Merge branch 'master' into xdatatype

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

@@ -31,6 +31,7 @@ namespace Avalonia.Animation.Animators
                         InterpolateStops(progress, oldValue.GradientStops, newValue.GradientStops),
                         s_doubleAnimator.Interpolate(progress, oldValue.Opacity, newValue.Opacity),
                         oldValue.Transform is { } ? new ImmutableTransform(oldValue.Transform.Value) : null,
+                        s_relativePointAnimator.Interpolate(progress, oldValue.TransformOrigin, newValue.TransformOrigin),
                         oldValue.SpreadMethod,
                         s_relativePointAnimator.Interpolate(progress, oldRadial.Center, newRadial.Center),
                         s_relativePointAnimator.Interpolate(progress, oldRadial.GradientOrigin, newRadial.GradientOrigin),
@@ -41,6 +42,7 @@ namespace Avalonia.Animation.Animators
                         InterpolateStops(progress, oldValue.GradientStops, newValue.GradientStops),
                         s_doubleAnimator.Interpolate(progress, oldValue.Opacity, newValue.Opacity),
                         oldValue.Transform is { } ? new ImmutableTransform(oldValue.Transform.Value) : null,
+                        s_relativePointAnimator.Interpolate(progress, oldValue.TransformOrigin, newValue.TransformOrigin),
                         oldValue.SpreadMethod,
                         s_relativePointAnimator.Interpolate(progress, oldConic.Center, newConic.Center),
                         s_doubleAnimator.Interpolate(progress, oldConic.Angle, newConic.Angle));
@@ -50,6 +52,7 @@ namespace Avalonia.Animation.Animators
                         InterpolateStops(progress, oldValue.GradientStops, newValue.GradientStops),
                         s_doubleAnimator.Interpolate(progress, oldValue.Opacity, newValue.Opacity),
                         oldValue.Transform is { } ? new ImmutableTransform(oldValue.Transform.Value) : null,
+                        s_relativePointAnimator.Interpolate(progress, oldValue.TransformOrigin, newValue.TransformOrigin),
                         oldValue.SpreadMethod,
                         s_relativePointAnimator.Interpolate(progress, oldLinear.StartPoint, newLinear.StartPoint),
                         s_relativePointAnimator.Interpolate(progress, oldLinear.EndPoint, newLinear.EndPoint));
@@ -102,18 +105,21 @@ namespace Avalonia.Animation.Animators
                     return new ImmutableRadialGradientBrush(
                         CreateStopsFromSolidColorBrush(solidColorBrush, oldRadial.GradientStops), solidColorBrush.Opacity,
                         oldRadial.Transform is { } ? new ImmutableTransform(oldRadial.Transform.Value) : null,
+                        oldRadial.TransformOrigin,
                         oldRadial.SpreadMethod, oldRadial.Center, oldRadial.GradientOrigin, oldRadial.Radius);
 
                 case IConicGradientBrush oldConic:
                     return new ImmutableConicGradientBrush(
                         CreateStopsFromSolidColorBrush(solidColorBrush, oldConic.GradientStops), solidColorBrush.Opacity,
                         oldConic.Transform is { } ? new ImmutableTransform(oldConic.Transform.Value) : null,
+                        oldConic.TransformOrigin,
                         oldConic.SpreadMethod, oldConic.Center, oldConic.Angle);
 
                 case ILinearGradientBrush oldLinear:
                     return new ImmutableLinearGradientBrush(
                         CreateStopsFromSolidColorBrush(solidColorBrush, oldLinear.GradientStops), solidColorBrush.Opacity,
                         oldLinear.Transform is { } ? new ImmutableTransform(oldLinear.Transform.Value) : null,
+                        oldLinear.TransformOrigin,
                         oldLinear.SpreadMethod, oldLinear.StartPoint, oldLinear.EndPoint);
 
                 default:

src/Avalonia.Base/Collections/Pooled/PooledList.cs

@@ -587,7 +587,7 @@ namespace Avalonia.Collections.Pooled
             if (size > 0 && _clearOnFree)
             {
                 // Clear the elements so that the gc can reclaim the references.
-                Array.Clear(_items, 0, _size);
+                Array.Clear(_items, 0, size);
             }
         }
 

