Merge branch 'master' into window-ownership

build.sh

@@ -67,6 +67,8 @@ else
     fi
 fi
 
+export PATH=$DOTNET_DIRECTORY:$PATH
+
 echo "Microsoft (R) .NET Core SDK version $("$DOTNET_EXE" --version)"
 
 "$DOTNET_EXE" run --project "$BUILD_PROJECT_FILE" -- ${BUILD_ARGUMENTS[@]}

native/Avalonia.Native/inc/avalonia-native.h

@@ -387,6 +387,9 @@ AVNCOM(IAvnClipboard, 0f) : IUnknown
     virtual HRESULT SetText (char* type, void* utf8Text) = 0;
     virtual HRESULT ObtainFormats(IAvnStringArray**ppv) = 0;
     virtual HRESULT GetStrings(char* type, IAvnStringArray**ppv) = 0;
+    virtual HRESULT SetBytes(char* type, void* utf8Text, int len) = 0;
+    virtual HRESULT GetBytes(char* type, IAvnString**ppv) = 0;
+    
     virtual HRESULT Clear() = 0;
 };
 

native/Avalonia.Native/src/OSX/AvnString.h

@@ -12,4 +12,5 @@
 extern IAvnString* CreateAvnString(NSString* string);
 extern IAvnStringArray* CreateAvnStringArray(NSArray<NSString*>* array);
 extern IAvnStringArray* CreateAvnStringArray(NSString* string);
+extern IAvnString* CreateByteArray(void* data, int len);
 #endif /* AvnString_h */

native/Avalonia.Native/src/OSX/AvnString.mm

@@ -29,6 +29,13 @@ public:
         memcpy((void*)_cstring, (void*)cstring, _length);
     }
     
+    AvnStringImpl(void*ptr, int len)
+    {
+        _length = len;
+        _cstring = (const char*)malloc(_length);
+        memcpy((void*)_cstring, ptr, len);
+    }
+    
     virtual ~AvnStringImpl()
     {
         free((void*)_cstring);
@@ -114,3 +121,8 @@ IAvnStringArray* CreateAvnStringArray(NSString* string)
 {
     return new AvnStringArrayImpl(string);
 }
+
+IAvnString* CreateByteArray(void* data, int len)
+{
+    return new AvnStringImpl(data, len);
+}

native/Avalonia.Native/src/OSX/clipboard.mm

@@ -82,6 +82,40 @@ public:
         
         return S_OK;
     }
+    
+    virtual HRESULT SetBytes(char* type, void* bytes, int len) override
+    {
+        auto typeString = [NSString stringWithUTF8String:(const char*)type];
+        auto data = [NSData dataWithBytes:bytes length:len];
+        if(_item == nil)
+            [_pb setData:data forType:typeString];
+        else
+            [_item setData:data forType:typeString];
+        return S_OK;
+    }
+       
+    virtual HRESULT GetBytes(char* type, IAvnString**ppv) override
+    {
+        *ppv = nil;
+        auto typeString = [NSString stringWithUTF8String:(const char*)type];
+        NSData*data;
+        @try
+        {
+            if(_item)
+                data = [_item dataForType:typeString];
+            else
+                data = [_pb dataForType:typeString];
+            if(data == nil)
+                return E_FAIL;
+        }
+        @catch(NSException* e)
+        {
+            return E_FAIL;
+        }
+        *ppv = CreateByteArray((void*)data.bytes, (int)data.length);
+        return S_OK;
+    }
+
 
     virtual HRESULT Clear() override
     {

samples/ControlCatalog/App.xaml

@@ -1,10 +1,8 @@
 <Application xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              x:Class="ControlCatalog.App">
-  <Application.Styles>
+  <Application.Styles>        
-    <StyleInclude Source="avares://Avalonia.Themes.Default/DefaultTheme.xaml"/>
+    <StyleInclude Source="avares://Avalonia.Controls.DataGrid/Themes/Default.xaml"/>
-    <StyleInclude Source="avares://Avalonia.Themes.Default/Accents/BaseLight.xaml"/>
-    <StyleInclude Source="avares://Avalonia.Controls.DataGrid/Themes/Default.xaml"/>    
     <Style Selector="TextBlock.h1">
       <Setter Property="FontSize" Value="{DynamicResource FontSizeLarge}"/>
       <Setter Property="FontWeight" Value="Medium"/>

samples/ControlCatalog/App.xaml.cs

@@ -1,14 +1,67 @@
+using System;
 using Avalonia;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
+using Avalonia.Markup.Xaml.Styling;
+using Avalonia.Styling;
 
 namespace ControlCatalog
 {
     public class App : Application
     {
+        public static Styles FluentDark = new Styles
+        {
+            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
+            {
+                Source = new Uri("resm:Avalonia.Themes.Default.Accents.BaseDark.xaml?assembly=Avalonia.Themes.Default")
+            },
+            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
+            {
+                Source = new Uri("resm:Avalonia.Themes.Fluent.Accents.FluentDark.xaml?assembly=Avalonia.Themes.Fluent")
+            },
+        };
+
+        public static Styles FluentLight = new Styles
+        {
+            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
+            {
+                Source = new Uri("resm:Avalonia.Themes.Default.Accents.BaseLight.xaml?assembly=Avalonia.Themes.Default")
+            },
+            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
+            {
+                Source = new Uri("resm:Avalonia.Themes.Fluent.Accents.FluentLight.xaml?assembly=Avalonia.Themes.Fluent")
+            },
+        };
+
+        public static Styles DefaultLight = new Styles
+        {
+            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
+            {
+                Source = new Uri("resm:Avalonia.Themes.Default.Accents.BaseLight.xaml?assembly=Avalonia.Themes.Default")
+            },
+            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
+            {
+                Source = new Uri("resm:Avalonia.Themes.Default.DefaultTheme.xaml?assembly=Avalonia.Themes.Default")
+            },
+        };
+
+        public static Styles DefaultDark = new Styles
+        {
+            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
+            {
+                Source = new Uri("resm:Avalonia.Themes.Default.Accents.BaseDark.xaml?assembly=Avalonia.Themes.Default")
+            },
+            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
+            {
+                Source = new Uri("resm:Avalonia.Themes.Default.DefaultTheme.xaml?assembly=Avalonia.Themes.Default")
+            },
+        };
+
         public override void Initialize()
         {
             AvaloniaXamlLoader.Load(this);
+
+            Styles.Insert(0, FluentDark);
         }
 
         public override void OnFrameworkInitializationCompleted()

samples/ControlCatalog/MainView.xaml

@@ -67,8 +67,10 @@
             <ComboBoxItem>Full Decorations</ComboBoxItem>
           </ComboBox>
           <ComboBox x:Name="Themes" SelectedIndex="0">
-            <ComboBoxItem>Light</ComboBoxItem>
+            <ComboBoxItem>Fluent - Dark</ComboBoxItem>
-            <ComboBoxItem>Dark</ComboBoxItem>
+            <ComboBoxItem>Fluent - Light</ComboBoxItem>
+            <ComboBoxItem>Simple - Light</ComboBoxItem>
+            <ComboBoxItem>Simple - Dark</ComboBoxItem>
           </ComboBox>
           <ComboBox x:Name="TransparencyLevels" SelectedIndex="0">
             <ComboBoxItem>None</ComboBoxItem>

samples/ControlCatalog/MainView.xaml.cs

@@ -32,30 +32,25 @@ namespace ControlCatalog
 
             }
 
-            var light = new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
-            {
-                Source = new Uri("resm:Avalonia.Themes.Default.Accents.BaseLight.xaml?assembly=Avalonia.Themes.Default")
-            };
-            var dark = new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
-            {
-                Source = new Uri("resm:Avalonia.Themes.Default.Accents.BaseDark.xaml?assembly=Avalonia.Themes.Default")
-            };
-
-
             var themes = this.Find<ComboBox>("Themes");
             themes.SelectionChanged += (sender, e) =>
             {
                 switch (themes.SelectedIndex)
                 {
                     case 0:
-                        Styles[0] = light;
+                        Application.Current.Styles[0] = App.FluentDark;
                         break;
                     case 1:
-                        Styles[0] = dark;
+                        Application.Current.Styles[0] = App.FluentLight;
+                        break;
+                    case 2:
+                        Application.Current.Styles[0] = App.DefaultLight;
+                        break;
+                    case 3:
+                        Application.Current.Styles[0] = App.DefaultDark;
                         break;
                 }
-            };
+            };            
-            Styles.Add(light);
 
             var decorations = this.Find<ComboBox>("Decorations");
             decorations.SelectionChanged += (sender, e) =>

samples/ControlCatalog/MainWindow.xaml

@@ -7,7 +7,7 @@
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:vm="clr-namespace:ControlCatalog.ViewModels"
         xmlns:v="clr-namespace:ControlCatalog.Views"
-        x:Class="ControlCatalog.MainWindow" WindowState="{Binding WindowState, Mode=TwoWay}" Background="Transparent">
+        x:Class="ControlCatalog.MainWindow" WindowState="{Binding WindowState, Mode=TwoWay}" Background="{DynamicResource SystemControlPageBackgroundAltHighBrush}">
   <NativeMenu.Menu>
     <NativeMenu>
       <NativeMenuItem Header="File">

samples/ControlCatalog/Pages/ButtonPage.xaml

@@ -24,7 +24,10 @@
             </Style>
           </Button.Styles>          
         </Button>
-      </StackPanel>
+        <RepeatButton Name="RepeatButton">
+          <TextBlock Name="RepeatButtonTextBlock" Text="Repeat Button: 0" />
+        </RepeatButton>      
+    </StackPanel>
 
       <StackPanel Orientation="Vertical" Spacing="8" Width="150">
         <Button BorderThickness="0">No Border</Button>

samples/ControlCatalog/Pages/ButtonPage.xaml.cs

@@ -5,5 +5,25 @@ namespace ControlCatalog.Pages
 {
     public class ButtonPage : UserControl
     {
+        private int repeatButtonClickCount = 0;
+
+        public ButtonPage()
+        {
+            InitializeComponent();
+
+            this.FindControl<RepeatButton>("RepeatButton").Click += OnRepeatButtonClick;
+        }
+
+        private void InitializeComponent()
+        {
+            AvaloniaXamlLoader.Load(this);
+        }
+
+        public void OnRepeatButtonClick(object sender, object args)
+        {
+            repeatButtonClickCount++;
+            var textBlock = this.FindControl<TextBlock>("RepeatButtonTextBlock");
+            textBlock.Text = $"Repeat Button: {repeatButtonClickCount}";
+        }
     }
 }

samples/ControlCatalog/Pages/SliderPage.xaml

@@ -9,12 +9,14 @@
       <Slider Value="0"
               Minimum="0"
               Maximum="100"
+              TickFrequency="10"
               Width="300"/>
       <Slider Value="0"
               Minimum="0"
               Maximum="100"
               Orientation="Vertical"
               IsSnapToTickEnabled="True"
+              TickPlacement="Outside"
               TickFrequency="10"
               Height="300"/>
     </StackPanel>

samples/ControlCatalog/Pages/TreeViewPage.xaml

@@ -20,6 +20,7 @@
 
         <Button Command="{Binding AddItemCommand}">Add</Button>
         <Button Command="{Binding RemoveItemCommand}">Remove</Button>
+        <Button Command="{Binding SelectRandomItemCommand}">Select Random</Button>
 
         <ComboBox SelectedIndex="{Binding SelectionMode, Mode=TwoWay}">
           <ComboBoxItem>Single</ComboBoxItem>

samples/ControlCatalog/ViewModels/TreeViewPageViewModel.cs

@@ -23,12 +23,14 @@ namespace ControlCatalog.ViewModels
 
             AddItemCommand = ReactiveCommand.Create(AddItem);
             RemoveItemCommand = ReactiveCommand.Create(RemoveItem);
+            SelectRandomItemCommand = ReactiveCommand.Create(SelectRandomItem);
         }
 
         public ObservableCollection<Node> Items { get; }
         public SelectionModel Selection { get; }
         public ReactiveCommand<Unit, Unit> AddItemCommand { get; }
         public ReactiveCommand<Unit, Unit> RemoveItemCommand { get; }
+        public ReactiveCommand<Unit, Unit> SelectRandomItemCommand { get; }
 
         public SelectionMode SelectionMode
         {
@@ -74,6 +76,15 @@ namespace ControlCatalog.ViewModels
             }
         }
 
+        private void SelectRandomItem()
+        {
+            var random = new Random();
+            var depth = random.Next(4);
+            var indexes = Enumerable.Range(0, 4).Select(x => random.Next(10));
+            var path = new IndexPath(indexes);
+            Selection.SelectedIndex = path;
+        }
+
         private void SelectionChanged(object sender, SelectionModelSelectionChangedEventArgs e)
         {
             var selected = string.Join(",", e.SelectedIndices);

src/Android/Avalonia.Android/Platform/ClipboardImpl.cs

@@ -43,5 +43,11 @@ namespace Avalonia.Android.Platform
 
             return Task.FromResult<object>(null);
         }
+
+        public Task SetDataObjectAsync(IDataObject data) => throw new PlatformNotSupportedException();
+
+        public Task<string[]> GetFormatsAsync() => throw new PlatformNotSupportedException();
+
+        public Task<object> GetDataAsync(string format) => throw new PlatformNotSupportedException();
     }
 }

src/Avalonia.Animation/Animatable.cs

@@ -93,17 +93,17 @@ namespace Avalonia.Animation
                 var oldTransitions = change.OldValue.GetValueOrDefault<Transitions>();
                 var newTransitions = change.NewValue.GetValueOrDefault<Transitions>();
 
-                if (oldTransitions is object)
-                {
-                    oldTransitions.CollectionChanged -= TransitionsCollectionChanged;
-                    RemoveTransitions(oldTransitions);
-                }
-
                 if (newTransitions is object)
                 {
                     newTransitions.CollectionChanged += TransitionsCollectionChanged;
                     AddTransitions(newTransitions);
                 }
+
+                if (oldTransitions is object)
+                {
+                    oldTransitions.CollectionChanged -= TransitionsCollectionChanged;
+                    RemoveTransitions(oldTransitions);
+                }
             }
             else if (_transitionsEnabled &&
                      Transitions is object &&
@@ -111,8 +111,10 @@ namespace Avalonia.Animation
                      !change.Property.IsDirect &&
                      change.Priority > BindingPriority.Animation)
             {
-                foreach (var transition in Transitions)
+                for (var i = Transitions.Count -1; i >= 0; --i)
                 {
+                    var transition = Transitions[i];
+
                     if (transition.Property == change.Property)
                     {
                         var state = _transitionState[transition];

src/Avalonia.Base/Data/Core/Plugins/InpcPropertyAccessorPlugin.cs

@@ -1,7 +1,5 @@
 using System;
 using System.ComponentModel;
-using System.Linq;
-using System.Reactive.Linq;
 using System.Reflection;
 using Avalonia.Utilities;
 
@@ -31,7 +29,11 @@ namespace Avalonia.Data.Core.Plugins
             Contract.Requires<ArgumentNullException>(propertyName != null);
 
             reference.TryGetTarget(out object instance);
-            var p = instance.GetType().GetRuntimeProperties().FirstOrDefault(x => x.Name == propertyName);
+
+            const BindingFlags bindingFlags = BindingFlags.NonPublic | BindingFlags.Public |
+                                              BindingFlags.Static | BindingFlags.Instance;
+
+            var p = instance.GetType().GetProperty(propertyName, bindingFlags);
 
             if (p != null)
             {

src/Avalonia.Base/Data/Core/Plugins/MethodAccessorPlugin.cs

@@ -1,13 +1,16 @@
 using System;
-using System.Linq;
+using System.Collections.Generic;
+using System.Linq.Expressions;
 using System.Reflection;
 
 namespace Avalonia.Data.Core.Plugins
 {
-    class MethodAccessorPlugin : IPropertyAccessorPlugin
+    public class MethodAccessorPlugin : IPropertyAccessorPlugin
     {
-        public bool Match(object obj, string methodName)
+        private readonly Dictionary<(Type, string), MethodInfo> _methodLookup =
-            => obj.GetType().GetRuntimeMethods().Any(x => x.Name == methodName);
+            new Dictionary<(Type, string), MethodInfo>();
+
+        public bool Match(object obj, string methodName) => GetFirstMethodWithName(obj.GetType(), methodName) != null;
 
         public IPropertyAccessor Start(WeakReference<object> reference, string methodName)
         {
@@ -15,17 +18,22 @@ namespace Avalonia.Data.Core.Plugins
             Contract.Requires<ArgumentNullException>(methodName != null);
 
             reference.TryGetTarget(out object instance);
-            var method = instance.GetType().GetRuntimeMethods().FirstOrDefault(x => x.Name == methodName);
+
+            var method = GetFirstMethodWithName(instance.GetType(), methodName);
 
             if (method != null)
             {
-                if (method.GetParameters().Length + (method.ReturnType == typeof(void) ? 0 : 1) > 8)
+                var parameters = method.GetParameters();
+
+                if (parameters.Length + (method.ReturnType == typeof(void) ? 0 : 1) > 8)
                 {
-                    var exception = new ArgumentException("Cannot create a binding accessor for a method with more than 8 parameters or more than 7 parameters if it has a non-void return type.", nameof(methodName));
+                    var exception = new ArgumentException(
+                        "Cannot create a binding accessor for a method with more than 8 parameters or more than 7 parameters if it has a non-void return type.",
+                        nameof(methodName));
                     return new PropertyError(new BindingNotification(exception, BindingErrorType.Error));
                 }
 
-                return new Accessor(reference, method);
+                return new Accessor(reference, method, parameters);
             }
             else
             {
@@ -35,31 +43,72 @@ namespace Avalonia.Data.Core.Plugins
             }
         }
 
+        private MethodInfo GetFirstMethodWithName(Type type, string methodName)
+        {
+            var key = (type, methodName);
+
+            if (!_methodLookup.TryGetValue(key, out MethodInfo methodInfo))
+            {
+                methodInfo = TryFindAndCacheMethod(type, methodName);
+            }
+
+            return methodInfo;
+        }
+
+        private MethodInfo TryFindAndCacheMethod(Type type, string methodName)
+        {
+            MethodInfo found = null;
+
+            const BindingFlags bindingFlags =
+                BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static | BindingFlags.Instance;
+
+            var methods = type.GetMethods(bindingFlags);
+
+            foreach (MethodInfo methodInfo in methods)
+            {
+                if (methodInfo.Name == methodName)
+                {
+                    found = methodInfo;
+
+                    break;
+                }
+            }
+
+            _methodLookup.Add((type, methodName), found);
+
+            return found;
+        }
+
         private sealed class Accessor : PropertyAccessorBase
         {
-            public Accessor(WeakReference<object> reference, MethodInfo method)
+            public Accessor(WeakReference<object> reference, MethodInfo method, ParameterInfo[] parameters)
             {
                 Contract.Requires<ArgumentNullException>(reference != null);
                 Contract.Requires<ArgumentNullException>(method != null);
 
-                var paramTypes = method.GetParameters().Select(param => param.ParameterType).ToArray();
                 var returnType = method.ReturnType;
-                
+                bool hasReturn = returnType != typeof(void);
-                if (returnType == typeof(void))
+
+                var signatureTypeCount = (hasReturn ? 1 : 0) + parameters.Length;
+
+                var paramTypes = new Type[signatureTypeCount];
+
+                for (var i = 0; i < parameters.Length; i++)
                 {
-                    if (paramTypes.Length == 0)
+                    ParameterInfo parameter = parameters[i];
-                    {
+
-                        PropertyType = typeof(Action);
+                    paramTypes[i] = parameter.ParameterType;
-                    }
+                }
-                    else
+
-                    {
+                if (hasReturn)
-                        PropertyType = Type.GetType($"System.Action`{paramTypes.Length}").MakeGenericType(paramTypes); 
+                {
-                    }
+                    paramTypes[paramTypes.Length - 1] = returnType;
+
+                    PropertyType = Expression.GetFuncType(paramTypes);
                 }
                 else
                 {
-                    var genericTypeParameters = paramTypes.Concat(new[] { returnType }).ToArray();
+                    PropertyType = Expression.GetActionType(paramTypes);
-                    PropertyType = Type.GetType($"System.Func`{genericTypeParameters.Length}").MakeGenericType(genericTypeParameters);
                 }
 
                 if (method.IsStatic)

src/Avalonia.Controls/IndexPath.cs

@@ -123,6 +123,26 @@ namespace Avalonia.Controls
             }
         }
 
+        public bool IsAncestorOf(in IndexPath other)
+        {
+            if (other.GetSize() <= GetSize())
+            {
+                return false;
+            }
+
+            var size = GetSize();
+
+            for (int i = 0; i < size; i++)
+            {
+                if (GetAt(i) != other.GetAt(i))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
         public override string ToString()
         {
             if (_path != null)

src/Avalonia.Controls/IndexRange.cs

@@ -132,6 +132,53 @@ namespace Avalonia.Controls
             return result;
         }
 
+        public static int Intersect(
+            IList<IndexRange> ranges,
+            IndexRange range,
+            IList<IndexRange>? removed = null)
+        {
+            var result = 0;
+
+            for (var i = 0; i < ranges.Count && range != s_invalid; ++i)
+            {
+                var existing = ranges[i];
+
+                if (existing.End < range.Begin || existing.Begin > range.End)
+                {
+                    removed?.Add(existing);
+                    ranges.RemoveAt(i--);
+                    result += existing.Count;
+                }
+                else
+                {
+                    if (existing.Begin < range.Begin)
+                    {
+                        var except = new IndexRange(existing.Begin, range.Begin - 1);
+                        removed?.Add(except);
+                        ranges[i] = existing = new IndexRange(range.Begin, existing.End);
+                        result += except.Count;
+                    }
+
+                    if (existing.End > range.End)
+                    {
+                        var except = new IndexRange(range.End + 1, existing.End);
+                        removed?.Add(except);
+                        ranges[i] = new IndexRange(existing.Begin, range.End);
+                        result += except.Count;
+                    }
+                }
+            }
+
+            MergeRanges(ranges);
+
+            if (removed is object)
+            {
+                MergeRanges(removed);
+            }
+
+            return result;
+        }
+
         public static int Remove(
             IList<IndexRange> ranges,
             IndexRange range,

src/Avalonia.Controls/Primitives/Track.cs

@@ -41,13 +41,16 @@ namespace Avalonia.Controls.Primitives
         public static readonly StyledProperty<bool> IsDirectionReversedProperty =
             AvaloniaProperty.Register<Track, bool>(nameof(IsDirectionReversed));
 
+        public static readonly StyledProperty<bool> IgnoreThumbDragProperty =
+            AvaloniaProperty.Register<Track, bool>(nameof(IsThumbDragHandled));
+
         private double _minimum;
         private double _maximum = 100.0;
         private double _value;
 
         static Track()
         {
-            ThumbProperty.Changed.AddClassHandler<Track>((x,e) => x.ThumbChanged(e));
+            ThumbProperty.Changed.AddClassHandler<Track>((x, e) => x.ThumbChanged(e));
             IncreaseButtonProperty.Changed.AddClassHandler<Track>((x, e) => x.ButtonChanged(e));
             DecreaseButtonProperty.Changed.AddClassHandler<Track>((x, e) => x.ButtonChanged(e));
             AffectsArrange<Track>(MinimumProperty, MaximumProperty, ValueProperty, OrientationProperty);
@@ -113,6 +116,12 @@ namespace Avalonia.Controls.Primitives
             set { SetValue(IsDirectionReversedProperty, value); }
         }
 
+        public bool IsThumbDragHandled
+        {
+            get { return GetValue(IgnoreThumbDragProperty); }
+            set { SetValue(IgnoreThumbDragProperty, value); }
+        }
+
         private double ThumbCenterOffset { get; set; }
         private double Density { get; set; }
 
@@ -422,6 +431,9 @@ namespace Avalonia.Controls.Primitives
 
         private void ThumbDragged(object sender, VectorEventArgs e)
         {
+            if (IsThumbDragHandled)
+                return;
+                
             Value = MathUtilities.Clamp(
                 Value + ValueFromDistance(e.Vector.X, e.Vector.Y),
                 Minimum,

src/Avalonia.Controls/SelectionModel.cs

@@ -46,17 +46,25 @@ namespace Avalonia.Controls
 
                     if (_rootNode.Source != null)
                     {
-                        if (_rootNode.Source != null)
+                        // Temporarily prevent auto-select when switching source.
+                        var restoreAutoSelect = _autoSelect;
+                        _autoSelect = false;
+
+                        try
                         {
                             using (var operation = new Operation(this))
                             {
                                 ClearSelection(resetAnchor: true);
                             }
                         }
+                        finally
+                        {
+                            _autoSelect = restoreAutoSelect;
+                        }
                     }
 
                     _rootNode.Source = value;
-                    ApplyAutoSelect();
+                    ApplyAutoSelect(true);
 
                     RaisePropertyChanged("Source");
 
@@ -114,7 +122,7 @@ namespace Avalonia.Controls
                 if (_autoSelect != value)
                 {
                     _autoSelect = value;
-                    ApplyAutoSelect();
+                    ApplyAutoSelect(true);
                 }
             }
         }
@@ -133,7 +141,7 @@ namespace Avalonia.Controls
                     while (current?.AnchorIndex >= 0)
                     {
                         path.Add(current.AnchorIndex);
-                        current = current.GetAt(current.AnchorIndex, false);
+                        current = current.GetAt(current.AnchorIndex, false, default);
                     }
 
                     anchor = new IndexPath(path);
@@ -188,7 +196,6 @@ namespace Avalonia.Controls
                     using var operation = new Operation(this);
                     ClearSelection(resetAnchor: true);
                     SelectWithPathImpl(value, select: true);
-                    ApplyAutoSelect();
                 }
             }
         }
@@ -384,21 +391,18 @@ namespace Avalonia.Controls
         {
             using var operation = new Operation(this);
             SelectImpl(index, select: false);
-            ApplyAutoSelect();
         }
 
         public void Deselect(int groupIndex, int itemIndex)
         {
             using var operation = new Operation(this);
             SelectWithGroupImpl(groupIndex, itemIndex, select: false);
-            ApplyAutoSelect();
         }
 
         public void DeselectAt(IndexPath index)
         {
             using var operation = new Operation(this);
             SelectWithPathImpl(index, select: false);
-            ApplyAutoSelect();
         }
 
         public bool IsSelected(int index) => _rootNode.IsSelected(index);
@@ -416,7 +420,7 @@ namespace Avalonia.Controls
             for (int i = 0; i < path.GetSize() - 1; i++)
             {
                 var childIndex = path.GetAt(i);
-                node = node.GetAt(childIndex, realizeChild: false);
+                node = node.GetAt(childIndex, false, default);
 
                 if (node == null)
                 {
@@ -451,7 +455,7 @@ namespace Avalonia.Controls
             }
 
             var isSelected = (bool?)false;
-            var childNode = _rootNode.GetAt(groupIndex, realizeChild: false);
+            var childNode = _rootNode.GetAt(groupIndex, false, default);
 
             if (childNode != null)
             {
@@ -470,7 +474,7 @@ namespace Avalonia.Controls
             for (int i = 0; i < path.GetSize() - 1; i++)
             {
                 var childIndex = path.GetAt(i);
-                node = node.GetAt(childIndex, realizeChild: false);
+                node = node.GetAt(childIndex, false, default);
 
                 if (node == null)
                 {
@@ -565,7 +569,6 @@ namespace Avalonia.Controls
         {
             using var operation = new Operation(this);
             ClearSelection(resetAnchor: true);
-            ApplyAutoSelect();
         }
 
         public IDisposable Update() => new Operation(this);
@@ -592,10 +595,13 @@ namespace Avalonia.Controls
             }
 
