Merge branch 'master' into fixes/Warning_CS0169

src/Avalonia.Animation/Animation.cs

@@ -3,10 +3,11 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Reactive.Disposables;
 using System.Reactive.Linq;
+using System.Threading;
 using System.Threading.Tasks;
+
 using Avalonia.Animation.Animators;
 using Avalonia.Animation.Easings;
-using Avalonia.Collections;
 using Avalonia.Data;
 using Avalonia.Metadata;
 
@@ -319,7 +320,7 @@ namespace Avalonia.Animation
             return (newAnimatorInstances, subscriptions);
         }
 
-        /// <inheritdocs/>
+        /// <inheritdoc/>
         public IDisposable Apply(Animatable control, IClock clock, IObservable<bool> match, Action onComplete)
         {
             var (animators, subscriptions) = InterpretKeyframes(control);
@@ -344,25 +345,40 @@ namespace Avalonia.Animation
 
                 if (onComplete != null)
                 {
-                    Task.WhenAll(completionTasks).ContinueWith(_ => onComplete());
+                    Task.WhenAll(completionTasks).ContinueWith(
+                        (_, state) => ((Action)state).Invoke(),
+                        onComplete);
                 }
             }
             return new CompositeDisposable(subscriptions);
         }
 
-        /// <inheritdocs/>
-        public Task RunAsync(Animatable control, IClock clock = null)
+        /// <inheritdoc/>
+        public Task RunAsync(Animatable control, IClock clock = null, CancellationToken cancellationToken = default)
         {
+            if (cancellationToken.IsCancellationRequested)
+            {
+                return Task.CompletedTask;
+            }
+
             var run = new TaskCompletionSource<object>();
 
             if (this.IterationCount == IterationCount.Infinite)
                 run.SetException(new InvalidOperationException("Looping animations must not use the Run method."));
 
-            IDisposable subscriptions = null;
+            IDisposable subscriptions = null, cancellation = null;
             subscriptions = this.Apply(control, clock, Observable.Return(true), () =>
             {
-                run.SetResult(null);
+                run.TrySetResult(null);
+                subscriptions?.Dispose();
+                cancellation?.Dispose();
+            });
+
+            cancellation = cancellationToken.Register(() =>
+            {
+                run.TrySetResult(null);
                 subscriptions?.Dispose();
+                cancellation?.Dispose();
             });
 
             return run.Task;

src/Avalonia.Animation/ApiCompatBaseline.txt

@@ -0,0 +1,6 @@
+Compat issues with assembly Avalonia.Animation:
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.Animation.RunAsync(Avalonia.Animation.Animatable, Avalonia.Animation.IClock)' does not exist in the implementation but it does exist in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public System.Threading.Tasks.Task Avalonia.Animation.IAnimation.RunAsync(Avalonia.Animation.Animatable, Avalonia.Animation.IClock)' is present in the contract but not in the implementation.
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.IAnimation.RunAsync(Avalonia.Animation.Animatable, Avalonia.Animation.IClock)' does not exist in the implementation but it does exist in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public System.Threading.Tasks.Task Avalonia.Animation.IAnimation.RunAsync(Avalonia.Animation.Animatable, Avalonia.Animation.IClock, System.Threading.CancellationToken)' is present in the implementation but not in the contract.
+Total Issues: 4

src/Avalonia.Animation/IAnimation.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Avalonia.Animation
@@ -16,6 +17,6 @@ namespace Avalonia.Animation
         /// <summary>
         /// Run the animation on the specified control.
         /// </summary>
-        Task RunAsync(Animatable control, IClock clock);
+        Task RunAsync(Animatable control, IClock clock, CancellationToken cancellationToken = default);
     }
 }

src/Avalonia.Controls/Expander.cs

@@ -1,7 +1,11 @@
+using System.Threading;
+
 using Avalonia.Animation;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 
+#nullable enable
+
 namespace Avalonia.Controls
 {
     /// <summary>
@@ -36,8 +40,8 @@ namespace Avalonia.Controls
     [PseudoClasses(":expanded", ":up", ":down", ":left", ":right")]
     public class Expander : HeaderedContentControl
     {
-        public static readonly StyledProperty<IPageTransition> ContentTransitionProperty =
-            AvaloniaProperty.Register<Expander, IPageTransition>(nameof(ContentTransition));
+        public static readonly StyledProperty<IPageTransition?> ContentTransitionProperty =
+            AvaloniaProperty.Register<Expander, IPageTransition?>(nameof(ContentTransition));
 