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

@@ -1,5 +1,6 @@
 using System;
 using System.Runtime.ExceptionServices;
+using Avalonia.Utilities;
 
 namespace Avalonia.Data.Core.Plugins
 {
@@ -60,11 +61,10 @@ namespace Avalonia.Data.Core.Plugins
             return AvaloniaPropertyRegistry.Instance.FindRegistered(o, propertyName);
         }
 
-        private class Accessor : PropertyAccessorBase, IObserver<object?>
+        private class Accessor : PropertyAccessorBase, IWeakEventSubscriber<AvaloniaPropertyChangedEventArgs>
         {
             private readonly WeakReference<AvaloniaObject> _reference;
             private readonly AvaloniaProperty _property;
-            private IDisposable? _subscription;
 
             public Accessor(WeakReference<AvaloniaObject> reference, AvaloniaProperty property)
             {
@@ -95,29 +95,45 @@ namespace Avalonia.Data.Core.Plugins
                 return false;
             }
 
-            protected override void SubscribeCore()
+            void IWeakEventSubscriber<AvaloniaPropertyChangedEventArgs>.
+                OnEvent(object? notifyPropertyChanged, WeakEvent ev, AvaloniaPropertyChangedEventArgs e)
             {
-                _subscription = Instance?.GetObservable(_property).Subscribe(this);
+                if (e.Property == _property)
+                {
+                    SendCurrentValue();
+                }
             }
 
-            protected override void UnsubscribeCore()
+            protected override void SubscribeCore()
             {
-                _subscription?.Dispose();
-                _subscription = null;
+                SubscribeToChanges();
+                SendCurrentValue();
             }
 
-            void IObserver<object?>.OnCompleted()
+            protected override void UnsubscribeCore()
             {
+                var instance = Instance;
+
+                if (instance != null)
+                    WeakEvents.AvaloniaPropertyChanged.Unsubscribe(instance, this);
             }
 
-            void IObserver<object?>.OnError(Exception error)
+            private void SendCurrentValue()
             {
-                ExceptionDispatchInfo.Capture(error).Throw();
+                try
+                {
+                    var value = Value;
+                    PublishValue(value);
+                }
+                catch { }
             }
 
-            void IObserver<object?>.OnNext(object? value)
+            private void SubscribeToChanges()
             {
-                PublishValue(value);
+                var instance = Instance;
+
+                if (instance != null)
+                    WeakEvents.AvaloniaPropertyChanged.Subscribe(instance, this);
             }
         }
     }

src/Avalonia.Base/Media/Brush.cs

@@ -24,6 +24,12 @@ namespace Avalonia.Media
         public static readonly StyledProperty<ITransform?> TransformProperty =
             AvaloniaProperty.Register<Brush, ITransform?>(nameof(Transform));
 
+        /// <summary>
+        /// Defines the <see cref="TransformOrigin"/> property
+        /// </summary>
+        public static readonly StyledProperty<RelativePoint> TransformOriginProperty =
+            AvaloniaProperty.Register<Brush, RelativePoint>(nameof(TransformOrigin));
+
         /// <inheritdoc/>
         public event EventHandler? Invalidated;
 
@@ -51,6 +57,15 @@ namespace Avalonia.Media
             set { SetValue(TransformProperty, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the origin of the brush <see cref="Transform"/>
+        /// </summary>
+        public RelativePoint TransformOrigin
+        {
+            get => GetValue(TransformOriginProperty);
+            set => SetValue(TransformOriginProperty, value);
+        }
+
         /// <summary>
         /// Parses a brush string.
         /// </summary>

src/Avalonia.Base/Media/IBrush.cs

@@ -19,5 +19,10 @@ namespace Avalonia.Media
         /// Gets the transform of the brush.
         /// </summary>
         ITransform? Transform { get; }
+
+        /// <summary>
+        /// Gets the origin of the brushes <see cref="Transform"/>
+        /// </summary>
+        RelativePoint TransformOrigin { get; }
     }
 }

src/Avalonia.Base/Media/Immutable/ImmutableConicGradientBrush.cs

@@ -13,6 +13,7 @@ namespace Avalonia.Media.Immutable
         /// <param name="gradientStops">The gradient stops.</param>
         /// <param name="opacity">The opacity of the brush.</param>
         /// <param name="transform">The transform of the brush.</param>
+        /// <param name="transformOrigin">The transform origin of the brush</param>
         /// <param name="spreadMethod">The spread method.</param>
         /// <param name="center">The center point for the gradient.</param>
         /// <param name="angle">The starting angle for the gradient.</param>
@@ -20,10 +21,11 @@ namespace Avalonia.Media.Immutable
             IReadOnlyList<ImmutableGradientStop> gradientStops,
             double opacity = 1,
             ImmutableTransform? transform = null,
+            RelativePoint? transformOrigin = null,
             GradientSpreadMethod spreadMethod = GradientSpreadMethod.Pad,
             RelativePoint? center = null,
             double angle = 0)
-            : base(gradientStops, opacity, transform, spreadMethod)
+            : base(gradientStops, opacity, transform, transformOrigin, spreadMethod)
         {
             Center = center ?? RelativePoint.Center;
             Angle = angle;