             OnSelectionChanged(e);
-            ApplyAutoSelect();
+            ApplyAutoSelect(true);
         }
 
-        internal IObservable<object?>? ResolvePath(object data, IndexPath dataIndexPath)
+        internal IObservable<object?>? ResolvePath(
+            object data,
+            IndexPath dataIndexPath,
+            IndexPath finalIndexPath)
         {
             IObservable<object?>? resolved = null;
 
@@ -604,18 +610,22 @@ namespace Avalonia.Controls
             {
                 if (_childrenRequestedEventArgs == null)
                 {
-                    _childrenRequestedEventArgs = new SelectionModelChildrenRequestedEventArgs(data, dataIndexPath, false);
+                    _childrenRequestedEventArgs = new SelectionModelChildrenRequestedEventArgs(
+                        data,
+                        dataIndexPath,
+                        finalIndexPath,
+                        false);
                 }
                 else
                 {
-                    _childrenRequestedEventArgs.Initialize(data, dataIndexPath, false);
+                    _childrenRequestedEventArgs.Initialize(data, dataIndexPath, finalIndexPath, false);
                 }
 
                 ChildrenRequested(this, _childrenRequestedEventArgs);
                 resolved = _childrenRequestedEventArgs.Children;
 
                 // Clear out the values in the args so that it cannot be used after the event handler call.
-                _childrenRequestedEventArgs.Initialize(null, default, true);
+                _childrenRequestedEventArgs.Initialize(null, default, default, true);
             }
 
             return resolved;
@@ -632,6 +642,8 @@ namespace Avalonia.Controls
             {
                 AnchorIndex = default;
             }
+
+            OnSelectionChanged();
         }
 
         private void OnSelectionChanged(SelectionModelSelectionChangedEventArgs? e = null)
@@ -667,6 +679,8 @@ namespace Avalonia.Controls
             {
                 AnchorIndex = new IndexPath(index);
             }
+
+            OnSelectionChanged();
         }
 
         private void SelectWithGroupImpl(int groupIndex, int itemIndex, bool select)
@@ -676,13 +690,15 @@ namespace Avalonia.Controls
                 ClearSelection(resetAnchor: true);
             }
 
-            var childNode = _rootNode.GetAt(groupIndex, realizeChild: true);
+            var childNode = _rootNode.GetAt(groupIndex, true, new IndexPath(groupIndex, itemIndex));
             var selected = childNode!.Select(itemIndex, select);
 
             if (selected)
             {
                 AnchorIndex = new IndexPath(groupIndex, itemIndex);
             }
+
+            OnSelectionChanged();
         }
 
         private void SelectWithPathImpl(IndexPath index, bool select)
@@ -711,6 +727,8 @@ namespace Avalonia.Controls
             {
                 AnchorIndex = index;
             }
+
+            OnSelectionChanged();
         }
 
         private void SelectRangeFromAnchorImpl(int index, bool select)
@@ -724,6 +742,7 @@ namespace Avalonia.Controls
             }
 
             _rootNode.SelectRange(new IndexRange(anchorIndex, index), select);
+            OnSelectionChanged();
         }
 
         private void SelectRangeFromAnchorWithGroupImpl(int endGroupIndex, int endItemIndex, bool select)
@@ -752,11 +771,13 @@ namespace Avalonia.Controls
 
             for (int groupIdx = startGroupIndex; groupIdx <= endGroupIndex; groupIdx++)
             {
-                var groupNode = _rootNode.GetAt(groupIdx, realizeChild: true)!;
+                var groupNode = _rootNode.GetAt(groupIdx, true, new IndexPath(endGroupIndex, endItemIndex))!;
                 int startIndex = groupIdx == startGroupIndex ? startItemIndex : 0;
                 int endIndex = groupIdx == endGroupIndex ? endItemIndex : groupNode.DataCount - 1;
                 groupNode.SelectRange(new IndexRange(startIndex, endIndex), select);
             }
+
+            OnSelectionChanged();
         }
 
         private void SelectRangeImpl(IndexPath start, IndexPath end, bool select)
@@ -784,6 +805,8 @@ namespace Avalonia.Controls
                         info.ParentNode!.Select(info.Path.GetAt(info.Path.GetSize() - 1), select);
                     }
                 });
+
+            OnSelectionChanged();
         }
 
         private void BeginOperation()
@@ -806,6 +829,8 @@ namespace Avalonia.Controls
 
             if (--_operationCount == 0)
             {
+                ApplyAutoSelect(false);
+
                 var changes = new List<SelectionNodeOperation>();
                 _rootNode.EndOperation(changes);
 
@@ -827,7 +852,7 @@ namespace Avalonia.Controls
             }
         }
 
-        private void ApplyAutoSelect()
+        private void ApplyAutoSelect(bool createOperation)
         {
             if (AutoSelect)
             {
@@ -835,8 +860,15 @@ namespace Avalonia.Controls
 
                 if (SelectedIndex == default && _rootNode.ItemsSourceView?.Count > 0)
                 {
-                    using var operation = new Operation(this);
+                    if (createOperation)
-                    SelectImpl(0, true);
+                    {
+                        using var operation = new Operation(this);
+                        SelectImpl(0, true);
+                    }
+                    else
+                    {
+                        SelectImpl(0, true);
+                    }
                 }
             }
         }

src/Avalonia.Controls/SelectionModelChangeSet.cs

@@ -135,7 +135,7 @@ namespace Avalonia.Controls
                 if (index >= currentIndex && index < currentIndex + currentCount)
                 {
                     int targetIndex = GetIndexAt(getRanges(info), index - currentIndex);
-                    item = info.Items?.GetAt(targetIndex);
+                    item = info.Items?.Count > targetIndex ? info.Items?.GetAt(targetIndex) : null;
                     break;
                 }
 

src/Avalonia.Controls/SelectionModelChildrenRequestedEventArgs.cs

@@ -16,15 +16,17 @@ namespace Avalonia.Controls
     {
         private object? _source;
         private IndexPath _sourceIndexPath;
+        private IndexPath _finalIndexPath;
         private bool _throwOnAccess;
         
         internal SelectionModelChildrenRequestedEventArgs(
             object source,
             IndexPath sourceIndexPath,
+            IndexPath finalIndexPath,
             bool throwOnAccess)
         {
             source = source ?? throw new ArgumentNullException(nameof(source));
-            Initialize(source, sourceIndexPath, throwOnAccess);
+            Initialize(source, sourceIndexPath, finalIndexPath, throwOnAccess);
         }
 
         /// <summary>
@@ -65,9 +67,26 @@ namespace Avalonia.Controls
             }
         }
 
+        /// <summary>
+        /// Gets the index of the final object which is being attempted to be retrieved.
+        /// </summary>
+        public IndexPath FinalIndex
+        {
+            get
+            {
+                if (_throwOnAccess)
+                {
+                    throw new ObjectDisposedException(nameof(SelectionModelChildrenRequestedEventArgs));
+                }
+
+                return _finalIndexPath;
+            }
+        }
+
         internal void Initialize(
             object? source,
             IndexPath sourceIndexPath,
+            IndexPath finalIndexPath,
             bool throwOnAccess)
         {
             if (!throwOnAccess && source == null)
@@ -77,6 +96,7 @@ namespace Avalonia.Controls
 
             _source = source;
             _sourceIndexPath = sourceIndexPath;
+            _finalIndexPath = finalIndexPath;
             _throwOnAccess = throwOnAccess;
         }
     }

src/Avalonia.Controls/SelectionNode.cs

@@ -101,6 +101,7 @@ namespace Avalonia.Controls
 
                     ItemsSourceView = newDataSource;
 
+                    TrimInvalidSelections();
                     PopulateSelectedItemsFromSelectedIndices();
                     HookupCollectionChangedHandler();
                     OnSelectionChanged();
@@ -108,6 +109,26 @@ namespace Avalonia.Controls
             }
         }
 
+        private void TrimInvalidSelections()
+        {
+            if (_selected == null || ItemsSourceView == null)
+            {
+                return;
+            }
+
+            var validRange = ItemsSourceView.Count > 0 ? new IndexRange(0, ItemsSourceView.Count - 1) : new IndexRange(-1, -1);
+            var removed = new List<IndexRange>();
+            var removedCount = IndexRange.Intersect(_selected, validRange, removed);
+
+            if (removedCount > 0)
+            {
+                using var operation = _manager.Update();
+                SelectedCount -= removedCount;
+                OnSelectionChanged();
+                _operation!.Deselected(removed);
+            }
+        }
+
         public ItemsSourceView? ItemsSourceView { get; private set; }
         public int DataCount => ItemsSourceView?.Count ?? 0;
         public int ChildrenNodeCount => _childrenNodes.Count;
@@ -141,7 +162,7 @@ namespace Avalonia.Controls
         // create a bunch of leaf node instances - instead i use the same instance m_leafNode to avoid 
         // an explosion of node objects. However, I'm still creating the m_childrenNodes 
         // collection unfortunately.
-        public SelectionNode? GetAt(int index, bool realizeChild)
+        public SelectionNode? GetAt(int index, bool realizeChild, IndexPath finalIndexPath)
         {
             SelectionNode? child = null;
             
@@ -171,7 +192,7 @@ namespace Avalonia.Controls
                     if (childData != null)
                     {
                         var childDataIndexPath = IndexPath.CloneWithChildIndex(index);
-                        resolver = _manager.ResolvePath(childData, childDataIndexPath);
+                        resolver = _manager.ResolvePath(childData, childDataIndexPath, finalIndexPath);
                     }
 
                     if (resolver != null)
@@ -843,7 +864,7 @@ namespace Avalonia.Controls
                     int notSelectedCount = 0;
                     for (int i = 0; i < ChildrenNodeCount; i++)
                     {
-                        var child = GetAt(i, realizeChild: false);
+                        var child = GetAt(i, false, default);
 
                         if (child != null)
                         {

src/Avalonia.Controls/Slider.cs

@@ -1,12 +1,40 @@
 using System;
+using Avalonia.Controls.Mixins;
 using Avalonia.Controls.Primitives;
-using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Layout;
+using Avalonia.Utilities;
 
 namespace Avalonia.Controls
 {
+
+    /// <summary>
+    /// Enum which describes how to position the ticks in a <see cref="Slider"/>.
+    /// </summary>
+    public enum TickPlacement
+    {
+        /// <summary>
+        /// No tick marks will appear.
+        /// </summary>
+        None,
+
+        /// <summary>
+        /// Tick marks  will appear above the track for a horizontal <see cref="Slider"/>, or to the left of the track for a vertical <see cref="Slider"/>.
+        /// </summary>
+        TopLeft,
+
+        /// <summary>
+        /// Tick marks will appear below the track for a horizontal <see cref="Slider"/>, or to the right of the track for a vertical <see cref="Slider"/>.
+        /// </summary>
+        BottomRight,
+
+        /// <summary>
+        /// Tick marks appear on both sides of either a horizontal or vertical <see cref="Slider"/>.
+        /// </summary>
+        Outside
+    }
+
     /// <summary>
     /// A control that lets the user select from a range of values by moving a Thumb control along a Track.
     /// </summary>
@@ -30,19 +58,31 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<double> TickFrequencyProperty =
             AvaloniaProperty.Register<Slider, double>(nameof(TickFrequency), 0.0);
 
+        /// <summary>
+        /// Defines the <see cref="TickPlacement"/> property.
+        /// </summary>
+        public static readonly StyledProperty<TickPlacement> TickPlacementProperty =
+            AvaloniaProperty.Register<TickBar, TickPlacement>(nameof(TickPlacement), 0d);
+
         // Slider required parts
+        private bool _isDragging = false;
         private Track _track;
         private Button _decreaseButton;
         private Button _increaseButton;
+        private IDisposable _decreaseButtonPressDispose;
+        private IDisposable _decreaseButtonReleaseDispose;
+        private IDisposable _increaseButtonSubscription;
+        private IDisposable _increaseButtonReleaseDispose;
+        private IDisposable _pointerMovedDispose;
 
         /// <summary>
         /// Initializes static members of the <see cref="Slider"/> class. 
         /// </summary>
         static Slider()
         {
+            PressedMixin.Attach<Slider>();
             OrientationProperty.OverrideDefaultValue(typeof(Slider), Orientation.Horizontal);
             Thumb.DragStartedEvent.AddClassHandler<Slider>((x, e) => x.OnThumbDragStarted(e), RoutingStrategies.Bubble);
-            Thumb.DragDeltaEvent.AddClassHandler<Slider>((x, e) => x.OnThumbDragDelta(e), RoutingStrategies.Bubble);
             Thumb.DragCompletedEvent.AddClassHandler<Slider>((x, e) => x.OnThumbDragCompleted(e), RoutingStrategies.Bubble);
         }
 
@@ -81,57 +121,88 @@ namespace Avalonia.Controls
             set { SetValue(TickFrequencyProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets a value that indicates where to draw 
+        /// tick marks in relation to the track.
+        /// </summary>
+        public TickPlacement TickPlacement
+        {
+            get { return GetValue(TickPlacementProperty); }
+            set { SetValue(TickPlacementProperty, value); }
+        }
+
         /// <inheritdoc/>
         protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
         {
-            if (_decreaseButton != null)
+            base.OnApplyTemplate(e);
-            {
+            
-                _decreaseButton.Click -= DecreaseClick;
+            _decreaseButtonPressDispose?.Dispose();
-            }
+            _decreaseButtonReleaseDispose?.Dispose();
-
+            _increaseButtonSubscription?.Dispose();
-            if (_increaseButton != null)
+            _increaseButtonReleaseDispose?.Dispose();
-            {
+            _pointerMovedDispose?.Dispose();
-                _increaseButton.Click -= IncreaseClick;
-            }
 
             _decreaseButton = e.NameScope.Find<Button>("PART_DecreaseButton");
             _track = e.NameScope.Find<Track>("PART_Track");
             _increaseButton = e.NameScope.Find<Button>("PART_IncreaseButton");
 
+            if (_track != null)
+            {
+                _track.IsThumbDragHandled = true;
+            }
+
             if (_decreaseButton != null)
             {
-                _decreaseButton.Click += DecreaseClick;
+                _decreaseButtonPressDispose = _decreaseButton.AddDisposableHandler(PointerPressedEvent, TrackPressed, RoutingStrategies.Tunnel);
+                _decreaseButtonReleaseDispose = _decreaseButton.AddDisposableHandler(PointerReleasedEvent, TrackReleased, RoutingStrategies.Tunnel);
             }
 
             if (_increaseButton != null)
             {
-                _increaseButton.Click += IncreaseClick;
+                _increaseButtonSubscription = _increaseButton.AddDisposableHandler(PointerPressedEvent, TrackPressed, RoutingStrategies.Tunnel);
+                _increaseButtonReleaseDispose = _increaseButton.AddDisposableHandler(PointerReleasedEvent, TrackReleased, RoutingStrategies.Tunnel);
             }
+
+            _pointerMovedDispose = this.AddDisposableHandler(PointerMovedEvent, TrackMoved, RoutingStrategies.Tunnel);
         }
 
-        private void DecreaseClick(object sender, RoutedEventArgs e)
+        private void TrackMoved(object sender, PointerEventArgs e)
         {
-            ChangeValueBy(-LargeChange);
+            if (_isDragging)
+            {
+                MoveToPoint(e.GetCurrentPoint(_track));
+            }
         }
 
-        private void IncreaseClick(object sender, RoutedEventArgs e)
+        private void TrackReleased(object sender, PointerReleasedEventArgs e)
         {
-            ChangeValueBy(LargeChange);
+            _isDragging = false;
         }
 
-        private void ChangeValueBy(double by)
+        private void TrackPressed(object sender, PointerPressedEventArgs e)
         {
-            if (IsSnapToTickEnabled)
+            if (e.GetCurrentPoint(this).Properties.IsLeftButtonPressed)
             {
-                by = by < 0 ? Math.Min(-TickFrequency, by) : Math.Max(TickFrequency, by);
+                MoveToPoint(e.GetCurrentPoint(_track));
+                _isDragging = true;
             }
+        }
 
-            var value = Value;
+        private void MoveToPoint(PointerPoint x)
-            var next = SnapToTick(Math.Max(Math.Min(value + by, Maximum), Minimum));
+        {
-            if (next != value)
+            var orient = Orientation == Orientation.Horizontal;
-            {
+
-                Value = next;
+            var pointDen = orient ? _track.Bounds.Width : _track.Bounds.Height;
-            }
+            pointDen += double.Epsilon; // Just add epsilon to avoid divide by zero exceptions.
+
+            var pointNum = orient ? x.Position.X : x.Position.Y;
+            var logicalPos = MathUtilities.Clamp(pointNum / pointDen, 0.0d, 1.0d);
+            var invert = orient ? 0 : 1;
+            var calcVal = Math.Abs(invert - logicalPos);
+            var range = Maximum - Minimum;
+            var finalValue = calcVal * range;
+
+            Value = IsSnapToTickEnabled ? SnapToTick(finalValue) : finalValue;
         }
 
         protected override void OnPropertyChanged<T>(AvaloniaPropertyChangedEventArgs<T> change)
@@ -150,19 +221,7 @@ namespace Avalonia.Controls
         /// <param name="e"></param>
         protected virtual void OnThumbDragStarted(VectorEventArgs e)
         {
-        }
+            _isDragging = true;
-
-        /// <summary>
-        /// Called when user dragging the <see cref="Thumb"/>.
-        /// </summary>
-        /// <param name="e"></param>
-        protected virtual void OnThumbDragDelta(VectorEventArgs e)
-        {
-            Thumb thumb = e.Source as Thumb;
-            if (thumb != null && _track?.Thumb == thumb)
-            {
-                MoveToNextTick(_track.Value);
-            }
         }
 
         /// <summary>
@@ -171,15 +230,7 @@ namespace Avalonia.Controls
         /// <param name="e"></param>
         protected virtual void OnThumbDragCompleted(VectorEventArgs e)
         {
-        }
+            _isDragging = false;
-
-        /// <summary>
-        /// Searches for the closest tick and sets Value to that tick.
-        /// </summary>
-        /// <param name="value">Value that want to snap to closest Tick.</param>
-        private void MoveToNextTick(double value)
-        {
-            Value = SnapToTick(Math.Max(Minimum, Math.Min(Maximum, value)));
         }
 
         /// <summary>
@@ -188,14 +239,17 @@ namespace Avalonia.Controls
         /// <param name="value">Value that want to snap to closest Tick.</param>
         private double SnapToTick(double value)
         {
-            if (IsSnapToTickEnabled && TickFrequency > 0.0)
+            var previous = Minimum;
+            var next = Maximum;
+
+            if (TickFrequency > 0.0)
             {
-                double previous = Minimum + (Math.Round(((value - Minimum) / TickFrequency)) * TickFrequency);
+                previous = Minimum + (Math.Round((value - Minimum) / TickFrequency) * TickFrequency);
-                double next = Math.Min(Maximum, previous + TickFrequency);
+                next = Math.Min(Maximum, previous + TickFrequency);
-                value = value > (previous + next) * 0.5 ? next : previous;
             }
 
-            return value;
+            // Choose the closest value between previous and next. If tie, snap to 'next'.
+            return MathUtilities.GreaterThanOrClose(value, (previous + next) * 0.5) ? next : previous;
         }
 
         private void UpdatePseudoClasses(Orientation o)

src/Avalonia.Controls/TickBar.cs

@@ -0,0 +1,416 @@
+using System;
+using System.Collections.Generic;
+using Avalonia.Controls.Primitives;
+using Avalonia.Data;
+using Avalonia.Data.Converters;
+using Avalonia.Layout;
+using Avalonia.Media;
+using Avalonia.Utilities;
+
+namespace Avalonia.Controls
+{
+    /// <summary>
+    /// Enum which describes how to position the TickBar.
+    /// </summary>
+    public enum TickBarPlacement
+    {
+        /// <summary>
+        /// Position this tick at the left of target element.
+        /// </summary>
+        Left,
+
+        /// <summary>
+        /// Position this tick at the top of target element.
+        /// </summary>
+        Top,
+
+        /// <summary>
+        /// Position this tick at the right of target element.
+        /// </summary>
+        Right,
+
+        /// <summary>
+        /// Position this tick at the bottom of target element.
+        /// </summary>
+        Bottom,
+    }
+
+
+    /// <summary>
+    /// An element that is used for drawing <see cref="Slider"/>'s Ticks.
+    /// </summary>
+    public class TickBar : Control
+    {
+        static TickBar()
+        {
+            AffectsRender<TickBar>(ReservedSpaceProperty,
+                                   MaximumProperty,
+                                   MinimumProperty,
+                                   OrientationProperty,
+                                   TickFrequencyProperty);
+        }
+
+        public TickBar() : base()
+        {
+        }
+
+        /// <summary>
+        /// Defines the <see cref="Fill"/> property.
+        /// </summary>
+        public static readonly StyledProperty<IBrush> FillProperty =
+            AvaloniaProperty.Register<TickBar, IBrush>(nameof(Fill));
+
+        /// <summary>
+        /// Brush used to fill the TickBar's Ticks.
+        /// </summary>
+        public IBrush Fill
+        {
+            get { return GetValue(FillProperty); }
+            set { SetValue(FillProperty, value); }
+        }
+
+        /// <summary>
+        /// Defines the <see cref="Minimum"/> property.
+        /// </summary>
+        public static readonly StyledProperty<double> MinimumProperty =
+            AvaloniaProperty.Register<TickBar, double>(nameof(Minimum), 0d);
+
+        /// <summary>
+        /// Logical position where the Minimum Tick will be drawn
+        /// </summary>
+        public double Minimum
+        {
+            get { return GetValue(MinimumProperty); }
+            set
+            {
+                SetValue(MinimumProperty, value);
+            }
+        }
+
+        /// <summary>
+        /// Defines the <see cref="Maximum"/> property.
+        /// </summary>
+        public static readonly StyledProperty<double> MaximumProperty =
+            AvaloniaProperty.Register<TickBar, double>(nameof(Maximum), 0d);
+
+        /// <summary>
+        /// Logical position where the Maximum Tick will be drawn
+        /// </summary>
+        public double Maximum
+        {
+            get { return GetValue(MaximumProperty); }
+            set { SetValue(MaximumProperty, value); }
+        }
+
+        /// <summary>
+        /// Defines the <see cref="TickFrequency"/> property.
+        /// </summary>
+        public static readonly StyledProperty<double> TickFrequencyProperty =
+            AvaloniaProperty.Register<TickBar, double>(nameof(TickFrequency), 0d);
+
+        /// <summary>
+        /// TickFrequency property defines how the tick will be drawn.
+        /// </summary>
+        public double TickFrequency
+        {
+            get { return GetValue(TickFrequencyProperty); }
+            set { SetValue(TickFrequencyProperty, value); }
+        }
+
+        /// <summary>
+        /// Defines the <see cref="Orientation"/> property.
+        /// </summary>
+        public static readonly StyledProperty<Orientation> OrientationProperty =
+            AvaloniaProperty.Register<TickBar, Orientation>(nameof(Orientation));
+
+        /// <summary>
+        /// TickBar parent's orientation.
+        /// </summary>
+        public Orientation Orientation
+        {
+            get { return GetValue(OrientationProperty); }
+            set { SetValue(OrientationProperty, value); }
+        }
+
+        /// <summary>
+        /// Defines the <see cref="Ticks"/> property.
+        /// </summary>
+        public static readonly StyledProperty<List<double>> TicksProperty =
+            AvaloniaProperty.Register<TickBar, List<double>>(nameof(Ticks));
+
+        /// <summary>
+        /// The Ticks property contains collection of value of type Double which
+        /// are the logical positions use to draw the ticks.
+        /// The property value is a <see cref="DoubleCollection" />.
+        /// </summary>
+        public List<double> Ticks
+        {
+            get { return GetValue(TicksProperty); }
+            set { SetValue(TicksProperty, value); }
+        }
+
+        /// <summary>
+        /// Defines the <see cref="IsDirectionReversed"/> property.
+        /// </summary>
+        public static readonly StyledProperty<bool> IsDirectionReversedProperty =
+            AvaloniaProperty.Register<TickBar, bool>(nameof(IsDirectionReversed), false);
+
+        /// <summary>
+        /// The IsDirectionReversed property defines the direction of value incrementation.
+        /// By default, if Tick's orientation is Horizontal, ticks will be drawn from left to right.
+        /// (And, bottom to top for Vertical orientation).
+        /// If IsDirectionReversed is 'true' the direction of the drawing will be in opposite direction.
+        /// </summary>
+        public bool IsDirectionReversed
+        {
+            get { return GetValue(IsDirectionReversedProperty); }
+            set { SetValue(IsDirectionReversedProperty, value); }
+        }
+
+        /// <summary>
+        /// Defines the <see cref="Placement"/> property.
+        /// </summary>
+        public static readonly StyledProperty<TickBarPlacement> PlacementProperty =
+            AvaloniaProperty.Register<TickBar, TickBarPlacement>(nameof(Placement), 0d);
+
+
+        /// <summary>
+        /// Placement property specified how the Tick will be placed.
+        /// This property affects the way ticks are drawn.
+        /// This property has type of <see cref="TickBarPlacement" />.
+        /// </summary>
+        public TickBarPlacement Placement
+        {
+            get { return GetValue(PlacementProperty); }
+            set { SetValue(PlacementProperty, value); }
+        }
+
+        /// <summary>
+        /// Defines the <see cref="ReservedSpace"/> property.
+        /// </summary>
+        public static readonly StyledProperty<Rect> ReservedSpaceProperty =
+            AvaloniaProperty.Register<TickBar, Rect>(nameof(ReservedSpace));
+
+        /// <summary>
+        /// TickBar will use ReservedSpaceProperty for left and right spacing (for horizontal orientation) or
+        /// tob and bottom spacing (for vertical orienation).
+        /// The space on both sides of TickBar is half of specified ReservedSpace.
+        /// This property has type of <see cref="Rect" />.
+        /// </summary>
+        public Rect ReservedSpace
+        {
+            get { return GetValue(ReservedSpaceProperty); }
+            set { SetValue(ReservedSpaceProperty, value); }
+        }
+
+        /// <summary>
+        /// Draw ticks.
+        /// Ticks can be draw in 8 diffrent ways depends on Placment property and IsDirectionReversed property.
+        ///
+        /// This function also draw selection-tick(s) if IsSelectionRangeEnabled is 'true' and
+        /// SelectionStart and SelectionEnd are valid.
+        ///
+        /// The primary ticks (for Mininum and Maximum value) height will be 100% of TickBar's render size (use Width or Height
+        /// depends on Placement property).
+        ///
+        /// The secondary ticks (all other ticks, including selection-tics) height will be 75% of TickBar's render size.
+        ///
+        /// Brush that use to fill ticks is specified by Shape.Fill property.
+        ///
+        /// Pen that use to draw ticks is specified by Shape.Pen property.
+        /// </summary>
+        public override void Render(DrawingContext dc)
+        {
+            var size = new Size(Bounds.Width, Bounds.Height);
+            var range = Maximum - Minimum;
+            var tickLen = 0.0d;   // Height for Primary Tick (for Mininum and Maximum value)
+            var tickLen2 = 0.0d;  // Height for Secondary Tick
+            var logicalToPhysical = 1.0;
+            var progression = 1.0d;
+            var startPoint = new Point();
+            var endPoint = new Point();
+            var rSpace = Orientation == Orientation.Horizontal ? ReservedSpace.Width : ReservedSpace.Height;
+
+            // Take Thumb size in to account
+            double halfReservedSpace = rSpace * 0.5;
+
+            switch (Placement)
+            {
+                case TickBarPlacement.Top:
+                    if (MathUtilities.GreaterThanOrClose(rSpace, size.Width))
+                    {
+                        return;
+                    }
+                    size = new Size(size.Width - rSpace, size.Height);
+                    tickLen = -size.Height;
+                    startPoint = new Point(halfReservedSpace, size.Height);
+                    endPoint = new Point(halfReservedSpace + size.Width, size.Height);
+                    logicalToPhysical = size.Width / range;
+                    progression = 1;
+                    break;
+
+                case TickBarPlacement.Bottom:
+                    if (MathUtilities.GreaterThanOrClose(rSpace, size.Width))
+                    {
+                        return;
+                    }
+                    size = new Size(size.Width - rSpace, size.Height);
+                    tickLen = size.Height;
+                    startPoint = new Point(halfReservedSpace, 0d);
+                    endPoint = new Point(halfReservedSpace + size.Width, 0d);
+                    logicalToPhysical = size.Width / range;
+                    progression = 1;
+                    break;
+
+                case TickBarPlacement.Left:
+                    if (MathUtilities.GreaterThanOrClose(rSpace, size.Height))
+                    {
+                        return;
+                    }
+                    size = new Size(size.Width, size.Height - rSpace);
+
+                    tickLen = -size.Width;
+                    startPoint = new Point(size.Width, size.Height + halfReservedSpace);
+                    endPoint = new Point(size.Width, halfReservedSpace);
+                    logicalToPhysical = size.Height / range * -1;
+                    progression = -1;
+                    break;
+
+                case TickBarPlacement.Right:
+                    if (MathUtilities.GreaterThanOrClose(rSpace, size.Height))
+                    {
+                        return;
+                    }
+                    size = new Size(size.Width, size.Height - rSpace);
+                    tickLen = size.Width;
+                    startPoint = new Point(0d, size.Height + halfReservedSpace);
+                    endPoint = new Point(0d, halfReservedSpace);
+                    logicalToPhysical = size.Height / range * -1;
+                    progression = -1;
+                    break;
+            };
+
+            tickLen2 = tickLen * 0.75;
+
+            // Invert direciton of the ticks
+            if (IsDirectionReversed)
+            {
+                progression *= -progression;
+                logicalToPhysical *= -1;
+
+                // swap startPoint & endPoint
+                var pt = startPoint;
+                startPoint = endPoint;
+                endPoint = pt;
+            }
+
+            var pen = new Pen(Fill, 1.0d);
+
+            // Is it Vertical?
+            if (Placement == TickBarPlacement.Left || Placement == TickBarPlacement.Right)
+            {
+                // Reduce tick interval if it is more than would be visible on the screen
+                double interval = TickFrequency;
+                if (interval > 0.0)
+                {
+                    double minInterval = (Maximum - Minimum) / size.Height;
+                    if (interval < minInterval)
+                    {
+                        interval = minInterval;
+                    }
+                }
+
+                // Draw Min & Max tick
+                dc.DrawLine(pen, startPoint, new Point(startPoint.X + tickLen, startPoint.Y));
+                dc.DrawLine(pen, new Point(startPoint.X, endPoint.Y),
+                                 new Point(startPoint.X + tickLen, endPoint.Y));
+
+                // This property is rarely set so let's try to avoid the GetValue
+                // caching of the mutable default value
+                var ticks = Ticks ?? null;
+
+                // Draw ticks using specified Ticks collection
+                if (ticks?.Count > 0)
+                {
+                    for (int i = 0; i < ticks.Count; i++)
+                    {
+                        if (MathUtilities.LessThanOrClose(ticks[i], Minimum) || MathUtilities.GreaterThanOrClose(ticks[i], Maximum))
+                        {
+                            continue;
+                        }
+
+                        double adjustedTick = ticks[i] - Minimum;
+
+                        double y = adjustedTick * logicalToPhysical + startPoint.Y;
+                        dc.DrawLine(pen,
+                            new Point(startPoint.X, y),
+                            new Point(startPoint.X + tickLen2, y));
+                    }
+                }
+                // Draw ticks using specified TickFrequency
+                else if (interval > 0.0)
+                {
+                    for (double i = interval; i < range; i += interval)
+                    {
+                        double y = i * logicalToPhysical + startPoint.Y;
+
+                        dc.DrawLine(pen,
+                            new Point(startPoint.X, y),
+                            new Point(startPoint.X + tickLen2, y));
+                    }
+                }
+            }
+            else  // Placement == Top || Placement == Bottom
+            {
+                // Reduce tick interval if it is more than would be visible on the screen
+                double interval = TickFrequency;
+                if (interval > 0.0)
+                {
+                    double minInterval = (Maximum - Minimum) / size.Width;
+                    if (interval < minInterval)
+                    {
+                        interval = minInterval;
+                    }
+                }
+
+                // Draw Min & Max tick
+                dc.DrawLine(pen, startPoint, new Point(startPoint.X, startPoint.Y + tickLen));
+                dc.DrawLine(pen, new Point(endPoint.X, startPoint.Y),
+                                 new Point(endPoint.X, startPoint.Y + tickLen));
+
+                // This property is rarely set so let's try to avoid the GetValue
+                // caching of the mutable default value
+                var ticks = Ticks ?? null;
+
+                // Draw ticks using specified Ticks collection
+                if (ticks?.Count > 0)
+                {
+                    for (int i = 0; i < ticks.Count; i++)
+                    {
+                        if (MathUtilities.LessThanOrClose(ticks[i], Minimum) || MathUtilities.GreaterThanOrClose(ticks[i], Maximum))
+                        {
+                            continue;
+                        }
+                        double adjustedTick = ticks[i] - Minimum;
+
+                        double x = adjustedTick * logicalToPhysical + startPoint.X;
+                        dc.DrawLine(pen,
+                            new Point(x, startPoint.Y),
+                            new Point(x, startPoint.Y + tickLen2));
+                    }
+                }
+                // Draw ticks using specified TickFrequency
+                else if (interval > 0.0)
+                {
+                    for (double i = interval; i < range; i += interval)
+                    {
+                        double x = i * logicalToPhysical + startPoint.X;
+                        dc.DrawLine(pen,
+                            new Point(x, startPoint.Y),
+                            new Point(x, startPoint.Y + tickLen2));
+                    }
+                }
+            }
+        }
+    }
+}