         public static readonly StyledProperty<ExpandDirection> ExpandDirectionProperty =
             AvaloniaProperty.Register<Expander, ExpandDirection>(nameof(ExpandDirection), ExpandDirection.Down);
@@ -50,6 +54,7 @@ namespace Avalonia.Controls
                 defaultBindingMode: Data.BindingMode.TwoWay);
 
         private bool _isExpanded;
+        private CancellationTokenSource? _lastTransitionCts;
 
         static Expander()
         {
@@ -61,7 +66,7 @@ namespace Avalonia.Controls
             UpdatePseudoClasses(ExpandDirection);
         }
 
-        public IPageTransition ContentTransition
+        public IPageTransition? ContentTransition
         {
             get => GetValue(ContentTransitionProperty);
             set => SetValue(ContentTransitionProperty, value);
@@ -83,19 +88,23 @@ namespace Avalonia.Controls
             }
         }
 
-        protected virtual void OnIsExpandedChanged(AvaloniaPropertyChangedEventArgs e)
+        protected virtual async void OnIsExpandedChanged(AvaloniaPropertyChangedEventArgs e)
         {
             if (Content != null && ContentTransition != null && Presenter is Visual visualContent)
             {
                 bool forward = ExpandDirection == ExpandDirection.Left ||
                                 ExpandDirection == ExpandDirection.Up;
+
+                _lastTransitionCts?.Cancel();
+                _lastTransitionCts = new CancellationTokenSource();
+
                 if (IsExpanded)
                 {
-                    ContentTransition.Start(null, visualContent, forward);
+                    await ContentTransition.Start(null, visualContent, forward, _lastTransitionCts.Token);
                 }
                 else
                 {
-                    ContentTransition.Start(visualContent, null, !forward);
+                    await ContentTransition.Start(visualContent, null, forward, _lastTransitionCts.Token);
                 }
             }
         }

src/Avalonia.Controls/Presenters/CarouselPresenter.cs

@@ -186,7 +186,7 @@ namespace Avalonia.Controls.Presenters
 
                 if (PageTransition != null && (from != null || to != null))
                 {
-                    await PageTransition.Start((Visual)from, (Visual)to, fromIndex < toIndex);
+                    await PageTransition.Start((Visual)from, (Visual)to, fromIndex < toIndex, default);
                 }
                 else if (to != null)
                 {

src/Avalonia.Controls/Primitives/AdornerLayer.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Specialized;
 using System.Linq;
+using System.Resources;
 using Avalonia.Media;
 using Avalonia.Rendering;
 using Avalonia.Utilities;
@@ -45,10 +46,27 @@ namespace Avalonia.Controls.Primitives
                 ?.AdornerLayer;
         }
 
-        protected override Size ArrangeOverride(Size finalSize)
+        protected override Size MeasureOverride(Size availableSize)
         {
-            var parent = Parent;
+            foreach (var child in Children)
+            {
+                var info = child.GetValue(s_adornedElementInfoProperty);
+
+                if (info != null && info.Bounds.HasValue)
+                {
+                    child.Measure(info.Bounds.Value.Bounds.Size);
+                }
+                else
+                {
+                    child.Measure(availableSize);
+                }
+            }
 
+            return default;
+        }
+
+        protected override Size ArrangeOverride(Size finalSize)
+        {
             foreach (var child in Children)
             {
                 var info = child.GetValue(s_adornedElementInfoProperty);

src/Avalonia.Controls/TextBox.cs

@@ -1290,7 +1290,7 @@ namespace Avalonia.Controls
 
         private void UpdatePseudoclasses()
         {
-            PseudoClasses.Set(":empty", string.IsNullOrWhiteSpace(Text));
+            PseudoClasses.Set(":empty", string.IsNullOrEmpty(Text));
         }
 
         private bool IsPasswordBox => PasswordChar != default(char);

