Restore 0.10.x behavior for re-creating visual brush content on property change (#15838)

src/Avalonia.Base/Media/Brush.cs

@@ -101,6 +101,8 @@ namespace Avalonia.Media
         private protected void RegisterForSerialization() =>
             _resource.RegisterForInvalidationOnAllCompositors(this);
 
+        private protected bool IsOnCompositor(Compositor c) => _resource.TryGetForCompositor(c) != null;
+
         private CompositorResourceHolder<ServerCompositionSimpleBrush> _resource;
 
         IBrush ICompositionRenderResource<IBrush>.GetForCompositor(Compositor c) => _resource.GetForCompositor(c);

src/Avalonia.Base/Media/DrawingBrush.cs

@@ -58,7 +58,7 @@ namespace Avalonia.Media
         internal override Func<Compositor, ServerCompositionSimpleBrush> Factory =>
             static c => new ServerCompositionSimpleContentBrush(c.Server);
 
-        private InlineDictionary<Compositor, CompositionRenderDataSceneBrushContent?> _renderDataDictionary;
+        private InlineDictionary<Compositor, CompositionRenderData?> _renderDataDictionary;
 
         private protected override void OnReferencedFromCompositor(Compositor c)
         {
@@ -69,33 +69,27 @@ namespace Avalonia.Media
         protected override void OnUnreferencedFromCompositor(Compositor c)
         {
             if (_renderDataDictionary.TryGetAndRemoveValue(c, out var content))
-                content?.RenderData.Dispose();
+                content?.Dispose();
             base.OnUnreferencedFromCompositor(c);
         }
         
         private protected override void SerializeChanges(Compositor c, BatchStreamWriter writer)
         {
             base.SerializeChanges(c, writer);
-            if (_renderDataDictionary.TryGetValue(c, out var content))
-                writer.WriteObject(content);
+            if (_renderDataDictionary.TryGetValue(c, out var content) && content != null)
+                writer.WriteObject(new CompositionRenderDataSceneBrushContent.Properties(content.Server, null, true));
             else
                 writer.WriteObject(null);
         }
         
-        CompositionRenderDataSceneBrushContent? CreateServerContent(Compositor c)
+        CompositionRenderData? CreateServerContent(Compositor c)
         {
             if (Drawing == null)
                 return null;
             
             using var recorder = new RenderDataDrawingContext(c);
             Drawing?.Draw(recorder);
-            var renderData = recorder.GetRenderResults();
-            if (renderData == null)
-                return null;
-            
-            return new CompositionRenderDataSceneBrushContent(
-                (ServerCompositionSimpleContentBrush)((ICompositionRenderResource<IBrush>)this).GetForCompositor(c),
-                renderData, null, true);
+            return recorder.GetRenderResults();
         }
     }
 }

src/Avalonia.Base/Media/VisualBrush.cs

@@ -1,4 +1,5 @@
 using System;
+using Avalonia.Collections.Pooled;
 using Avalonia.Media.Immutable;
 using Avalonia.Rendering;
 using Avalonia.Rendering.Composition;
@@ -62,31 +63,65 @@ namespace Avalonia.Media
         internal override Func<Compositor, ServerCompositionSimpleBrush> Factory =>
             static c => new ServerCompositionSimpleContentBrush(c.Server);
 
-        private InlineDictionary<Compositor, CompositionRenderDataSceneBrushContent?> _renderDataDictionary;
-
-        private protected override void OnReferencedFromCompositor(Compositor c)
+        class RenderDataItem(CompositionRenderData data, Rect rect) : IDisposable
         {
-            _renderDataDictionary.Add(c, CreateServerContent(c));
-            base.OnReferencedFromCompositor(c);
+            public CompositionRenderData Data { get; } = data;
+            public Rect Rect { get; } = rect;
+            public bool IsDirty;
+            public void Dispose() => Data?.Dispose();
         }
-
+        
+        private InlineDictionary<Compositor, RenderDataItem?> _renderDataDictionary;
+        
         protected override void OnUnreferencedFromCompositor(Compositor c)
         {
             if (_renderDataDictionary.TryGetAndRemoveValue(c, out var content))
-                content?.RenderData.Dispose();
+                content?.Dispose();
             base.OnUnreferencedFromCompositor(c);
         }
         
         private protected override void SerializeChanges(Compositor c, BatchStreamWriter writer)
         {
             base.SerializeChanges(c, writer);
-            if (_renderDataDictionary.TryGetValue(c, out var content))
-                writer.WriteObject(content);
-            else
-                writer.WriteObject(null);
+            CompositionRenderDataSceneBrushContent.Properties? content = null;
+            if (IsOnCompositor(c)) // Should always be true here, but just in case do this check
+            {
+                _renderDataDictionary.TryGetValue(c, out var data);
+                if (data == null || data.IsDirty)
+                {
+                    var created = CreateServerContent(c);
+                    // Dispose the old render list _after_ creating a new one to avoid unnecessary detach/attach
+                    // sequence for referenced resources
+                    if (data != null) 
+                        data.Dispose();
+                    
+                    _renderDataDictionary[c] = data = created;
+                }
+
+                if (data != null)
+                    content = new(data.Data.Server, data.Rect, false);
+            }
+            
+            writer.WriteObject(content);
         }
         