src/Avalonia.Controls/ToolTip.cs

@@ -204,13 +204,15 @@ namespace Avalonia.Controls
         private static void IsOpenChanged(AvaloniaPropertyChangedEventArgs e)
         {
             var control = (Control)e.Sender;
+            var newValue = (bool)e.NewValue;
+            ToolTip toolTip;
 
-            if ((bool)e.NewValue)
+            if (newValue)
             {
                 var tip = GetTip(control);
                 if (tip == null) return;
 
-                var toolTip = control.GetValue(ToolTipProperty);
+                toolTip = control.GetValue(ToolTipProperty);
                 if (toolTip == null || (tip != toolTip && tip != toolTip.Content))
                 {
                     toolTip?.Close();
@@ -223,9 +225,11 @@ namespace Avalonia.Controls
             }
             else
             {
-                var toolTip = control.GetValue(ToolTipProperty);
+                toolTip = control.GetValue(ToolTipProperty);
                 toolTip?.Close();
             }
+
+            toolTip?.UpdatePseudoClasses(newValue);
         }
 
         private void Open(Control control)
@@ -238,6 +242,9 @@ namespace Avalonia.Controls
             
             _popup.ConfigurePosition(control, GetPlacement(control), 
                 new Point(GetHorizontalOffset(control), GetVerticalOffset(control)));
+
+            WindowManagerAddShadowHintChanged(_popup, false);
+
             _popup.Show();
         }
 
@@ -250,5 +257,18 @@ namespace Avalonia.Controls
                 _popup = null;
             }
         }
+
+        private void WindowManagerAddShadowHintChanged(IPopupHost host, bool hint)
+        {
+            if (host is PopupRoot pr)
+            {
+                pr.PlatformImpl.SetWindowManagerAddShadowHint(hint);
+            }
+        }
+
+        private void UpdatePseudoClasses(bool newValue)
+        {
+            PseudoClasses.Set(":open", newValue);
+        }
     }
 }

src/Avalonia.Controls/TreeView.cs

@@ -119,9 +119,10 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets or sets the selected item.
         /// </summary>
-        /// <summary>
+        /// <remarks>
-        /// Gets or sets the selected item.
+        /// Note that setting this property only currently works if the item is expanded to be visible.
-        /// </summary>
+        /// To select non-expanded nodes use `Selection.SelectedIndex`.
+        /// </remarks>
         public object SelectedItem
         {
             get => Selection.SelectedItem;
@@ -346,7 +347,7 @@ namespace Avalonia.Controls
 
                 if (container != null)
                 {
-                    container.BringIntoView();
+                    DispatcherTimer.RunOnce(container.BringIntoView, TimeSpan.Zero);
                 }
             }
         }
@@ -395,10 +396,17 @@ namespace Avalonia.Controls
 
         private void OnSelectionModelChildrenRequested(object sender, SelectionModelChildrenRequestedEventArgs e)
         {
-            var container = ItemContainerGenerator.Index.ContainerFromItem(e.Source) as ItemsControl;
+            var container = ItemContainerGenerator.Index.ContainerFromItem(e.Source) as TreeViewItem;
 
             if (container is object)
             {
+                if (e.SourceIndex.IsAncestorOf(e.FinalIndex))
+                {
+                    container.IsExpanded = true;
+                    container.ApplyTemplate();
+                    container.Presenter?.ApplyTemplate();
+                }
+
                 e.Children = Observable.CombineLatest(
                     container.GetObservable(TreeViewItem.IsExpandedProperty),
                     container.GetObservable(ItemsProperty),

src/Avalonia.Controls/Utils/SelectionTreeHelper.cs

@@ -28,7 +28,7 @@ namespace Avalonia.Controls.Utils
 
                 if (depth < path.GetSize() - 1)
                 {
-                    node = node.GetAt(childIndex, realizeChildren)!;
+                    node = node.GetAt(childIndex, realizeChildren, path)!;
                 }
             }
         }
@@ -50,7 +50,7 @@ namespace Avalonia.Controls.Utils
                 int count = realizeChildren ? nextNode.Node.DataCount : nextNode.Node.ChildrenNodeCount;
                 for (int i = count - 1; i >= 0; i--)
                 {
-                    var child = nextNode.Node.GetAt(i, realizeChildren);
+                    var child = nextNode.Node.GetAt(i, realizeChildren, nextNode.Path);
                     var childPath = nextNode.Path.CloneWithChildIndex(i);
                     if (child != null)
                     {
@@ -90,7 +90,7 @@ namespace Avalonia.Controls.Utils
 
                     for (int i = endIndex; i >= startIndex; i--)
                     {
-                        var child = node.GetAt(i, realizeChild: true);
+                        var child = node.GetAt(i, true, end);
                         if (child != null)
                         {
                             var childPath = currentPath.CloneWithChildIndex(i);
@@ -112,7 +112,7 @@ namespace Avalonia.Controls.Utils
                 int endIndex = depth < end.GetSize() && isEndPath ? end.GetAt(depth) : info.Node.DataCount - 1;
                 for (int i = endIndex; i >= startIndex; i--)
                 {
-                    var child = info.Node.GetAt(i, realizeChild: true);
+                    var child = info.Node.GetAt(i, true, end);
                     if (child != null)
                     {
                         var childPath = info.Path.CloneWithChildIndex(i);

src/Avalonia.DesignerSupport/Remote/Stubs.cs

@@ -160,6 +160,10 @@ namespace Avalonia.DesignerSupport.Remote
         public Task SetTextAsync(string text) => Task.CompletedTask;
 
         public Task ClearAsync() => Task.CompletedTask;
+        public Task SetDataObjectAsync(IDataObject data) => Task.CompletedTask;
+        public Task<string[]> GetFormatsAsync() => Task.FromResult(new string[0]);
+
+        public Task<object> GetDataAsync(string format) => Task.FromResult((object)null);
     }
 
     class CursorFactoryStub : IStandardCursorFactory

src/Avalonia.Diagnostics/Diagnostics/ViewModels/MainViewModel.cs

@@ -2,6 +2,7 @@
 using Avalonia.Controls;
 using Avalonia.Diagnostics.Models;
 using Avalonia.Input;
+using Avalonia.Threading;
 
 namespace Avalonia.Diagnostics.ViewModels
 {
@@ -49,7 +50,21 @@ namespace Avalonia.Diagnostics.ViewModels
                     value is TreePageViewModel newTree &&
                     oldTree?.SelectedNode?.Visual is IControl control)
                 {
-                    newTree.SelectControl(control);
+                    // HACK: We want to select the currently selected control in the new tree, but
+                    // to select nested nodes in TreeView, currently the TreeView has to be able to
+                    // expand the parent nodes. Because at this point the TreeView isn't visible,
+                    // this will fail unless we schedule the selection to run after layout.
+                    DispatcherTimer.RunOnce(
+                        () =>
+                        {
+                            try
+                            {
+                                newTree.SelectControl(control);
+                            }
+                            catch { }
+                        },
+                        TimeSpan.FromMilliseconds(0),
+                        DispatcherPriority.ApplicationIdle);
                 }
 
                 RaiseAndSetIfChanged(ref _content, value);

src/Avalonia.Diagnostics/Diagnostics/ViewModels/TreeNode.cs

@@ -1,11 +1,11 @@
 using System;
+using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Reactive;
 using System.Reactive.Linq;
 using Avalonia.Collections;
 using Avalonia.Controls;
 using Avalonia.LogicalTree;
-using Avalonia.Styling;
 using Avalonia.VisualTree;
 
 namespace Avalonia.Diagnostics.ViewModels
@@ -82,5 +82,41 @@ namespace Avalonia.Diagnostics.ViewModels
             get;
             private set;
         }
+
+        public IndexPath Index
+        {
+            get
+            {
+                var indices = new List<int>();
+                var child = this;
+                var parent = Parent;
+                
+                while (parent is object)
+                {
+                    indices.Add(IndexOf(parent.Children, child));
+                    child = child.Parent;
+                    parent = parent.Parent;
+                }
+
+                indices.Add(0);
+                indices.Reverse();
+                return new IndexPath(indices);
+            }
+        }
+
+        private static int IndexOf(IReadOnlyList<TreeNode> collection, TreeNode item)
+        {
+            var count = collection.Count;
+
+            for (var i = 0; i < count; ++i)
+            {
+                if (collection[i] == item)
+                {
+                    return i;
+                }
+            }
+
+            throw new AvaloniaInternalException("TreeNode was not present in parent Children collection.");
+        }
     }
 }

src/Avalonia.Diagnostics/Diagnostics/ViewModels/TreePageViewModel.cs

@@ -6,28 +6,40 @@ namespace Avalonia.Diagnostics.ViewModels
 {
     internal class TreePageViewModel : ViewModelBase, IDisposable
     {
-        private TreeNode _selected;
+        private TreeNode _selectedNode;
         private ControlDetailsViewModel _details;
         private string _propertyFilter;
 
         public TreePageViewModel(TreeNode[] nodes)
         {
             Nodes = nodes;
-        }
+            Selection = new SelectionModel
+            { 
+                SingleSelect = true,
+                Source = Nodes 
+            };
+
+            Selection.SelectionChanged += (s, e) =>
+            {
+                SelectedNode = (TreeNode)Selection.SelectedItem;
+            };
+       }
 
         public TreeNode[] Nodes { get; protected set; }
 
+        public SelectionModel Selection { get; }
+
         public TreeNode SelectedNode
         {
-            get => _selected;
+            get => _selectedNode;
-            set
+            private set
             {
                 if (Details != null)
                 {
                     _propertyFilter = Details.PropertyFilter;
                 }
 
-                if (RaiseAndSetIfChanged(ref _selected, value))
+                if (RaiseAndSetIfChanged(ref _selectedNode, value))
                 {
                     Details = value != null ?
                         new ControlDetailsViewModel(value.Visual, _propertyFilter) :
@@ -83,8 +95,8 @@ namespace Avalonia.Diagnostics.ViewModels
 
             if (node != null)
             {
-                SelectedNode = node;
                 ExpandNode(node.Parent);
+                Selection.SelectedIndex = node.Index;
             }
         }
 

src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml

@@ -6,7 +6,7 @@
     <TreeView Name="tree"
               BorderThickness="0"
               Items="{Binding Nodes}"
-              SelectedItem="{Binding SelectedNode, Mode=TwoWay}">
+              Selection="{Binding Selection}">
       <TreeView.DataTemplates>
         <TreeDataTemplate DataType="vm:TreeNode"
                           ItemsSource="{Binding Children}">

src/Avalonia.Input/Platform/IClipboard.cs

@@ -9,5 +9,11 @@ namespace Avalonia.Input.Platform
         Task SetTextAsync(string text);
 
         Task ClearAsync();
+
+        Task SetDataObjectAsync(IDataObject data);
+        
+        Task<string[]> GetFormatsAsync();
+        
+        Task<object> GetDataAsync(string format);
     }
 }

src/Avalonia.Native/AvnString.cs

@@ -5,6 +5,7 @@ namespace Avalonia.Native.Interop
     unsafe partial class IAvnString
     {
         private string _managed;
+        private byte[] _bytes;
 
         public string String
         {
@@ -22,6 +23,20 @@ namespace Avalonia.Native.Interop
             }
         }
 
+        public byte[] Bytes
+        {
+            get
+            {
+                if (_bytes == null)
+                {
+                    _bytes = new byte[Length()];
+                    Marshal.Copy(Pointer(), _bytes, 0, _bytes.Length);
+                }
+
+                return _bytes;
+            }
+        }
+
         public override string ToString() => String;
     }
     

src/Avalonia.Native/ClipboardImpl.cs

@@ -82,6 +82,38 @@ namespace Avalonia.Native
             using (var strings = _native.GetStrings(NSFilenamesPboardType))
                 return strings.ToStringArray();
         }
+
+        public unsafe Task SetDataObjectAsync(IDataObject data)
+        {
+            _native.Clear();
+            foreach (var fmt in data.GetDataFormats())
+            {
+                var o = data.Get(fmt);
+                if(o is string s)
+                    using (var b = new Utf8Buffer(s))
+                        _native.SetText(fmt, b.DangerousGetHandle());
+                else if(o is byte[] bytes)
+                    fixed (byte* pbytes = bytes)
+                        _native.SetBytes(fmt, new IntPtr(pbytes), bytes.Length);
+            }
+            return Task.CompletedTask;
+        }
+
+        public Task<string[]> GetFormatsAsync()
+        {
+            using (var n = _native.ObtainFormats())
+                return Task.FromResult(n.ToStringArray());
+        }
+
+        public async Task<object> GetDataAsync(string format)
+        {
+            if (format == DataFormats.Text)
+                return await GetTextAsync();
+            if (format == DataFormats.FileNames)
+                return GetFileNames();
+            using (var n = _native.GetBytes(format))
+                return n.Bytes;
+        }
     }
     
     class ClipboardDataObject : IDataObject, IDisposable

src/Avalonia.Themes.Fluent/Accents/FluentBaseDark.xaml

@@ -1,4 +1,6 @@
-<Style xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:sys="clr-namespace:System;assembly=netstandard">
+<Style xmlns="https://github.com/avaloniaui" 
+  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
+  xmlns:sys="clr-namespace:System;assembly=netstandard">
   <Style.Resources>
     <Color x:Key="SystemAccentColor">#FF0078D7</Color>
     <Color x:Key="SystemAltHighColor">#FF000000</Color>
@@ -31,6 +33,10 @@
     <Color x:Key="SystemRevealListLowColor">#FF1D1D1D</Color>
     <Color x:Key="SystemRevealListMediumColor">#FF333333</Color>
     <!--<AcrylicBrush x:Key="SystemControlAcrylicWindowBrush" BackgroundSource="HostBackdrop" TintColor="{ThemeResource SystemChromeAltHighColor}" TintOpacity="0.8" FallbackColor="{ThemeResource SystemChromeMediumColor}" />-->
+    <!--<RevealBackgroundBrush x:Key="SystemControlTransparentRevealBackgroundBrush" TargetTheme="Dark" Color="Transparent" FallbackColor="Transparent" />-->
+    <SolidColorBrush x:Key="SystemControlTransparentRevealBackgroundBrush" Color="Transparent" />
+    <!--<RevealBorderBrush x:Key="SystemControlTransparentRevealBorderBrush" TargetTheme="Dark" Color="Transparent" FallbackColor="Transparent" />-->
+    <SolidColorBrush x:Key="SystemControlTransparentRevealBorderBrush" Color="Transparent" />
     
     <!-- Override system shape defaults -->
     <CornerRadius x:Key="ControlCornerRadius">2,2,2,2</CornerRadius>
@@ -312,5 +318,38 @@
     <StaticResource x:Key="RadioButtonCheckGlyphStrokePointerOver" ResourceKey="SystemControlTransparentBrush" />
     <StaticResource x:Key="RadioButtonCheckGlyphStrokePressed" ResourceKey="SystemControlTransparentBrush" />
     <StaticResource x:Key="RadioButtonCheckGlyphStrokeDisabled" ResourceKey="SystemControlTransparentBrush" />
+    
+    <!-- BaseResources for Slider.xaml -->
+    <StaticResource x:Key="SliderContainerBackground" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundPointerOver" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundPressed" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundDisabled" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderThumbBackground" ResourceKey="SystemControlForegroundAccentBrush" />
+    <StaticResource x:Key="SliderThumbBackgroundPointerOver" ResourceKey="SystemControlHighlightChromeAltLowBrush" />
+    <StaticResource x:Key="SliderThumbBackgroundPressed" ResourceKey="SystemControlHighlightChromeHighBrush" />
+    <StaticResource x:Key="SliderThumbBackgroundDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderTrackFill" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTrackFillPointerOver" ResourceKey="SystemControlForegroundBaseMediumBrush" />
+    <StaticResource x:Key="SliderTrackFillPressed" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTrackFillDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderTrackValueFill" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillPointerOver" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillPressed" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderHeaderForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="SliderHeaderForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTickBarFill" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTickBarFillDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderInlineTickBarFill" ResourceKey="SystemControlBackgroundAltHighBrush" />
+
+    <!-- Resources for ToolTip.xaml -->
+    <x:Double x:Key="ToolTipContentThemeFontSize">12</x:Double>
+    <Thickness x:Key="ToolTipBorderThemeThickness">1</Thickness>
+    <StaticResource x:Key="ToolTipForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="ToolTipBackground" ResourceKey="SystemControlBackgroundChromeMediumLowBrush" />
+    <StaticResource x:Key="ToolTipBorderBrush" ResourceKey="SystemControlForegroundChromeHighBrush" />
+    <SolidColorBrush x:Key="ToolTipBackgroundThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="ToolTipBorderThemeBrush" Color="#FF808080" />
+    <SolidColorBrush x:Key="ToolTipForegroundThemeBrush" Color="#FF666666" />
   </Style.Resources>
 </Style>

src/Avalonia.Themes.Fluent/Accents/FluentBaseLight.xaml

@@ -1,4 +1,6 @@
-<Style xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:sys="clr-namespace:System;assembly=netstandard">
+<Style xmlns="https://github.com/avaloniaui" 
+  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
+  xmlns:sys="clr-namespace:System;assembly=netstandard">
   <Style.Resources>
     <Color x:Key="SystemAccentColor">#FF0078D7</Color>
     <Color x:Key="SystemAltHighColor">#FFFFFFFF</Color>
@@ -31,6 +33,10 @@
     <Color x:Key="SystemRevealListLowColor">#FFE6E6E6</Color>
     <Color x:Key="SystemRevealListMediumColor">#FFCCCCCC</Color>
     <!--<AcrylicBrush x:Key="SystemControlAcrylicWindowBrush" BackgroundSource="HostBackdrop" TintColor="{ThemeResource SystemChromeAltHighColor}" TintOpacity="0.8" FallbackColor="{ThemeResource SystemChromeMediumColor}" />-->
+    <!--<RevealBackgroundBrush x:Key="SystemControlTransparentRevealBackgroundBrush" TargetTheme="Dark" Color="Transparent" FallbackColor="Transparent" />-->
+    <SolidColorBrush x:Key="SystemControlTransparentRevealBackgroundBrush" Color="Transparent" />
+    <!--<RevealBorderBrush x:Key="SystemControlTransparentRevealBorderBrush" TargetTheme="Dark" Color="Transparent" FallbackColor="Transparent" />-->
+    <SolidColorBrush x:Key="SystemControlTransparentRevealBorderBrush" Color="Transparent" />
     
     <!-- Override system shape defaults -->
     <CornerRadius x:Key="ControlCornerRadius">2,2,2,2</CornerRadius>
@@ -313,5 +319,38 @@
     <StaticResource x:Key="RadioButtonCheckGlyphStrokePointerOver" ResourceKey="SystemControlTransparentBrush" />
     <StaticResource x:Key="RadioButtonCheckGlyphStrokePressed" ResourceKey="SystemControlTransparentBrush" />
     <StaticResource x:Key="RadioButtonCheckGlyphStrokeDisabled" ResourceKey="SystemControlTransparentBrush" />
+    
+    <!-- BaseResources for Slider.xaml -->
+    <StaticResource x:Key="SliderContainerBackground" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundPointerOver" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundPressed" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundDisabled" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderThumbBackground" ResourceKey="SystemControlForegroundAccentBrush" />
+    <StaticResource x:Key="SliderThumbBackgroundPointerOver" ResourceKey="SystemControlHighlightChromeAltLowBrush" />
+    <StaticResource x:Key="SliderThumbBackgroundPressed" ResourceKey="SystemControlHighlightChromeHighBrush" />
+    <StaticResource x:Key="SliderThumbBackgroundDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderTrackFill" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTrackFillPointerOver" ResourceKey="SystemControlForegroundBaseMediumBrush" />
+    <StaticResource x:Key="SliderTrackFillPressed" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTrackFillDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderTrackValueFill" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillPointerOver" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillPressed" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderHeaderForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="SliderHeaderForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTickBarFill" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTickBarFillDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderInlineTickBarFill" ResourceKey="SystemControlBackgroundAltHighBrush" />
+
+    <!-- Resources for ToolTip.xaml -->
+    <x:Double x:Key="ToolTipContentThemeFontSize">12</x:Double>
+    <Thickness x:Key="ToolTipBorderThemeThickness">1</Thickness>
+    <StaticResource x:Key="ToolTipForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="ToolTipBackground" ResourceKey="SystemControlBackgroundChromeMediumLowBrush" />
+    <StaticResource x:Key="ToolTipBorderBrush" ResourceKey="SystemControlForegroundChromeHighBrush" />
+    <SolidColorBrush x:Key="ToolTipBackgroundThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="ToolTipBorderThemeBrush" Color="#FF808080" />
+    <SolidColorBrush x:Key="ToolTipForegroundThemeBrush" Color="#FF666666" />
   </Style.Resources>
 </Style>

src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesDark.xaml

@@ -1,6 +1,6 @@
-<Style xmlns="https://github.com/avaloniaui"
+<Style xmlns="https://github.com/avaloniaui" 
-       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
-       xmlns:sys="clr-namespace:System;assembly=netstandard">
+  xmlns:sys="clr-namespace:System;assembly=netstandard">
   <Style.Resources>
     <!-- Resources for Button.xaml -->
     <StaticResource x:Key="AccentButtonBackground" ResourceKey="SystemControlBackgroundAccentBrush" />
@@ -290,6 +290,33 @@
     <SolidColorBrush x:Key="CheckBoxPressedBorderThemeBrush" Color="#FFFFFFFF" />
     <SolidColorBrush x:Key="CheckBoxPressedForegroundThemeBrush" Color="#FF000000" />
 