src/Avalonia.ReactiveUI/TransitioningContentControl.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Threading;
+
 using Avalonia.Animation;
 using Avalonia.Controls;
 using Avalonia.Styling;
@@ -22,7 +24,9 @@ namespace Avalonia.ReactiveUI
         /// </summary>
         public static readonly StyledProperty<object?> DefaultContentProperty =
             AvaloniaProperty.Register<TransitioningContentControl, object?>(nameof(DefaultContent));
-        
+
+        private CancellationTokenSource? _lastTransitionCts;
+
         /// <summary>
         /// Gets or sets the animation played when content appears and disappears.
         /// </summary>
@@ -62,11 +66,14 @@ namespace Avalonia.ReactiveUI
         /// <param name="content">New content to set.</param>
         private async void UpdateContentWithTransition(object? content)
         {
+            _lastTransitionCts?.Cancel();
+            _lastTransitionCts = new CancellationTokenSource();
+
             if (PageTransition != null)
-                await PageTransition.Start(this, null, true);
+                await PageTransition.Start(this, null, true, _lastTransitionCts.Token);
             base.Content = content;
             if (PageTransition != null)
-                await PageTransition.Start(null, this, true);
+                await PageTransition.Start(null, this, true, _lastTransitionCts.Token);
         }
     }
 }

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

@@ -112,9 +112,7 @@
                 <Panel Height="12"
                        Width="12" />
                 <Path x:Name="DropDownGlyph"
-                      Stretch="Uniform"
-                      VerticalAlignment="Center"
-                      Data="M1939 486L2029 576L1024 1581L19 576L109 486L1024 1401L1939 486Z" />
+                      VerticalAlignment="Center" />
               </Panel>
             </Viewbox>
             <Popup Name="PART_Popup"
@@ -160,6 +158,8 @@
 
   <Style Selector="ComboBox /template/ Path#DropDownGlyph">
     <Setter Property="Fill" Value="{DynamicResource ComboBoxDropDownGlyphForeground}" />
+    <Setter Property="Data" Value="M1939 486L2029 576L1024 1581L19 576L109 486L1024 1401L1939 486Z" />
+    <Setter Property="Stretch" Value="Uniform" />
   </Style>
 
   <!--  PointerOver State  -->

src/Avalonia.Visuals/Animation/CompositePageTransition.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using Avalonia.Metadata;
 
@@ -35,25 +36,11 @@ namespace Avalonia.Animation
         [Content]
         public List<IPageTransition> PageTransitions { get; set; } = new List<IPageTransition>();
 
-        /// <summary>
-        /// Starts the animation.
-        /// </summary>
-        /// <param name="from">
-        /// The control that is being transitioned away from. May be null.
-        /// </param>
-        /// <param name="to">
-        /// The control that is being transitioned to. May be null.
-        /// </param>
-        /// <param name="forward">
-        /// Defines the direction of the transition.
-        /// </param>
-        /// <returns>
-        /// A <see cref="Task"/> that tracks the progress of the animation.
-        /// </returns>
-        public Task Start(Visual from, Visual to, bool forward)
+        /// <inheritdoc />
+        public Task Start(Visual from, Visual to, bool forward, CancellationToken cancellationToken)
         {
             var transitionTasks = PageTransitions
-                .Select(transition => transition.Start(from, to, forward))
+                .Select(transition => transition.Start(from, to, forward, cancellationToken))
                 .ToList();
             return Task.WhenAll(transitionTasks);
         }

src/Avalonia.Visuals/Animation/CrossFade.cs

@@ -1,5 +1,7 @@
 using System;
 using System.Collections.Generic;
+using System.Reactive.Disposables;
+using System.Threading;
 using System.Threading.Tasks;
 using Avalonia.Animation.Easings;
 using Avalonia.Styling;
@@ -97,49 +99,39 @@ namespace Avalonia.Animation
             set => _fadeOutAnimation.Easing = value;
         }
 
-        /// <summary>
-        /// Starts the animation.
-        /// </summary>
-        /// <param name="from">
-        /// The control that is being transitioned away from. May be null.
-        /// </param>
-        /// <param name="to">
-        /// The control that is being transitioned to. May be null.
-        /// </param>
-        /// <returns>
-        /// A <see cref="Task"/> that tracks the progress of the animation.
-        /// </returns>
-        public async Task Start(Visual from, Visual to)
+        /// <inheritdoc cref="Start(Visual, Visual, CancellationToken)" />
+        public async Task Start(Visual from, Visual to, CancellationToken cancellationToken)
         {
-            var tasks = new List<Task>();
-
-            if (to != null)
-            {
-                to.Opacity = 0;
-            }
-
-            if (from != null)
+            if (cancellationToken.IsCancellationRequested)
             {
-                tasks.Add(_fadeOutAnimation.RunAsync(from));
+                return;
             }
 
