Merge branch 'master' into xaml-group-transfomers

src/Avalonia.Base/Rendering/Composition/Animations/KeyFrameAnimationInstance.cs

@@ -128,8 +128,11 @@ namespace Avalonia.Rendering.Composition.Animations
 
                     left = kf;
                     right = _keyFrames[c + 1];
-                    break;
                 }
+                else if (c == 0)
+                    return ExpressionVariant.Create(GetKeyFrame(ref ctx, kf));
+                else
+                    break;
             }
 
             var keyProgress = Math.Max(0, Math.Min(1, (iterationProgress - left.Key) / (right.Key - left.Key)));

src/Avalonia.Base/Rendering/Composition/CompositingRenderer.cs

@@ -146,8 +146,18 @@ public class CompositingRenderer : IRendererWithCompositor
                 return result == 0 ? lhs.index.CompareTo(rhs.index) : result;
             });
         }
-
+        
-        if (compositionChildren.Count == visualChildren.Count)
+        var childVisual = v.ChildCompositionVisual;
+        
+        // Check if the current visual somehow got migrated to another compositor
+        if (childVisual != null && childVisual.Compositor != v.CompositionVisual.Compositor)
+            childVisual = null;
+        
+        var expectedCount = visualChildren.Count;
+        if (childVisual != null)
+            expectedCount++;
+        
+        if (compositionChildren.Count == expectedCount)
         {
             bool mismatch = false;
             if (sortedChildren != null)
@@ -167,6 +177,9 @@ public class CompositingRenderer : IRendererWithCompositor
                         break;
                     }
 
+            if (childVisual != null &&
+                !ReferenceEquals(compositionChildren[compositionChildren.Count - 1], childVisual))
+                mismatch = true;
 
             if (!mismatch)
             {
@@ -193,6 +206,9 @@ public class CompositingRenderer : IRendererWithCompositor
                 if (compositionChild != null)
                     compositionChildren.Add(compositionChild);
             }
+
+        if (childVisual != null)
+            compositionChildren.Add(childVisual);
     }
 
     private void UpdateCore()

src/Avalonia.Base/Rendering/Composition/Compositor.Factories.cs

@@ -29,4 +29,7 @@ public partial class Compositor
     public ImplicitAnimationCollection CreateImplicitAnimationCollection() => new ImplicitAnimationCollection(this);
 
     public CompositionAnimationGroup CreateAnimationGroup() => new CompositionAnimationGroup(this);
+
+    public CompositionSolidColorVisual CreateSolidColorVisual() =>
+        new(this, new ServerCompositionSolidColorVisual(Server));
 }

src/Avalonia.Base/Rendering/Composition/ElementCompositionPreview.cs

@@ -1,5 +1,8 @@
 // Special license applies <see href="https://raw.githubusercontent.com/AvaloniaUI/Avalonia/master/src/Avalonia.Base/Rendering/Composition/License.md">License.md</see>
 
+using System;
+using Avalonia.VisualTree;
+
 namespace Avalonia.Rendering.Composition;
 
 /// <summary>
@@ -13,4 +16,22 @@ public static class ElementComposition
     /// <param name="visual"></param>
     /// <returns></returns>
     public static CompositionVisual? GetElementVisual(Visual visual) => visual.CompositionVisual;
+
+    /// <summary>
+    /// Sets a custom <see cref="CompositionVisual"/> as the last child of the element’s visual tree.
+    /// </summary>
+    public static void SetElementChildVisual(Visual visual, CompositionVisual? compositionVisual)
+    {
+        if (compositionVisual != null && visual.CompositionVisual != null &&
+            compositionVisual.Compositor != visual.CompositionVisual.Compositor)
+            throw new InvalidOperationException("Composition visuals belong to different compositor instances");
+        
+        visual.ChildCompositionVisual = compositionVisual;
+        visual.GetVisualRoot()?.Renderer.RecalculateChildren(visual);
+    }
+
+    /// <summary>
+    /// Retrieves a <see cref="CompositionVisual"/> object previously set by a call to <see cref="SetElementChildVisual" />.
+    /// </summary>
+    public static CompositionVisual? GetElementChildVisual(Visual visual) => visual.ChildCompositionVisual;
 }

src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionSolidColorVisual.cs

@@ -0,0 +1,11 @@
+using Avalonia.Media.Immutable;
+
+namespace Avalonia.Rendering.Composition.Server;
+
+internal partial class ServerCompositionSolidColorVisual
+{
+    protected override void RenderCore(CompositorDrawingContextProxy canvas, Rect currentTransformedClip)
+    {
+        canvas.DrawRectangle(new ImmutableSolidColorBrush(Color), null, new Rect(0, 0, Size.X, Size.Y));
+    }
+}

