Merge branch 'feature/selectionmodel-reset-handling' into feature/selectionmodel-autoselect

src/Avalonia.Controls/SelectionNode.cs

@@ -375,17 +375,29 @@ namespace Avalonia.Controls
             }
         }
 
-        public void Cleanup()
+        public bool Cleanup()
         {
-            foreach (var child in _childrenNodes)
+            var result = SelectedCount == 0;
+
+            for (var i = 0; i < _childrenNodes.Count; ++i)
             {
-                child?.Cleanup();
+                var child = _childrenNodes[i];
 
-                if (child?.SelectedCount == 0)
+                if (child != null)
                 {
-                    child.Dispose();
+                    if (child.Cleanup())
+                    {
+                        child.Dispose();
+                        _childrenNodes[i] = null;
+                    }
+                    else
+                    {
+                        result = false;
+                    }
                 }
             }
+
+            return result;
         }
 
         public bool Select(int index, bool select)
@@ -729,6 +741,7 @@ namespace Avalonia.Controls
                         {
                             removed.AddRange(_childrenNodes[index]!.SelectedItems);
                             RealizedChildrenNodeCount--;
+                            _childrenNodes[index]!.Dispose();
                         }
                         _childrenNodes.RemoveAt(index);
                     }

tests/Avalonia.Controls.UnitTests/SelectionModelTests.cs

@@ -931,6 +931,21 @@ namespace Avalonia.Controls.UnitTests
             });
         }
 
+        [Fact]
+        public void Should_Listen_For_Changes_After_Deselect()
+        {
+            var target = new SelectionModel();
+            var data = CreateNestedData(1, 2, 3);
+
+            target.Source = data;
+            target.Select(1, 0);
+            target.Deselect(1, 0);
+            target.Select(1, 0);
+            ((AvaloniaList<object>)data[1]).Insert(0, "foo");
+
+            Assert.Equal(new IndexPath(1, 1), target.SelectedIndex);
+        }
+
         [Fact]
         public void Selecting_Item_Raises_SelectionChanged()
         {
@@ -1405,6 +1420,20 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
+        [Fact]
+        public void Removing_Item_Unhooks_CollectionChanged_Handlers()
+        {
+            var data = CreateNestedData(2, 2, 2);
+            var target = new SelectionModel { Source = data };
+
+            target.SelectAll();
+
+            var toRemove = (AvaloniaList<object>)data[1];
+            data.Remove(toRemove);
+
+            Assert.Equal(0, GetSubscriberCount(toRemove));
+        }
+
         [Fact]
         public void Should_Not_Treat_Strings_As_Nested_Selections()
         {