-            if (to != null)
+            var tasks = new List<Task>();
+            using (var disposables = new CompositeDisposable())
             {
-                to.IsVisible = true;
-                tasks.Add(_fadeInAnimation.RunAsync(to));
+                if (to != null)
+                {
+                    disposables.Add(to.SetValue(Visual.OpacityProperty, 0, Data.BindingPriority.Animation));
+                }
 
-            }
+                if (from != null)
+                {
+                    tasks.Add(_fadeOutAnimation.RunAsync(from, null, cancellationToken));
+                }
 
-            await Task.WhenAll(tasks);
+                if (to != null)
+                {
+                    to.IsVisible = true;
+                    tasks.Add(_fadeInAnimation.RunAsync(to, null, cancellationToken));
+                }
 
-            if (from != null)
-            {
-                from.IsVisible = false;
-            }
+                await Task.WhenAll(tasks);
 
-            if (to != null)
-            {
-                to.Opacity = 1;
+                if (from != null && !cancellationToken.IsCancellationRequested)
+                {
+                    from.IsVisible = false;
+                }
             }
         }
 
@@ -158,9 +150,9 @@ namespace Avalonia.Animation
         /// <returns>
         /// A <see cref="Task"/> that tracks the progress of the animation.
         /// </returns>
-        Task IPageTransition.Start(Visual from, Visual to, bool forward)
+        Task IPageTransition.Start(Visual from, Visual to, bool forward, CancellationToken cancellationToken)
         {
-            return Start(from, to);
+            return Start(from, to, cancellationToken);
         }
     }
 }

src/Avalonia.Visuals/Animation/IPageTransition.cs

@@ -1,3 +1,4 @@
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Avalonia.Animation
@@ -19,9 +20,12 @@ namespace Avalonia.Animation
         /// <param name="forward">
         /// If the animation is bidirectional, controls the direction of the animation.
         /// </param>
+        /// <param name="cancellationToken">
+        /// Animation cancellation.
+        /// </param>
         /// <returns>
         /// A <see cref="Task"/> that tracks the progress of the animation.
         /// </returns>
-        Task Start(Visual from, Visual to, bool forward);
+        Task Start(Visual from, Visual to, bool forward, CancellationToken cancellationToken);
     }
 }

src/Avalonia.Visuals/Animation/PageSlide.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
 using Avalonia.Animation.Easings;
 using Avalonia.Media;
@@ -60,23 +61,14 @@ namespace Avalonia.Animation
         /// </summary>
         public Easing SlideOutEasing { get; set; } = new LinearEasing();
 
-        /// <summary>
-        /// Starts the animation.
-        /// </summary>
-        /// <param name="from">
-        /// The control that is being transitioned away from. May be null.
-        /// </param>
-        /// <param name="to">
-        /// The control that is being transitioned to. May be null.
-        /// </param>
-        /// <param name="forward">
-        /// If true, the new page is slid in from the right, or if false from the left.
-        /// </param>
-        /// <returns>
-        /// A <see cref="Task"/> that tracks the progress of the animation.
-        /// </returns>
-        public async Task Start(Visual from, Visual to, bool forward)
+        /// <inheritdoc />
+        public async Task Start(Visual from, Visual to, bool forward, CancellationToken cancellationToken)
         {
+            if (cancellationToken.IsCancellationRequested)
+            {
+                return;
+            }
+
             var tasks = new List<Task>();
             var parent = GetVisualParent(from, to);
             var distance = Orientation == SlideAxis.Horizontal ? parent.Bounds.Width : parent.Bounds.Height;
@@ -109,7 +101,7 @@ namespace Avalonia.Animation
                     },
                     Duration = Duration
                 };
-                tasks.Add(animation.RunAsync(from));
+                tasks.Add(animation.RunAsync(from, null, cancellationToken));
             }
 
             if (to != null)
@@ -140,12 +132,12 @@ namespace Avalonia.Animation
                     },
                     Duration = Duration
                 };
-                tasks.Add(animation.RunAsync(to));
+                tasks.Add(animation.RunAsync(to, null, cancellationToken));
             }
 
             await Task.WhenAll(tasks);
 