+    <!-- Resources for Calendar.xaml, CalendarButton.xaml, CalendarDayButton.xaml, CalendarItem.xaml -->
+    <StaticResource x:Key="CalendarViewFocusBorderBrush" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewSelectedHoverBorderBrush" ResourceKey="SystemControlHighlightListAccentMediumBrush" />
+    <StaticResource x:Key="CalendarViewSelectedPressedBorderBrush" ResourceKey="SystemControlHighlightListAccentHighBrush" />
+    <StaticResource x:Key="CalendarViewSelectedBorderBrush" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="CalendarViewHoverBorderBrush" ResourceKey="SystemControlHighlightBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewPressedBorderBrush" ResourceKey="SystemControlHighlightBaseMediumBrush" />
+    <StaticResource x:Key="CalendarViewTodayForeground" ResourceKey="SystemControlHighlightAltChromeWhiteBrush" />
+    <StaticResource x:Key="CalendarViewBlackoutForeground" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewSelectedForeground" ResourceKey="SystemControlHighlightBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewPressedForeground" ResourceKey="SystemControlHighlightBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewOutOfScopeForeground" ResourceKey="SystemControlHyperlinkBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewOutOfScopeBackground" ResourceKey="SystemControlDisabledChromeMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemBackground" ResourceKey="SystemControlBackgroundAltHighBrush" />
+    <StaticResource x:Key="CalendarViewForeground" ResourceKey="SystemControlHyperlinkBaseMediumHighBrush" />
+    <StaticResource x:Key="CalendarViewBackground" ResourceKey="SystemControlBackgroundAltHighBrush" />
+    <StaticResource x:Key="CalendarViewBorderBrush" ResourceKey="SystemControlForegroundChromeMediumBrush" />
+    <StaticResource x:Key="CalendarViewWeekDayForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBackground" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundPointerOver" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundPressed" ResourceKey="SystemControlForegroundBaseMediumBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemRevealBackground" ResourceKey="SystemControlTransparentRevealBackgroundBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemRevealBorderBrush" ResourceKey="SystemControlTransparentRevealBorderBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBorderBrushPointerOver" ResourceKey="SystemControlHighlightTransparentBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBorderBrush" ResourceKey="SystemControlTransparentBrush" />
     <!-- Resources for RadioButton.xaml -->
     <x:Double x:Key="RadioButtonBorderThemeThickness">1</x:Double>
     <StaticResource x:Key="RadioButtonForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
@@ -343,5 +370,66 @@
     <SolidColorBrush x:Key="RadioButtonPressedBorderThemeBrush" Color="#FFFFFFFF" />
     <SolidColorBrush x:Key="RadioButtonPressedForegroundThemeBrush" Color="#FF000000" />
     <SolidColorBrush x:Key="RadioButtonContentPointerOverForegroundThemeBrush" Color="{DynamicResource SystemColorHighlightTextColor}" />
+    
+    <!-- Resources for Slider.xaml -->
+    <x:Double x:Key="SliderOutsideTickBarThemeHeight">4</x:Double>
+    <x:Double x:Key="SliderTrackThemeHeight">2</x:Double>
+    <Thickness x:Key="SliderBorderThemeThickness">0</Thickness>
+    <Thickness x:Key="SliderHeaderThemeMargin">0,0,0,4</Thickness>
+    <FontWeight x:Key="SliderHeaderThemeFontWeight">Normal</FontWeight>
+    <StaticResource x:Key="SliderContainerBackground" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundPointerOver" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundPressed" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundDisabled" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderThumbBackground" ResourceKey="SystemControlForegroundAccentBrush" />
+    <StaticResource x:Key="SliderThumbBackgroundPointerOver" ResourceKey="SystemAccentColorLight1" />
+    <StaticResource x:Key="SliderThumbBackgroundPressed" ResourceKey="SystemAccentColorDark1" />
+    <StaticResource x:Key="SliderThumbBackgroundDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderTrackFill" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTrackFillPointerOver" ResourceKey="SystemControlForegroundBaseMediumBrush" />
+    <StaticResource x:Key="SliderTrackFillPressed" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTrackFillDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderTrackValueFill" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillPointerOver" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillPressed" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderHeaderForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="SliderHeaderForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTickBarFill" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTickBarFillDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderInlineTickBarFill" ResourceKey="SystemControlBackgroundAltHighBrush" />
+    <SolidColorBrush x:Key="SliderBorderThemeBrush" Color="Transparent" />
+    <SolidColorBrush x:Key="SliderDisabledBorderThemeBrush" Color="Transparent" />
+    <SolidColorBrush x:Key="SliderThumbBackgroundThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="SliderThumbBorderThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="SliderThumbDisabledBackgroundThemeBrush" Color="#FF7E7E7E" />
+    <SolidColorBrush x:Key="SliderThumbPointerOverBackgroundThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="SliderThumbPointerOverBorderThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="SliderThumbPressedBackgroundThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="SliderThumbPressedBorderThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="SliderTickMarkInlineBackgroundThemeBrush" Color="Black" />
+    <SolidColorBrush x:Key="SliderTickMarkInlineDisabledForegroundThemeBrush" Color="Black" />
+    <SolidColorBrush x:Key="SliderTickmarkOutsideBackgroundThemeBrush" Color="#80FFFFFF" />
+    <SolidColorBrush x:Key="SliderTickMarkOutsideDisabledForegroundThemeBrush" Color="#80FFFFFF" />
+    <SolidColorBrush x:Key="SliderTrackBackgroundThemeBrush" Color="#29FFFFFF" />
+    <SolidColorBrush x:Key="SliderTrackDecreaseBackgroundThemeBrush" Color="#FF5B2EC5" />
+    <SolidColorBrush x:Key="SliderTrackDecreaseDisabledBackgroundThemeBrush" Color="#1FFFFFFF" />
+    <SolidColorBrush x:Key="SliderTrackDecreasePointerOverBackgroundThemeBrush" Color="#FF724BCD" />
+    <SolidColorBrush x:Key="SliderTrackDecreasePressedBackgroundThemeBrush" Color="#FF8152EF" />
+    <SolidColorBrush x:Key="SliderTrackDisabledBackgroundThemeBrush" Color="#29FFFFFF" />
+    <SolidColorBrush x:Key="SliderTrackPointerOverBackgroundThemeBrush" Color="#46FFFFFF" />
+    <SolidColorBrush x:Key="SliderTrackPressedBackgroundThemeBrush" Color="#59FFFFFF" />
+    <SolidColorBrush x:Key="SliderHeaderForegroundThemeBrush" Color="#FFFFFFFF" />
+
+    <!-- Resources for ToolTip.xaml -->
+    <x:Double x:Key="ToolTipContentThemeFontSize">12</x:Double>
+    <Thickness x:Key="ToolTipBorderThemeThickness">1</Thickness>
+    <StaticResource x:Key="ToolTipForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="ToolTipBackground" ResourceKey="SystemControlBackgroundChromeMediumLowBrush" />
+    <StaticResource x:Key="ToolTipBorderBrush" ResourceKey="SystemControlTransientBorderBrush" />
+    <SolidColorBrush x:Key="ToolTipBackgroundThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="ToolTipBorderThemeBrush" Color="#FF808080" />
+    <SolidColorBrush x:Key="ToolTipForegroundThemeBrush" Color="#FF666666" />
+    <Thickness x:Key="ToolTipBorderThemePadding">8,5,8,7</Thickness>
   </Style.Resources>
 </Style>

src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesLight.xaml

@@ -1,6 +1,6 @@
-<Style xmlns="https://github.com/avaloniaui"
+<Style xmlns="https://github.com/avaloniaui" 
-       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
-       xmlns:sys="clr-namespace:System;assembly=netstandard">
+  xmlns:sys="clr-namespace:System;assembly=netstandard">
   <Style.Resources>
     <!-- Resources for Button.xaml -->
     <StaticResource x:Key="AccentButtonBackground" ResourceKey="SystemControlBackgroundAccentBrush" />
@@ -290,6 +290,33 @@
     <SolidColorBrush x:Key="CheckBoxPressedBorderThemeBrush" Color="#FF000000" />
     <SolidColorBrush x:Key="CheckBoxPressedForegroundThemeBrush" Color="#FFFFFFFF" />
 
+    <!-- Resources for Calendar.xaml, CalendarButton.xaml, CalendarDayButton.xaml, CalendarItem.xaml -->
+    <StaticResource x:Key="CalendarViewFocusBorderBrush" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewSelectedHoverBorderBrush" ResourceKey="SystemControlHighlightListAccentMediumBrush" />
+    <StaticResource x:Key="CalendarViewSelectedPressedBorderBrush" ResourceKey="SystemControlHighlightListAccentHighBrush" />
+    <StaticResource x:Key="CalendarViewSelectedBorderBrush" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="CalendarViewHoverBorderBrush" ResourceKey="SystemControlHighlightBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewPressedBorderBrush" ResourceKey="SystemControlHighlightBaseMediumBrush" />
+    <StaticResource x:Key="CalendarViewTodayForeground" ResourceKey="SystemControlHighlightAltChromeWhiteBrush" />
+    <StaticResource x:Key="CalendarViewBlackoutForeground" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewSelectedForeground" ResourceKey="SystemControlHighlightBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewPressedForeground" ResourceKey="SystemControlHighlightBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewOutOfScopeForeground" ResourceKey="SystemControlHyperlinkBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewOutOfScopeBackground" ResourceKey="SystemControlDisabledChromeMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemBackground" ResourceKey="SystemControlBackgroundAltHighBrush" />
+    <StaticResource x:Key="CalendarViewForeground" ResourceKey="SystemControlHyperlinkBaseMediumHighBrush" />
+    <StaticResource x:Key="CalendarViewBackground" ResourceKey="SystemControlBackgroundAltHighBrush" />
+    <StaticResource x:Key="CalendarViewBorderBrush" ResourceKey="SystemControlForegroundChromeMediumBrush" />
+    <StaticResource x:Key="CalendarViewWeekDayForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBackground" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundPointerOver" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundPressed" ResourceKey="SystemControlForegroundBaseMediumBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemRevealBackground" ResourceKey="SystemControlTransparentRevealBackgroundBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemRevealBorderBrush" ResourceKey="SystemControlTransparentRevealBorderBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBorderBrushPointerOver" ResourceKey="SystemControlHighlightTransparentBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBorderBrush" ResourceKey="SystemControlTransparentBrush" />
     <!-- Resources for RadioButton.xaml -->
     <x:Double x:Key="RadioButtonBorderThemeThickness">1</x:Double>
     <StaticResource x:Key="RadioButtonForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
@@ -343,5 +370,66 @@
     <SolidColorBrush x:Key="RadioButtonPressedBorderThemeBrush" Color="#FF000000" />
     <SolidColorBrush x:Key="RadioButtonPressedForegroundThemeBrush" Color="#FFFFFFFF" />
     <SolidColorBrush x:Key="RadioButtonContentPointerOverForegroundThemeBrush" Color="{DynamicResource SystemColorHighlightTextColor}" />
+    
+    <!-- Resources for Slider.xaml -->
+    <x:Double x:Key="SliderOutsideTickBarThemeHeight">4</x:Double>
+    <x:Double x:Key="SliderTrackThemeHeight">2</x:Double>
+    <Thickness x:Key="SliderBorderThemeThickness">0</Thickness>
+    <Thickness x:Key="SliderHeaderThemeMargin">0,0,0,4</Thickness>
+    <FontWeight x:Key="SliderHeaderThemeFontWeight">Normal</FontWeight>
+    <StaticResource x:Key="SliderContainerBackground" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundPointerOver" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundPressed" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderContainerBackgroundDisabled" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="SliderThumbBackground" ResourceKey="SystemControlForegroundAccentBrush" />
+    <StaticResource x:Key="SliderThumbBackgroundPointerOver" ResourceKey="SystemAccentColorLight1" />
+    <StaticResource x:Key="SliderThumbBackgroundPressed" ResourceKey="SystemAccentColorDark1" />
+    <StaticResource x:Key="SliderThumbBackgroundDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderTrackFill" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTrackFillPointerOver" ResourceKey="SystemControlForegroundBaseMediumBrush" />
+    <StaticResource x:Key="SliderTrackFillPressed" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTrackFillDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderTrackValueFill" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillPointerOver" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillPressed" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="SliderTrackValueFillDisabled" ResourceKey="SystemControlDisabledChromeDisabledHighBrush" />
+    <StaticResource x:Key="SliderHeaderForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="SliderHeaderForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTickBarFill" ResourceKey="SystemControlForegroundBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderTickBarFillDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="SliderInlineTickBarFill" ResourceKey="SystemControlBackgroundAltHighBrush" />
+    <SolidColorBrush x:Key="SliderBorderThemeBrush" Color="Transparent" />
+    <SolidColorBrush x:Key="SliderDisabledBorderThemeBrush" Color="Transparent" />
+    <SolidColorBrush x:Key="SliderThumbBackgroundThemeBrush" Color="#FF000000" />
+    <SolidColorBrush x:Key="SliderThumbBorderThemeBrush" Color="#FF000000" />
+    <SolidColorBrush x:Key="SliderThumbDisabledBackgroundThemeBrush" Color="#FF929292" />
+    <SolidColorBrush x:Key="SliderThumbPointerOverBackgroundThemeBrush" Color="#FF000000" />
+    <SolidColorBrush x:Key="SliderThumbPointerOverBorderThemeBrush" Color="#FF000000" />
+    <SolidColorBrush x:Key="SliderThumbPressedBackgroundThemeBrush" Color="#FF000000" />
+    <SolidColorBrush x:Key="SliderThumbPressedBorderThemeBrush" Color="#FF000000" />
+    <SolidColorBrush x:Key="SliderTickMarkInlineBackgroundThemeBrush" Color="White" />
+    <SolidColorBrush x:Key="SliderTickMarkInlineDisabledForegroundThemeBrush" Color="White" />
+    <SolidColorBrush x:Key="SliderTickmarkOutsideBackgroundThemeBrush" Color="#80000000" />
+    <SolidColorBrush x:Key="SliderTickMarkOutsideDisabledForegroundThemeBrush" Color="#80000000" />
+    <SolidColorBrush x:Key="SliderTrackBackgroundThemeBrush" Color="#1A000000" />
+    <SolidColorBrush x:Key="SliderTrackDecreaseBackgroundThemeBrush" Color="#FF4617B4" />
+    <SolidColorBrush x:Key="SliderTrackDecreaseDisabledBackgroundThemeBrush" Color="#1C000000" />
+    <SolidColorBrush x:Key="SliderTrackDecreasePointerOverBackgroundThemeBrush" Color="#FF5F37BE" />
+    <SolidColorBrush x:Key="SliderTrackDecreasePressedBackgroundThemeBrush" Color="#FF7241E4" />
+    <SolidColorBrush x:Key="SliderTrackDisabledBackgroundThemeBrush" Color="#1A000000" />
+    <SolidColorBrush x:Key="SliderTrackPointerOverBackgroundThemeBrush" Color="#26000000" />
+    <SolidColorBrush x:Key="SliderTrackPressedBackgroundThemeBrush" Color="#33000000" />
+    <SolidColorBrush x:Key="SliderHeaderForegroundThemeBrush" Color="#FF000000" />
+
+    <!-- Resources for ToolTip.xaml -->
+    <x:Double x:Key="ToolTipContentThemeFontSize">12</x:Double>
+    <Thickness x:Key="ToolTipBorderThemeThickness">1</Thickness>
+    <StaticResource x:Key="ToolTipForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="ToolTipBackground" ResourceKey="SystemControlBackgroundChromeMediumLowBrush" />
+    <StaticResource x:Key="ToolTipBorderBrush" ResourceKey="SystemControlTransientBorderBrush" />
+    <SolidColorBrush x:Key="ToolTipBackgroundThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="ToolTipBorderThemeBrush" Color="#FF808080" />
+    <SolidColorBrush x:Key="ToolTipForegroundThemeBrush" Color="#FF666666" />
+    <Thickness x:Key="ToolTipBorderThemePadding">8,5,8,7</Thickness>
   </Style.Resources>
 </Style>

src/Avalonia.Themes.Fluent/Accents/FluentDark.xaml

@@ -5,4 +5,5 @@
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.Accents.Base.xaml?assembly=Avalonia.Themes.Fluent" />
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.Accents.FluentBaseDark.xaml?assembly=Avalonia.Themes.Fluent" />
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.Accents.FluentControlResourcesDark.xaml?assembly=Avalonia.Themes.Fluent" />
+  <StyleInclude Source="resm:Avalonia.Themes.Fluent.FluentTheme.xaml?assembly=Avalonia.Themes.Fluent" />
 </Styles>

src/Avalonia.Themes.Fluent/Accents/FluentLight.xaml

@@ -5,4 +5,5 @@
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.Accents.Base.xaml?assembly=Avalonia.Themes.Fluent" />  
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.Accents.FluentBaseLight.xaml?assembly=Avalonia.Themes.Fluent" />
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.Accents.FluentControlResourcesLight.xaml?assembly=Avalonia.Themes.Fluent" />
+  <StyleInclude Source="resm:Avalonia.Themes.Fluent.FluentTheme.xaml?assembly=Avalonia.Themes.Fluent" />
 </Styles>

src/Avalonia.Themes.Fluent/Button.xaml

@@ -4,13 +4,14 @@
       <StackPanel Spacing="20">
         <Button Content="Click Me!" />
         <Button Classes="accent" Content="Click Me!" />
-      </StackPanel>      
+        <RepeatButton Content="RepeatButton" Width="100" />
+      </StackPanel>
     </Border>
   </Design.PreviewWith>
   <Styles.Resources>
     <Thickness x:Key="ButtonPadding">8,5,8,6</Thickness>
   </Styles.Resources>
-  <Style Selector="Button">
+  <Style Selector="Button, RepeatButton">
     <Setter Property="Background" Value="{DynamicResource ButtonBackground}" />
     <!--<Setter Property="BackgroundSizing" Value="OuterBorderEdge" />-->
     <Setter Property="Foreground" Value="{DynamicResource ButtonForeground}" />
@@ -24,65 +25,63 @@
     <Setter Property="FontWeight" Value="Normal" />
     <Setter Property="FontSize" Value="{DynamicResource ControlContentThemeFontSize}" />
     <!--<Setter Property="UseSystemFocusVisuals" Value="{StaticResource UseSystemFocusVisuals}" />
-    <Setter Property="FocusVisualMargin" Value="-3" />-->    
+    <Setter Property="FocusVisualMargin" Value="-3" />-->
     <Setter Property="Template">
       <ControlTemplate>
-        <ContentPresenter
+        <ContentPresenter x:Name="PART_ContentPresenter"
-                        x:Name="PART_ContentPresenter"
+                          Background="{TemplateBinding Background}"
-                        Background="{TemplateBinding Background}"
+                          BorderBrush="{TemplateBinding BorderBrush}"
-                        BorderBrush="{TemplateBinding BorderBrush}"
+                          BorderThickness="{TemplateBinding BorderThickness}"
-                        BorderThickness="{TemplateBinding BorderThickness}"
+                          Content="{TemplateBinding Content}"
-                        Content="{TemplateBinding Content}"
+                          ContentTemplate="{TemplateBinding ContentTemplate}"
-                        ContentTemplate="{TemplateBinding ContentTemplate}"                        
+                          CornerRadius="{DynamicResource ControlCornerRadius}"
-                        CornerRadius="{DynamicResource ControlCornerRadius}"
+                          Padding="{TemplateBinding Padding}"
-                        Padding="{TemplateBinding Padding}"
+                          HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
-                        HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
+                          VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" />
-                        VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}">
-          </ContentPresenter>        
       </ControlTemplate>
     </Setter>
   </Style>
 
-  <!-- PointerOverState -->  
+  <!--  PointerOverState  -->
-  <Style Selector="Button:pointerover /template/ ContentPresenter">
+  <Style Selector="Button:pointerover /template/ ContentPresenter, RepeatButton:pointerover /template/ ContentPresenter">
     <Setter Property="Background" Value="{DynamicResource ButtonBackgroundPointerOver}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource ButtonBorderBrushPointerOver}"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource ButtonBorderBrushPointerOver}" />
     <Setter Property="TextBlock.Foreground" Value="{DynamicResource ButtonForegroundPointerOver}" />
   </Style>
-  
+
-  <Style Selector="Button:pressed  /template/ ContentPresenter">
+  <Style Selector="Button:pressed  /template/ ContentPresenter, RepeatButton:pressed  /template/ ContentPresenter">
     <Setter Property="Background" Value="{DynamicResource ButtonBackgroundPressed}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource ButtonBorderBrushPressed}"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource ButtonBorderBrushPressed}" />
     <Setter Property="TextBlock.Foreground" Value="{DynamicResource ButtonForegroundPressed}" />
   </Style>
-  
+
-  <Style Selector="Button:disabled">
+  <Style Selector="Button:disabled, RepeatButton:disabled">
     <Setter Property="Background" Value="{DynamicResource ButtonBackgroundDisabled}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource ButtonBorderBrushDisabled}"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource ButtonBorderBrushDisabled}" />
     <Setter Property="TextBlock.Foreground" Value="{DynamicResource ButtonForegroundDisabled}" />
   </Style>
 
-  <Style Selector="Button.accent">
+  <Style Selector="Button.accent, RepeatButton.accent">
     <Setter Property="Foreground" Value="{DynamicResource AccentButtonForeground}" />
     <Setter Property="Background" Value="{DynamicResource AccentButtonBackground}" />
     <Setter Property="BorderBrush" Value="{DynamicResource AccentButtonBorderBrush}" />
   </Style>
 
-  <Style Selector="Button.accent:pointerover /template/ ContentPresenter">
+  <Style Selector="Button.accent:pointerover /template/ ContentPresenter, RepeatButton.accent:pointerover /template/ ContentPresenter">
     <Setter Property="Background" Value="{DynamicResource AccentButtonBackgroundPointerOver}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource AccentButtonBorderBrushPointerOver}"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource AccentButtonBorderBrushPointerOver}" />
     <Setter Property="TextBlock.Foreground" Value="{DynamicResource AccentButtonForegroundPointerOver}" />
   </Style>
 
-  <Style Selector="Button.accent:pressed  /template/ ContentPresenter">
+  <Style Selector="Button.accent:pressed  /template/ ContentPresenter, RepeatButton.accent:pressed  /template/ ContentPresenter">
     <Setter Property="Background" Value="{DynamicResource AccentButtonBackgroundPressed}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource AccentButtonBorderBrushPressed}"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource AccentButtonBorderBrushPressed}" />
     <Setter Property="TextBlock.Foreground" Value="{DynamicResource AccentButtonForegroundPressed}" />
   </Style>
 
-  <Style Selector="Button.accent:disabled">
+  <Style Selector="Button.accent:disabled, RepeatButton.accent:disabled">
     <Setter Property="Background" Value="{DynamicResource AccentButtonBackgroundDisabled}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource AccentButtonBorderBrushDisabled}"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource AccentButtonBorderBrushDisabled}" />
     <Setter Property="TextBlock.Foreground" Value="{DynamicResource AccentButtonForegroundDisabled}" />
   </Style>
 </Styles>

src/Avalonia.Themes.Fluent/Calendar.xaml

@@ -5,13 +5,14 @@
 // All other rights reserved.
 -->
 
-<Styles xmlns="https://github.com/avaloniaui">
+<Styles xmlns="https://github.com/avaloniaui">  
   <Style Selector="Calendar">
-    <!--<Setter Property="Focusable" Value="False" />-->
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewForeground}" />
-    <Setter Property="BorderThickness" Value="{DynamicResource ThemeBorderThickness}" />
+    <Setter Property="Background" Value="{DynamicResource CalendarViewBackground}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource ThemeBorderHighBrush}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewBorderBrush}" />
-    <Setter Property="Background" Value="{DynamicResource ThemeBackgroundBrush}" />
+    <Setter Property="BorderThickness" Value="1" />
-    <Setter Property="HeaderBackground" Value="{DynamicResource ThemeAccentBrush2}" />
+    <Setter Property="HorizontalAlignment" Value="Left" />
+    <Setter Property="VerticalAlignment" Value="Center" />
     <Setter Property="Template">
       <ControlTemplate>
         <StackPanel Name="Root"
@@ -28,4 +29,4 @@
       </ControlTemplate>
     </Setter>
   </Style>
-</Styles>
+</Styles>

src/Avalonia.Themes.Fluent/CalendarButton.xaml

@@ -7,75 +7,115 @@
 
 <Styles xmlns="https://github.com/avaloniaui">
   <Style Selector="CalendarButton">
-    <Setter Property="Foreground" Value="{DynamicResource ThemeBorderHighBrush}" />
+    <Setter Property="ClickMode" Value="Release"/>
-    <Setter Property="Background" Value="{DynamicResource ThemeAccentBrush2}" />
+    <Setter Property="MinWidth" Value="40"/>
-    <Setter Property="FontSize" Value="{DynamicResource FontSizeSmall}" />
+    <Setter Property="MinHeight" Value="40"/>
-    <Setter Property="HorizontalContentAlignment" Value="Center" />
+    <Setter Property="Margin" Value="1"/>
-    <Setter Property="VerticalContentAlignment" Value="Center" />
+    <Setter Property="Padding" Value="0,0,0,4"/>
-    <Setter Property="MinWidth" Value="37" />
+    <!--These are actually set on the CalendarView in WinUI-->
-    <Setter Property="MinHeight" Value="38" />
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewCalendarItemForeground}"/>
-    <Setter Property="Focusable" Value="False"/>
+    <Setter Property="Background" Value="{DynamicResource CalendarViewCalendarItemRevealBackground}"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewCalendarItemRevealBorderBrush}"/>
+    <Setter Property="BorderThickness" Value="2"/>
+    <Setter Property="FontSize" Value="20"/>
+    <Setter Property="ClipToBounds" Value="False"/>
+    <Setter Property="HorizontalContentAlignment" Value="Center"/>
+    <Setter Property="VerticalContentAlignment" Value="Center"/>
     <Setter Property="Template">
       <ControlTemplate>
-        <Grid>
+        <Panel>
+          <!-- To mimic WinUI SystemFocusVisual, Focus visual is drawn outside the bounds of the item -->
+          <Border Name="Root" Background="{TemplateBinding Background}"
+                  BorderThickness="0" ClipToBounds="True">
 
-          <Rectangle Name="SelectedBackground"
+            <ContentControl Name="Content"
-                     Opacity="0.75"
+                  ContentTemplate="{TemplateBinding ContentTemplate}"
-                     Fill="{TemplateBinding Background}"/>
+                  Content="{TemplateBinding Content}"
+                  HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
+                  VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
+                  FontSize="{TemplateBinding FontSize}"
+                  Margin="{TemplateBinding Padding}"/>
 
-          <Rectangle Name="Background"
+          </Border>
-                     Opacity="0.5"
-                     Fill="{TemplateBinding Background}"/>
 
-          <!--Focusable="False"-->
+          <!-- Drawn Border should render on top of background to preserve the 1px
-          <ContentControl Name="Content"
+                        margin between items-->
-                          Foreground="{TemplateBinding Foreground}"
+          <Border Name="Border"
-                          ContentTemplate="{TemplateBinding ContentTemplate}"
+                  BorderThickness="2"
-                          Content="{TemplateBinding Content}"
+                  BorderBrush="{TemplateBinding BorderBrush}"/>
-                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
-                          VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
-                          FontSize="{TemplateBinding FontSize}"
-                          Margin="1,0,1,1"/>
 
