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SKAutoCanvasRestore avoid crash at Dispose when canvas was already disposed #3291

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Merged
mattleibow merged 5 commits into from
Jun 24, 2025
Merged

SKAutoCanvasRestore avoid crash at Dispose when canvas was already disposed #3291

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9ed0ca6
SKAutoCanvasRestore avoid crash at Dispose when canvas was already di…
taublast Jun 13, 2025
25a4490
add safety checks to mappers
taublast Jun 17, 2025
e77da13
add null check to dispatch
taublast Jun 17, 2025
c56d670
Merge branch 'main' into main
mattleibow Jun 20, 2025
ee44737
Update SKCanvas.cs
mattleibow Jun 24, 2025
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5 changes: 3 additions & 2 deletions binding/SkiaSharp/SKCanvas.cs
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1078,10 +1078,11 @@ public void Dispose ()
/// </summary>
public void Restore ()
{
if (canvas != null) {
// canvas can be GC-ed before us
if (canvas != null && canvas.Handle != IntPtr.Zero) {
canvas.RestoreToCount (saveCount);
canvas = null;
}
canvas = null;
}
}

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9 changes: 9 additions & 0 deletions ...p.Views.Maui/SkiaSharp.Views.Maui.Core/Handlers/SKCanvasView/SKCanvasViewHandler.Apple.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -36,16 +36,25 @@ protected override void DisconnectHandler(SKCanvasView platformView)

public static void OnInvalidateSurface(SKCanvasViewHandler handler, ISKCanvasView canvasView, object? args)
{
if (handler?.PlatformView == null)
return;

handler.PlatformView.SetNeedsDisplay();
}

public static void MapIgnorePixelScaling(SKCanvasViewHandler handler, ISKCanvasView canvasView)
{
if (handler?.PlatformView == null)
return;

handler.PlatformView.IgnorePixelScaling = canvasView.IgnorePixelScaling;
}

public static void MapEnableTouchEvents(SKCanvasViewHandler handler, ISKCanvasView canvasView)
{
if (handler?.PlatformView == null)
return;

handler.touchProxy?.UpdateEnableTouchEvents(handler.PlatformView, canvasView.EnableTouchEvents);
}

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9 changes: 9 additions & 0 deletions ...p.Views.Maui/SkiaSharp.Views.Maui.Core/Handlers/SKCanvasView/SKCanvasViewHandler.Tizen.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -33,16 +33,25 @@ protected override void DisconnectHandler(SKCanvasView platformView)

public static void OnInvalidateSurface(SKCanvasViewHandler handler, ISKCanvasView canvasView, object? args)
{
if (handler?.PlatformView == null)
return;

handler.PlatformView.Invalidate();
}

public static void MapIgnorePixelScaling(SKCanvasViewHandler handler, ISKCanvasView canvasView)
{
if (handler?.PlatformView == null)
return;

handler.PlatformView.IgnorePixelScaling = canvasView.IgnorePixelScaling;
}

public static void MapEnableTouchEvents(SKCanvasViewHandler handler, ISKCanvasView canvasView)
{
if (handler?.PlatformView == null)
return;

handler.touchHandler ??= new SKTouchHandler(
args => canvasView.OnTouch(args),
(x, y) => handler.OnGetScaledCoord(x, y));
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8 changes: 7 additions & 1 deletion ...Views.Maui/SkiaSharp.Views.Maui.Core/Handlers/SKCanvasView/SKCanvasViewHandler.Windows.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -33,17 +33,23 @@ protected override void DisconnectHandler(SKXamlCanvas platformView)

public static void OnInvalidateSurface(SKCanvasViewHandler handler, ISKCanvasView canvasView, object? args)
{
if (handler?.PlatformView == null)
return;

handler.PlatformView.Invalidate();
}

public static void MapIgnorePixelScaling(SKCanvasViewHandler handler, ISKCanvasView canvasView)
{
if (handler?.PlatformView == null)
return;