-            if (from != null)
+            if (from != null && !cancellationToken.IsCancellationRequested)
             {
                 from.IsVisible = false;
             }

src/Avalonia.Visuals/ApiCompatBaseline.txt

@@ -1,4 +1,10 @@
 Compat issues with assembly Avalonia.Visuals:
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.CompositePageTransition.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.CrossFade.Start(Avalonia.Visual, Avalonia.Visual)' does not exist in the implementation but it does exist in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public System.Threading.Tasks.Task Avalonia.Animation.IPageTransition.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean)' is present in the contract but not in the implementation.
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.IPageTransition.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean)' does not exist in the implementation but it does exist in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public System.Threading.Tasks.Task Avalonia.Animation.IPageTransition.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean, System.Threading.CancellationToken)' is present in the implementation but not in the contract.
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.PageSlide.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'public void Avalonia.Media.TextFormatting.DrawableTextRun.Draw(Avalonia.Media.DrawingContext)' does not exist in the implementation but it does exist in the contract.
 CannotAddAbstractMembers : Member 'public void Avalonia.Media.TextFormatting.DrawableTextRun.Draw(Avalonia.Media.DrawingContext, Avalonia.Point)' is abstract in the implementation but is missing in the contract.
 CannotSealType : Type 'Avalonia.Media.TextFormatting.GenericTextParagraphProperties' is actually (has the sealed modifier) sealed in the implementation but not sealed in the contract.
@@ -63,9 +69,8 @@ InterfacesShouldHaveSameMembers : Interface member 'public System.Boolean Avalon
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IGlyphRunImpl Avalonia.Platform.IPlatformRenderInterface.CreateGlyphRun(Avalonia.Media.GlyphRun)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IGlyphRunImpl Avalonia.Platform.IPlatformRenderInterface.CreateGlyphRun(Avalonia.Media.GlyphRun, System.Double)' is present in the contract but not in the implementation.
 MembersMustExist : Member 'public Avalonia.Platform.IGlyphRunImpl Avalonia.Platform.IPlatformRenderInterface.CreateGlyphRun(Avalonia.Media.GlyphRun, System.Double)' does not exist in the implementation but it does exist in the contract.
-Total Issues: 64
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWriteableBitmapImpl Avalonia.Platform.IPlatformRenderInterface.LoadWriteableBitmap(System.IO.Stream)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWriteableBitmapImpl Avalonia.Platform.IPlatformRenderInterface.LoadWriteableBitmap(System.String)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWriteableBitmapImpl Avalonia.Platform.IPlatformRenderInterface.LoadWriteableBitmapToHeight(System.IO.Stream, System.Int32, Avalonia.Visuals.Media.Imaging.BitmapInterpolationMode)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWriteableBitmapImpl Avalonia.Platform.IPlatformRenderInterface.LoadWriteableBitmapToWidth(System.IO.Stream, System.Int32, Avalonia.Visuals.Media.Imaging.BitmapInterpolationMode)' is present in the implementation but not in the contract.
-Total Issues: 11
+Total Issues: 74

src/Linux/Avalonia.LinuxFramebuffer/LinuxFramebufferPlatform.cs

@@ -132,7 +132,10 @@ public static class LinuxFramebufferPlatformExtensions
 {
     public static int StartLinuxFbDev<T>(this T builder, string[] args, string fbdev = null, double scaling = 1)
         where T : AppBuilderBase<T>, new() =>
-        StartLinuxDirect(builder, args, new FbdevOutput(fbdev) {Scaling = scaling});
+        StartLinuxDirect(builder, args, new FbdevOutput(fileName: fbdev, format: null) { Scaling = scaling });
+    public static int StartLinuxFbDev<T>(this T builder, string[] args, string fbdev, PixelFormat? format, double scaling)
+        where T : AppBuilderBase<T>, new() =>
+        StartLinuxDirect(builder, args, new FbdevOutput(fileName: fbdev, format: format) { Scaling = scaling });
 
     public static int StartLinuxDrm<T>(this T builder, string[] args, string card = null, double scaling = 1)
         where T : AppBuilderBase<T>, new() => StartLinuxDirect(builder, args, new DrmOutput(card) {Scaling = scaling});

src/Linux/Avalonia.LinuxFramebuffer/LockedFramebuffer.cs

@@ -41,6 +41,6 @@ namespace Avalonia.LinuxFramebuffer
         public PixelSize Size => new PixelSize((int)_varInfo.xres, (int) _varInfo.yres);
         public int RowBytes => (int) _fixedInfo.line_length;
         public Vector Dpi { get; }
-        public PixelFormat Format => _varInfo.blue.offset == 16 ? PixelFormat.Rgba8888 : PixelFormat.Bgra8888;
+        public PixelFormat Format => _varInfo.bits_per_pixel == 16 ? PixelFormat.Rgb565 : _varInfo.blue.offset == 16 ? PixelFormat.Rgba8888 : PixelFormat.Bgra8888;
     }
 }

src/Linux/Avalonia.LinuxFramebuffer/Output/FbdevOutput.cs

@@ -16,16 +16,33 @@ namespace Avalonia.LinuxFramebuffer
         private IntPtr _mappedAddress;
         public double Scaling { get; set; }
 