src/Avalonia.Base/Media/Immutable/ImmutableGradientBrush.cs

@@ -13,16 +13,19 @@ namespace Avalonia.Media.Immutable
         /// <param name="gradientStops">The gradient stops.</param>
         /// <param name="opacity">The opacity of the brush.</param>
         /// <param name="transform">The transform of the brush.</param>
+        /// <param name="transformOrigin">The transform origin of the brush</param>
         /// <param name="spreadMethod">The spread method.</param>
         protected ImmutableGradientBrush(
             IReadOnlyList<ImmutableGradientStop> gradientStops,
             double opacity,
             ImmutableTransform? transform,
+            RelativePoint? transformOrigin,
             GradientSpreadMethod spreadMethod)
         {
             GradientStops = gradientStops;
             Opacity = opacity;
             Transform = transform;
+            TransformOrigin = transformOrigin.HasValue ? transformOrigin.Value : RelativePoint.TopLeft;
             SpreadMethod = spreadMethod;
         }
 
@@ -31,7 +34,8 @@ namespace Avalonia.Media.Immutable
         /// </summary>
         /// <param name="source">The brush from which this brush's properties should be copied.</param>
         protected ImmutableGradientBrush(GradientBrush source)
-            : this(source.GradientStops.ToImmutable(), source.Opacity, source.Transform?.ToImmutable(), source.SpreadMethod)
+            : this(source.GradientStops.ToImmutable(), source.Opacity, source.Transform?.ToImmutable(), 
+                  source.TransformOrigin, source.SpreadMethod)
         {
 
         }
@@ -47,6 +51,11 @@ namespace Avalonia.Media.Immutable
         /// </summary>
         public ITransform? Transform { get; }
 
+        /// <summary>
+        /// Gets the transform origin of the brush
+        /// </summary>
+        public RelativePoint TransformOrigin { get; }
+
         /// <inheritdoc/>
         public GradientSpreadMethod SpreadMethod { get; }
     }

src/Avalonia.Base/Media/Immutable/ImmutableImageBrush.cs

@@ -16,6 +16,7 @@ namespace Avalonia.Media.Immutable
         /// <param name="destinationRect">The rectangle on the destination in which to paint a tile.</param>
         /// <param name="opacity">The opacity of the brush.</param>
         /// <param name="transform">The transform of the brush.</param>
+        /// <param name="transformOrigin">The transform origin of the brush</param>
         /// <param name="sourceRect">The rectangle of the source image that will be displayed.</param>
         /// <param name="stretch">
         /// How the source rectangle will be stretched to fill the destination rect.
@@ -29,6 +30,7 @@ namespace Avalonia.Media.Immutable
             RelativeRect? destinationRect = null,
             double opacity = 1,
             ImmutableTransform? transform = null,
+            RelativePoint transformOrigin = new RelativePoint(),
             RelativeRect? sourceRect = null,
             Stretch stretch = Stretch.Uniform,
             TileMode tileMode = TileMode.None,
@@ -39,6 +41,7 @@ namespace Avalonia.Media.Immutable
                   destinationRect ?? RelativeRect.Fill,
                   opacity,
                   transform,
+                  transformOrigin,
                   sourceRect ?? RelativeRect.Fill,
                   stretch,
                   tileMode,

