diff --git a/src/Avalonia.Base/Layout/LayoutManager.cs b/src/Avalonia.Base/Layout/LayoutManager.cs index f47738f2e4..7873f83edb 100644 --- a/src/Avalonia.Base/Layout/LayoutManager.cs +++ b/src/Avalonia.Base/Layout/LayoutManager.cs @@ -21,6 +21,7 @@ namespace Avalonia.Layout private readonly Layoutable _owner; private readonly LayoutQueue _toMeasure = new LayoutQueue(v => !v.IsMeasureValid); private readonly LayoutQueue _toArrange = new LayoutQueue(v => !v.IsArrangeValid); + private readonly List _toArrangeAfterMeasure = new(); private readonly Action _executeLayoutPass; private List? _effectiveViewportChangedListeners; private bool _disposed; @@ -266,9 +267,14 @@ namespace Avalonia.Layout if (!control.IsArrangeValid) { - Arrange(control); + if (Arrange(control) == ArrangeResult.AncestorMeasureInvalid) + _toArrangeAfterMeasure.Add(control); } } + + foreach (var i in _toArrangeAfterMeasure) + InvalidateArrange(i); + _toArrangeAfterMeasure.Clear(); } private bool Measure(Layoutable control) @@ -304,19 +310,19 @@ namespace Avalonia.Layout return true; } - private bool Arrange(Layoutable control) + private ArrangeResult Arrange(Layoutable control) { if (!control.IsVisible || !control.IsAttachedToVisualTree) - return false; + return ArrangeResult.NotVisible; if (control.VisualParent is Layoutable parent) { - if (!Arrange(parent)) - return false; + if (Arrange(parent) is var parentResult && parentResult != ArrangeResult.Arranged) + return parentResult; } if (!control.IsMeasureValid) - return false; + return ArrangeResult.AncestorMeasureInvalid; if (!control.IsArrangeValid) { @@ -332,7 +338,7 @@ namespace Avalonia.Layout } } - return true; + return ArrangeResult.Arranged; } private void QueueLayoutPass() @@ -435,5 +441,12 @@ namespace Avalonia.Layout public Layoutable Listener { get; } public Rect Viewport { get; set; } } + + private enum ArrangeResult + { + Arranged, + NotVisible, + AncestorMeasureInvalid, + } } } diff --git a/tests/Avalonia.Base.UnitTests/Layout/LayoutManagerTests.cs b/tests/Avalonia.Base.UnitTests/Layout/LayoutManagerTests.cs index 45a6efdd4a..cadf23c754 100644 --- a/tests/Avalonia.Base.UnitTests/Layout/LayoutManagerTests.cs +++ b/tests/Avalonia.Base.UnitTests/Layout/LayoutManagerTests.cs @@ -547,5 +547,38 @@ namespace Avalonia.Base.UnitTests.Layout Assert.True(root.IsMeasureValid); Assert.True(root.IsArrangeValid); } + + [Fact] + public void GreatGrandparent_Can_Invalidate_Grandparent_Measure_During_Arrange() + { + // Issue #7706 (second part: scrollbar gets stuck) + var child = new LayoutTestControl(); + var parent = new LayoutTestControl { Child = child }; + var grandparent = new LayoutTestControl { Child = parent }; + var greatGrandparent = new LayoutTestControl { Child = grandparent }; + var root = new LayoutTestRoot { Child = greatGrandparent }; + + root.LayoutManager.ExecuteInitialLayoutPass(); + + greatGrandparent.DoArrangeOverride = (_, s) => + { + grandparent.InvalidateMeasure(); + return s; + }; + + child.InvalidateArrange(); + greatGrandparent.InvalidateArrange(); + + root.LayoutManager.ExecuteLayoutPass(); + + Assert.True(child.IsMeasureValid); + Assert.True(child.IsArrangeValid); + Assert.True(parent.IsMeasureValid); + Assert.True(parent.IsArrangeValid); + Assert.True(greatGrandparent.IsMeasureValid); + Assert.True(greatGrandparent.IsArrangeValid); + Assert.True(root.IsMeasureValid); + Assert.True(root.IsArrangeValid); + } } }