-          <Rectangle Name="FocusVisual"
+          <!--Removed for now...WinUI doesn't have selection follow focus, and only uses 
-                     StrokeThickness="1"
+              focus visual w/ keyboard focus
-                     Stroke="{DynamicResource HighlightBrush}"
+          <Border Name="FocusVisual" BorderThickness="2"
-                     IsHitTestVisible="False"/>
+                     BorderBrush="{DynamicResource SystemControlHighlightBaseHighBrush}"
-
+                     IsHitTestVisible="False"
-        </Grid>
+                     Margin="-2"  CornerRadius="{DynamicResource ControlCornerRadius}"/>-->
+        </Panel>
       </ControlTemplate>
     </Setter>
   </Style>
-
+  <!--<Style Selector="CalendarButton /template/ Border#FocusVisual">
-  <Style Selector="CalendarButton /template/ Rectangle#Background">
     <Setter Property="IsVisible" Value="False"/>
+  </Style>-->
+
+  <Style Selector="CalendarButton:pointerover /template/ Border#Border">
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewHoverBorderBrush}"/>
   </Style>
-  <Style Selector="CalendarButton:pointerover /template/ Rectangle#Background">
+  <Style Selector="CalendarButton:pressed /template/ Border#Border">
-    <Setter Property="IsVisible" Value="True"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewPressedBorderBrush}"/>
-  </Style>
-  <Style Selector="CalendarButton:pressed /template/ Rectangle#Background">
-    <Setter Property="IsVisible" Value="True"/>
   </Style>
 
-  <Style Selector="CalendarButton /template/ Rectangle#SelectedBackground">
+  <!-- Adjusted :selected to look like :today from DayItem -->
-    <Setter Property="IsVisible" Value="False"/>
+  <Style Selector="CalendarButton:selected /template/ Border#Root">
+    <Setter Property="Background" Value="{DynamicResource SystemAccentBrush}"/>
   </Style>
-  <Style Selector="CalendarButton:selected /template/ Rectangle#SelectedBackground">
+  <Style Selector="CalendarButton:selected /template/ Border#Border">
-    <Setter Property="IsVisible" Value="True"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewSelectedBorderBrush}"/>
+  </Style>
+  <Style Selector="CalendarButton:selected:pointerover /template/ Border#Root">
+    <Setter Property="Background">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColor}"/>
+    </Setter>
+  </Style>
+  <Style Selector="CalendarButton:selected:pointerover /template/ Border#Border">
+    <Setter Property="BorderBrush">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColorDark1}"/>
+    </Setter>
+  </Style>
+  <Style Selector="CalendarButton:selected:pressed /template/ Border#Root">
+    <Setter Property="Background">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColor}"/>
+    </Setter>
+  </Style>
+  <Style Selector="CalendarButton:pressed /template/ Border#Border">
+    <Setter Property="BorderBrush">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColorDark2}"/>
+    </Setter>
+  </Style>
+
+  <Style Selector="CalendarButton:selected /template/ ContentControl#Content">
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewTodayForeground}"/>
+    <Setter Property="FontWeight" Value="SemiBold"/>
   </Style>
 
-  <Style Selector="CalendarButton /template/ ContentControl#Content">
+  <!-- WinUI calls this OutOfFocus -->
-    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}"/>
+  <Style Selector="CalendarButton:inactive /template/ Border#Root">
+    <!-- These are probably set in code, but consistent -->
+    <Setter Property="Background" Value="{DynamicResource CalendarViewOutOfScopeBackground}"/>
   </Style>
   <Style Selector="CalendarButton:inactive /template/ ContentControl#Content">
-    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundLowBrush}"/>
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewOutOfScopeForeground}"/>
   </Style>
 
-
+  <Style Selector="CalendarButton:blackout /template/ ContentControl#Content">
-  <Style Selector="CalendarButton /template/ Rectangle#FocusVisual">
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewBlackoutForeground}"/>
-    <Setter Property="IsVisible" Value="False"/>
   </Style>
-  <Style Selector="CalendarButton:btnfocused /template/ Rectangle#FocusVisual">
+
-    <Setter Property="IsVisible" Value="True"/>
+  <!--<Style Selector="CalendarButton:dayfocused /template/ Border#FocusVisual">
+            <Setter Property="IsVisible" Value="True"/>
+      </Style>-->
+
+  <Style Selector="CalendarDayButton:disabled /template/ ContentControl#Content">
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewWeekDayForegroundDisabled}"/>
   </Style>
 </Styles>

src/Avalonia.Themes.Fluent/CalendarDayButton.xaml

@@ -7,110 +7,110 @@
 
 <Styles xmlns="https://github.com/avaloniaui">
   <Style Selector="CalendarDayButton">
-    <Setter Property="Background" Value="{DynamicResource ThemeAccentBrush2}" />
+    <Setter Property="ClickMode" Value="Release"/>
-    <Setter Property="FontSize" Value="{DynamicResource FontSizeSmall}" />
+    <Setter Property="MinWidth" Value="40"/>
-    <Setter Property="HorizontalContentAlignment" Value="Center" />
+    <Setter Property="MinHeight" Value="40"/>
-    <Setter Property="VerticalContentAlignment" Value="Center" />
+    <Setter Property="Margin" Value="1"/>
-    <Setter Property="MinWidth" Value="5" />
+    <Setter Property="Padding" Value="0,0,0,4"/>
-    <Setter Property="MinHeight" Value="5" />
+    <!--These are actually set on the CalendarView in WinUI-->
-    <Setter Property="Focusable" Value="False"/>
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewCalendarItemForeground}"/>
+    <Setter Property="Background" Value="{DynamicResource CalendarViewCalendarItemRevealBackground}"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewCalendarItemRevealBorderBrush}"/>
+    <Setter Property="BorderThickness" Value="2"/>
+    <Setter Property="FontSize" Value="20"/>
+    <Setter Property="ClipToBounds" Value="False"/>
+    <Setter Property="HorizontalContentAlignment" Value="Center"/>
+    <Setter Property="VerticalContentAlignment" Value="Center"/>
     <Setter Property="Template">
       <ControlTemplate>
-        <Panel Background="Transparent">
+        <Panel>
-
+          <!-- To mimic WinUI SystemFocusVisual, Focus visual is drawn outside the bounds of the item -->
-          <Rectangle Name="TodayBackground"
+          <Border Name="Root" Background="{TemplateBinding Background}"
-                     Fill="{DynamicResource HighlightBrush}"/>
+                  BorderThickness="0" ClipToBounds="True">
-
+
-          <Rectangle Name="SelectedBackground"
+            <ContentControl Name="Content"
-                     Opacity="0.75"
+                  ContentTemplate="{TemplateBinding ContentTemplate}"
-                     Fill="{TemplateBinding Background}"/>
+                  Content="{TemplateBinding Content}"
-
+                  HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
-          <Rectangle Name="Background"
+                  VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
-                     Opacity="0.5"
+                  FontSize="{TemplateBinding FontSize}"
-                     Fill="{TemplateBinding Background}"/>
+                  Margin="{TemplateBinding Padding}"/>
-
+
-          <ContentControl Name="Content"
+          </Border>
-                          ContentTemplate="{TemplateBinding ContentTemplate}"
+
-                          Content="{TemplateBinding Content}"
+          <!-- Drawn Border should render on top of background to preserve the 1px
-                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
+                        margin between items-->
-                          VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
+          <Border Name="Border"
-                          FontSize="{TemplateBinding FontSize}"
+                  BorderThickness="2"
-                          Margin="5,1,5,1"/>
+                  BorderBrush="{TemplateBinding BorderBrush}"/>
-
+
-          <Path Name="BlackoutVisual"
+          <!--Removed for now...WinUI doesn't have selection follow focus, and only uses 
-                Margin="3"
+              focus visual w/ keyboard focus
-                HorizontalAlignment="Stretch"
+                <Border Name="FocusVisual" BorderThickness="2"
-                VerticalAlignment="Stretch"
+                            BorderBrush="{DynamicResource SystemControlHighlightBaseHighBrush}"
-                RenderTransformOrigin="0.5,0.5"
+                            IsHitTestVisible="False"
-                Fill="{DynamicResource ThemeForegroundBrush}"
+                            Margin="-2"  CornerRadius="2"/>-->
-                Stretch="Fill"
-                Data="M8.1772461,11.029181 L10.433105,11.029181 L11.700684,12.801641 L12.973633,11.029181 L15.191895,11.029181 L12.844727,13.999395 L15.21875,17.060919 L12.962891,17.060919 L11.673828,15.256231 L10.352539,17.060919 L8.1396484,17.060919 L10.519043,14.042364 z" />
-          
-          <Rectangle Name="FocusVisual"
-                     StrokeThickness="1"
-                     Stroke="{DynamicResource HighlightBrush}"
-                     IsHitTestVisible="False"/>
-
         </Panel>
       </ControlTemplate>
     </Setter>
   </Style>
-
+  <!--<Style Selector="CalendarDayButton /template/ Border#FocusVisual">
-  <Style Selector="CalendarDayButton /template/ Rectangle#Background">
     <Setter Property="IsVisible" Value="False"/>
-  </Style>
+  </Style>-->
-  <Style Selector="CalendarDayButton:pointerover /template/ Rectangle#Background">
-    <Setter Property="IsVisible" Value="True"/>
-  </Style>
-  <Style Selector="CalendarDayButton:pressed /template/ Rectangle#Background">
-    <Setter Property="IsVisible" Value="True"/>
-  </Style>
 
-  <Style Selector="CalendarDayButton /template/ Rectangle#SelectedBackground">
+  <Style Selector="CalendarDayButton:pointerover /template/ Border#Border">
-    <Setter Property="IsVisible" Value="False"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewHoverBorderBrush}"/>
   </Style>
-  <Style Selector="CalendarDayButton:selected /template/ Rectangle#SelectedBackground">
+  <Style Selector="CalendarDayButton:pressed /template/ Border#Border">
-    <Setter Property="IsVisible" Value="True"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewPressedBorderBrush}"/>
   </Style>
-
+  <Style Selector="CalendarDayButton:selected /template/ Border#Border">
-  <Style Selector="CalendarDayButton /template/ ContentControl#Content">
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewSelectedBorderBrush}"/>
-    <Setter Property="Opacity" Value="1"/>
-    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}"/>
   </Style>
-  <Style Selector="CalendarDayButton:disabled /template/ Rectangle#Background">
+  <Style Selector="CalendarDayButton:selected:pointerover /template/ Border#Border">
-    <Setter Property="IsVisible" Value="False"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewSelectedHoverBorderBrush}"/>
   </Style>
-  <Style Selector="CalendarDayButton:disabled /template/ ContentControl#Content">
+  <Style Selector="CalendarDayButton:selected:pressed /template/ Border#Border">
-    <Setter Property="Opacity" Value="0.3"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewSelectedPressedBorderBrush}"/>
   </Style>
 
-  <Style Selector="CalendarDayButton /template/ Rectangle#FocusVisual">
+  <Style Selector="CalendarDayButton:today /template/ Border#Root">
-    <Setter Property="IsVisible" Value="False"/>
+    <!-- These are probably set in code, but consistent -->
+    <Setter Property="Background">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColor}"/>
+    </Setter>
   </Style>
-  <Style Selector="CalendarDayButton:dayfocused /template/ Rectangle#FocusVisual">
+  <Style Selector="CalendarDayButton:today:pointerover /template/ Border#Border">
-    <Setter Property="IsVisible" Value="True"/>
+    <Setter Property="BorderBrush">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColorDark1}"/>
+    </Setter>
   </Style>
-
+  <Style Selector="CalendarDayButton:today:pressed /template/ Border#Border">
-  <Style Selector="CalendarDayButton /template/ Rectangle#TodayBackground">
+    <Setter Property="BorderBrush">
-    <Setter Property="IsVisible" Value="False"/>
+      <SolidColorBrush Color="{DynamicResource SystemAccentColorDark2}"/>
+    </Setter>
   </Style>
-  <Style Selector="CalendarDayButton:today /template/ Rectangle#TodayBackground">
+  <Style Selector="CalendarDayButton:today /template/ ContentControl#Content">
-    <Setter Property="IsVisible" Value="True"/>
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewTodayForeground}"/>
+    <Setter Property="FontWeight" Value="SemiBold"/>
   </Style>
 
-
+  <!-- WinUI calls this OutOfFocus -->
-  <Style Selector="CalendarDayButton:inactive /template/ ContentControl#Content">
+  <Style Selector="CalendarDayButton:inactive /template/ Border#Root">
-    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundLowBrush}"/>
+    <Setter Property="Background" Value="{DynamicResource CalendarViewOutOfScopeBackground}"/>
   </Style>
-  <Style Selector="CalendarDayButton:today /template/ ContentControl#Content">
+  <Style Selector="CalendarDayButton:inactive /template/ ContentControl#Content">
-    <Setter Property="Foreground" Value="{DynamicResource ThemeControlLowBrush}"/>
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewOutOfScopeForeground}"/>
   </Style>
 
-  <Style Selector="CalendarDayButton /template/ Path#BlackoutVisual">
+  <Style Selector="CalendarDayButton:blackout /template/ ContentControl#Content">
-    <Setter Property="Opacity" Value="0"/>
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewBlackoutForeground}"/>
   </Style>
-  <Style Selector="CalendarDayButton:blackout /template/ Path#BlackoutVisual">
-    <Setter Property="Opacity" Value="0.3"/>
-  </Style>  
 
+  <!--<Style Selector="CalendarDayButton:dayfocused /template/ Border#FocusVisual">
+            <Setter Property="IsVisible" Value="True"/>
+      </Style>-->
+  <Style Selector="CalendarDayButton:disabled /template/ ContentControl#Content">
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewWeekDayForegroundDisabled}"/>
+  </Style>
 </Styles>

src/Avalonia.Themes.Fluent/CalendarItem.xaml

@@ -8,176 +8,127 @@
 <Styles xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
   <Style Selector="CalendarItem">
-    <Setter Property="Template">
-      <ControlTemplate>
-        <Panel>
-          <Border BorderThickness="{TemplateBinding BorderThickness}"
-                  BorderBrush="{TemplateBinding BorderBrush}"
-                  Background="{TemplateBinding Background}"
-                  Margin="0,2,0,2"
-                  CornerRadius="1">
-
-            <Border CornerRadius="1"
-                    BorderBrush="{DynamicResource ThemeBackgroundBrush}"
-                    BorderThickness="2">
-              <Grid>
-                <Grid.RowDefinitions>
-                  <RowDefinition Height="Auto" />
-                  <RowDefinition Height="*" />
-                </Grid.RowDefinitions>
-                <Grid.ColumnDefinitions>
-                  <ColumnDefinition Width="Auto" />
-                  <ColumnDefinition Width="*" />
-                  <ColumnDefinition Width="Auto" />
-                </Grid.ColumnDefinitions>
-
-                <Grid.Styles>
-                  <Style Selector="Button.CalendarHeader">
-                    <Setter Property="Cursor" Value="Hand"/>
-                    <Setter Property="Background" Value="Transparent"/>
-                    <Setter Property="BorderThickness" Value="0"/>
-                  </Style>
-                    <Style Selector="Button.CalendarHeader:pressed  /template/ ContentPresenter">
-                    <Setter Property="Background" Value="Transparent"/>
-                  </Style>
-
-                  <Style Selector="Button.CalendarNavigation">
-                    <Setter Property="Height" Value="20"/>
-                    <Setter Property="Width" Value="28"/>
-                  </Style>
-                  <Style Selector="Button.CalendarNavigation > Path">
-                    <Setter Property="Fill" Value="{DynamicResource ThemeForegroundBrush}"/>
-                  </Style>
-                  <Style Selector="Button.CalendarNavigation:pointerover > Path">
-                    <Setter Property="Fill" Value="{DynamicResource HighlightBrush}"/>
-                  </Style>
-
-                  <Style Selector="Button#HeaderButton:pointerover">
-                    <Setter Property="Foreground" Value="{DynamicResource HighlightBrush}"/>
-                  </Style>
-                </Grid.Styles>
-
-                <Rectangle Grid.ColumnSpan="3"
-                           Fill="{TemplateBinding HeaderBackground}"
-                           Stretch="Fill"
-                           VerticalAlignment="Top"
-                           Height="22"/>
-
-                <Button Name="PreviousButton"
-                        Classes="CalendarHeader CalendarNavigation"
-                        IsVisible="False"
-                        HorizontalAlignment="Left">
-
-                  <Path Margin="14,-6,0,0"
-                        Height="10"
-                        Width="6"
-                        VerticalAlignment="Center"
-                        HorizontalAlignment="Left"
-                        Stretch="Fill"
-                        Data="M288.75,232.25 L288.75,240.625 L283,236.625 z" />
-                  
-                </Button>
-                
-                <Button Name="HeaderButton"
-                        Classes="CalendarHeader"
-                        Grid.Column="1"
-                        FontWeight="Bold"
-                        FontSize="10.5"
-                        HorizontalAlignment="Center"
-                        VerticalAlignment="Center" 
-                        Padding="1,5,1,9"/>
-
-                <Button Name="NextButton"
-                        Classes="CalendarHeader CalendarNavigation"
-                        Grid.Column="2"
-                        IsVisible="False"
-                        HorizontalAlignment="Right" >
-
-                  <Path Margin="0,-6,14,0"
-                        Height="10"
-                        Width="6"
-                        Stretch="Fill"
-                        VerticalAlignment="Center"
-                        HorizontalAlignment="Right"
-                        Data="M282.875,231.875 L282.875,240.375 L288.625,236 z" />
-                  
-                </Button>
-
-                <Grid Name="MonthView"
-                      Grid.Row="1"
-                      Grid.ColumnSpan="3"
-                      IsVisible="False"
-                      Margin="6,-1,6,6">
-                  <Grid.RowDefinitions>
-                    <RowDefinition Height="Auto" />
-                    <RowDefinition Height="Auto" />
-                    <RowDefinition Height="Auto" />
-                    <RowDefinition Height="Auto" />
-                    <RowDefinition Height="Auto" />
-                    <RowDefinition Height="Auto" />
-                    <RowDefinition Height="Auto" />
-                  </Grid.RowDefinitions>
-                  <Grid.ColumnDefinitions>
-                    <ColumnDefinition Width="Auto" />
-                    <ColumnDefinition Width="Auto" />
-                    <ColumnDefinition Width="Auto" />
-                    <ColumnDefinition Width="Auto" />
-                    <ColumnDefinition Width="Auto" />
-                    <ColumnDefinition Width="Auto" />
-                    <ColumnDefinition Width="Auto" />
-                  </Grid.ColumnDefinitions>
-                </Grid>
-
-                <Grid Name="YearView"
-                      Grid.Row="1"
-                      Grid.ColumnSpan="3"
-                      IsVisible="False"
-                      Margin="6,-3,7,6">
-                  <Grid.RowDefinitions>
-                    <RowDefinition Height="Auto" />
-                    <RowDefinition Height="Auto" />
-                    <RowDefinition Height="Auto" />
-                  </Grid.RowDefinitions>
-                  <Grid.ColumnDefinitions>
-                    <ColumnDefinition Width="Auto" />
-                    <ColumnDefinition Width="Auto" />
-                    <ColumnDefinition Width="Auto" />
-                    <ColumnDefinition Width="Auto" />
-                  </Grid.ColumnDefinitions>
-                </Grid>
-
-              </Grid>
-            </Border>
-          </Border>
-
-
-          <Rectangle Name="DisabledVisual"
-                     Stretch="Fill"
-                     Fill="{DynamicResource ThemeControlLowBrush}"
-                     Opacity="{DynamicResource ThemeDisabledOpacity}"
-                     Margin="0,2,0,2" />
-
-        </Panel>
-      </ControlTemplate>
-    </Setter>
     <Setter Property="DayTitleTemplate">
       <Template>
-        <TextBlock FontWeight="Bold"
+        <TextBlock Text="{Binding}"
-                   FontSize="9.5"
-                   Margin="0,4,0,4"
                    HorizontalAlignment="Center"
                    VerticalAlignment="Center"
-                   Text="{Binding}" />
+                   FontSize="12"/>
       </Template>
-
+    </Setter>
+    <Setter Property="Template">
+      <ControlTemplate>
+        <Border BorderThickness="{TemplateBinding BorderThickness}"
+                Background="{TemplateBinding Background}"
+                BorderBrush="{TemplateBinding BorderBrush}"
+                CornerRadius="{DynamicResource ControlCornerRadius}">
+          <Border.Styles>
+            <Style Selector="Button.CalendarHeader">
+              <Setter Property="HorizontalAlignment" Value="Stretch" />
+              <Setter Property="VerticalAlignment" Value="Stretch" />
+              <Setter Property="FontSize" Value="20" />
+              <Setter Property="Background" Value="{DynamicResource CalendarViewNavigationButtonBackground}"/>
+              <Setter Property="Template">
+                <ControlTemplate>
+                  <!-- HCA was changed here to ensure nav arrows display correctly -->
+                  <ContentPresenter Name="Text" Background="{TemplateBinding Background}"
+                                    BorderBrush="{DynamicResource CalendarViewNavigationButtonBorderBrush}"
+                                    BorderThickness="{TemplateBinding BorderThickness}"
+                                    Content="{TemplateBinding Content}"
+                                    Margin="{TemplateBinding Padding}"
+                                    HorizontalContentAlignment="Stretch"
+                                    VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" />
+                </ControlTemplate>
+              </Setter>
+            </Style>
+            <Style Selector="Button.CalendarNavigation > Path">
+              <Setter Property="Stroke" Value="{DynamicResource CalendarViewForeground}"/>
+            </Style>
+            <Style Selector="Button.CalendarNavigation:pointerover > Path">
+              <Setter Property="Stroke" Value="{DynamicResource CalendarViewNavigationButtonForegroundPointerOver}"/>
+            </Style>
+            <Style Selector="Button.CalendarNavigation:pressed > Path">
+              <Setter Property="Stroke" Value="{DynamicResource CalendarViewNavigationButtonForegroundPressed}"/>
+            </Style>
+            <Style Selector="Button.CalendarHeader:pointerover /template/ ContentPresenter#Text">
+              <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewNavigationButtonBorderBrushPointerOver}" />
+              <Setter Property="TextBlock.Foreground" Value="{DynamicResource CalendarViewNavigationButtonForegroundPointerOver}"/>
+              <!-- Prevent base button template:pointerover from overriding background here -->
+              <Setter Property="Background" Value="{DynamicResource CalendarViewNavigationButtonBackground}"/>
+            </Style>
+            <Style Selector="Button.CalendarHeader:pressed /template/ ContentPresenter#Text">
+              <Setter Property="TextBlock.Foreground" Value="{DynamicResource CalendarViewNavigationButtonForegroundPressed}"/>
+              <!-- Prevent base button template:pointerover from overriding background here -->
+              <Setter Property="Background" Value="{DynamicResource CalendarViewNavigationButtonBackground}"/>
+            </Style>
+            <Style Selector="Button.CalendarHeader:disabled /template/ ContentPresenter">
+              <Setter Property="TextBlock.Foreground" Value="{DynamicResource CalendarViewWeekDayForegroundDisabled}"/>
+            </Style>
+          </Border.Styles>
+          <!--  To keep calendar from resizing when switching DisplayMode
+                In WinUI Min-Width from TemplateSettings
+                basically...MinWidth of DayItem = 40, 40 * 7 = 280 + margins/padding = ~294
+                Viewport height is set from # of rows displayed (2-8) in Month mode, = ~290 for 6 weeks (+ day names)
+                -->
+          <Grid VerticalAlignment="Stretch" HorizontalAlignment="Stretch" RowDefinitions="40,*" MinWidth="294">
+            <Grid ColumnDefinitions="5*,*,*">
+              <Button Name="HeaderButton" Classes="CalendarHeader" Foreground="{TemplateBinding Foreground}" Padding="12,0,0,0" HorizontalContentAlignment="Left" />
+              <Button Name="PreviousButton" Grid.Column="1" Classes="CalendarHeader CalendarNavigation" Foreground="{TemplateBinding Foreground}" Padding="1" HorizontalContentAlignment="Left">
+                <!--Path mimics Segoe MDL2 Assets font glyph used in WinUI-->
+                <Path StrokeThickness="1.5" Data="M 0,9 L 9,0 L 18,9"  HorizontalAlignment="Center" VerticalAlignment="Center"/>
+              </Button>
+              <Button Name="NextButton" Grid.Column="2" Classes="CalendarHeader CalendarNavigation" Foreground="{TemplateBinding Foreground}" Padding="1" HorizontalContentAlignment="Left">
+                <!--Path mimics Segoe MDL2 Assets font glyph used in WinUI-->
+                <Path StrokeThickness="1.5" Data="M 0,0 L 9,9 L 18,0" HorizontalAlignment="Center" VerticalAlignment="Center"/>
+              </Button>
+            </Grid>
+            <Border Name="BackgroundLayer" Background="{TemplateBinding BorderBrush}" Grid.Row="1" />
+            <Grid Name="MonthView" Grid.Row="1" IsVisible="False" MinHeight="290" >
+              <Grid.RowDefinitions>
+                <!--This should always be the week day names??-->
+                <RowDefinition Height="38" />
+                <RowDefinition Height="Auto" />
+                <RowDefinition Height="Auto" />
+                <RowDefinition Height="Auto" />
+                <RowDefinition Height="Auto" />
+                <RowDefinition Height="Auto" />
+                <RowDefinition Height="Auto" />
+              </Grid.RowDefinitions>
+              <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="Auto" />
+                <ColumnDefinition Width="Auto" />
+                <ColumnDefinition Width="Auto" />
+                <ColumnDefinition Width="Auto" />
+                <ColumnDefinition Width="Auto" />
+                <ColumnDefinition Width="Auto" />
+                <ColumnDefinition Width="Auto" />
+              </Grid.ColumnDefinitions>
+            </Grid>
+            <Grid Name="YearView" MinHeight="290"
+                    Grid.Row="1" IsVisible="False">
+              <Grid.RowDefinitions>
+                <RowDefinition Height="*" />
+                <RowDefinition Height="*" />
+                <RowDefinition Height="*" />
+              </Grid.RowDefinitions>
+              <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="*" />
+              </Grid.ColumnDefinitions>
+            </Grid>
+
+          </Grid>
+
+        </Border>
+      </ControlTemplate>
     </Setter>
   </Style>
 
-  <Style Selector="CalendarItem /template/ Rectangle#DisabledVisual">
+  <!-- BackgroundLayer shouldn't show in the week day names row-->
-    <Setter Property="IsVisible" Value="False"/>
+  <Style Selector="Calendar[DisplayMode=Month] CalendarItem /template/ Border#BackgroundLayer">
-  </Style>
+    <Setter Property="Margin" Value="0,38,0,0"/>
-  <Style Selector="CalendarItem:calendardisabled /template/ Rectangle#DisabledVisual">
-    <Setter Property="IsVisible" Value="True"/>
   </Style>
   