src/Avalonia.Base/Media/Immutable/ImmutableLinearGradientBrush.cs

@@ -13,6 +13,7 @@ namespace Avalonia.Media.Immutable
         /// <param name="gradientStops">The gradient stops.</param>
         /// <param name="opacity">The opacity of the brush.</param>
         /// <param name="transform">The transform of the brush.</param>
+        /// <param name="transformOrigin">The transform origin of the brush</param>
         /// <param name="spreadMethod">The spread method.</param>
         /// <param name="startPoint">The start point for the gradient.</param>
         /// <param name="endPoint">The end point for the gradient.</param>
@@ -20,10 +21,11 @@ namespace Avalonia.Media.Immutable
             IReadOnlyList<ImmutableGradientStop> gradientStops,
             double opacity = 1,
             ImmutableTransform? transform = null,
+            RelativePoint? transformOrigin = null,
             GradientSpreadMethod spreadMethod = GradientSpreadMethod.Pad,
             RelativePoint? startPoint = null,
             RelativePoint? endPoint = null)
-            : base(gradientStops, opacity, transform, spreadMethod)
+            : base(gradientStops, opacity, transform, transformOrigin, spreadMethod)
         {
             StartPoint = startPoint ?? RelativePoint.TopLeft;
             EndPoint = endPoint ?? RelativePoint.BottomRight;

src/Avalonia.Base/Media/Immutable/ImmutableRadialGradientBrush.cs

@@ -13,6 +13,7 @@ namespace Avalonia.Media.Immutable
         /// <param name="gradientStops">The gradient stops.</param>
         /// <param name="opacity">The opacity of the brush.</param>
         /// <param name="transform">The transform of the brush.</param>
+        /// <param name="transformOrigin">The transform origin of the brush</param>
         /// <param name="spreadMethod">The spread method.</param>
         /// <param name="center">The start point for the gradient.</param>
         /// <param name="gradientOrigin">
@@ -25,11 +26,12 @@ namespace Avalonia.Media.Immutable
             IReadOnlyList<ImmutableGradientStop> gradientStops,
             double opacity = 1,
             ImmutableTransform? transform = null,
+            RelativePoint? transformOrigin = null,
             GradientSpreadMethod spreadMethod = GradientSpreadMethod.Pad,
             RelativePoint? center = null,
             RelativePoint? gradientOrigin = null,
             double radius = 0.5)
-            : base(gradientStops, opacity, transform, spreadMethod)
+            : base(gradientStops, opacity, transform, transformOrigin, spreadMethod)
         {
             Center = center ?? RelativePoint.Center;
             GradientOrigin = gradientOrigin ?? RelativePoint.Center;

src/Avalonia.Base/Media/Immutable/ImmutableSolidColorBrush.cs

@@ -53,6 +53,11 @@ namespace Avalonia.Media.Immutable
         /// </summary>
         public ITransform? Transform { get; }
 
+        /// <summary>
+        /// Gets the transform origin of the brush
+        /// </summary>
+        public RelativePoint TransformOrigin { get; }
+
         public bool Equals(ImmutableSolidColorBrush? other)
         {
             if (ReferenceEquals(null, other)) return false;

src/Avalonia.Base/Media/Immutable/ImmutableTileBrush.cs

@@ -15,6 +15,7 @@ namespace Avalonia.Media.Immutable
         /// <param name="destinationRect">The rectangle on the destination in which to paint a tile.</param>
         /// <param name="opacity">The opacity of the brush.</param>
         /// <param name="transform">The transform of the brush.</param>
+        /// <param name="transformOrigin">The transform origin of the brush</param>
         /// <param name="sourceRect">The rectangle of the source image that will be displayed.</param>
         /// <param name="stretch">
         /// How the source rectangle will be stretched to fill the destination rect.
@@ -27,6 +28,7 @@ namespace Avalonia.Media.Immutable
             RelativeRect destinationRect,
             double opacity,
             ImmutableTransform? transform,
+            RelativePoint transformOrigin,
             RelativeRect sourceRect,
             Stretch stretch,
             TileMode tileMode,
@@ -37,6 +39,7 @@ namespace Avalonia.Media.Immutable
             DestinationRect = destinationRect;
             Opacity = opacity;
             Transform = transform;
+            TransformOrigin = transformOrigin;
             SourceRect = sourceRect;
             Stretch = stretch;
             TileMode = tileMode;
@@ -54,6 +57,7 @@ namespace Avalonia.Media.Immutable
                   source.DestinationRect,
                   source.Opacity,
                   source.Transform?.ToImmutable(),
+                  source.TransformOrigin,
                   source.SourceRect,
                   source.Stretch,
                   source.TileMode,
@@ -78,6 +82,11 @@ namespace Avalonia.Media.Immutable
         /// </summary>
         public ITransform? Transform { get; }
 