-        public FbdevOutput(string fileName = null)
+        /// <summary>
+        /// Create a Linux frame buffer device output
+        /// </summary>
+        /// <param name="fileName">The frame buffer device name.
+        /// Defaults to the value in environment variable FRAMEBUFFER or /dev/fb0 when FRAMEBUFFER is not set</param>
+        public FbdevOutput(string fileName = null) : this(fileName, null)
         {
-            fileName = fileName ?? Environment.GetEnvironmentVariable("FRAMEBUFFER") ?? "/dev/fb0";
+        }
+
+        /// <summary>
+        /// Create a Linux frame buffer device output
+        /// </summary>
+        /// <param name="fileName">The frame buffer device name.
+        /// Defaults to the value in environment variable FRAMEBUFFER or /dev/fb0 when FRAMEBUFFER is not set</param>
+        /// <param name="format">The required pixel format for the frame buffer.
+        /// A null value will leave the frame buffer in the current pixel format.
+        /// Otherwise sets the frame buffer to the required format</param>
+        public FbdevOutput(string fileName, PixelFormat? format)
+        {
+            fileName ??= Environment.GetEnvironmentVariable("FRAMEBUFFER") ?? "/dev/fb0";
             _fd = NativeUnsafeMethods.open(fileName, 2, 0);
             if (_fd <= 0)
                 throw new Exception("Error: " + Marshal.GetLastWin32Error());
 
             try
             {
-                Init();
+                Init(format);
             }
             catch
             {
@@ -34,25 +51,28 @@ namespace Avalonia.LinuxFramebuffer
             }
         }
 
-        void Init()
+        void Init(PixelFormat? format)
         {
             fixed (void* pnfo = &_varInfo)
             {
                 if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOGET_VSCREENINFO, pnfo))
                     throw new Exception("FBIOGET_VSCREENINFO error: " + Marshal.GetLastWin32Error());
 
-                SetBpp();
+                if (format.HasValue)
+                {
+                    SetBpp(format.Value);
 
-                if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOPUT_VSCREENINFO, pnfo))
-                    _varInfo.transp = new fb_bitfield();
+                    if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOPUT_VSCREENINFO, pnfo))
+                        _varInfo.transp = new fb_bitfield();
 
-                NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOPUT_VSCREENINFO, pnfo);
+                    NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOPUT_VSCREENINFO, pnfo);
 
-                if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOGET_VSCREENINFO, pnfo))
-                    throw new Exception("FBIOGET_VSCREENINFO error: " + Marshal.GetLastWin32Error());
+                    if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOGET_VSCREENINFO, pnfo))
+                        throw new Exception("FBIOGET_VSCREENINFO error: " + Marshal.GetLastWin32Error());
 
-                if (_varInfo.bits_per_pixel != 32)
-                    throw new Exception("Unable to set 32-bit display mode");
+                    if (_varInfo.bits_per_pixel != 32)
+                        throw new Exception("Unable to set 32-bit display mode");
+                }
             }
             fixed(void*pnfo = &_fixedInfo)
                 if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOGET_FSCREENINFO, pnfo))
@@ -70,17 +90,43 @@ namespace Avalonia.LinuxFramebuffer
             }
         }
 
