer);
                     gl.ActiveTexture(GL_TEXTURE0);
+                    gl.BindTexture(GL_TEXTURE_2D, _frontBuffer);
 
                     gl.CopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, _bitmap.PixelSize.Width,
                         _bitmap.PixelSize.Height);
 
                     gl.BindFramebuffer(GL_FRAMEBUFFER, oldFbo);
-                    gl.BindTexture(GL_TEXTURE_2D, oldTexture);
                     gl.ActiveTexture(oldActive);
+                    gl.BindTexture(GL_TEXTURE_2D, oldTexture);
                     
                     gl.Finish();
                 }
@@ -192,9 +191,8 @@ namespace Avalonia.Skia
                 if(_disposed)
                     return;
                 _disposed = true;
-                var tex = new[] { _texture, _frontBuffer };
-                fixed (int* ptex = tex)
-                    gl.DeleteTextures(2, ptex);
+                var ptex = stackalloc[] { _texture, _frontBuffer };
+                gl.DeleteTextures(2, ptex);
             }
         }
 

tests/Avalonia.Base.UnitTests/Collections/AvaloniaListExtenionsTests.cs

@@ -1,155 +0,0 @@
-using System.Linq;
-using Avalonia.Collections;
-using Xunit;
-
-namespace Avalonia.Base.UnitTests.Collections
-{
-    public class AvaloniaListExtenionsTests
-    {
-#pragma warning disable CS0618 // Type or member is obsolete
-        [Fact]
-        public void CreateDerivedList_Creates_Initial_Items()
-        {
-            var source = new AvaloniaList<int>(new[] { 0, 1, 2, 3 });
-
-            var target = source.CreateDerivedList(x => new Wrapper(x));
-            var result = target.Select(x => x.Value).ToList();
-
-            Assert.Equal(source, result);
-        }
-
-        [Fact]
-        public void CreateDerivedList_Handles_Add()
-        {
-            var source = new AvaloniaList<int>(new[] { 0, 1, 2, 3 });
-            var target = source.CreateDerivedList(x => new Wrapper(x));
-
-            source.Add(4);
-
-            var result = target.Select(x => x.Value).ToList();
-
-            Assert.Equal(source, result);
-        }
-
-        [Fact]
-        public void CreateDerivedList_Handles_Insert()
-        {
-            var source = new AvaloniaList<int>(new[] { 0, 1, 2, 3 });
-            var target = source.CreateDerivedList(x => new Wrapper(x));
-
-            source.Insert(1, 4);
-
-            var result = target.Select(x => x.Value).ToList();
-
-            Assert.Equal(source, result);
-        }
-
-        [Fact]
-        public void CreateDerivedList_Handles_Remove()
-        {
-            var source = new AvaloniaList<int>(new[] { 0, 1, 2, 3 });
-            var target = source.CreateDerivedList(x => new Wrapper(x));
-
-            source.Remove(2);
-
-            var result = target.Select(x => x.Value).ToList();
-
-            Assert.Equal(source, result);
-        }
-
-        [Fact]
-        public void CreateDerivedList_Handles_RemoveRange()
-        {
-            var source = new AvaloniaList<int>(new[] { 0, 1, 2, 3 });
-            var target = source.CreateDerivedList(x => new Wrapper(x));
-
-            source.RemoveRange(1, 2);
-
-            var result = target.Select(x => x.Value).ToList();
-
-            Assert.Equal(source, result);
-        }
-
-        [Fact]
-        public void CreateDerivedList_Handles_Move()
-        {
-            var source = new AvaloniaList<int>(new[] { 0, 1, 2, 3 });
-            var target = source.CreateDerivedList(x => new Wrapper(x));
-
-            source.Move(2, 0);
-
-            var result = target.Select(x => x.Value).ToList();
-
-            Assert.Equal(source, result);
-        }
-
-        [Theory]
-        [InlineData(0, 2, 3)]
-        [InlineData(0, 2, 4)]
-        [InlineData(0, 2, 5)]
-        [InlineData(0, 4, 4)]
-        [InlineData(1, 2, 0)]
-        [InlineData(1, 2, 4)]
-        [InlineData(1, 2, 5)]
-        [InlineData(1, 4, 0)]
-        [InlineData(2, 2, 0)]
-        [InlineData(2, 2, 1)]
-        [InlineData(2, 2, 3)]
-        [InlineData(2, 2, 4)]
-        [InlineData(2, 2, 5)]
-        [InlineData(4, 2, 0)]
-        [InlineData(4, 2, 1)]
-        [InlineData(4, 2, 3)]
-        [InlineData(5, 1, 0)]
-        [InlineData(5, 1, 3)]
-        public void CreateDerivedList_Handles_MoveRange(int oldIndex, int count, int newIndex)
-        {
-            var source = new AvaloniaList<int>(new[] { 0, 1, 2, 3, 4, 5 });
-            var target = source.CreateDerivedList(x => new Wrapper(x));
-
-            source.MoveRange(oldIndex, count, newIndex);
-
-            var result = target.Select(x => x.Value).ToList();
-
-            Assert.Equal(source, result);
-        }
-
-        [Fact]
-        public void CreateDerivedList_Handles_Replace()
-        {
-            var source = new AvaloniaList<int>(new[] { 0, 1, 2, 3 });
-            var target = source.CreateDerivedList(x => new Wrapper(x));
-
-            source[1] = 4;
-
-            var result = target.Select(x => x.Value).ToList();
-
-            Assert.Equal(source, result);
-        }
-
-        [Fact]
-        public void CreateDerivedList_Handles_Clear()
-        {
-            var source = new AvaloniaList<int>(new[] { 0, 1, 2, 3 });
-            var target = source.CreateDerivedList(x => new Wrapper(x));
-
-            source.Clear();
-
-            var result = target.Select(x => x.Value).ToList();
-
-            Assert.Equal(source, result);
-        }
-#pragma warning restore CS0618 // Type or member is obsolete
-
-
-        private class Wrapper
-        {
-            public Wrapper(int value)
-            {
-                Value = value;
-            }
-
-            public int Value { get; }
-        }
-    }
-}