 </Styles>

src/Avalonia.Themes.Fluent/FluentTheme.xaml

@@ -23,7 +23,6 @@
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.PopupRoot.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.ProgressBar.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.RadioButton.xaml?assembly=Avalonia.Themes.Fluent"/>
-  <StyleInclude Source="resm:Avalonia.Themes.Fluent.RepeatButton.xaml?assembly=Avalonia.Themes.Fluent" />
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.Separator.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.Slider.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.ScrollBar.xaml?assembly=Avalonia.Themes.Fluent"/>

src/Avalonia.Themes.Fluent/RepeatButton.xaml

@@ -1,40 +0,0 @@
-<Styles xmlns="https://github.com/avaloniaui">
-    <Style Selector="RepeatButton">
-        <Setter Property="Background"
-                Value="{DynamicResource ThemeControlMidBrush}" />
-        <Setter Property="BorderBrush"
-                Value="{DynamicResource ThemeBorderLowBrush}" />
-        <Setter Property="BorderThickness"
-                Value="{DynamicResource ThemeBorderThickness}" />
-        <Setter Property="Foreground"
-                Value="{DynamicResource ThemeForegroundBrush}" />
-        <Setter Property="HorizontalContentAlignment"
-                Value="Center" />
-        <Setter Property="VerticalContentAlignment"
-                Value="Center" />
-        <Setter Property="Padding"
-                Value="4" />
-        <Setter Property="Template">
-            <ControlTemplate>
-                <ContentPresenter Name="PART_ContentPresenter"
-                                  Background="{TemplateBinding Background}"
-                                  BorderBrush="{TemplateBinding BorderBrush}"
-                                  BorderThickness="{TemplateBinding BorderThickness}"
-                                  ContentTemplate="{TemplateBinding ContentTemplate}"
-                                  Content="{TemplateBinding Content}"
-                                  Padding="{TemplateBinding Padding}"
-                                  TextBlock.Foreground="{TemplateBinding Foreground}"
-                                  HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
-                                  VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
-            </ControlTemplate>
-        </Setter>
-    </Style>
-    <Style Selector="RepeatButton:pointerover /template/ ContentPresenter">
-        <Setter Property="BorderBrush"
-                Value="{DynamicResource ThemeBorderMidBrush}" />
-    </Style>
-    <Style Selector="RepeatButton:disabled">
-        <Setter Property="Opacity"
-                Value="{DynamicResource ThemeDisabledOpacity}" />
-    </Style>
-</Styles>

src/Avalonia.Themes.Fluent/Slider.xaml

@@ -1,93 +1,264 @@
-<Styles xmlns="https://github.com/avaloniaui">
+<Styles xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+  <Design.PreviewWith>
+    <Border Margin="20" Width="200" Height="200">
+      <DockPanel LastChildFill="True">
+        <StackPanel Spacing="10" DockPanel.Dock="Top">
+          <Slider Value="50" />
+          <Slider IsEnabled="False" Value="50" />
+        </StackPanel>
+        <StackPanel Spacing="10" Orientation="Horizontal">
+          <Slider Value="50" Orientation="Vertical" />
+          <Slider IsEnabled="False" Orientation="Vertical" Value="50" />
+        </StackPanel>
+      </DockPanel>
+    </Border>
+  </Design.PreviewWith>
+  <Styles.Resources>
+    <Thickness x:Key="SliderTopHeaderMargin">0,0,0,4</Thickness>
+    <GridLength x:Key="SliderPreContentMargin">15</GridLength>
+    <GridLength x:Key="SliderPostContentMargin">15</GridLength>
+    <x:Double x:Key="SliderHorizontalHeight">32</x:Double>
+    <x:Double x:Key="SliderVerticalWidth">32</x:Double>
+    <CornerRadius x:Key="SliderThumbCornerRadius">10</CornerRadius>
+    <x:Double x:Key="SliderHorizontalThumbWidth">20</x:Double>
+    <x:Double x:Key="SliderHorizontalThumbHeight">20</x:Double>
+    <x:Double x:Key="SliderVerticalThumbWidth">20</x:Double>
+    <x:Double x:Key="SliderVerticalThumbHeight">20</x:Double>
+  </Styles.Resources>
+  <Style Selector="Thumb.SliderThumbStyle">
+    <Setter Property="BorderThickness" Value="0" />
+    <Setter Property="Template">
+      <Setter.Value>
+        <ControlTemplate>
+          <Border Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{DynamicResource SliderThumbCornerRadius}" />
+        </ControlTemplate>
+      </Setter.Value>
+    </Setter>
+  </Style>
   <Style Selector="Slider:horizontal">
-    <Setter Property="MinWidth" Value="40"/>
+    <Setter Property="Background" Value="{DynamicResource SliderTrackFill}" />
-    <Setter Property="MinHeight" Value="20"/>
+    <Setter Property="BorderThickness" Value="{DynamicResource SliderBorderThemeThickness}" />
+    <Setter Property="Foreground" Value="{DynamicResource SliderTrackValueFill}" />
+    <Setter Property="FontFamily" Value="{DynamicResource ContentControlThemeFontFamily}" />
+    <Setter Property="FontSize" Value="{DynamicResource ControlContentThemeFontSize}" />
     <Setter Property="Template">
       <ControlTemplate>
-        <Grid Name="grid">
+        <Border BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" CornerRadius="{DynamicResource ControlCornerRadius}">
-          <Grid.RowDefinitions>
+          <Grid Name="grid" Margin="{TemplateBinding Padding}" RowDefinitions="Auto, *">
-            <RowDefinition Height="Auto"/>
+            <ContentPresenter x:Name="HeaderContentPresenter" Grid.Row="0" TextBlock.FontWeight="{DynamicResource SliderHeaderThemeFontWeight}" TextBlock.Foreground="{DynamicResource SliderHeaderForeground}"
-            <RowDefinition Height="Auto" MinHeight="20"/>
+            Margin="{DynamicResource SliderTopHeaderMargin}" />
-            <RowDefinition Height="Auto"/>
+            <Grid x:Name="SliderContainer" Grid.Row="1">
-          </Grid.RowDefinitions>
+              <Grid.Styles>
-          <Border Name="TrackBackground" Grid.Row="1" Height="4" Margin="6,0" VerticalAlignment="Center"/>
+                <Style Selector="TickBar">
-          <Track Name="PART_Track" Grid.Row="1" Orientation="Horizontal">
+                  <Setter Property="ReservedSpace" Value="{Binding #PART_Track.Thumb.Bounds}" />
-            <Track.DecreaseButton>
+                </Style>
-               <RepeatButton Name="PART_DecreaseButton"
+              </Grid.Styles>
-                             Classes="repeattrack" />
+              <Grid x:Name="HorizontalTemplate" ColumnDefinitions="Auto,Auto,*" MinHeight="{DynamicResource SliderHorizontalHeight}">
-            </Track.DecreaseButton>
+                <Grid.RowDefinitions>
-            <Track.IncreaseButton>
+                  <RowDefinition Height="{DynamicResource SliderPreContentMargin}" />
-               <RepeatButton Name="PART_IncreaseButton"
+                  <RowDefinition Height="Auto" />
-                             Classes="repeattrack" />
+                  <RowDefinition Height="{DynamicResource SliderPostContentMargin}" />
-            </Track.IncreaseButton>
+                </Grid.RowDefinitions>
-            <Thumb Name="thumb" MinWidth="20" MinHeight="20">
+                <TickBar Name="TopTickBar" Placement="Top" Height="{DynamicResource SliderOutsideTickBarThemeHeight}" VerticalAlignment="Bottom" Margin="0,0,0,4" Grid.ColumnSpan="3" />
-              <Thumb.Template>
+                <!-- <TickBar Name="HorizontalInlineTickBar" Placement="Top" Fill="{DynamicResource SliderInlineTickBarFill}" Height="{DynamicResource SliderTrackThemeHeight}" Grid.Row="1" Grid.ColumnSpan="3" /> -->
-                <ControlTemplate>
+                <TickBar Name="BottomTickBar" Placement="Bottom" Height="{DynamicResource SliderOutsideTickBarThemeHeight}" VerticalAlignment="Top" Margin="0,4,0,0" Grid.Row="2" Grid.ColumnSpan="3" />
-                  <Grid>
+                <Track Name="PART_Track" Grid.Row="1" Grid.ColumnSpan="3" Orientation="Horizontal">
-                    <Ellipse Width="12" Height="12" Fill="{DynamicResource ThemeAccentBrush}"/>
+                  <Track.DecreaseButton>
-                  </Grid>
+                    <RepeatButton Name="PART_DecreaseButton" Background="{TemplateBinding Foreground}">
-                </ControlTemplate>
+                      <RepeatButton.Template>
-              </Thumb.Template>
+                        <ControlTemplate>
-            </Thumb>
+                          <Grid>
-          </Track>
+                            <Border Name="FocusTarget" Background="Transparent" Margin="0,-10" />
-        </Grid>
+                            <Border Name="TrackBackground" Background="{TemplateBinding Background}" CornerRadius="{DynamicResource ControlCornerRadius}" Height="{DynamicResource SliderTrackThemeHeight}" VerticalAlignment="Center" />
+                          </Grid>
+                        </ControlTemplate>
+                      </RepeatButton.Template>
+                    </RepeatButton>
+                  </Track.DecreaseButton>
+                  <Track.IncreaseButton>
+                    <RepeatButton Name="PART_IncreaseButton" Background="{TemplateBinding Background}">
+                      <RepeatButton.Template>
+                        <ControlTemplate>
+                          <Grid>
+                            <Border Name="FocusTarget" Background="Transparent" Margin="0,-10" />
+                            <Border Name="TrackBackground" Background="{TemplateBinding Background}" CornerRadius="{DynamicResource ControlCornerRadius}" Height="{DynamicResource SliderTrackThemeHeight}" VerticalAlignment="Center" />
+                          </Grid>
+                        </ControlTemplate>
+                      </RepeatButton.Template>
+                    </RepeatButton>
+                  </Track.IncreaseButton>
+                  <Thumb Classes="SliderThumbStyle" Name="thumb" Margin="0" Padding="0" DataContext="{TemplateBinding Value}" Height="{DynamicResource SliderHorizontalThumbHeight}" Width="{DynamicResource SliderHorizontalThumbWidth}" />
+                </Track>
+              </Grid>
+            </Grid>
+          </Grid>
+        </Border>
       </ControlTemplate>
     </Setter>
   </Style>
   <Style Selector="Slider:vertical">
-    <Setter Property="MinWidth" Value="20"/>
+    <Setter Property="Background" Value="{DynamicResource SliderTrackFill}" />
-    <Setter Property="MinHeight" Value="40"/>
+    <Setter Property="BorderThickness" Value="{DynamicResource SliderBorderThemeThickness}" />
+    <Setter Property="Foreground" Value="{DynamicResource SliderTrackValueFill}" />
+    <Setter Property="FontFamily" Value="{DynamicResource ContentControlThemeFontFamily}" />
+    <Setter Property="FontSize" Value="{DynamicResource ControlContentThemeFontSize}" />
     <Setter Property="Template">
       <ControlTemplate>
-        <Grid>
+        <Border BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" CornerRadius="{DynamicResource ControlCornerRadius}">
-          <Grid.ColumnDefinitions>
+          <Grid Name="grid" Margin="{TemplateBinding Padding}" RowDefinitions="Auto, *">
-            <ColumnDefinition Width="Auto"/>
+            <ContentPresenter x:Name="HeaderContentPresenter" Grid.Row="0" TextBlock.FontWeight="{DynamicResource SliderHeaderThemeFontWeight}" TextBlock.Foreground="{DynamicResource SliderHeaderForeground}"
-            <ColumnDefinition Width="Auto" MinWidth="26"/>
+            Margin="{DynamicResource SliderTopHeaderMargin}" />
-            <ColumnDefinition Width="Auto"/>
+            <Grid x:Name="SliderContainer" Grid.Row="1">
-          </Grid.ColumnDefinitions>
+              <Grid.Styles>
-          <Border Name="TrackBackground" Grid.Column="1" Width="4" Margin="0,6" HorizontalAlignment="Center"/>
+                <Style Selector="TickBar">
-          <Track Name="PART_Track" Grid.Column="1" Orientation="Vertical" IsDirectionReversed="True">
+                  <Setter Property="ReservedSpace" Value="{Binding #PART_Track.Thumb.Bounds}" />
-            <Track.DecreaseButton>
+                </Style>
-               <RepeatButton Name="PART_DecreaseButton"
+              </Grid.Styles>
-                             Classes="repeattrack" />
+              <Grid x:Name="VerticalTemplate" RowDefinitions="*,Auto,Auto" MinWidth="{DynamicResource SliderVerticalWidth}">
-            </Track.DecreaseButton>
+                <Grid.ColumnDefinitions>
-            <Track.IncreaseButton>
+                  <ColumnDefinition Width="{DynamicResource SliderPreContentMargin}" />
-               <RepeatButton Name="PART_IncreaseButton"
+                  <ColumnDefinition Width="Auto" />
-                             Classes="repeattrack" />
+                  <ColumnDefinition Width="{DynamicResource SliderPostContentMargin}" />
-            </Track.IncreaseButton>
+                </Grid.ColumnDefinitions>
-            <Thumb Name="thumb" MinWidth="20" MinHeight="20">
+                <TickBar Name="LeftTickBar" Placement="Left" Width="{DynamicResource SliderOutsideTickBarThemeHeight}" HorizontalAlignment="Right" Margin="0,0,4,0" Grid.RowSpan="3" />
-              <Thumb.Template>
+                <!-- <TickBar Name="VerticalInlineTickBar" Placement="Inline" Fill="{DynamicResource SliderInlineTickBarFill}" Width="{DynamicResource SliderTrackThemeHeight}" Grid.Column="1" Grid.RowSpan="3" /> -->
-                <ControlTemplate>
+                <TickBar Name="RightTickBar" Placement="Right" Width="{DynamicResource SliderOutsideTickBarThemeHeight}" HorizontalAlignment="Left" Margin="4,0,0,0" Grid.Column="2" Grid.RowSpan="3" />
-                  <Grid>
+                <Track Name="PART_Track" Grid.Column="1" Grid.ColumnSpan="1" Grid.RowSpan="3" Orientation="Vertical">
-                    <Ellipse Width="12" Height="12" Fill="{DynamicResource ThemeAccentBrush}"/>
+                  <Track.DecreaseButton>
-                  </Grid>
+                    <RepeatButton Name="PART_DecreaseButton" Background="{TemplateBinding Foreground}">
-                </ControlTemplate>
+                      <RepeatButton.Template>
-              </Thumb.Template>
+                        <ControlTemplate>
-            </Thumb>
+                          <Grid>
-          </Track>
+                            <Border Name="FocusTarget" Background="Transparent" Margin="0,-10" />
-        </Grid>
+                            <Border Name="TrackBackground" Background="{TemplateBinding Background}" CornerRadius="{DynamicResource ControlCornerRadius}" Width="{DynamicResource SliderTrackThemeHeight}" HorizontalAlignment="Center" />
+                          </Grid>
+                        </ControlTemplate>
+                      </RepeatButton.Template>
+                    </RepeatButton>
+                  </Track.DecreaseButton>
+                  <Track.IncreaseButton>
+                    <RepeatButton Name="PART_IncreaseButton" Background="{TemplateBinding Background}">
+                      <RepeatButton.Template>
+                        <ControlTemplate>
+                          <Grid>
+                            <Border Name="FocusTarget" Background="Transparent" Margin="0,-10" />
+                            <Border Name="TrackBackground" Background="{TemplateBinding Background}" CornerRadius="{DynamicResource ControlCornerRadius}" Width="{DynamicResource SliderTrackThemeHeight}" HorizontalAlignment="Center" />
+                          </Grid>
+                        </ControlTemplate>
+                      </RepeatButton.Template>
+                    </RepeatButton>
+                  </Track.IncreaseButton>
+                  <Thumb Classes="SliderThumbStyle" Name="SliderThumb" Margin="0" Padding="0" DataContext="{TemplateBinding Value}" Height="{DynamicResource SliderVerticalThumbHeight}" Width="{DynamicResource SliderVerticalThumbWidth}" />
+                </Track>
+              </Grid>
+            </Grid>
+          </Grid>
+        </Border>
       </ControlTemplate>
     </Setter>
   </Style>
   <Style Selector="Slider /template/ Track#PART_Track">
-    <Setter Property="Minimum" Value="{TemplateBinding Minimum}"/>
+    <Setter Property="Minimum" Value="{TemplateBinding Minimum}" />
-    <Setter Property="Maximum" Value="{TemplateBinding Maximum}"/>
+    <Setter Property="Maximum" Value="{TemplateBinding Maximum}" />
-    <Setter Property="Value" Value="{TemplateBinding Value, Mode=TwoWay}"/>
+    <Setter Property="Value" Value="{TemplateBinding Value, Mode=TwoWay}" />
   </Style>
-  <Style Selector="Slider /template/ Border#TrackBackground">
+  <Style Selector="Slider /template/ TickBar">
-    <Setter Property="BorderThickness" Value="2"/>
+    <Setter Property="Fill" Value="{DynamicResource SliderTickBarFill}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource ThemeBorderLowBrush}"/>
+    <Setter Property="TickFrequency" Value="{TemplateBinding Slider.TickFrequency}" />
+    <Setter Property="Orientation" Value="{TemplateBinding Slider.Orientation}" />
+    <Setter Property="Minimum" Value="{TemplateBinding Slider.Minimum}" />
+    <Setter Property="Maximum" Value="{TemplateBinding Slider.Maximum}" />
   </Style>
-  <Style Selector="Slider /template/ RepeatButton.repeattrack">
+  
-    <Setter Property="Background" Value="Transparent"/>
+  <!-- Normal State -->
-    <Setter Property="Foreground" Value="{DynamicResource ThemeBorderLowBrush}"/>
+  
-    <Setter Property="Template">
+  <Style Selector="Slider /template/ Thumb.SliderThumbStyle">
-        <ControlTemplate>
+    <Setter Property="Background" Value="{DynamicResource SliderThumbBackground}" />
-            <Border Background="{TemplateBinding Background}" />
+  </Style>
-        </ControlTemplate>
+
-    </Setter>
+  <Style Selector="Slider /template/ Grid#SliderContainer">
+    <Setter Property="Background" Value="{DynamicResource SliderContainerBackground}" />
+  </Style>
+
+  <Style Selector="Slider /template/ TickBar">
+    <Setter Property="IsVisible" Value="False" />
+  </Style>
+
+  <!-- TickBar Placement States -->
+
+  <Style Selector="Slider[TickPlacement=TopLeft] /template/ TickBar#LeftTickBar, Slider[TickPlacement=Outside] /template/ TickBar#LeftTickBar">
+    <Setter Property="IsVisible" Value="True" />
+  </Style>
+ 
+  <Style Selector="Slider[TickPlacement=TopLeft] /template/ TickBar#TopTickBar, Slider[TickPlacement=Outside] /template/ TickBar#TopTickBar">
+    <Setter Property="IsVisible" Value="True" />
+  </Style>
+ 
+  <Style Selector="Slider[TickPlacement=BottomRight] /template/ TickBar#BottomTickBar, Slider[TickPlacement=Outside] /template/ TickBar#BottomTickBar">
+    <Setter Property="IsVisible" Value="True" />
+  </Style>
+ 
+  <Style Selector="Slider[TickPlacement=BottomRight] /template/ TickBar#RightTickBar, Slider[TickPlacement=Outside] /template/ TickBar#RightTickBar">
+    <Setter Property="IsVisible" Value="True" />
+  </Style>
+ 
+  <!-- Disabled State -->
+
+  <Style Selector="Slider:disabled /template/ ContentPresenter#HeaderContentPresenter">
+    <Setter Property="TextBlock.Foreground" Value="{DynamicResource SliderHeaderForegroundDisabled}" />
+  </Style>
+  
+  <Style Selector="Slider:disabled /template/ RepeatButton#PART_DecreaseButton">
+    <Setter Property="Background" Value="{DynamicResource SliderTrackValueFillDisabled}" />
+  </Style>
+  
+  <Style Selector="Slider:disabled /template/ RepeatButton#PART_IncreaseButton">
+    <Setter Property="Background" Value="{DynamicResource SliderTrackFillDisabled}" />
+  </Style>
+  
+  <Style Selector="Slider:disabled /template/ Thumb.SliderThumbStyle">
+    <Setter Property="Background" Value="{DynamicResource SliderThumbBackgroundDisabled}" />
+  </Style>
+  
+  <Style Selector="Slider:disabled /template/ TickBar">
+    <Setter Property="Fill" Value="{DynamicResource SliderTickBarFillDisabled}" />
+  </Style>
+  
+  <Style Selector="Slider:pointerover /template/ Grid#SliderContainer">
+    <Setter Property="Background" Value="{DynamicResource SliderContainerBackgroundDisabled}" />
+  </Style>
+
+  <!-- PointerOver State -->
+  <Style Selector="Slider:pointerover /template/ RepeatButton#PART_IncreaseButton">
+    <Setter Property="Background" Value="{DynamicResource SliderTrackFillPointerOver}" />
+  </Style>
+  
+  <Style Selector="Slider:pointerover /template/ Thumb.SliderThumbStyle">
+    <Setter Property="Background" Value="{DynamicResource SliderThumbBackgroundPointerOver}" />
+  </Style>
+  
+  <Style Selector="Slider:pointerover /template/ Grid#SliderContainer">
+    <Setter Property="Background" Value="{DynamicResource SliderContainerBackgroundPointerOver}" />
+  </Style>
+  
+  <Style Selector="Slider:pointerover /template/ RepeatButton#PART_DecreaseButton">
+    <Setter Property="Background" Value="{DynamicResource SliderTrackValueFillPointerOver}" />
+  </Style>
+
+  <!-- Pressed State -->
+  <Style Selector="Slider:pressed /template/ RepeatButton#PART_IncreaseButton">
+    <Setter Property="Background" Value="{DynamicResource SliderTrackFillPressed}" />
+  </Style>
+
+  <Style Selector="Slider:pressed /template/ Thumb.SliderThumbStyle">
+    <Setter Property="Background" Value="{DynamicResource SliderThumbBackgroundPressed}" />
+  </Style>
+  
+  <Style Selector="Slider:pointerover /template/ Grid#SliderContainer">
+    <Setter Property="Background" Value="{DynamicResource SliderContainerBackgroundPressed}" />
+  </Style>
+  
+  <Style Selector="Slider:pointerover /template/ RepeatButton#PART_DecreaseButton">
+    <Setter Property="Background" Value="{DynamicResource SliderTrackValueFillPressed}" />
   </Style>
-    <Style Selector="Slider:disabled /template/ Grid#grid">
-        <Setter Property="Opacity" Value="{DynamicResource ThemeDisabledOpacity}" />
-    </Style>
 </Styles>

src/Avalonia.Themes.Fluent/ToolTip.xaml

@@ -1,17 +1,78 @@
-<Style xmlns="https://github.com/avaloniaui" Selector="ToolTip">
+<Styles xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
-  <Setter Property="Background" Value="{DynamicResource ThemeBackgroundBrush}"/>
+  <Design.PreviewWith>
-  <Setter Property="BorderBrush" Value="{DynamicResource ThemeBorderMidBrush}"/>
+    <Grid RowDefinitions="Auto,Auto"
-  <Setter Property="BorderThickness" Value="{DynamicResource ThemeBorderThickness}"/>
+          ColumnDefinitions="Auto,Auto"
-  <Setter Property="Padding" Value="4,2"/>
+          HorizontalAlignment="Center">
-  <Setter Property="Template">
+      <Border Grid.Column="0"
-    <ControlTemplate>
+              Grid.Row="1"
-      <ContentPresenter Name="PART_ContentPresenter"
+              Background="{DynamicResource ThemeAccentBrush}"
-                        Background="{TemplateBinding Background}"
+              Margin="5"
-                        BorderBrush="{TemplateBinding BorderBrush}"
+              Padding="50"
-                        BorderThickness="{TemplateBinding BorderThickness}"
+              ToolTip.Tip="Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.">
-                        ContentTemplate="{TemplateBinding ContentTemplate}"
+        <TextBlock>Hover Here</TextBlock>
-                        Content="{TemplateBinding Content}" 
+      </Border>
-                        Padding="{TemplateBinding Padding}"/>
+      <CheckBox Grid.Column="1"
-    </ControlTemplate>
+                Margin="5"
-  </Setter>
+                Grid.Row="0"
-</Style>
+                IsChecked="{Binding ElementName=Border, Path=(ToolTip.IsOpen)}"
+                Content="ToolTip Open" />
+      <Border Name="Border"
+              Grid.Column="1"
+              Grid.Row="1"
+              Background="{DynamicResource ThemeAccentBrush}"
+              Margin="5"
+              Padding="50"
+              ToolTip.Placement="Bottom">
+        <ToolTip.Tip>
+          <StackPanel>
+            <TextBlock Classes="h1">ToolTip</TextBlock>
+            <TextBlock Classes="h2">A control which pops up a hint when a control is hovered</TextBlock>
+          </StackPanel>
+        </ToolTip.Tip>
+        <TextBlock>ToolTip bottom placement</TextBlock>
+      </Border>
+    </Grid>
+  </Design.PreviewWith>
+
+  <Style Selector="ToolTip">
+    <Setter Property="Foreground" Value="{DynamicResource ToolTipForeground}" />
+    <Setter Property="Background" Value="{DynamicResource ToolTipBackground}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource ToolTipBorderBrush}" />
+    <Setter Property="BorderThickness" Value="{DynamicResource ToolTipBorderThemeThickness}" />
+    <Setter Property="FontFamily" Value="{DynamicResource ContentControlThemeFontFamily}" />
+    <Setter Property="FontSize" Value="{DynamicResource ToolTipContentThemeFontSize}" />
+    <Setter Property="Padding" Value="{DynamicResource ToolTipBorderThemePadding}" />
+    <Setter Property="Transitions">
+      <Transitions>
+        <DoubleTransition Property="Opacity" Duration="0:0:0.15" />
+      </Transitions>
+    </Setter>
+    <Setter Property="Template">
+      <ControlTemplate>
+        <Border Name="PART_LayoutRoot"
+                BorderThickness="{TemplateBinding BorderThickness}"
+                Background="{TemplateBinding Background}"
+                BorderBrush="{TemplateBinding BorderBrush}"
+                Padding="{TemplateBinding Padding}"
+                CornerRadius="{DynamicResource OverlayCornerRadius}">
+          <ContentPresenter Name="PART_ContentPresenter"
+                            MaxWidth="320"
+                            Content="{TemplateBinding Content}"
+                            ContentTemplate="{TemplateBinding ContentTemplate}" />
+        </Border>
+      </ControlTemplate>
+    </Setter>
+  </Style>
+
+  <Style Selector="ToolTip > TextBlock">
+    <Setter Property="TextWrapping" Value="Wrap" />
+  </Style>
+
+  <Style Selector="ToolTip">
+    <Setter Property="Opacity" Value="0" />
+  </Style>
+
+  <Style Selector="ToolTip:open">
+    <Setter Property="Opacity" Value="1" />
+  </Style>
+</Styles>

src/Avalonia.X11/X11Atoms.cs

@@ -22,6 +22,7 @@
 //
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using static Avalonia.X11.XLib;
 // ReSharper disable FieldCanBeMadeReadOnly.Global
@@ -40,8 +41,9 @@ namespace Avalonia.X11
 
     internal class X11Atoms
     {
+        private readonly IntPtr _display;
 
-// Our atoms
+        // Our atoms
         public readonly IntPtr AnyPropertyType = (IntPtr)0;
         public readonly IntPtr XA_PRIMARY = (IntPtr)1;
         public readonly IntPtr XA_SECONDARY = (IntPtr)2;
@@ -187,10 +189,13 @@ namespace Avalonia.X11
         public readonly IntPtr ATOM_PAIR;
         public readonly IntPtr MANAGER;
         public readonly IntPtr _KDE_NET_WM_BLUR_BEHIND_REGION;
+        public readonly IntPtr INCR;
 
-
+        private readonly Dictionary<string, IntPtr> _namesToAtoms  = new Dictionary<string, IntPtr>();
+        private readonly Dictionary<IntPtr, string> _atomsToNames = new Dictionary<IntPtr, string>();
         public X11Atoms(IntPtr display)
         {
+            _display = display;
 