-        void SetBpp()
+        void SetBpp(PixelFormat format)
         {
-            _varInfo.bits_per_pixel = 32;
-            _varInfo.grayscale = 0;
-            _varInfo.red = _varInfo.blue = _varInfo.green = _varInfo.transp = new fb_bitfield
+            switch (format)
             {
-                length = 8
-            };
-            _varInfo.green.offset = 8;
-            _varInfo.blue.offset = 16;
-            _varInfo.transp.offset = 24;
+            case PixelFormat.Rgba8888:
+                _varInfo.bits_per_pixel = 32;
+                _varInfo.grayscale = 0;
+                _varInfo.red = _varInfo.blue = _varInfo.green = _varInfo.transp = new fb_bitfield
+                {
+                    length = 8
+                };
+                _varInfo.green.offset = 8;
+                _varInfo.blue.offset = 16;
+                _varInfo.transp.offset = 24;
+                 break;
+            case PixelFormat.Bgra8888:
+                _varInfo.bits_per_pixel = 32;
+                _varInfo.grayscale = 0;
+                _varInfo.red = _varInfo.blue = _varInfo.green = _varInfo.transp = new fb_bitfield
+                {
+                    length = 8
+                };
+                _varInfo.green.offset = 8;
+                _varInfo.red.offset = 16;
+                _varInfo.transp.offset = 24;
+                 break;
+            case PixelFormat.Rgb565:
+                _varInfo.bits_per_pixel = 16;
+                _varInfo.grayscale = 0;
+                _varInfo.red = _varInfo.blue = _varInfo.green = _varInfo.transp = new fb_bitfield();
+                _varInfo.red.length = 5;
+                _varInfo.green.offset = 5;
+                _varInfo.green.length = 6;
+                _varInfo.blue.offset = 11;
+                _varInfo.blue.length = 5;
+                 break;
+            }
         }
 
         public string Id { get; private set; }

tests/Avalonia.Animation.UnitTests/AnimationIterationTests.cs

@@ -9,6 +9,8 @@ using Avalonia.UnitTests;
 using Avalonia.Data;
 using Xunit;
 using Avalonia.Animation.Easings;
+using System.Threading;
+using System.Reactive.Linq;
 
