Merge pull request #456 from irihitech/issue-455

Fix breadcrumb indexing when insertion from itemssource.

src/Ursa/Controls/Breadcrumb/Breadcrumb.cs

@@ -5,6 +5,7 @@ using Avalonia.Controls.Templates;
 using Avalonia.Data;
 using Avalonia.Layout;
 using Avalonia.Metadata;
+using Avalonia.VisualTree;
 
 namespace Ursa.Controls;
 
@@ -84,17 +85,6 @@ public class Breadcrumb: ItemsControl
         return new BreadcrumbItem();
     }
 
-    protected override void LogicalChildrenCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
-    {
-        base.LogicalChildrenCollectionChanged(sender, e);
-        var breadcrumbItems = LogicalChildren.OfType<BreadcrumbItem>().ToList();
-        for (var i = 0; i < breadcrumbItems.Count; i++)
-        {
-            var breadcrumbItem = breadcrumbItems[i];
-            breadcrumbItem.SetPseudoClassLast(i == breadcrumbItems.Count - 1);
-        }
-    }
-
     protected override void PrepareContainerForItemOverride(Control container, object? item, int index)
     {
         if (container is not BreadcrumbItem breadcrumbItem) return;
@@ -149,4 +139,13 @@ public class Breadcrumb: ItemsControl
         ITemplate<Control?> t => t.Build(),
         _ => separator.ToString()
     };
+
+    internal void InvalidateContainers()
+    {
+        var breadcrumbItems = this.GetVisualDescendants().OfType<BreadcrumbItem>().ToList();
+        for (var i = 0; i < breadcrumbItems.Count; i++)
+        {
+            breadcrumbItems[i].SetPseudoClassLast(i == breadcrumbItems.Count - 1);
+        }
+    }
 }

src/Ursa/Controls/Breadcrumb/BreadcrumbItem.cs

@@ -79,4 +79,11 @@ public class BreadcrumbItem: ContentControl
     {
         PseudoClasses.Set(PC_Last, isLast);
     }
+
+    protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
+    {
+        base.OnAttachedToVisualTree(e);
+        var parent = this.Parent as Breadcrumb;
+        parent?.InvalidateContainers();
+    }
 }

tests/HeadlessTest.Ursa/Controls/BreadcrumbTests/BreadcrumbTests.cs

@@ -2,6 +2,7 @@ using System.Collections.ObjectModel;
 using Avalonia.Controls;
 using Avalonia.Headless.XUnit;
 using Avalonia.LogicalTree;
+using Avalonia.VisualTree;
 using Ursa.Controls;
 
 namespace HeadlessTest.Ursa.Controls;
@@ -24,6 +25,22 @@ public class BreadcrumbTests
         Assert.DoesNotContain(":last", item1.Classes);
     }
     
+    [AvaloniaFact]
+    public void BreadcrumbItem_Should_Have_Correct_PseudoClasses_When_Insert()
+    {
+        var window = new Window();
+        var breadcrumb = new Breadcrumb();
+        window.Content = breadcrumb;
+        window.Show();
+        var item1 = new BreadcrumbItem();
+        var item2 = new BreadcrumbItem();
+        breadcrumb.Items.Add(item1);
+        Assert.Contains(":last", item1.Classes);
+        breadcrumb.Items.Insert(0, item2);
+        Assert.Contains(":last", item1.Classes);
+        Assert.DoesNotContain(":last", item2.Classes);
+    }
+    
     [AvaloniaFact]
     public void Generated_BreadcrumbItem_Should_Have_Correct_PseudoClasses()
     {
@@ -34,16 +51,38 @@ public class BreadcrumbTests
         var item1 = new TextBlock();
         var item2 = new TextBlock();
         breadcrumb.Items.Add(item1);
-        var firstItem = breadcrumb.GetLogicalChildren().OfType<BreadcrumbItem>().FirstOrDefault();
+        var firstItem = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().FirstOrDefault();
         Assert.NotNull(firstItem);
         Assert.Contains(":last", firstItem.Classes);
         breadcrumb.Items.Add(item2);
-        var lastItem = breadcrumb.GetLogicalChildren().OfType<BreadcrumbItem>().LastOrDefault();
+        var lastItem = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().LastOrDefault();
         Assert.NotNull(lastItem);
         Assert.Contains(":last", lastItem.Classes);
         Assert.DoesNotContain(":last", firstItem.Classes);
     }
     
