diff --git a/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs b/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs index 00d896925a..83a0313dd5 100644 --- a/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs +++ b/src/Avalonia.Controls/Presenters/ItemVirtualizerSimple.cs @@ -116,7 +116,7 @@ namespace Avalonia.Controls.Presenters CreateAndRemoveContainers(); if (e.NewStartingIndex >= FirstIndex && - e.NewStartingIndex + e.NewItems.Count <= NextIndex) + e.NewStartingIndex < NextIndex) { RecycleContainers(); } @@ -125,7 +125,7 @@ namespace Avalonia.Controls.Presenters case NotifyCollectionChangedAction.Remove: if (e.OldStartingIndex >= FirstIndex && - e.OldStartingIndex + e.OldItems.Count <= NextIndex) + e.OldStartingIndex < NextIndex) { RecycleContainersOnRemove(); } diff --git a/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization_Simple.cs b/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization_Simple.cs index 53e81de241..8390ec6c03 100644 --- a/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization_Simple.cs +++ b/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization_Simple.cs @@ -554,6 +554,110 @@ namespace Avalonia.Controls.UnitTests.Presenters } } + [Fact] + public void InsertRange_Items_Should_Update_Containers() + { + var target = CreateTarget(useAvaloniaList: true); + + target.ApplyTemplate(); + target.Measure(new Size(100, 100)); + target.Arrange(new Rect(0, 0, 100, 100)); + + var expected = Enumerable.Range(0, 10).Select(x => $"Item {x}").ToList(); + var items = (AvaloniaList)target.Items; + var actual = target.Panel.Children.Select(x => x.DataContext).ToList(); + + Assert.Equal(expected, actual); + + var toAdd = Enumerable.Range(0, 3).Select(x => $"New Item {x}").ToList(); + + int index = 1; + + items.InsertRange(index, toAdd); + expected.InsertRange(index, toAdd); + expected.RemoveRange(10, toAdd.Count); + + actual = target.Panel.Children.Select(x => x.DataContext).ToList(); + Assert.Equal(expected, actual); + } + + [Fact] + public void InsertRange_Items_Before_Last_Should_Update_Containers() + { + var target = CreateTarget(useAvaloniaList: true); + + target.ApplyTemplate(); + target.Measure(new Size(100, 100)); + target.Arrange(new Rect(0, 0, 100, 100)); + + var expected = Enumerable.Range(0, 10).Select(x => $"Item {x}").ToList(); + var items = (AvaloniaList)target.Items; + var actual = target.Panel.Children.Select(x => x.DataContext).ToList(); + + Assert.Equal(expected, actual); + + var toAdd = Enumerable.Range(0, 3).Select(x => $"New Item {x}").ToList(); + + int index = 8; + + items.InsertRange(index, toAdd); + expected.InsertRange(index, toAdd); + expected.RemoveRange(10, toAdd.Count); + + actual = target.Panel.Children.Select(x => x.DataContext).ToList(); + Assert.Equal(expected, actual); + } + + [Fact] + public void RemoveRange_Items_Should_Update_Containers() + { + var target = CreateTarget(useAvaloniaList: true); + + target.ApplyTemplate(); + target.Measure(new Size(100, 100)); + target.Arrange(new Rect(0, 0, 100, 100)); + + var expected = Enumerable.Range(0, 13).Select(x => $"Item {x}").ToList(); + var items = (AvaloniaList)target.Items; + var actual = target.Panel.Children.Select(x => x.DataContext).ToList(); + + Assert.Equal(expected.Take(10), actual); + + int index = 5; + int count = 3; + + items.RemoveRange(index, count); + expected.RemoveRange(index, count); + + actual = target.Panel.Children.Select(x => x.DataContext).ToList(); + Assert.Equal(expected, actual); + } + + [Fact] + public void RemoveRange_Items_Before_Last_Should_Update_Containers() + { + var target = CreateTarget(useAvaloniaList: true); + + target.ApplyTemplate(); + target.Measure(new Size(100, 100)); + target.Arrange(new Rect(0, 0, 100, 100)); + + var expected = Enumerable.Range(0, 13).Select(x => $"Item {x}").ToList(); + var items = (AvaloniaList)target.Items; + var actual = target.Panel.Children.Select(x => x.DataContext).ToList(); + + Assert.Equal(expected.Take(10), actual); + + int index = 8; + int count = 3; + + items.RemoveRange(index, count); + expected.RemoveRange(index, count); + + actual = target.Panel.Children.Select(x => x.DataContext).ToList(); + Assert.Equal(expected, actual); + } + public class Vertical { [Fact] @@ -877,4 +981,4 @@ namespace Avalonia.Controls.UnitTests.Presenters } } } -} +} \ No newline at end of file