fix(dragdrop): Fix reordering item at the bottom of the list has no e…

…ffect (but still within LV bounds)

src/SamplesApp/SamplesApp.UITests/Windows_UI_Xaml/DragAndDropTests/DragDrop_ListViewReorder_Automated.cs

@@ -49,6 +49,11 @@ public partial class DragDrop_ListViewReorder_Automated : SampleControlUITestBas
 		[ActivePlatforms(Platform.Browser)] // TODO: support drag-and-drop testing on mobile https://github.com/unoplatform/Uno.UITest/issues/31
 		public void When_Reorder_To_Last() => Test_Reorder(3, 5);
 
+		[Test]
+		[AutoRetry]
+		[ActivePlatforms(Platform.Browser)] // TODO: support drag-and-drop testing on mobile https://github.com/unoplatform/Uno.UITest/issues/31
+		public void When_Reorder_To_Last_2() => Test_Reorder(3, 6 /* out of range */, expectedTo: 5);
+
 		[Test]
 		[AutoRetry]
 		[ActivePlatforms(Platform.Browser)] // TODO: support drag-and-drop testing on mobile https://github.com/unoplatform/Uno.UITest/issues/31
@@ -63,11 +68,6 @@ public partial class DragDrop_ListViewReorder_Automated : SampleControlUITestBas
 
 
 
-
-
-
-
-
 		[Test]
 		[AutoRetry]
 		[ActivePlatforms(Platform.Browser)] // TODO: support drag-and-drop testing on mobile https://github.com/unoplatform/Uno.UITest/issues/31
@@ -128,7 +128,7 @@ public partial class DragDrop_ListViewReorder_Automated : SampleControlUITestBas
 		[ActivePlatforms(Platform.Browser)] // TODO: support drag-and-drop testing on mobile https://github.com/unoplatform/Uno.UITest/issues/31
 		public void When_ReorderWithMultiSelectStartingFromASelectedItem_To_Last() => Test_ReorderMulti(2, 5, expectedTo: 4);
 
-		private void Test_Reorder(int from, int to)
+		private void Test_Reorder(int from, int to, int? expectedTo = null)
 		{
 			Run("UITests.Windows_UI_Xaml.DragAndDrop.DragDrop_ListView", skipInitialScreenshot: true);
 
@@ -141,12 +141,13 @@ private void Test_Reorder(int from, int to)
 			var x = sutBounds.X + 50;
 			var srcY = Item(sutBounds, from);
 			var dstY = Item(sutBounds, to);
+			var expectedY = expectedTo is null ? dstY : Item(sutBounds, expectedTo.Value);
 
 			_app.DragCoordinates(x, srcY, x, dstY);
 
 			var result = TakeScreenshot("Result", ignoreInSnapshotCompare: true);
 
-			ImageAssert.HasColorAt(result, x, dstY, _items[from], tolerance: 10);
+			ImageAssert.HasColorAt(result, x, expectedY, _items[from], tolerance: 10);
 			Assert.IsTrue(op.GetDependencyPropertyValue<string>("Text").Contains("Move"));
 		}
 

src/Uno.UI/UI/Xaml/Controls/Border/BorderLayerRenderer.iOSmacOS.cs

@@ -74,7 +74,7 @@ internal class BorderLayerRenderer
 				_currentState = newState;
 			}
 
-			return newState.BoundsPath;
+			return newState.BoundsPath; // Will be null if not updated !!!
 		}
 
 		/// <summary>

src/Uno.UI/UI/Xaml/Controls/ListViewBase/ListViewBase.DragDrop.cs

@@ -184,10 +184,7 @@ private static void OnItemContainerDragCompleted(UIElement sender, DropCompleted
 			}
 		}
 
-		private static void OnReorderDragUpdated(object sender, _DragEventArgs dragEventArgs) => OnReorderUpdated(sender, dragEventArgs, setVelocity: true);
-		private static void OnReorderDragLeave(object sender, _DragEventArgs dragEventArgs) => OnReorderUpdated(sender, dragEventArgs, setVelocity: false);
-
-		private static void OnReorderUpdated(object sender, _DragEventArgs dragEventArgs, bool setVelocity)
+		private static void OnReorderDragUpdated(object sender, _DragEventArgs dragEventArgs)
 		{
 			var that = sender as ListView;
 			var src = dragEventArgs.DataView.FindRawData(ReorderOwnerFormatId) as ListView;
@@ -213,17 +210,25 @@ private static void OnReorderUpdated(object sender, _DragEventArgs dragEventArgs
 			var position = dragEventArgs.GetPosition(that);
 			that.UpdateReordering(position, container, item);
 