+        /// <summary>
+        /// Gets the transform origin of the brush
+        /// </summary>
+        public RelativePoint TransformOrigin { get; }
+
         /// <inheritdoc/>
         public RelativeRect SourceRect { get; }
 

src/Avalonia.Base/Media/Immutable/ImmutableVisualBrush.cs

@@ -17,6 +17,7 @@ namespace Avalonia.Media.Immutable
         /// <param name="destinationRect">The rectangle on the destination in which to paint a tile.</param>
         /// <param name="opacity">The opacity of the brush.</param>
         /// <param name="transform">The transform of the brush.</param>
+        /// <param name="transformOrigin">The transform origin of the brush</param>
         /// <param name="sourceRect">The rectangle of the source image that will be displayed.</param>
         /// <param name="stretch">
         /// How the source rectangle will be stretched to fill the destination rect.
@@ -30,6 +31,7 @@ namespace Avalonia.Media.Immutable
             RelativeRect? destinationRect = null,
             double opacity = 1,
             ImmutableTransform? transform = null,
+            RelativePoint transformOrigin = new RelativePoint(),
             RelativeRect? sourceRect = null,
             Stretch stretch = Stretch.Uniform,
             TileMode tileMode = TileMode.None,
@@ -40,6 +42,7 @@ namespace Avalonia.Media.Immutable
                   destinationRect ?? RelativeRect.Fill,
                   opacity,
                   transform,
+                  transformOrigin,
                   sourceRect ?? RelativeRect.Fill,
                   stretch,
                   tileMode,

src/Avalonia.Base/Utilities/WeakEvents.cs

@@ -31,10 +31,23 @@ public class WeakEvents
                 return () => s.PropertyChanged -= handler;
             });
 
+
+    /// <summary>
+    /// Represents PropertyChanged event from <see cref="AvaloniaObject"/>
+    /// </summary>
+    public static readonly WeakEvent<AvaloniaObject, AvaloniaPropertyChangedEventArgs>
+        AvaloniaPropertyChanged = WeakEvent.Register<AvaloniaObject, AvaloniaPropertyChangedEventArgs>(
+            (s, h) =>
+            {
+                EventHandler<AvaloniaPropertyChangedEventArgs> handler = (_, e) => h(s, e);
+                s.PropertyChanged += handler;
+                return () => s.PropertyChanged -= handler;
+            });
+
     /// <summary>
     /// Represents CanExecuteChanged event from <see cref="ICommand"/>
     /// </summary>
     public static readonly WeakEvent<ICommand, EventArgs> CommandCanExecuteChanged =
         WeakEvent.Register<ICommand>((s, h) => s.CanExecuteChanged += h,
             (s, h) => s.CanExecuteChanged -= h);
-}
+}

src/Skia/Avalonia.Skia/DrawingContextImpl.cs

@@ -181,7 +181,8 @@ namespace Avalonia.Skia
             var size = geometry.Bounds.Size;
 
             using (var fill = brush != null ? CreatePaint(_fillPaint, brush, size) : default(PaintWrapper))
-            using (var stroke = pen?.Brush != null ? CreatePaint(_strokePaint, pen, size) : default(PaintWrapper))
+            using (var stroke = pen?.Brush != null ? CreatePaint(_strokePaint, pen, 
+                size.Inflate(new Thickness(pen?.Thickness / 2 ?? 0))) : default(PaintWrapper))
             {
                 if (fill.Paint != null)
                 {
@@ -398,7 +399,7 @@ namespace Avalonia.Skia
 
             if (pen?.Brush != null)
             {
-                using (var paint = CreatePaint(_strokePaint, pen, rect.Rect.Size))
+                using (var paint = CreatePaint(_strokePaint, pen, rect.Rect.Size.Inflate(new Thickness(pen?.Thickness / 2 ?? 0))))
                 {
                     if (paint.Paint is object)
                     {
@@ -433,7 +434,7 @@ namespace Avalonia.Skia
 