src/Avalonia.Base/Rendering/Composition/Server/ServerCompositionVisual.cs

@@ -48,7 +48,7 @@ namespace Avalonia.Rendering.Composition.Server
             if (Opacity != 1)
                 canvas.PushOpacity(Opacity);
             var boundsRect = new Rect(new Size(Size.X, Size.Y));
-            if(ClipToBounds)
+            if (ClipToBounds && !HandlesClipToBounds)
                 canvas.PushClip(Root!.SnapToDevicePixels(boundsRect));
             if (Clip != null) 
                 canvas.PushGeometryClip(Clip);
@@ -65,11 +65,13 @@ namespace Avalonia.Rendering.Composition.Server
                 canvas.PopOpacityMask();
             if (Clip != null)
                 canvas.PopGeometryClip();
-            if (ClipToBounds)
+            if (ClipToBounds && !HandlesClipToBounds)
                 canvas.PopClip();
             if(Opacity != 1)
                 canvas.PopOpacity();
         }
+
+        protected virtual bool HandlesClipToBounds => false;
         
         private ReadbackData _readback0, _readback1, _readback2;
 

src/Avalonia.Base/Threading/DispatcherPriority.cs

@@ -45,32 +45,37 @@ namespace Avalonia.Threading
         /// <summary>
         /// The job will be processed after other non-idle operations have completed.
         /// </summary>
-        public static readonly DispatcherPriority Background = new(1);
+        public static readonly DispatcherPriority Background = new(MinValue + 1);
 
         /// <summary>
         /// The job will be processed with the same priority as input.
         /// </summary>
-        public static readonly DispatcherPriority Input = new(2);
+        public static readonly DispatcherPriority Input = new(Background + 1);
 
         /// <summary>
         /// The job will be processed after layout and render but before input.
         /// </summary>
-        public static readonly DispatcherPriority Loaded = new(3);
+        public static readonly DispatcherPriority Loaded = new(Input + 1);
-        
+
         /// <summary>
         /// The job will be processed with the same priority as render.
         /// </summary>
-        public static readonly DispatcherPriority Render = new(5);
+        public static readonly DispatcherPriority Render = new(Loaded + 1);
-        
+
         /// <summary>
         /// The job will be processed with the same priority as composition updates.
         /// </summary>
-        public static readonly DispatcherPriority Composition = new(6);
+        public static readonly DispatcherPriority Composition = new(Render + 1);
-        
+
         /// <summary>
-        /// The job will be processed with the same priority as render.
+        /// The job will be processed with before composition updates.
+        /// </summary>
+        public static readonly DispatcherPriority PreComposition = new(Composition + 1);
+
+        /// <summary>
+        /// The job will be processed with the same priority as layout.
         /// </summary>
-        public static readonly DispatcherPriority Layout = new(7);
+        public static readonly DispatcherPriority Layout = new(PreComposition + 1);
 
         /// <summary>
         /// The job will be processed with the same priority as data binding.
@@ -80,7 +85,7 @@ namespace Avalonia.Threading
         /// <summary>
         /// The job will be processed before other asynchronous operations.
         /// </summary>
-        public static readonly DispatcherPriority Send = new(8);
+        public static readonly DispatcherPriority Send = new(Layout + 1);
 
         /// <summary>
         /// Maximum possible priority
@@ -123,4 +128,4 @@ namespace Avalonia.Threading
         /// <inheritdoc />
         public int CompareTo(DispatcherPriority other) => Value.CompareTo(other.Value);
     }
-}
+}

src/Avalonia.Base/Visual.cs

@@ -292,6 +292,7 @@ namespace Avalonia
         protected IRenderRoot? VisualRoot => _visualRoot ?? (this as IRenderRoot);
 
         internal CompositionDrawListVisual? CompositionVisual { get; private set; }
+        internal CompositionVisual? ChildCompositionVisual { get; set; }
         
         public bool HasNonUniformZIndexChildren { get; private set; }
 
@@ -452,12 +453,15 @@ namespace Avalonia
             }
         }
 
+        private protected virtual CompositionDrawListVisual CreateCompositionVisual(Compositor compositor)
+            => new CompositionDrawListVisual(compositor,
+                new ServerCompositionDrawListVisual(compositor.Server, this), this);
+        
         internal CompositionVisual AttachToCompositor(Compositor compositor)
         {
             if (CompositionVisual == null || CompositionVisual.Compositor != compositor)
             {
-                CompositionVisual = new CompositionDrawListVisual(compositor,
+                CompositionVisual = CreateCompositionVisual(compositor);
-                    new ServerCompositionDrawListVisual(compositor.Server, this), this);
             }
 
             return CompositionVisual;