             // make sure this array stays in sync with the statements below
 
@@ -204,7 +209,33 @@ namespace Avalonia.X11
             XInternAtoms(display, atomNames, atomNames.Length, true, atoms);
 
             for (var c = 0; c < fields.Length; c++)
+            {
+                _namesToAtoms[fields[c].Name] = atoms[c];
+                _atomsToNames[atoms[c]] = fields[c].Name;
                 fields[c].SetValue(this, atoms[c]);
+            }
+        }
+
+        public IntPtr GetAtom(string name)
+        {
+            if (_namesToAtoms.TryGetValue(name, out var rv))
+                return rv;
+            var atom = XInternAtom(_display, name, false);
+            _namesToAtoms[name] = atom;
+            _atomsToNames[atom] = name;
+            return atom;
+        }
+
+        public string GetAtomName(IntPtr atom)
+        {
+            if (_atomsToNames.TryGetValue(atom, out var rv))
+                return rv;
+            var name = XLib.GetAtomName(_display, atom);
+            if (name == null)
+                return null;
+            _atomsToNames[atom] = name;
+            _namesToAtoms[name] = atom;
+            return name;
         }
     }
 }

src/Avalonia.X11/X11Clipboard.cs

@@ -1,8 +1,10 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.InteropServices;
 using System.Text;
 using System.Threading.Tasks;
+using Avalonia.Input;
 using Avalonia.Input.Platform;
 using static Avalonia.X11.XLib;
 namespace Avalonia.X11
@@ -10,12 +12,14 @@ namespace Avalonia.X11
     class X11Clipboard : IClipboard
     {
         private readonly X11Info _x11;
-        private string _storedString;
+        private IDataObject _storedDataObject;
         private IntPtr _handle;
         private TaskCompletionSource<IntPtr[]> _requestedFormatsTcs;
-        private TaskCompletionSource<string> _requestedTextTcs;
+        private TaskCompletionSource<object> _requestedDataTcs;
         private readonly IntPtr[] _textAtoms;
         private readonly IntPtr _avaloniaSaveTargetsAtom;
+        private readonly Dictionary<string, IntPtr> _formatAtoms = new Dictionary<string, IntPtr>();
+        private readonly Dictionary<IntPtr, string> _atomFormats = new Dictionary<IntPtr, string>();
 
         public X11Clipboard(AvaloniaX11Platform platform)
         {
@@ -31,6 +35,11 @@ namespace Avalonia.X11
             }.Where(a => a != IntPtr.Zero).ToArray();
         }
 
+        bool IsStringAtom(IntPtr atom)
+        {
+            return _textAtoms.Contains(atom);
+        }
+        
         Encoding GetStringEncoding(IntPtr atom)
         {
             return (atom == _x11.Atoms.XA_STRING
@@ -75,21 +84,31 @@ namespace Avalonia.X11
                 Encoding textEnc;
                 if (target == _x11.Atoms.TARGETS)
                 {
-                    var atoms = _textAtoms;
+                    var atoms = new HashSet<IntPtr> { _x11.Atoms.TARGETS, _x11.Atoms.MULTIPLE };
-                    atoms = atoms.Concat(new[] {_x11.Atoms.TARGETS, _x11.Atoms.MULTIPLE})
+                    foreach (var fmt in _storedDataObject.GetDataFormats())
-                        .ToArray();
+                    {
+                        if (fmt == DataFormats.Text)
+                            foreach (var ta in _textAtoms)
+                                atoms.Add(ta);
+                        else
+                            atoms.Add(_x11.Atoms.GetAtom(fmt));
+                    }
+
                     XChangeProperty(_x11.Display, window, property,
-                        _x11.Atoms.XA_ATOM, 32, PropertyMode.Replace, atoms, atoms.Length);
+                        _x11.Atoms.XA_ATOM, 32, PropertyMode.Replace, atoms.ToArray(), atoms.Count);
                     return property;
                 }
                 else if(target == _x11.Atoms.SAVE_TARGETS && _x11.Atoms.SAVE_TARGETS != IntPtr.Zero)
                 {
                     return property;
                 }
-                else if ((textEnc = GetStringEncoding(target)) != null)
+                else if ((textEnc = GetStringEncoding(target)) != null 
+                         && _storedDataObject?.Contains(DataFormats.Text) == true)
                 {
-
+                    var text = _storedDataObject.GetText();
-                    var data = textEnc.GetBytes(_storedString ?? "");
+                    if(text == null)
+                        return IntPtr.Zero;
+                    var data = textEnc.GetBytes(text);
                     fixed (void* pdata = data)
                         XChangeProperty(_x11.Display, window, property, target, 8,
                             PropertyMode.Replace,
@@ -121,6 +140,23 @@ namespace Avalonia.X11
 
                     return property;
                 }
+                else if(_storedDataObject?.Contains(_x11.Atoms.GetAtomName(target)) == true)
+                {
+                    var objValue = _storedDataObject.Get(_x11.Atoms.GetAtomName(target));
+                    
+                    if(!(objValue is byte[] bytes))
+                    {
+                        if (objValue is string s)
+                            bytes = Encoding.UTF8.GetBytes(s);
+                        else
+                            return IntPtr.Zero;
+                    }
+
+                    XChangeProperty(_x11.Display, window, property, target, 8,
+                        PropertyMode.Replace,
+                        bytes, bytes.Length);
+                    return property;
+                }
                 else
                     return IntPtr.Zero;
             }
@@ -131,15 +167,15 @@ namespace Avalonia.X11
                 if (sel.property == IntPtr.Zero)
                 {
                     _requestedFormatsTcs?.TrySetResult(null);
-                    _requestedTextTcs?.TrySetResult(null);
+                    _requestedDataTcs?.TrySetResult(null);
                 }
                 XGetWindowProperty(_x11.Display, _handle, sel.property, IntPtr.Zero, new IntPtr (0x7fffffff), true, (IntPtr)Atom.AnyPropertyType,
-                    out var actualAtom, out var actualFormat, out var nitems, out var bytes_after, out var prop);
+                    out var actualTypeAtom, out var actualFormat, out var nitems, out var bytes_after, out var prop);
                 Encoding textEnc = null;
                 if (nitems == IntPtr.Zero)
                 {
                     _requestedFormatsTcs?.TrySetResult(null);
-                    _requestedTextTcs?.TrySetResult(null);
+                    _requestedDataTcs?.TrySetResult(null);
                 }
                 else
                 {
@@ -154,10 +190,24 @@ namespace Avalonia.X11
                             _requestedFormatsTcs?.TrySetResult(formats);
                         }
                     }
-                    else if ((textEnc = GetStringEncoding(sel.property)) != null)
+                    else if ((textEnc = GetStringEncoding(actualTypeAtom)) != null)
                     {
                         var text = textEnc.GetString((byte*)prop.ToPointer(), nitems.ToInt32());
-                        _requestedTextTcs?.TrySetResult(text);
+                        _requestedDataTcs?.TrySetResult(text);
+                    }
+                    else
+                    {
+                        if (actualTypeAtom == _x11.Atoms.INCR)
+                        {
+                            // TODO: Actually implement that monstrosity
+                            _requestedDataTcs.TrySetResult(null);
+                        }
+                        else
+                        {
+                            var data = new byte[(int)nitems * (actualFormat / 8)];
+                            Marshal.Copy(prop, data, 0, data.Length);
+                            _requestedDataTcs?.TrySetResult(data);
+                        }
                     }
                 }
 
@@ -174,17 +224,19 @@ namespace Avalonia.X11
             return _requestedFormatsTcs.Task;
         }
 
-        Task<string> SendTextRequest(IntPtr format)
+        Task<object> SendDataRequest(IntPtr format)
         {
-            if (_requestedTextTcs == null || _requestedFormatsTcs.Task.IsCompleted)
+            if (_requestedDataTcs == null || _requestedFormatsTcs.Task.IsCompleted)
-                _requestedTextTcs = new TaskCompletionSource<string>();
+                _requestedDataTcs = new TaskCompletionSource<object>();
             XConvertSelection(_x11.Display, _x11.Atoms.CLIPBOARD, format, format, _handle, IntPtr.Zero);
-            return _requestedTextTcs.Task;
+            return _requestedDataTcs.Task;
         }
+
+        bool HasOwner => XGetSelectionOwner(_x11.Display, _x11.Atoms.CLIPBOARD) != IntPtr.Zero;
         
         public async Task<string> GetTextAsync()
         {
-            if (XGetSelectionOwner(_x11.Display, _x11.Atoms.CLIPBOARD) == IntPtr.Zero)
+            if (!HasOwner)
                 return null;
             var res = await SendFormatRequest();
             var target = _x11.Atoms.UTF8_STRING;
@@ -199,7 +251,7 @@ namespace Avalonia.X11
                     }
             }
 
-            return await SendTextRequest(target);
+            return (string)await SendDataRequest(target);
         }
 
         void StoreAtomsInClipboardManager(IntPtr[] atoms)
@@ -220,15 +272,52 @@ namespace Avalonia.X11
 
         public Task SetTextAsync(string text)
         {
-            _storedString = text;
+            var data = new DataObject();
+            data.Set(DataFormats.Text, text);
+            return SetDataObjectAsync(data);
+        }
+
+        public Task ClearAsync()
+        {
+            return SetTextAsync(null);
+        }
+
+        public Task SetDataObjectAsync(IDataObject data)
+        {
+            _storedDataObject = data;
             XSetSelectionOwner(_x11.Display, _x11.Atoms.CLIPBOARD, _handle, IntPtr.Zero);
             StoreAtomsInClipboardManager(_textAtoms);
             return Task.CompletedTask;
         }
 
-        public Task ClearAsync()
+        public async Task<string[]> GetFormatsAsync()
         {
-            return SetTextAsync(null);
+            if (!HasOwner)
+                return null;
+            var res = await SendFormatRequest();
+            if (res == null)
+                return null;
+            var rv = new List<string>();
+            if (_textAtoms.Any(res.Contains))
+                rv.Add(DataFormats.Text);
+            foreach (var t in res)
+                rv.Add(_x11.Atoms.GetAtomName(t));
+            return rv.ToArray();
+        }
+
+        public async Task<object> GetDataAsync(string format)
+        {
+            if (!HasOwner)
+                return null;
+            if (format == DataFormats.Text)
+                return await GetTextAsync();
+
+            var formatAtom = _x11.Atoms.GetAtom(format);
+            var res = await SendFormatRequest();
+            if (!res.Contains(formatAtom))
+                return null;
+            
+            return await SendDataRequest(formatAtom);
         }
     }
 }

src/Avalonia.X11/XLib.cs

@@ -236,6 +236,10 @@ namespace Avalonia.X11
         public static extern int XChangeProperty(IntPtr display, IntPtr window, IntPtr property, IntPtr type,
             int format, PropertyMode mode, ref IntPtr value, int nelements);
 
+        [DllImport(libX11)]
+        public static extern int XChangeProperty(IntPtr display, IntPtr window, IntPtr property, IntPtr type,
+            int format, PropertyMode mode, byte[] data, int nelements);
+        
         [DllImport(libX11)]
         public static extern int XChangeProperty(IntPtr display, IntPtr window, IntPtr property, IntPtr type,
             int format, PropertyMode mode, uint[] data, int nelements);

src/Markup/Avalonia.Markup/Data/MultiBinding.cs

@@ -107,6 +107,14 @@ namespace Avalonia.Data
 
         private object ConvertValue(IList<object> values, Type targetType, IMultiValueConverter converter)
         {
+            for (var i = 0; i < values.Count; ++i)
+            {
+                if (values[i] is BindingNotification notification)
+                {
+                    values[i] = notification.Value;
+                }
+            }
+
             var culture = CultureInfo.CurrentCulture;
             var converted = converter.Convert(values, targetType, ConverterParameter, culture);
 

src/Windows/Avalonia.Win32/Avalonia.Win32.csproj

@@ -6,6 +6,7 @@
   </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\..\packages\Avalonia\Avalonia.csproj" />
+    <PackageReference Include="Avalonia.Angle.Windows.Natives" Version="2.1.0.2019013001" />
   </ItemGroup>
-  <Import Project="$(MSBuildThisFileDirectory)\..\..\..\build\System.Drawing.Common.props" />
+  <Import Project="$(MSBuildThisFileDirectory)\..\..\..\build\System.Drawing.Common.props" />  
 </Project>

src/Windows/Avalonia.Win32/ClipboardImpl.cs

@@ -1,25 +1,30 @@
 using System;
+using System.Linq;
+using System.Reactive.Disposables;
 using System.Runtime.InteropServices;
 using System.Threading.Tasks;
+using Avalonia.Input;
 using Avalonia.Input.Platform;
+using Avalonia.Threading;
 using Avalonia.Win32.Interop;
 
 namespace Avalonia.Win32
 {
     internal class ClipboardImpl : IClipboard
     {
-        private async Task OpenClipboard()
+        private async Task<IDisposable> OpenClipboard()
         {
             while (!UnmanagedMethods.OpenClipboard(IntPtr.Zero))
             {
                 await Task.Delay(100);
             }
+
+            return Disposable.Create(() => UnmanagedMethods.CloseClipboard());
         }
 
         public async Task<string> GetTextAsync()
         {
-            await OpenClipboard();
+            using(await OpenClipboard())
-            try
             {
                 IntPtr hText = UnmanagedMethods.GetClipboardData(UnmanagedMethods.ClipboardFormat.CF_UNICODETEXT);
                 if (hText == IntPtr.Zero)
@@ -37,10 +42,6 @@ namespace Avalonia.Win32
                 UnmanagedMethods.GlobalUnlock(hText);
                 return rv;
             }
-            finally
-            {
-                UnmanagedMethods.CloseClipboard();
-            }
         }
 
         public async Task SetTextAsync(string text)
@@ -50,31 +51,66 @@ namespace Avalonia.Win32
                 throw new ArgumentNullException(nameof(text));
             }
 
-            await OpenClipboard();
+            using(await OpenClipboard())
-
-            UnmanagedMethods.EmptyClipboard();
-
-            try
             {
+                UnmanagedMethods.EmptyClipboard();
+
                 var hGlobal = Marshal.StringToHGlobalUni(text);
                 UnmanagedMethods.SetClipboardData(UnmanagedMethods.ClipboardFormat.CF_UNICODETEXT, hGlobal);
             }
-            finally
-            {
-                UnmanagedMethods.CloseClipboard();
-            }
         }
 
         public async Task ClearAsync()
         {
-            await OpenClipboard();
+            using(await OpenClipboard())
-            try
             {
                 UnmanagedMethods.EmptyClipboard();
             }
-            finally
+        }
+
+        public async Task SetDataObjectAsync(IDataObject data)
+        {
+            Dispatcher.UIThread.VerifyAccess();
+            var wrapper = new DataObject(data);
+            while (true)
             {
-                UnmanagedMethods.CloseClipboard();
+                if (UnmanagedMethods.OleSetClipboard(wrapper) == 0)
+                    break;
+                await Task.Delay(100);
+            }
+        }
+
+        public async Task<string[]> GetFormatsAsync()
+        {
+            Dispatcher.UIThread.VerifyAccess();
+            while (true)
+            {
+                if (UnmanagedMethods.OleGetClipboard(out var dataObject) == 0)
+                {
+                    var wrapper = new OleDataObject(dataObject);
+                    var formats = wrapper.GetDataFormats().ToArray();
+                    Marshal.ReleaseComObject(dataObject);
+                    return formats;
+                }
+
+                await Task.Delay(100);
+            }
+        }
+
+        public async Task<object> GetDataAsync(string format)
+        {
+            Dispatcher.UIThread.VerifyAccess();
+            while (true)
+            {
+                if (UnmanagedMethods.OleGetClipboard(out var dataObject) == 0)
+                {
+                    var wrapper = new OleDataObject(dataObject);
+                    var rv = wrapper.Get(format);
+                    Marshal.ReleaseComObject(dataObject);
+                    return rv;
+                }
+
+                await Task.Delay(100);
             }
         }
     }

src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs

@@ -1169,6 +1169,12 @@ namespace Avalonia.Win32.Interop
         [DllImport("user32.dll")]
         public static extern IntPtr SetClipboardData(ClipboardFormat uFormat, IntPtr hMem);
 
+        [DllImport("ole32.dll", PreserveSig = false)]
+        public static extern int OleGetClipboard(out IOleDataObject dataObject);
+
+        [DllImport("ole32.dll", PreserveSig = true)]
+        public static extern int OleSetClipboard(IOleDataObject dataObject);
+
         [DllImport("kernel32.dll", ExactSpelling = true)]
         public static extern IntPtr GlobalLock(IntPtr handle);
 

src/Windows/Avalonia.Win32/Win32Platform.cs

@@ -36,7 +36,7 @@ namespace Avalonia
     public class Win32PlatformOptions
     {
         public bool UseDeferredRendering { get; set; } = true;
-        public bool AllowEglInitialization { get; set; }
+        public bool AllowEglInitialization { get; set; } = true;
         public bool? EnableMultitouch { get; set; }
         public bool OverlayPopups { get; set; }
     }

src/iOS/Avalonia.iOS/Clipboard.cs

@@ -22,5 +22,11 @@ namespace Avalonia.iOS
             UIPasteboard.General.String = "";
             return Task.FromResult(0);
         }
+
+        public Task SetDataObjectAsync(IDataObject data) => throw new PlatformNotSupportedException();
+
+        public Task<string[]> GetFormatsAsync() => throw new PlatformNotSupportedException();
+
+        public Task<object> GetDataAsync(string format) => throw new PlatformNotSupportedException();
     }
 }

tests/Avalonia.Animation.UnitTests/AnimatableTests.cs

@@ -2,6 +2,7 @@
 using Avalonia.Controls;
 using Avalonia.Data;
 using Avalonia.Layout;
+using Avalonia.Media;
 using Avalonia.Styling;
 using Avalonia.UnitTests;
 using Moq;
@@ -265,6 +266,70 @@ namespace Avalonia.Animation.UnitTests
             }
         }
 
+        [Fact]
+        public void Replacing_Transitions_During_Animation_Does_Not_Throw_KeyNotFound()
+        {
+            // Issue #4059
+            using (UnitTestApplication.Start(TestServices.RealStyler))
+            {
+                Border target;
+                var clock = new TestClock();
+                var root = new TestRoot
+                {
+                    Clock = clock,
+                    Styles =
+                    {
+                        new Style(x => x.OfType<Border>())
+                        {
+                            Setters =
+                            {
+                                new Setter(Border.TransitionsProperty,
+                                    new Transitions
+                                    {
+                                        new DoubleTransition
+                                        {
+                                            Property = Border.OpacityProperty,
+                                            Duration = TimeSpan.FromSeconds(1),
+                                        },
+                                    }),
+                            },
+                        },
+                        new Style(x => x.OfType<Border>().Class("foo"))
+                        {
+                            Setters =
+                            {
+                                new Setter(Border.TransitionsProperty,
+                                    new Transitions
+                                    {
+                                        new DoubleTransition
+                                        {
+                                            Property = Border.OpacityProperty,
+                                            Duration = TimeSpan.FromSeconds(1),
+                                        },
+                                    }),
+                                new Setter(Border.OpacityProperty, 0.0),
+                            },
+                        },
+                    },
+                    Child = target = new Border
+                    {
+                        Background = Brushes.Red,
+                    }
+                };
+
+                root.Measure(Size.Infinity);
+                root.Arrange(new Rect(root.DesiredSize));
+
+                target.Classes.Add("foo");
+                clock.Step(TimeSpan.FromSeconds(0));
+                clock.Step(TimeSpan.FromSeconds(0.5));
+
+                Assert.Equal(0.5, target.Opacity);
+
+                target.Classes.Remove("foo");
+            }
+        }
+
         private static Mock<ITransition> CreateTarget()
         {
             return CreateTransition(Visual.OpacityProperty);

tests/Avalonia.Benchmarks/Data/PropertyAccessorBenchmarks.cs

@@ -0,0 +1,88 @@
+using System;
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+using Avalonia.Data.Core.Plugins;
+using BenchmarkDotNet.Attributes;
+using JetBrains.Annotations;
+
+namespace Avalonia.Benchmarks.Data
+{
+    [MemoryDiagnoser, InProcess]
+    public class PropertyAccessorBenchmarks
+    {
+        private readonly InpcPropertyAccessorPlugin _inpcPlugin = new InpcPropertyAccessorPlugin();
+        private readonly MethodAccessorPlugin _methodPlugin = new MethodAccessorPlugin();
+        private readonly TestObject _targetStrongRef = new TestObject();
+        private readonly WeakReference<object> _targetWeakRef;
+
+        public PropertyAccessorBenchmarks()
+        {
+            _targetWeakRef = new WeakReference<object>(_targetStrongRef);
+        }
+
+        [Benchmark]
+        public void InpcAccessorMatch()
+        {
+            _inpcPlugin.Match(_targetWeakRef, nameof(TestObject.Test));
+        }
+
+        [Benchmark]
+        public void InpcAccessorStart()
+        {
+            _inpcPlugin.Start(_targetWeakRef, nameof(TestObject.Test));
+        }
+
+        [Benchmark]
+        public void MethodAccessorMatch()
+        {
+            _methodPlugin.Match(_targetWeakRef, nameof(TestObject.Execute));
+        }
+
+        [Benchmark]
+        public void MethodAccessorStart()
+        {
+            _methodPlugin.Start(_targetWeakRef, nameof(TestObject.Execute));
+        }
+
+        private class TestObject : INotifyPropertyChanged
+        {
+            private string _test;
+
+            public string Test
+            {
+                get => _test;
+                set
+                {
+                    if (_test == value)
+                    {
+                        return;
+                    }
+
+                    _test = value;
+
+                    OnPropertyChanged();
+                }
+            }
+
+            public void Execute()
+            {
+            }
+
+            public void Execute(object p0)
+            {
+            }
+
+            public void Execute(object p0, object p1)
+            {
+            }
+
+            public event PropertyChangedEventHandler PropertyChanged;
+
+            [NotifyPropertyChangedInvocator]
+            protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
+            {
+                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+            }
+        }
+    }
+}

tests/Avalonia.Controls.UnitTests/IndexRangeTests.cs

@@ -127,6 +127,88 @@ namespace Avalonia.Controls.UnitTests
             Assert.Empty(selected);
         }
 
+        [Fact]
+        public void Intersect_Should_Remove_Items_From_Beginning()
+        {
+            var ranges = new List<IndexRange> { new IndexRange(0, 10) };
+            var removed = new List<IndexRange>();
+            var result = IndexRange.Intersect(ranges, new IndexRange(2, 12), removed);
+
+            Assert.Equal(2, result);
+            Assert.Equal(new[] { new IndexRange(2, 10) }, ranges);
+            Assert.Equal(new[] { new IndexRange(0, 1) }, removed);
+        }
+
+        [Fact]
+        public void Intersect_Should_Remove_Items_From_End()
+        {
+            var ranges = new List<IndexRange> { new IndexRange(0, 10) };
+            var removed = new List<IndexRange>();
+            var result = IndexRange.Intersect(ranges, new IndexRange(0, 8), removed);
+
+            Assert.Equal(2, result);
+            Assert.Equal(new[] { new IndexRange(0, 8) }, ranges);
+            Assert.Equal(new[] { new IndexRange(9, 10) }, removed);
+        }
+
+        [Fact]
+        public void Intersect_Should_Remove_Entire_Range_Start()
+        {
+            var ranges = new List<IndexRange> { new IndexRange(0, 5), new IndexRange(6, 10) };
+            var removed = new List<IndexRange>();
+            var result = IndexRange.Intersect(ranges, new IndexRange(6, 10), removed);
+
+            Assert.Equal(6, result);
+            Assert.Equal(new[] { new IndexRange(6, 10) }, ranges);
+            Assert.Equal(new[] { new IndexRange(0, 5) }, removed);
+        }
+
+        [Fact]
+        public void Intersect_Should_Remove_Entire_Range_End()
+        {
+            var ranges = new List<IndexRange> { new IndexRange(0, 5), new IndexRange(6, 10) };
+            var removed = new List<IndexRange>();
+            var result = IndexRange.Intersect(ranges, new IndexRange(0, 4), removed);
+
+            Assert.Equal(6, result);
+            Assert.Equal(new[] { new IndexRange(0, 4) }, ranges);
+            Assert.Equal(new[] { new IndexRange(5, 10) }, removed);
+        }
+
+        [Fact]
+        public void Intersect_Should_Remove_Entire_Range_Start_End()
+        {
+            var ranges = new List<IndexRange> 
+            { 
+                new IndexRange(0, 2),
+                new IndexRange(3, 7), 
+                new IndexRange(8, 10) 
+            };
+            var removed = new List<IndexRange>();
+            var result = IndexRange.Intersect(ranges, new IndexRange(3, 7), removed);
+
+            Assert.Equal(6, result);
+            Assert.Equal(new[] { new IndexRange(3, 7) }, ranges);
+            Assert.Equal(new[] { new IndexRange(0, 2), new IndexRange(8, 10) }, removed);
+        }
+
+        [Fact]
+        public void Intersect_Should_Remove_Entire_And_Partial_Range_Start_End()
+        {
+            var ranges = new List<IndexRange>
+            {
+                new IndexRange(0, 2),
+                new IndexRange(3, 7),
+                new IndexRange(8, 10)
+            };
+            var removed = new List<IndexRange>();
+            var result = IndexRange.Intersect(ranges, new IndexRange(4, 6), removed);
+
+            Assert.Equal(8, result);
+            Assert.Equal(new[] { new IndexRange(4, 6) }, ranges);
+            Assert.Equal(new[] { new IndexRange(0, 3), new IndexRange(7, 10) }, removed);
+        }
+
         [Fact]
         public void Remove_Should_Remove_Entire_Range()
         {

tests/Avalonia.Controls.UnitTests/SelectionModelTests.cs

@@ -1512,6 +1512,47 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(0, raised);
         }
 
+        [Fact]
+        public void Batch_Update_Selection_Is_Correct_Throughout()
+        {
+            var data = new[] { "foo", "bar", "baz", "qux" };
+            var target = new SelectionModel { Source = data };
+            var raised = 0;
+
+            using (target.Update())
+            {
+                target.Select(1);
+
+                Assert.Equal(new IndexPath(1), target.SelectedIndex);
+                Assert.Equal(new[] { new IndexPath(1) }, target.SelectedIndices);
+                Assert.Equal("bar", target.SelectedItem);
+                Assert.Equal(new[] { "bar" }, target.SelectedItems);
+
+                target.Deselect(1);
+
+                Assert.Equal(new IndexPath(), target.SelectedIndex);
+                Assert.Empty(target.SelectedIndices);
+                Assert.Null(target.SelectedItem);
+                Assert.Empty(target.SelectedItems);
+
+                target.SelectRange(new IndexPath(1), new IndexPath(1));
+
+                Assert.Equal(new IndexPath(1), target.SelectedIndex);
+                Assert.Equal(new[] { new IndexPath(1) }, target.SelectedIndices);
+                Assert.Equal("bar", target.SelectedItem);
+                Assert.Equal(new[] { "bar" }, target.SelectedItems);
+
+                target.ClearSelection();
+
+                Assert.Equal(new IndexPath(), target.SelectedIndex);
+                Assert.Empty(target.SelectedIndices);
+                Assert.Null(target.SelectedItem);
+                Assert.Empty(target.SelectedItems);
+            }
+
+            Assert.Equal(0, raised);
+        }
+
         [Fact]
         public void AutoSelect_Selects_When_Enabled()
         {
@@ -1713,6 +1754,30 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(0, raised);
         }
 
+        [Fact]
+        public void AutoSelect_Is_Applied_At_End_Of_Batch_Update()
+        {
+            var data = new[] { "foo", "bar", "baz" };
+            var target = new SelectionModel { AutoSelect = true, Source = data };
+
+            using (target.Update())
+            {
+                target.ClearSelection();
+
+                Assert.Equal(new IndexPath(), target.SelectedIndex);
+                Assert.Empty(target.SelectedIndices);
+                Assert.Null(target.SelectedItem);
+                Assert.Empty(target.SelectedItems);
+            }
+
+            Assert.Equal(new IndexPath(0), target.SelectedIndex);
+            Assert.Equal(new[] { new IndexPath(0) }, target.SelectedIndices);
+            Assert.Equal("foo", target.SelectedItem);
+            Assert.Equal(new[] { "foo" }, target.SelectedItems);
+
+            Assert.Equal(new IndexPath(0), target.SelectedIndex);
+        }
+
         [Fact]
         public void Can_Replace_Parent_Children_Collection()
         {
@@ -1806,6 +1871,87 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(0, node.PropertyChangedSubscriptions);
         }
 
