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

src/Avalonia.Controls/SelectionModel.cs

@@ -533,6 +533,8 @@ namespace Avalonia.Controls
             ApplyAutoSelect();
         }
 
+        public IDisposable Update() => new Operation(this);
+
         protected void OnPropertyChanged(string propertyName)
         {
             RaisePropertyChanged(propertyName);

tests/Avalonia.Controls.UnitTests/SelectionModelTests.cs

@@ -1639,6 +1639,33 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(3, raised);
             Assert.Equal(new[] { new IndexPath(2) }, target.SelectedIndices);
         }
+        
+        [Fact]
+        public void Can_Batch_Update()
+        {
+            var target = new SelectionModel();
+            var raised = 0;
+
+            target.Source = Enumerable.Range(0, 10).ToList();
+            target.Select(1);
+
+            target.SelectionChanged += (s, e) =>
+            {
+                Assert.Equal(new[] { new IndexPath(1) }, e.DeselectedIndices);
+                Assert.Equal(new object[] { 1 }, e.DeselectedItems);
+                Assert.Equal(new[] { new IndexPath(4) }, e.SelectedIndices);
+                Assert.Equal(new object[] { 4 }, e.SelectedItems);
+                ++raised;
+            };
+
+            using (target.Update())
+            {
+                target.Deselect(1);
+                target.Select(4);
+            }
+
+            Assert.Equal(1, raised);
+        }
 
         [Fact]
         public void AutoSelect_Selects_When_Enabled()