src/Avalonia.Base/composition-schema.xml

@@ -27,6 +27,9 @@
         <Property Name="OpacityMaskBrush" Type="Avalonia.Media.IBrush?" Internal="true" />
     </Object>
     <Object Name="CompositionContainerVisual" Inherits="CompositionVisual"/>
+    <Object Name="CompositionSolidColorVisual" Inherits="CompositionContainerVisual">
+        <Property Name="Color" Type="Avalonia.Media.Color" Animated="true" />
+    </Object>
     <List Name="CompositionVisualCollection" ItemType="CompositionVisual" CustomCtor="true"/>
     <Object Name="CompositionTarget" CustomServerCtor="true">
         <Property Name="Root" Type="CompositionVisual?"/>

src/Avalonia.Controls/Border.cs

@@ -4,6 +4,7 @@ using Avalonia.Controls.Shapes;
 using Avalonia.Controls.Utils;
 using Avalonia.Layout;
 using Avalonia.Media;
+using Avalonia.Rendering.Composition;
 using Avalonia.Utilities;
 using Avalonia.VisualTree;
 
@@ -73,6 +74,7 @@ namespace Avalonia.Controls
         private readonly BorderRenderHelper _borderRenderHelper = new BorderRenderHelper();
         private Thickness? _layoutThickness;
         private double _scale;
+        private CompositionBorderVisual? _borderVisual;
 
         /// <summary>
         /// Initializes static members of the <see cref="Border"/> class.
@@ -101,6 +103,10 @@ namespace Avalonia.Controls
                 case nameof(BorderThickness):
                     _layoutThickness = null;
                     break;
+                case nameof(CornerRadius):
+                    if (_borderVisual != null)
+                        _borderVisual.CornerRadius = CornerRadius;
+                    break;
             }
         }
 
@@ -245,6 +251,14 @@ namespace Avalonia.Controls
             return LayoutHelper.ArrangeChild(Child, finalSize, Padding, BorderThickness);
         }
 
+        private protected override CompositionDrawListVisual CreateCompositionVisual(Compositor compositor)
+        {
+            return _borderVisual = new CompositionBorderVisual(compositor, this)
+            {
+                CornerRadius = CornerRadius
+            };
+        }
+
         public CornerRadius ClipToBoundsRadius => CornerRadius;
     }
 }

src/Avalonia.Controls/BorderVisual.cs

@@ -0,0 +1,76 @@
+using System;
+using Avalonia.Rendering.Composition;
+using Avalonia.Rendering.Composition.Server;
+using Avalonia.Rendering.Composition.Transport;
+using Avalonia.Rendering.SceneGraph;
+
+namespace Avalonia.Controls;
+
+class CompositionBorderVisual : CompositionDrawListVisual
+{
+    private CornerRadius _cornerRadius;
+    private bool _cornerRadiusChanged;
+    
+    public CompositionBorderVisual(Compositor compositor, Visual visual) : base(compositor,
+        new ServerBorderVisual(compositor.Server, visual), visual)
+    {
+    }
+
+    public CornerRadius CornerRadius
+    {
+        get => _cornerRadius;
+        set
+        {
+            if (_cornerRadius != value)
+            {
+                _cornerRadiusChanged = true;
+                _cornerRadius = value;
+                RegisterForSerialization();
+            }
+        }
+    }
+
+    private protected override void SerializeChangesCore(BatchStreamWriter writer)
+    {
+        base.SerializeChangesCore(writer);
+        writer.Write(_cornerRadiusChanged);
+        if (_cornerRadiusChanged)
+            writer.Write(_cornerRadius);
+    }
+
+    class ServerBorderVisual : ServerCompositionDrawListVisual
+    {
+        private CornerRadius _cornerRadius;
+        public ServerBorderVisual(ServerCompositor compositor, Visual v) : base(compositor, v)
+        {
+        }
+
+        protected override void RenderCore(CompositorDrawingContextProxy canvas, Rect currentTransformedClip)
+        {
+            if (ClipToBounds)
+            {
+                var clipRect = Root!.SnapToDevicePixels(new Rect(new Size(Size.X, Size.Y)));
+                if (_cornerRadius.IsEmpty)
+                    canvas.PushClip(clipRect);
+                else
+                    canvas.PushClip(new RoundedRect(clipRect, _cornerRadius));
+            }
+
+            base.RenderCore(canvas, currentTransformedClip);
+            
+            if(ClipToBounds)
+                canvas.PopClip();
+            
+        }
+
+        protected override void DeserializeChangesCore(BatchStreamReader reader, TimeSpan commitedAt)
+        {
+            base.DeserializeChangesCore(reader, commitedAt);
+            if (reader.Read<bool>())
+                _cornerRadius = reader.Read<CornerRadius>();
+        }
+
+        protected override bool HandlesClipToBounds => true;
+    }
+
+}