             if (pen?.Brush != null)
             {
-                using (var paint = CreatePaint(_strokePaint, pen, rect.Size))
+                using (var paint = CreatePaint(_strokePaint, pen, rect.Size.Inflate(new Thickness(pen?.Thickness / 2 ?? 0))))
                 {
                     if (paint.Paint is object)
                     {
@@ -625,8 +626,12 @@ namespace Avalonia.Skia
                     }
                     else
                     {
+                        var transformOrigin = linearGradient.TransformOrigin.ToPixels(targetSize);
+                        var offset = Matrix.CreateTranslation(transformOrigin);
+                        var transform = (-offset) * linearGradient.Transform.Value * (offset);
+
                         using (var shader =
-                            SKShader.CreateLinearGradient(start, end, stopColors, stopOffsets, tileMode, linearGradient.Transform.Value.ToSKMatrix()))
+                            SKShader.CreateLinearGradient(start, end, stopColors, stopOffsets, tileMode, transform.ToSKMatrix()))
                         {
                             paintWrapper.Paint.Shader = shader;
                         }   
@@ -654,8 +659,12 @@ namespace Avalonia.Skia
                         }
                         else
                         {
+                            var transformOrigin = radialGradient.TransformOrigin.ToPixels(targetSize);
+                            var offset = Matrix.CreateTranslation(transformOrigin);
+                            var transform = (-offset) * radialGradient.Transform.Value * (offset);
+                        
                             using (var shader =
-                                SKShader.CreateRadialGradient(center, radius, stopColors, stopOffsets, tileMode, radialGradient.Transform.Value.ToSKMatrix()))
+                                SKShader.CreateRadialGradient(center, radius, stopColors, stopOffsets, tileMode, transform.ToSKMatrix()))
                             {
                                 paintWrapper.Paint.Shader = shader;
                             }
@@ -694,9 +703,14 @@ namespace Avalonia.Skia
                         }
                         else
                         {
+                                
+                            var transformOrigin = radialGradient.TransformOrigin.ToPixels(targetSize);
+                            var offset = Matrix.CreateTranslation(transformOrigin);
+                            var transform = (-offset) * radialGradient.Transform.Value * (offset);
+                           
                             using (var shader = SKShader.CreateCompose(
                                 SKShader.CreateColor(reversedColors[0]),
-                                SKShader.CreateTwoPointConicalGradient(center, radius, origin, 0, reversedColors, reversedStops, tileMode, radialGradient.Transform.Value.ToSKMatrix())
+                                SKShader.CreateTwoPointConicalGradient(center, radius, origin, 0, reversedColors, reversedStops, tileMode, transform.ToSKMatrix())
                             ))
                             {
                                 paintWrapper.Paint.Shader = shader;
@@ -717,7 +731,12 @@ namespace Avalonia.Skia
 
                     if (conicGradient.Transform is { })
                     {
-                        rotation = rotation.PreConcat(conicGradient.Transform.Value.ToSKMatrix());
+                            
+                        var transformOrigin = conicGradient.TransformOrigin.ToPixels(targetSize);
+                        var offset = Matrix.CreateTranslation(transformOrigin);
+                        var transform = (-offset) * conicGradient.Transform.Value * (offset);
+
+                        rotation = rotation.PreConcat(transform.ToSKMatrix());
                     }
 
                     using (var shader = 
@@ -794,7 +813,11 @@ namespace Avalonia.Skia
 
             if (tileBrush.Transform is { })
             {
-                paintTransform = paintTransform.PreConcat(tileBrush.Transform.Value.ToSKMatrix());
+                var origin = tileBrush.TransformOrigin.ToPixels(targetSize);
+                var offset = Matrix.CreateTranslation(origin);
+                var transform = (-offset) * tileBrush.Transform.Value * (offset);
+
+                paintTransform = paintTransform.PreConcat(transform.ToSKMatrix());
             }
 
             using (var shader = image.ToShader(tileX, tileY, paintTransform))

src/Windows/Avalonia.Win32/Input/Imm32InputMethod.cs

@@ -37,6 +37,24 @@ namespace Avalonia.Win32.Input
             IsComposing = false;
         }
 
+        public void ClearLanguageAndWindow()
+        {
+            if (HWND != IntPtr.Zero && _defaultImc != IntPtr.Zero)
+            {
+                ImmReleaseContext(HWND, _defaultImc);
+            }
+
+            _defaultImc = IntPtr.Zero;
+            HWND = IntPtr.Zero;
+            _parent = null;
+            _active = false;
+            _langId = 0;
+            _showCompositionWindow = false;
+            _showCandidateList = false;
+
+            IsComposing = false;
+        }
+
         //Dependant on CurrentThread. When Avalonia will support Multiple Dispatchers -
         //every Dispatcher should have their own InputMethod.
         public static Imm32InputMethod Current { get; } = new Imm32InputMethod();

src/Windows/Avalonia.Win32/WindowImpl.AppWndProc.cs

@@ -82,6 +82,12 @@ namespace Avalonia.Win32
                 case WindowsMessage.WM_DESTROY:
                     {
                         UiaCoreProviderApi.UiaReturnRawElementProvider(_hwnd, IntPtr.Zero, IntPtr.Zero, null);
+                        
+                        // We need to release IMM context and state to avoid leaks.
+                        if (Imm32InputMethod.Current.HWND == _hwnd)
+                        {
+                            Imm32InputMethod.Current.ClearLanguageAndWindow();
+                        }
 