-        CompositionRenderDataSceneBrushContent? CreateServerContent(Compositor c)
+        void InvalidateContent()
+        {
+            foreach(var item in _renderDataDictionary)
+                if (item.Value != null)
+                    item.Value.IsDirty = true;
+            RegisterForSerialization();
+        }
+
+        protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
+        {
+            // We are supposed to be only calling this when content is actually changed,
+            // but instead we are calling this on brush property change for backwards compat with 0.10.x
+            InvalidateContent();
+            base.OnPropertyChanged(change);
+        }
+
+        RenderDataItem? CreateServerContent(Compositor c)
         {
             if (Visual == null)
                 return null;
@@ -99,10 +134,8 @@ namespace Avalonia.Media
             var renderData = recorder.GetRenderResults();
             if (renderData == null)
                 return null;
-            
-            return new CompositionRenderDataSceneBrushContent(
-                (ServerCompositionSimpleContentBrush)((ICompositionRenderResource<IBrush>)this).GetForCompositor(c),
-                renderData, new(Visual.Bounds.Size), false);
+
+            return new(renderData, new(Visual.Bounds.Size));
         }
     }
 }

src/Avalonia.Base/Rendering/Composition/Brushes/ServerSimpleContentBrush.cs

@@ -7,18 +7,21 @@ namespace Avalonia.Rendering.Composition.Server;
 
 internal sealed class ServerCompositionSimpleContentBrush : ServerCompositionSimpleTileBrush, ITileBrush, ISceneBrush
 {
-    private CompositionRenderDataSceneBrushContent? _content;
+    private CompositionRenderDataSceneBrushContent.Properties? _content;
+    
 
     internal ServerCompositionSimpleContentBrush(ServerCompositor compositor) : base(compositor)
     {
     }
 
-    // TODO: Figure out something about disposable
-    public ISceneBrushContent? CreateContent() => _content;
+    public ISceneBrushContent? CreateContent() =>
+        _content == null || _content.RenderData.IsDisposed
+            ? null
+            : new CompositionRenderDataSceneBrushContent(this, _content);
 
     protected override void DeserializeChangesCore(BatchStreamReader reader, TimeSpan committedAt)
     {
         base.DeserializeChangesCore(reader, committedAt);
-        _content = reader.ReadObject<CompositionRenderDataSceneBrushContent?>();
+        _content = reader.ReadObject<CompositionRenderDataSceneBrushContent.Properties?>();
     }
 }

src/Avalonia.Base/Rendering/Composition/Drawing/CompositionRenderDataSceneBrushContent.cs

@@ -6,20 +6,21 @@ namespace Avalonia.Rendering.Composition.Drawing;
 
 internal class CompositionRenderDataSceneBrushContent : ISceneBrushContent
 {
-    public CompositionRenderData RenderData { get; }
+    public ServerCompositionRenderData RenderData { get; }
     private readonly Rect? _rect;
 
-    public CompositionRenderDataSceneBrushContent(ITileBrush brush, CompositionRenderData renderData, Rect? rect,
-        bool useScalableRasterization)
+    public record Properties(ServerCompositionRenderData RenderData, Rect? Rect, bool UseScalableRasterization);
+
+    public CompositionRenderDataSceneBrushContent(ITileBrush brush, Properties properties)
     {
         Brush = brush;
-        _rect = rect;
-        UseScalableRasterization = useScalableRasterization;
-        RenderData = renderData;
+        _rect = properties.Rect;
+        UseScalableRasterization = properties.UseScalableRasterization;
+        RenderData = properties.RenderData;
     }
 
     public ITileBrush Brush { get; }
-    public Rect Rect => _rect ?? (RenderData.Server?.Bounds?.ToRect() ?? default);
+    public Rect Rect => _rect ?? (RenderData?.Bounds?.ToRect() ?? default);
 
     public double Opacity => Brush.Opacity;
     public ITransform? Transform => Brush.Transform;
@@ -36,11 +37,11 @@ internal class CompositionRenderDataSceneBrushContent : ISceneBrushContent
         {
             var oldTransform = context.Transform;
             context.Transform = transform.Value * oldTransform;
-            RenderData.Server.Render(context);
+            RenderData.Render(context);
             context.Transform = oldTransform;
         }
         else
-            RenderData.Server.Render(context);
+            RenderData.Render(context);
     }
 
     public bool UseScalableRasterization { get; }

src/Avalonia.Base/Utilities/SmallDictionary.cs

@@ -127,6 +127,18 @@ internal struct InlineDictionary<TKey, TValue> : IEnumerable<KeyValuePair<TKey,
         return false;
     }
 
+    public void Clear()
+    {
+        if(_data == null)
+            return;
+        if(_data is KeyValuePair[] arr)
+            Array.Clear(arr, 0, arr.Length);
+        else if (_data is Dictionary<TKey, TValue?> dic)
+            dic.Clear();
+        else
+            _data = null;
+    }
+
     public bool HasEntries => _data != null;
     
     public bool TryGetValue(TKey key, [MaybeNullWhen(false)]out TValue value)