+        [Fact]
+        public void Setting_SelectedIndex_To_Minus_1_Clears_Selection()
+        {
+            var data = new[] { "foo", "bar", "baz" };
+            var target = new SelectionModel { Source = data };
+            target.SelectedIndex = new IndexPath(1);
+            target.SelectedIndex = new IndexPath(-1);
+            Assert.Empty(target.SelectedIndices);
+        }
+
+        [Fact]
+        public void Assigning_Source_With_Less_Items_Than_Previous_Clears_Selection()
+        {
+            var data = new[] { "foo", "bar", "baz", "boo", "hoo" };
+            var smallerData = new[] { "foo", "bar", "baz" };
+            var target = new SelectionModel { RetainSelectionOnReset = true };
+            target.Source = data;
+            target.SelectedIndex = new IndexPath(4);
+            target.Source = smallerData;
+            Assert.Empty(target.SelectedIndices);
+        }
+
+        [Fact]
+        public void Initializing_Source_With_Less_Items_Than_Selection_Trims_Selection()
+        {
+            var data = new[] { "foo", "bar", "baz" };
+            var target = new SelectionModel();
+            target.SelectedIndex = new IndexPath(4);
+            target.Source = data;
+            Assert.Empty(target.SelectedIndices);
+        }
+
+        [Fact]
+        public void Initializing_Source_With_Less_Items_Than_Selection_Trims_Selection_RetainSelection()
+        {
+            var data = new[] { "foo", "bar", "baz" };
+            var target = new SelectionModel { RetainSelectionOnReset = true };
+            target.SelectedIndex = new IndexPath(4);
+            target.Source = data;
+            Assert.Empty(target.SelectedIndices);
+        }
+
+        [Fact]
+        public void Initializing_Source_With_Less_Items_Than_Multiple_Selection_Trims_Selection()
+        {
+            var data = new[] { "foo", "bar", "baz" };
+            var target = new SelectionModel { RetainSelectionOnReset = true };
+            target.Select(4);
+            target.Select(2);
+            target.Source = data;
+            Assert.Equal(1, target.SelectedIndices.Count);
+            Assert.Equal(new IndexPath(2), target.SelectedIndices.First());
+        }
+
+        [Fact]
+        public void Initializing_Source_With_Less_Items_Than_Selection_Raises_SelectionChanged()
+        {
+            var data = new[] { "foo", "bar", "baz" };
+            var target = new SelectionModel();
+            var raised = 0;
+
+            target.SelectedIndex = new IndexPath(4);
+
+            target.SelectionChanged += (s, e) =>
+            {
+                if (raised == 0)
+                {
+                    Assert.Equal(new[] { Path(4) }, e.DeselectedIndices);
+                    Assert.Equal(new object[] { null }, e.DeselectedItems);
+                    Assert.Empty(e.SelectedIndices);
+                    Assert.Empty(e.SelectedItems);
+                }
+
+                ++raised;
+            };
+
+            target.Source = data;
+            
+            Assert.Equal(2, raised);
+        }
+
         private int GetSubscriberCount(AvaloniaList<object> list)
         {
             return ((INotifyCollectionChangedDebug)list).GetCollectionChangedSubscribers()?.Length ?? 0;

tests/Avalonia.Controls.UnitTests/TabControlTests.cs

@@ -1,10 +1,12 @@
 using System;
+using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
 using Avalonia.Collections;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
+using Avalonia.Controls.Utils;
 using Avalonia.LogicalTree;
 using Avalonia.Styling;
 using Avalonia.UnitTests;
@@ -325,6 +327,28 @@ namespace Avalonia.Controls.UnitTests
             Assert.NotEqual(dataContext, tabItem.Content);
         }
 
+        [Fact]
+        public void Can_Have_Empty_Tab_Control()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
+        xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.Xaml;assembly=Avalonia.Markup.Xaml.UnitTests'>
+    <TabControl Name='tabs' Items='{Binding Tabs}'/>
+</Window>";
+                var loader = new Markup.Xaml.AvaloniaXamlLoader();
+                var window = (Window)loader.Load(xaml);
+                var tabControl = window.FindControl<TabControl>("tabs");
+
+                tabControl.DataContext = new { Tabs = new List<string>() };
+                window.ApplyTemplate();
+
+                Assert.Equal(0, tabControl.Items.Count());
+            }
+        }
+
         private IControlTemplate TabControlTemplate()
         {
             return new FuncControlTemplate<TabControl>((parent, scope) =>

tests/Avalonia.Controls.UnitTests/TextBoxTests.cs

@@ -654,6 +654,11 @@ namespace Avalonia.Controls.UnitTests
             public Task SetTextAsync(string text) => Task.CompletedTask;
 
             public Task ClearAsync() => Task.CompletedTask;
+            public Task SetDataObjectAsync(IDataObject data) => Task.CompletedTask;
+
+            public Task<string[]> GetFormatsAsync() => Task.FromResult(Array.Empty<string>());
+
+            public Task<object> GetDataAsync(string format) => Task.FromResult((object)null);
         }
     }
 }

tests/Avalonia.Controls.UnitTests/ToolTipTests.cs

@@ -102,5 +102,76 @@ namespace Avalonia.Controls.UnitTests
                 Assert.True(ToolTip.GetIsOpen(target));
             }
         }
+
+        [Fact]
+        public void Open_Class_Should_Not_Initially_Be_Added()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var toolTip = new ToolTip();
+                var window = new Window();
+
+                var decorator = new Decorator()
+                {
+                    [ToolTip.TipProperty] = toolTip
+                };
+
+                window.Content = decorator;
+
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                Assert.Empty(toolTip.Classes);
+            }
+        }
+
+        [Fact]
+        public void Setting_IsOpen_Should_Add_Open_Class()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var toolTip = new ToolTip();
+                var window = new Window();
+
+                var decorator = new Decorator()
+                {
+                    [ToolTip.TipProperty] = toolTip
+                };
+
+                window.Content = decorator;
+
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                ToolTip.SetIsOpen(decorator, true);
+
+                Assert.Equal(new[] { ":open" }, toolTip.Classes);
+            }
+        }
+
+        [Fact]
+        public void Clearing_IsOpen_Should_Remove_Open_Class()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var toolTip = new ToolTip();
+                var window = new Window();
+
+                var decorator = new Decorator()
+                {
+                    [ToolTip.TipProperty] = toolTip
+                };
+
+                window.Content = decorator;
+
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                ToolTip.SetIsOpen(decorator, true);
+                ToolTip.SetIsOpen(decorator, false);
+
+                Assert.Empty(toolTip.Classes);
+            }
+        }
     }
 }

tests/Avalonia.Controls.UnitTests/TreeViewTests.cs

@@ -118,313 +118,340 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Clicking_Item_Should_Select_It()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree,
+                var target = new TreeView
-            };
+                {
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree,
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            ExpandAll(target);
+                ExpandAll(target);
 
-            var item = tree[0].Children[1].Children[0];
+                var item = tree[0].Children[1].Children[0];
-            var container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item);
+                var container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item);
 
-            Assert.NotNull(container);
+                Assert.NotNull(container);
 
-            _mouse.Click(container);
+                _mouse.Click(container);
 
-            Assert.Equal(item, target.SelectedItem);
+                Assert.Equal(item, target.SelectedItem);
-            Assert.True(container.IsSelected);
+                Assert.True(container.IsSelected);
+            }
         }
 
         [Fact]
         public void Clicking_WithControlModifier_Selected_Item_Should_Deselect_It()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree
+                var target = new TreeView
-            };
+                {
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            ExpandAll(target);
+                ExpandAll(target);
 
-            var item = tree[0].Children[1].Children[0];
+                var item = tree[0].Children[1].Children[0];
-            var container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item);
+                var container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item);
 
-            Assert.NotNull(container);
+                Assert.NotNull(container);
 
-            target.SelectedItem = item;
+                target.SelectedItem = item;
 
-            Assert.True(container.IsSelected);
+                Assert.True(container.IsSelected);
 
-            _mouse.Click(container, modifiers: KeyModifiers.Control);
+                _mouse.Click(container, modifiers: KeyModifiers.Control);
 
-            Assert.Null(target.SelectedItem);
+                Assert.Null(target.SelectedItem);
-            Assert.False(container.IsSelected);
+                Assert.False(container.IsSelected);
+            }
         }
 
         [Fact]
         public void Clicking_WithControlModifier_Not_Selected_Item_Should_Select_It()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree
+                var target = new TreeView
-            };
+                {
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            ExpandAll(target);
+                ExpandAll(target);
 
-            var item1 = tree[0].Children[1].Children[0];
+                var item1 = tree[0].Children[1].Children[0];
-            var container1 = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item1);
+                var container1 = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item1);
 
-            var item2 = tree[0].Children[1];
+                var item2 = tree[0].Children[1];
-            var container2 = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item2);
+                var container2 = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item2);
 
-            Assert.NotNull(container1);
+                Assert.NotNull(container1);
-            Assert.NotNull(container2);
+                Assert.NotNull(container2);
 
-            target.SelectedItem = item1;
+                target.SelectedItem = item1;
 
-            Assert.True(container1.IsSelected);
+                Assert.True(container1.IsSelected);
 
-            _mouse.Click(container2, modifiers: KeyModifiers.Control);
+                _mouse.Click(container2, modifiers: KeyModifiers.Control);
-            
+
-            Assert.Equal(item2, target.SelectedItem);
+                Assert.Equal(item2, target.SelectedItem);
-            Assert.False(container1.IsSelected);
+                Assert.False(container1.IsSelected);
-            Assert.True(container2.IsSelected);
+                Assert.True(container2.IsSelected);
+            }
         }
 
         [Fact]
         public void Clicking_WithControlModifier_Selected_Item_Should_Deselect_And_Remove_From_SelectedItems()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree,
+                var target = new TreeView
-                SelectionMode = SelectionMode.Multiple
+                {
-            };
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree,
+                    SelectionMode = SelectionMode.Multiple
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            ExpandAll(target);
+                ExpandAll(target);
 
-            var rootNode = tree[0];
+                var rootNode = tree[0];
 
-            var item1 = rootNode.Children[0];
+                var item1 = rootNode.Children[0];
-            var item2 = rootNode.Children.Last();
+                var item2 = rootNode.Children.Last();
 
-            var item1Container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item1);
+                var item1Container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item1);
-            var item2Container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item2);
+                var item2Container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item2);
 
-            ClickContainer(item1Container, KeyModifiers.Control);
+                ClickContainer(item1Container, KeyModifiers.Control);
-            Assert.True(item1Container.IsSelected);
+                Assert.True(item1Container.IsSelected);
 
-            ClickContainer(item2Container, KeyModifiers.Control);
+                ClickContainer(item2Container, KeyModifiers.Control);
-            Assert.True(item2Container.IsSelected);
+                Assert.True(item2Container.IsSelected);
 
-            Assert.Equal(new[] {item1, item2}, target.Selection.SelectedItems.OfType<Node>());
+                Assert.Equal(new[] { item1, item2 }, target.Selection.SelectedItems.OfType<Node>());
 
-            ClickContainer(item1Container, KeyModifiers.Control);
+                ClickContainer(item1Container, KeyModifiers.Control);
-            Assert.False(item1Container.IsSelected);
+                Assert.False(item1Container.IsSelected);
 
-            Assert.DoesNotContain(item1, target.Selection.SelectedItems.OfType<Node>());
+                Assert.DoesNotContain(item1, target.Selection.SelectedItems.OfType<Node>());
+            }
         }
 
         [Fact]
         public void Clicking_WithShiftModifier_DownDirection_Should_Select_Range_Of_Items()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree,
+                var target = new TreeView
-                SelectionMode = SelectionMode.Multiple
+                {
-            };
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree,
+                    SelectionMode = SelectionMode.Multiple
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            ExpandAll(target);
+                ExpandAll(target);
 
-            var rootNode = tree[0];
+                var rootNode = tree[0];
 
-            var from = rootNode.Children[0];
+                var from = rootNode.Children[0];
-            var to = rootNode.Children.Last();
+                var to = rootNode.Children.Last();
 
-            var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(from);
+                var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(from);
-            var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
+                var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
 
-            ClickContainer(fromContainer, KeyModifiers.None);
+                ClickContainer(fromContainer, KeyModifiers.None);
 
-            Assert.True(fromContainer.IsSelected);
+                Assert.True(fromContainer.IsSelected);
 
-            ClickContainer(toContainer, KeyModifiers.Shift);
+                ClickContainer(toContainer, KeyModifiers.Shift);
-            AssertChildrenSelected(target, rootNode);
+                AssertChildrenSelected(target, rootNode);
+            }
         }
 
         [Fact]
         public void Clicking_WithShiftModifier_UpDirection_Should_Select_Range_Of_Items()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree,
+                var target = new TreeView
-                SelectionMode = SelectionMode.Multiple
+                {
-            };
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree,
+                    SelectionMode = SelectionMode.Multiple
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            ExpandAll(target);
+                ExpandAll(target);
 
-            var rootNode = tree[0];
+                var rootNode = tree[0];
 
-            var from = rootNode.Children.Last();
+                var from = rootNode.Children.Last();
-            var to = rootNode.Children[0];
+                var to = rootNode.Children[0];
 
-            var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(from);
+                var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(from);
-            var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
+                var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
 
-            ClickContainer(fromContainer, KeyModifiers.None);
+                ClickContainer(fromContainer, KeyModifiers.None);
 
-            Assert.True(fromContainer.IsSelected);
+                Assert.True(fromContainer.IsSelected);
 
-            ClickContainer(toContainer, KeyModifiers.Shift);
+                ClickContainer(toContainer, KeyModifiers.Shift);
-            AssertChildrenSelected(target, rootNode);
+                AssertChildrenSelected(target, rootNode);
+            }
         }
 
         [Fact]
         public void Clicking_First_Item_Of_SelectedItems_Should_Select_Only_It()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree,
+                var target = new TreeView
-                SelectionMode = SelectionMode.Multiple
+                {
-            };
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree,
+                    SelectionMode = SelectionMode.Multiple
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            ExpandAll(target);
+                ExpandAll(target);
 
-            var rootNode = tree[0];
+                var rootNode = tree[0];
 
-            var from = rootNode.Children.Last();
+                var from = rootNode.Children.Last();
-            var to = rootNode.Children[0];
+                var to = rootNode.Children[0];
 
-            var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(from);
+                var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(from);
-            var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
+                var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
 
-            ClickContainer(fromContainer, KeyModifiers.None);
+                ClickContainer(fromContainer, KeyModifiers.None);
 
-            ClickContainer(toContainer, KeyModifiers.Shift);
+                ClickContainer(toContainer, KeyModifiers.Shift);
-            AssertChildrenSelected(target, rootNode);
+                AssertChildrenSelected(target, rootNode);
 
-            ClickContainer(fromContainer, KeyModifiers.None);
+                ClickContainer(fromContainer, KeyModifiers.None);
 
-            Assert.True(fromContainer.IsSelected);
+                Assert.True(fromContainer.IsSelected);
 
-            foreach (var child in rootNode.Children)
+                foreach (var child in rootNode.Children)
-            {
-                if (child == from)
                 {
-                    continue;
+                    if (child == from)
-                }
+                    {
+                        continue;
+                    }
 
-                var container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(child);
+                    var container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(child);
 
-                Assert.False(container.IsSelected);
+                    Assert.False(container.IsSelected);
+                }
             }
         }
 
         [Fact]
         public void Setting_SelectedItem_Should_Set_Container_Selected()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree,
+                var target = new TreeView
-            };
+                {
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree,
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            ExpandAll(target);
+                ExpandAll(target);
 
-            var item = tree[0].Children[1].Children[0];
+                var item = tree[0].Children[1].Children[0];
-            var container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item);
+                var container = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(item);
 
-            Assert.NotNull(container);
+                Assert.NotNull(container);
 
-            target.SelectedItem = item;
+                target.SelectedItem = item;
 
-            Assert.True(container.IsSelected);
+                Assert.True(container.IsSelected);
+            }
         }
 
         [Fact]
         public void Setting_SelectedItem_Should_Raise_SelectedItemChanged_Event()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree,
+                var target = new TreeView
-            };
+                {
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree,
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            ExpandAll(target);
+                ExpandAll(target);
 
-            var item = tree[0].Children[1].Children[0];
+                var item = tree[0].Children[1].Children[0];
 
-            var called = false;
+                var called = false;
-            target.SelectionChanged += (s, e) =>
+                target.SelectionChanged += (s, e) =>
-            {
+                {
-                Assert.Empty(e.RemovedItems);
+                    Assert.Empty(e.RemovedItems);
-                Assert.Equal(1, e.AddedItems.Count);
+                    Assert.Equal(1, e.AddedItems.Count);
-                Assert.Same(item, e.AddedItems[0]);
+                    Assert.Same(item, e.AddedItems[0]);
-                called = true;
+                    called = true;
-            };
+                };
 
-            target.SelectedItem = item;
+                target.SelectedItem = item;
-            Assert.True(called);
+                Assert.True(called);
+            }
         }
 
         [Fact]
@@ -564,7 +591,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Keyboard_Navigation_Should_Move_To_Last_Selected_Node()
         {
-            using (UnitTestApplication.Start(TestServices.RealFocus))
+            using (Application())
             {
                 var focus = FocusManager.Instance;
                 var navigation = AvaloniaLocator.Current.GetService<IKeyboardNavigationHandler>();
@@ -647,7 +674,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Pressing_SelectAll_Gesture_With_Downward_Range_Selected_Should_Select_All_Nodes()
         {
-            using (UnitTestApplication.Start())
+            using (Application())
             {
                 var tree = CreateTestTreeData();
                 var target = new TreeView
@@ -694,7 +721,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Pressing_SelectAll_Gesture_With_Upward_Range_Selected_Should_Select_All_Nodes()
         {
-            using (UnitTestApplication.Start())
+            using (Application())
             {
                 var tree = CreateTestTreeData();
                 var target = new TreeView
@@ -768,97 +795,106 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Right_Click_On_UnselectedItem_Should_Clear_Existing_Selection()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree,
+                var target = new TreeView
-                SelectionMode = SelectionMode.Multiple,
+                {
-            };
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree,
+                    SelectionMode = SelectionMode.Multiple,
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            target.ExpandSubTree((TreeViewItem)target.Presenter.Panel.Children[0]);
+                target.ExpandSubTree((TreeViewItem)target.Presenter.Panel.Children[0]);
 
-            var rootNode = tree[0];
+                var rootNode = tree[0];
-            var to = rootNode.Children[0];
+                var to = rootNode.Children[0];
-            var then = rootNode.Children[1];
+                var then = rootNode.Children[1];
 
-            var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(rootNode);
+                var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(rootNode);
-            var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
+                var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
-            var thenContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(then);
+                var thenContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(then);
 
-            ClickContainer(fromContainer, KeyModifiers.None);
+                ClickContainer(fromContainer, KeyModifiers.None);
-            ClickContainer(toContainer, KeyModifiers.Shift);
+                ClickContainer(toContainer, KeyModifiers.Shift);
 
-            Assert.Equal(2, target.Selection.SelectedItems.Count);
+                Assert.Equal(2, target.Selection.SelectedItems.Count);
 
-            _mouse.Click(thenContainer, MouseButton.Right);
+                _mouse.Click(thenContainer, MouseButton.Right);
 
-            Assert.Equal(1, target.Selection.SelectedItems.Count);
+                Assert.Equal(1, target.Selection.SelectedItems.Count);
+            }
         }
 
         [Fact]
         public void Shift_Right_Click_Should_Not_Select_Multiple()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree,
+                var target = new TreeView
-                SelectionMode = SelectionMode.Multiple,
+                {
-            };
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree,
+                    SelectionMode = SelectionMode.Multiple,
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            target.ExpandSubTree((TreeViewItem)target.Presenter.Panel.Children[0]);
+                target.ExpandSubTree((TreeViewItem)target.Presenter.Panel.Children[0]);
 
-            var rootNode = tree[0];
+                var rootNode = tree[0];
-            var from = rootNode.Children[0];
+                var from = rootNode.Children[0];
-            var to = rootNode.Children[1];
+                var to = rootNode.Children[1];
-            var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(from);
+                var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(from);
-            var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
+                var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
 
-            _mouse.Click(fromContainer);
+                _mouse.Click(fromContainer);
-            _mouse.Click(toContainer, MouseButton.Right, modifiers: KeyModifiers.Shift);
+                _mouse.Click(toContainer, MouseButton.Right, modifiers: KeyModifiers.Shift);
 
-            Assert.Equal(1, target.Selection.SelectedItems.Count);
+                Assert.Equal(1, target.Selection.SelectedItems.Count);
+            }
         }
 
         [Fact]
         public void Ctrl_Right_Click_Should_Not_Select_Multiple()
         {
-            var tree = CreateTestTreeData();
+            using (Application())
-            var target = new TreeView
             {
-                Template = CreateTreeViewTemplate(),
+                var tree = CreateTestTreeData();
-                Items = tree,
+                var target = new TreeView
-                SelectionMode = SelectionMode.Multiple,
+                {
-            };
+                    Template = CreateTreeViewTemplate(),
+                    Items = tree,
+                    SelectionMode = SelectionMode.Multiple,
+                };
 
-            var visualRoot = new TestRoot();
+                var visualRoot = new TestRoot();
-            visualRoot.Child = target;
+                visualRoot.Child = target;
 
-            CreateNodeDataTemplate(target);
+                CreateNodeDataTemplate(target);
-            ApplyTemplates(target);
+                ApplyTemplates(target);
-            target.ExpandSubTree((TreeViewItem)target.Presenter.Panel.Children[0]);
+                target.ExpandSubTree((TreeViewItem)target.Presenter.Panel.Children[0]);
 
-            var rootNode = tree[0];
+                var rootNode = tree[0];
-            var from = rootNode.Children[0];
+                var from = rootNode.Children[0];
-            var to = rootNode.Children[1];
+                var to = rootNode.Children[1];
-            var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(from);
+                var fromContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(from);
-            var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
+                var toContainer = (TreeViewItem)target.ItemContainerGenerator.Index.ContainerFromItem(to);
 
-            _mouse.Click(fromContainer);
+                _mouse.Click(fromContainer);
-            _mouse.Click(toContainer, MouseButton.Right, modifiers: KeyModifiers.Control);
+                _mouse.Click(toContainer, MouseButton.Right, modifiers: KeyModifiers.Control);
 
-            Assert.Equal(1, target.Selection.SelectedItems.Count);
+                Assert.Equal(1, target.Selection.SelectedItems.Count);
+            }
         }
 
         [Fact]
@@ -944,7 +980,7 @@ namespace Avalonia.Controls.UnitTests
         public void Auto_Expanding_In_Style_Should_Not_Break_Range_Selection()
         {
             /// Issue #2980.
-            using (UnitTestApplication.Start(TestServices.RealStyler))
+            using (Application())
             {
                 var target = new DerivedTreeView
                 {
@@ -1183,12 +1219,12 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
-        void ClickContainer(IControl container, KeyModifiers modifiers)
+        private void ClickContainer(IControl container, KeyModifiers modifiers)
         {
             _mouse.Click(container, modifiers: modifiers);
         }
 
-        void AssertChildrenSelected(TreeView treeView, Node rootNode)
+        private void AssertChildrenSelected(TreeView treeView, Node rootNode)
         {
             foreach (var child in rootNode.Children)
             {
@@ -1198,6 +1234,16 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
+        private IDisposable Application()
+        {
+            return UnitTestApplication.Start(
+                TestServices.MockThreadingInterface.With(
+                    focusManager: new FocusManager(),
+                    keyboardDevice: () => new KeyboardDevice(),
+                    keyboardNavigation: new KeyboardNavigationHandler(),
+                    inputManager: new InputManager()));
+        }
+
         private class Node : NotifyingBase
         {
             private IAvaloniaList<Node> _children;

tests/Avalonia.Markup.UnitTests/Data/MultiBindingTests.cs

@@ -113,6 +113,50 @@ namespace Avalonia.Markup.UnitTests.Data
             Assert.Equal("(null)", target.Text);
         }
 
+        [Fact]
+        public void Should_Pass_UnsetValue_To_Converter_For_Broken_Binding()
+        {
+            var source = new { A = 1, B = 2, C = 3 };
+            var target = new TextBlock { DataContext = source };
+
+            var binding = new MultiBinding
+            {
+                Converter = new ConcatConverter(),
+                Bindings = new[]
+                {
+                    new Binding { Path = "A" },
+                    new Binding { Path = "B" },
+                    new Binding { Path = "Missing" },
+                },
+            };
+
+            target.Bind(TextBlock.TextProperty, binding);
+
+            Assert.Equal("1,2,(unset)", target.Text);
+        }
+
+        [Fact]
+        public void Should_Pass_FallbackValue_To_Converter_For_Broken_Binding()
+        {
+            var source = new { A = 1, B = 2, C = 3 };
+            var target = new TextBlock { DataContext = source };
+
+            var binding = new MultiBinding
+            {
+                Converter = new ConcatConverter(),
+                Bindings = new[]
+                {
+                    new Binding { Path = "A" },
+                    new Binding { Path = "B" },
+                    new Binding { Path = "Missing", FallbackValue = "Fallback" },
+                },
+            };
+
+            target.Bind(TextBlock.TextProperty, binding);
+
+            Assert.Equal("1,2,Fallback", target.Text);
+        }
+
         private class ConcatConverter : IMultiValueConverter
         {
             public object Convert(IList<object> values, Type targetType, object parameter, CultureInfo culture)

tests/Avalonia.Markup.Xaml.UnitTests/Data/BindingTests.cs

@@ -1,6 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
 using Avalonia.Controls;
+using Avalonia.Controls.Presenters;
 using Avalonia.Data;
+using Avalonia.Data.Converters;
 using Avalonia.UnitTests;
+using Avalonia.VisualTree;
 using Xunit;
 
 namespace Avalonia.Markup.Xaml.UnitTests.Data
@@ -54,5 +61,51 @@ namespace Avalonia.Markup.Xaml.UnitTests.Data
                 Assert.Equal("bar", textBlock.Text);
             }
         }
+
+        [Fact]
+        public void MultiBinding_TemplatedParent_Works()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
+        xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.Data;assembly=Avalonia.Markup.Xaml.UnitTests'>
+    <TextBox Name='textBox' Text='Foo' Watermark='Bar'>
+        <TextBox.Template>
+            <ControlTemplate>
+                <TextPresenter Name='PART_TextPresenter'>
+                    <TextPresenter.Text>
+                        <MultiBinding Converter='{x:Static local:ConcatConverter.Instance}'>
+                            <Binding RelativeSource='{RelativeSource TemplatedParent}' Path='Text'/>
+                            <Binding RelativeSource='{RelativeSource TemplatedParent}' Path='Watermark'/>
+                        </MultiBinding>
+                    </TextPresenter.Text>
+                </TextPresenter>
+            </ControlTemplate>
+        </TextBox.Template>
+    </TextBox>
+</Window>";
+                var loader = new AvaloniaXamlLoader();
+                var window = (Window)loader.Load(xaml);
+                var textBox = window.FindControl<TextBox>("textBox");
+
+                window.ApplyTemplate();
+                textBox.ApplyTemplate();
+
+                var target = (TextPresenter)textBox.GetVisualChildren().Single();
+                Assert.Equal("Foo,Bar", target.Text);
+            }
+        }
+    }
+
+    public class ConcatConverter : IMultiValueConverter
+    {
+        public static ConcatConverter Instance { get; } = new ConcatConverter();
+
+        public object Convert(IList<object> values, Type targetType, object parameter, CultureInfo culture)
+        {
+            return string.Join(",", values);
+        }
     }
 }