handler.PlatformView.IgnorePixelScaling = canvasView.IgnorePixelScaling;
}

public static void MapEnableTouchEvents(SKCanvasViewHandler handler, ISKCanvasView canvasView)
{
if (handler.PlatformView == null)
if (handler?.PlatformView == null)
return;

handler.touchHandler ??= new SKTouchHandler(
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11 changes: 10 additions & 1 deletion ...iaSharp.Views.Maui/SkiaSharp.Views.Maui.Core/Handlers/SKGLView/SKGLViewHandler.Android.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -42,13 +42,16 @@ protected override void DisconnectHandler(SKGLTextureView platformView)

public static void OnInvalidateSurface(SKGLViewHandler handler, ISKGLView view, object? args)
{
if (handler?.PlatformView == null)
return;

if (handler.PlatformView.RenderMode == Rendermode.WhenDirty)
handler.PlatformView.RequestRender();
}

public static void MapIgnorePixelScaling(SKGLViewHandler handler, ISKGLView view)
{
if (handler.PlatformView is not MauiSKGLTextureView pv)
if (handler?.PlatformView is not MauiSKGLTextureView pv)
return;

pv.IgnorePixelScaling = view.IgnorePixelScaling;
Expand All @@ -57,13 +60,19 @@ public static void MapIgnorePixelScaling(SKGLViewHandler handler, ISKGLView view

public static void MapHasRenderLoop(SKGLViewHandler handler, ISKGLView view)
{
if (handler?.PlatformView == null)
return;

handler.PlatformView.RenderMode = view.HasRenderLoop
? Rendermode.Continuously
: Rendermode.WhenDirty;
}

public static void MapEnableTouchEvents(SKGLViewHandler handler, ISKGLView view)
{
if (handler?.PlatformView == null)
return;

handler.touchHandler ??= new SKTouchHandler(
args => view.OnTouch(args),
(x, y) => handler.OnGetScaledCoord(x, y));
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11 changes: 10 additions & 1 deletion ...arp.Views.Maui/SkiaSharp.Views.Maui.Core/Handlers/SKGLView/SKGLViewHandler.MacCatalyst.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -42,13 +42,16 @@ protected override void DisconnectHandler(SKMetalView platformView)

public static void OnInvalidateSurface(SKGLViewHandler handler, ISKGLView view, object? args)
{
if (handler?.PlatformView == null)
return;

if (handler.PlatformView.Paused && handler.PlatformView.EnableSetNeedsDisplay)
handler.PlatformView.SetNeedsDisplay();
}

public static void MapIgnorePixelScaling(SKGLViewHandler handler, ISKGLView view)
{
if (handler.PlatformView is MauiSKMetalView pv)
if (handler?.PlatformView is MauiSKMetalView pv)
{
pv.IgnorePixelScaling = view.IgnorePixelScaling;
handler.PlatformView.SetNeedsDisplay();
Expand All @@ -57,12 +60,18 @@ public static void MapIgnorePixelScaling(SKGLViewHandler handler, ISKGLView view

public static void MapHasRenderLoop(SKGLViewHandler handler, ISKGLView view)
{
if (handler?.PlatformView == null)
return;

handler.PlatformView.Paused = !view.HasRenderLoop;
handler.PlatformView.EnableSetNeedsDisplay = !view.HasRenderLoop;
}

public static void MapEnableTouchEvents(SKGLViewHandler handler, ISKGLView view)
{
if (handler?.PlatformView == null)
return;

handler.touchProxy?.UpdateEnableTouchEvents(handler.PlatformView, view.EnableTouchEvents);
}