+    [AvaloniaFact]
+    public void Generated_BreadcrumbItem_Should_Have_Correct_PseudoClasses_When_Insert()
+    {
+        var window = new Window();
+        var breadcrumb = new Breadcrumb();
+        window.Content = breadcrumb;
+        window.Show();
+        var item1 = new TextBlock();
+        var item2 = new TextBlock();
+        breadcrumb.Items.Add(item1);
+        var firstItem = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().FirstOrDefault();
+        Assert.NotNull(firstItem);
+        Assert.Contains(":last", firstItem.Classes);
+        breadcrumb.Items.Insert(0, item2);
+        var lastItem = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().LastOrDefault();
+        Assert.NotNull(lastItem);
+        Assert.Contains(":last", lastItem.Classes);
+        firstItem = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().FirstOrDefault();
+        Assert.NotNull(firstItem);
+        Assert.DoesNotContain(":last", firstItem.Classes);
+    }
+    
     [AvaloniaFact]
     public void BreadcrumbItem_FromItemsSource_Should_Have_Correct_PseudoClasses()
     {
@@ -54,16 +93,38 @@ public class BreadcrumbTests
         var items = new ObservableCollection<string>();
         breadcrumb.ItemsSource = items;
         items.Add("Item 1");
-        var item1 = breadcrumb.GetLogicalChildren().OfType<BreadcrumbItem>().FirstOrDefault();
+        var item1 = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().FirstOrDefault();
         Assert.NotNull(item1);
         Assert.Contains(":last", item1.Classes);
         items.Add("Item 2");
-        var item2 = breadcrumb.GetLogicalChildren().OfType<BreadcrumbItem>().LastOrDefault();
+        var item2 = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().LastOrDefault();
         Assert.NotNull(item2);
         Assert.Contains(":last", item2.Classes);
         Assert.DoesNotContain(":last", item1.Classes);
     }
     
+    [AvaloniaFact]
+    public void BreadcrumbItem_FromItemsSource_Should_Have_Correct_PseudoClasses_When_Insert() 
+    {
+        var window = new Window();
+        var breadcrumb = new Breadcrumb();
+        window.Content = breadcrumb;
+        window.Show();
+        var items = new ObservableCollection<string>();
+        breadcrumb.ItemsSource = items;
+        items.Add("Item 1");
+        var item1 = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().FirstOrDefault();
+        Assert.NotNull(item1);
+        Assert.Contains(":last", item1.Classes);
+        items.Insert(0, "Item 2");
+        var item2 = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().LastOrDefault();
+        Assert.NotNull(item2);
+        Assert.Contains(":last", item2.Classes);
+        var newItem1 = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().FirstOrDefault();
+        Assert.NotNull(newItem1);
+        Assert.DoesNotContain(":last", newItem1.Classes);
+    }
+    
     [AvaloniaFact]
     public void Bulk_Added_BreadcrumbItem_Should_Have_Correct_PseudoClasses()
     {
@@ -77,8 +138,8 @@ public class BreadcrumbTests
             "Item 2"
         };
         breadcrumb.ItemsSource = items;
-        var item1 = breadcrumb.GetLogicalChildren().OfType<BreadcrumbItem>().FirstOrDefault();
+        var item1 = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().FirstOrDefault();
-        var item2 = breadcrumb.GetLogicalChildren().OfType<BreadcrumbItem>().LastOrDefault();
+        var item2 = breadcrumb.GetVisualDescendants().OfType<BreadcrumbItem>().LastOrDefault();
         Assert.NotNull(item1);
         Assert.NotNull(item2);
         Assert.Contains(":last", item2.Classes);