diff --git a/src/Avalonia.Base/Layout/Layoutable.cs b/src/Avalonia.Base/Layout/Layoutable.cs index df7aa937a0..f30925f489 100644 --- a/src/Avalonia.Base/Layout/Layoutable.cs +++ b/src/Avalonia.Base/Layout/Layoutable.cs @@ -141,7 +141,6 @@ namespace Avalonia.Layout static Layoutable() { AffectsMeasure( - IsVisibleProperty, WidthProperty, HeightProperty, MinWidthProperty, @@ -791,6 +790,25 @@ namespace Avalonia.Layout { } + protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change) + { + base.OnPropertyChanged(change); + + if (change.Property == IsVisibleProperty) + { + DesiredSize = default; + + // All changes to visibility cause the parent element to be notified. + this.GetVisualParent()?.ChildDesiredSizeChanged(this); + + // We only invalidate outselves when visibility is changed to true. + if (change.GetNewValue()) + { + InvalidateMeasure(); + } + } + } + /// protected sealed override void OnVisualParentChanged(IVisual? oldParent, IVisual? newParent) { diff --git a/tests/Avalonia.Base.UnitTests/Layout/LayoutableTests.cs b/tests/Avalonia.Base.UnitTests/Layout/LayoutableTests.cs index 87fa8cf1f3..184aada6cd 100644 --- a/tests/Avalonia.Base.UnitTests/Layout/LayoutableTests.cs +++ b/tests/Avalonia.Base.UnitTests/Layout/LayoutableTests.cs @@ -321,6 +321,103 @@ namespace Avalonia.Base.UnitTests.Layout Times.Once); } + [Fact] + public void Making_Control_Invisible_Should_Invalidate_Parent_Measure() + { + Border child; + var target = new StackPanel + { + Children = + { + (child = new Border + { + Width = 100, + }), + } + }; + + target.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity)); + target.Arrange(new Rect(target.DesiredSize)); + + Assert.True(target.IsMeasureValid); + Assert.True(target.IsArrangeValid); + Assert.True(child.IsMeasureValid); + Assert.True(child.IsArrangeValid); + + child.IsVisible = false; + + Assert.False(target.IsMeasureValid); + Assert.False(target.IsArrangeValid); + Assert.True(child.IsMeasureValid); + Assert.True(child.IsArrangeValid); + } + + [Fact] + public void Making_Control_Visible_Should_Invalidate_Own_And_Parent_Measure() + { + Border child; + var target = new StackPanel + { + Children = + { + (child = new Border + { + Width = 100, + IsVisible = false, + }), + } + }; + + target.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity)); + target.Arrange(new Rect(target.DesiredSize)); + + Assert.True(target.IsMeasureValid); + Assert.True(target.IsArrangeValid); + Assert.True(child.IsMeasureValid); + Assert.False(child.IsArrangeValid); + + child.IsVisible = true; + + Assert.False(target.IsMeasureValid); + Assert.False(target.IsArrangeValid); + Assert.False(child.IsMeasureValid); + Assert.False(child.IsArrangeValid); + } + + [Fact] + public void Measuring_Invisible_Control_Should_Not_Invalidate_Parent_Measure() + { + Border child; + var target = new StackPanel + { + Children = + { + (child = new Border + { + Width = 100, + }), + } + }; + + target.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity)); + target.Arrange(new Rect(target.DesiredSize)); + + Assert.True(target.IsMeasureValid); + Assert.True(target.IsArrangeValid); + Assert.Equal(new Size(100, 0), child.DesiredSize); + + child.IsVisible = false; + Assert.Equal(default, child.DesiredSize); + + target.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity)); + target.Arrange(new Rect(target.DesiredSize)); + child.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity)); + + Assert.True(target.IsMeasureValid); + Assert.True(target.IsArrangeValid); + Assert.Equal(default, child.DesiredSize); + } + private class TestLayoutable : Layoutable { public Size ArrangeSize { get; private set; }