                         //Window doesn't exist anymore
                         _hwnd = IntPtr.Zero;

tests/Avalonia.LeakTests/ControlTests.cs

@@ -2,17 +2,18 @@ using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
-using System.Runtime.Remoting.Contexts;
+using System.Reactive.Disposables;
 using Avalonia.Controls;
 using Avalonia.Controls.Shapes;
 using Avalonia.Controls.Templates;
+using Avalonia.Data;
 using Avalonia.Diagnostics;
 using Avalonia.Input;
-using Avalonia.Layout;
 using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Rendering;
 using Avalonia.Styling;
+using Avalonia.Threading;
 using Avalonia.UnitTests;
 using Avalonia.VisualTree;
 using JetBrains.dotMemoryUnit;
@@ -661,14 +662,96 @@ namespace Avalonia.LeakTests
             }
         }
 
+        [Fact]
+        public void ElementName_Binding_In_DataTemplate_Is_Freed()
+        {
+            using (Start())
+            {
+                var items = new ObservableCollection<int>(Enumerable.Range(0, 10));
+                NameScope ns;
+                TextBox tb;
+                ListBox lb;
+                var window = new Window
+                {
+                    [NameScope.NameScopeProperty] = ns = new NameScope(),
+                    Width = 100,
+                    Height = 100,
+                    Content = new StackPanel
+                    {
+                        Children =
+                        {
+                            (tb = new TextBox
+                            {
+                                Name = "tb",
+                                Text = "foo",
+                            }),
+                            (lb = new ListBox
+                            {
+                                Items = items,
+                                ItemTemplate = new FuncDataTemplate<int>((_, _) =>
+                                    new Canvas
+                                    {
+                                        Width = 10,
+                                        Height = 10,
+                                        [!Control.TagProperty] = new Binding
+                                        {
+                                            ElementName = "tb",
+                                            Path = "Text",
+                                            NameScope = new WeakReference<INameScope>(ns),
+                                        }
+                                    })
+                            }),
+                        }
+                    }
+                };
+
+                tb.RegisterInNameScope(ns);
+
+                window.Show();
+                window.LayoutManager.ExecuteInitialLayoutPass();
+
+                void AssertInitialItemState()
+                {
+                    var item0 = (ListBoxItem)lb.ItemContainerGenerator.Containers.First().ContainerControl;
+                    var canvas0 = (Canvas)item0.Presenter.Child;
+                    Assert.Equal("foo", canvas0.Tag);
+                }
+               
+                Assert.Equal(10, lb.ItemContainerGenerator.Containers.Count());
+                AssertInitialItemState();
+
+                items.Clear();
+                window.LayoutManager.ExecuteLayoutPass();
+
+                Assert.Empty(lb.ItemContainerGenerator.Containers);
+
+                dotMemory.Check(memory =>
+                    Assert.Equal(0, memory.GetObjects(where => where.Type.Is<Canvas>()).ObjectsCount));
+            }
+        }
+
         private IDisposable Start()
         {
-            return UnitTestApplication.Start(TestServices.StyledWindow.With(
-                focusManager: new FocusManager(),
-                keyboardDevice: () => new KeyboardDevice(),
-                inputManager: new InputManager()));
+            void Cleanup()
+            {
+                // KeyboardDevice holds a reference to the focused item.
+                KeyboardDevice.Instance.SetFocusedElement(null, NavigationMethod.Unspecified, KeyModifiers.None);
+                
+                // Empty the dispatcher queue.
+                Dispatcher.UIThread.RunJobs();
+            }
+
+            return new CompositeDisposable
+            {
+                Disposable.Create(Cleanup),
+                UnitTestApplication.Start(TestServices.StyledWindow.With(
+                    focusManager: new FocusManager(),
+                    keyboardDevice: () => new KeyboardDevice(),
+                    inputManager: new InputManager()))
+            };
         }
 
+
         private class Node
         {
             public string Name { get; set; }