 namespace Avalonia.Animation.UnitTests
 {
@@ -176,5 +178,271 @@ namespace Avalonia.Animation.UnitTests
             clock.Step(TimeSpan.FromSeconds(0.100d));
             Assert.Equal(border.Width, 300d);
         }
+
+        [Fact(Skip = "See #6111")]
+        public void Dispose_Subscription_Should_Stop_Animation()
+        {
+            var keyframe1 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 200d),
+                },
+                Cue = new Cue(1d)
+            };
+
+            var keyframe2 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 100d),
+                },
+                Cue = new Cue(0d)
+            };
+
+            var animation = new Animation()
+            {
+                Duration = TimeSpan.FromSeconds(10),
+                Delay = TimeSpan.FromSeconds(0),
+                DelayBetweenIterations = TimeSpan.FromSeconds(0),
+                IterationCount = new IterationCount(1),
+                Children =
+                {
+                    keyframe2,
+                    keyframe1
+                }
+            };
+
+            var border = new Border()
+            {
+                Height = 100d,
+                Width = 50d
+            };
+            var propertyChangedCount = 0;
+            var animationCompletedCount = 0;
+            border.PropertyChanged += (sender, e) =>
+            {
+                if (e.Property == Control.WidthProperty)
+                {
+                    propertyChangedCount++;
+                }
+            };
+
+            var clock = new TestClock();
+            var disposable = animation.Apply(border, clock, Observable.Return(true), () => animationCompletedCount++);
+
+            Assert.Equal(0, propertyChangedCount);
+
+            clock.Step(TimeSpan.FromSeconds(0));
+            Assert.Equal(0, animationCompletedCount);
+            Assert.Equal(1, propertyChangedCount);
+
+            disposable.Dispose();
+
+            // Clock ticks should be ignored after Dispose
+            clock.Step(TimeSpan.FromSeconds(5));
+            clock.Step(TimeSpan.FromSeconds(6));
+            clock.Step(TimeSpan.FromSeconds(7));
+
+            // On animation disposing (cancellation) on completed is not invoked (is it expected?)
+            Assert.Equal(0, animationCompletedCount);
+            // Initial property changed before cancellation + animation value removal.
+            Assert.Equal(2, propertyChangedCount);
+        }
+
+        [Fact]
+        public void Do_Not_Run_Cancelled_Animation()
+        {
+            var keyframe1 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 200d),
+                },
+                Cue = new Cue(1d)
+            };
+
+            var keyframe2 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 100d),
+                },
+                Cue = new Cue(0d)
+            };
+
+            var animation = new Animation()
+            {
+                Duration = TimeSpan.FromSeconds(10),
+                Delay = TimeSpan.FromSeconds(0),
+                DelayBetweenIterations = TimeSpan.FromSeconds(0),
+                IterationCount = new IterationCount(1),
+                Children =
+                {
+                    keyframe2,
+                    keyframe1
+                }
+            };
+
+            var border = new Border()
+            {
+                Height = 100d,
+                Width = 100d
+            };
+            var propertyChangedCount = 0;
+            border.PropertyChanged += (sender, e) =>
+            {
+                if (e.Property == Control.WidthProperty)
+                {
+                    propertyChangedCount++;
+                }
+            };
+
+            var clock = new TestClock();
+            var cancellationTokenSource = new CancellationTokenSource();
+            cancellationTokenSource.Cancel();
+            var animationRun = animation.RunAsync(border, clock, cancellationTokenSource.Token);
+
+            clock.Step(TimeSpan.FromSeconds(10));
+            Assert.Equal(0, propertyChangedCount);
+            Assert.True(animationRun.IsCompleted);
+        }
+
+        [Fact(Skip = "See #6111")]
+        public void Cancellation_Should_Stop_Animation()
+        {
+            var keyframe1 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 200d),
+                },
+                Cue = new Cue(1d)
+            };
+
+            var keyframe2 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 100d),
+                },
+                Cue = new Cue(0d)
+            };
+
+            var animation = new Animation()
+            {
+                Duration = TimeSpan.FromSeconds(10),
+                Delay = TimeSpan.FromSeconds(0),
+                DelayBetweenIterations = TimeSpan.FromSeconds(0),
+                IterationCount = new IterationCount(1),
+                Children =
+                {
+                    keyframe2,
+                    keyframe1
+                }
+            };
+
+            var border = new Border()
+            {
+                Height = 100d,
+                Width = 50d
+            };
+            var propertyChangedCount = 0;
+            border.PropertyChanged += (sender, e) =>
+            {
+                if (e.Property == Control.WidthProperty)
+                {
+                    propertyChangedCount++;
+                }
+            };
+
+            var clock = new TestClock();
+            var cancellationTokenSource = new CancellationTokenSource();
+            var animationRun = animation.RunAsync(border, clock, cancellationTokenSource.Token);
+
+            Assert.Equal(0, propertyChangedCount);
+
+            clock.Step(TimeSpan.FromSeconds(0));
+            Assert.False(animationRun.IsCompleted);
+            Assert.Equal(1, propertyChangedCount);
+
+            cancellationTokenSource.Cancel();
+            clock.Step(TimeSpan.FromSeconds(1));
+            clock.Step(TimeSpan.FromSeconds(2));
+            clock.Step(TimeSpan.FromSeconds(3));
+            //Assert.Equal(2, propertyChangedCount);
+
+            animationRun.Wait();
+
+            clock.Step(TimeSpan.FromSeconds(6));
+            Assert.True(animationRun.IsCompleted);
+            Assert.Equal(2, propertyChangedCount);
+        }
+
+        [Fact]
+        public void Cancellation_Of_Completed_Animation_Does_Not_Fail()
+        {
+            var keyframe1 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 200d),
+                },
+                Cue = new Cue(1d)
+            };
+
+            var keyframe2 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 100d),
+                },
+                Cue = new Cue(0d)
+            };
+
+            var animation = new Animation()
+            {
+                Duration = TimeSpan.FromSeconds(10),
+                Delay = TimeSpan.FromSeconds(0),
+                DelayBetweenIterations = TimeSpan.FromSeconds(0),
+                IterationCount = new IterationCount(1),
+                Children =
+                {
+                    keyframe2,
+                    keyframe1
+                }
+            };
+
+            var border = new Border()
+            {
+                Height = 100d,
+                Width = 50d
+            };
+            var propertyChangedCount = 0;
+            border.PropertyChanged += (sender, e) =>
+            {
+                if (e.Property == Control.WidthProperty)
+                {
+                    propertyChangedCount++;
+                }
+            };
+
+            var clock = new TestClock();
+            var cancellationTokenSource = new CancellationTokenSource();
+            var animationRun = animation.RunAsync(border, clock, cancellationTokenSource.Token);
+
+            Assert.Equal(0, propertyChangedCount);
+
+            clock.Step(TimeSpan.FromSeconds(0));
+            Assert.False(animationRun.IsCompleted);
+            Assert.Equal(1, propertyChangedCount);
+
+            clock.Step(TimeSpan.FromSeconds(10));
+            Assert.True(animationRun.IsCompleted);
+            Assert.Equal(2, propertyChangedCount);
+
+            cancellationTokenSource.Cancel();
+            animationRun.Wait();
+        }
     }
 }