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10 changes: 8 additions & 2 deletions ...iaSharp.Views.Maui/SkiaSharp.Views.Maui.Core/Handlers/SKGLView/SKGLViewHandler.Windows.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -33,13 +33,16 @@ protected override void DisconnectHandler(SKSwapChainPanel platformView)

public static void OnInvalidateSurface(SKGLViewHandler handler, ISKGLView view, object? args)
{
if (handler?.PlatformView == null)
return;

if (!handler.PlatformView.EnableRenderLoop)
handler.PlatformView.Invalidate();
}

public static void MapIgnorePixelScaling(SKGLViewHandler handler, ISKGLView view)
{
if (handler.PlatformView is not MauiSKSwapChainPanel pv)
if (handler?.PlatformView is not MauiSKSwapChainPanel pv)
return;

pv.IgnorePixelScaling = view.IgnorePixelScaling;
Expand All @@ -48,12 +51,15 @@ public static void MapIgnorePixelScaling(SKGLViewHandler handler, ISKGLView view

public static void MapHasRenderLoop(SKGLViewHandler handler, ISKGLView view)
{
if (handler?.PlatformView == null)
return;

handler.PlatformView.EnableRenderLoop = view.HasRenderLoop;
}

public static void MapEnableTouchEvents(SKGLViewHandler handler, ISKGLView view)
{
if (handler.PlatformView == null)
if (handler?.PlatformView == null)
return;

handler.touchHandler ??= new SKTouchHandler(
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11 changes: 10 additions & 1 deletion ...e/SkiaSharp.Views.Maui/SkiaSharp.Views.Maui.Core/Handlers/SKGLView/SKGLViewHandler.iOS.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -53,12 +53,15 @@ protected override void DisconnectHandler(SKGLView platformView)

public static void OnInvalidateSurface(SKGLViewHandler handler, ISKGLView view, object? args)
{
if (handler?.PlatformView == null)
Comment on lines 54 to +56
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Copilot AI Jun 24, 2025

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[nitpick] This null-check pattern is repeated across multiple handler methods; consider extracting a shared guard or helper method to reduce duplication and improve maintainability.

Suggested change
public static void OnInvalidateSurface(SKGLViewHandler handler, ISKGLView view, object? args)
{
if (handler?.PlatformView == null)
private static bool IsHandlerValid(SKGLViewHandler? handler) =>
handler?.PlatformView != null;
public static void OnInvalidateSurface(SKGLViewHandler handler, ISKGLView view, object? args)
{
if (!IsHandlerValid(handler))

Copilot uses AI. Check for mistakes.
return;

handler.renderLoopManager?.RequestDisplay();
}

public static void MapIgnorePixelScaling(SKGLViewHandler handler, ISKGLView view)
{
if (handler.PlatformView is MauiSKGLView pv)
if (handler?.PlatformView is MauiSKGLView pv)
{
pv.IgnorePixelScaling = view.IgnorePixelScaling;
handler.renderLoopManager?.RequestDisplay();
Expand All @@ -67,6 +70,9 @@ public static void MapIgnorePixelScaling(SKGLViewHandler handler, ISKGLView view

public static void MapHasRenderLoop(SKGLViewHandler handler, ISKGLView view)
{
if (handler?.PlatformView == null)
return;

if (view.HasRenderLoop)
handler.renderLoopManager?.RequestRenderLoop();
else
Expand All @@ -75,6 +81,9 @@ public static void MapHasRenderLoop(SKGLViewHandler handler, ISKGLView view)

public static void MapEnableTouchEvents(SKGLViewHandler handler, ISKGLView view)
{
if (handler?.PlatformView == null)
return;

handler.touchProxy?.UpdateEnableTouchEvents(handler.PlatformView, view.EnableTouchEvents);
}

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4 changes: 2 additions & 2 deletions source/SkiaSharp.Views/SkiaSharp.Views.WinUI/SKXamlCanvas.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -161,9 +161,9 @@ private void OnUnloaded(object sender, RoutedEventArgs e)
public void Invalidate()
{
#if WINDOWS
DispatcherQueue.TryEnqueue(DispatcherQueuePriority.Normal, DoInvalidate);
DispatcherQueue?.TryEnqueue(DispatcherQueuePriority.Normal, DoInvalidate);
#else
Dispatcher.RunAsync(CoreDispatcherPriority.Normal, DoInvalidate);
Dispatcher?.RunAsync(CoreDispatcherPriority.Normal, DoInvalidate);
#endif
}

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