-			if (setVelocity)
-			{
-				// See what our edge scrolling action should be...
-				var panVelocity = that.ComputeEdgeScrollVelocity(position);
-				// And request it.
-				that.SetPendingAutoPanVelocity(panVelocity);
-			}
-			else
+			// See what our edge scrolling action should be...
+			var panVelocity = that.ComputeEdgeScrollVelocity(position);
+			// And request it.
+			that.SetPendingAutoPanVelocity(panVelocity);
+		}
+
+		private static void OnReorderDragLeave(object sender, _DragEventArgs dragEventArgs)
+		{
+			var that = sender as ListView;
+			var src = dragEventArgs.DataView.FindRawData(ReorderOwnerFormatId) as ListView;
+			if (that is null || src != that)
 			{
-				that.SetPendingAutoPanVelocity(PanVelocity.Stationary);
+				dragEventArgs.Log().Warn("Invalid reorder event.");
+
+				return;
 			}
+
+			that.CleanupReordering();
+			that.SetPendingAutoPanVelocity(PanVelocity.Stationary);
 		}
 
 		private static void OnReorderCompleted(object sender, _DragEventArgs dragEventArgs)
@@ -363,11 +368,7 @@ private void UpdateReordering(Point location, FrameworkElement draggedContainer,
 			=> VirtualizingPanel?.GetLayouter().CompleteReorderingItem(draggedContainer, draggedItem);
 
 		private void CleanupReordering()
-#if __ANDROID__
 			=> VirtualizingPanel?.GetLayouter().CleanupReordering();
-#else
-		{ }
-#endif
 
 		#region Helpers
 		private static bool IsObservableCollection(object src)

src/Uno.UI/UI/Xaml/Controls/ListViewBase/VirtualizingPanelLayout.Stub.cs

@@ -18,6 +18,8 @@ abstract partial class VirtualizingPanelLayout
 		internal void UpdateReorderingItem(Point location, FrameworkElement element, object item) { }
 
 		internal Uno.UI.IndexPath? CompleteReorderingItem(FrameworkElement element, object item) => null;
+
+		internal void CleanupReordering() { }
 	}
 }
 #endif

src/Uno.UI/UI/Xaml/Controls/ListViewBase/VirtualizingPanelLayout.iOS.cs

@@ -1487,13 +1487,18 @@ internal void UpdateReorderingItem(Point location, FrameworkElement element, obj
 		}
 
 		internal Uno.UI.IndexPath? CompleteReorderingItem(FrameworkElement element, object item)
+		{
+			var dropTarget = _reorderingDropTarget?.ToIndexPath();
+			CleanupReordering();
+			return dropTarget;
+		}
+
+		internal void CleanupReordering()
 		{
 			_reorderingState = null;
 			ResetReorderedLayoutAttributes();
-			var dropTarget = _reorderingDropTarget?.ToIndexPath();
 			_reorderingDropTarget = null;
 			InvalidateLayout();
-			return dropTarget;
 		}
 
 		/// <summary>
@@ -1506,13 +1511,25 @@ private void UpdateLayoutForReordering()
 			if (_reorderingState is { } reorderingState && reorderingState.LayoutAttributes is { } draggedAttributes)
 			{
 				var dropTargetAttributes = GetLayoutAttributesUnderPoint(reorderingState.Location);
+				if (dropTargetAttributes is null)
+				{
+					// If we have a reorderingState, it means that the pointer is still over the LV.
+					// But if we didn't found any item under the pointer it means that it's after the last item,
+					// so we should consider that the item is going to be placed after the last item.
+					dropTargetAttributes = _itemLayoutInfos
+						.Values
+						.SelectMany(dict => dict.Values)
+						.OrderBy(attr => GetExtentStart(attr.Frame))
+						.LastOrDefault();
+				}
+
 				if (dropTargetAttributes == draggedAttributes)
 				{
 					// The item being dragged is currently under the point, no need to shift any items
 					dropTargetAttributes = null;
 				}
 				_reorderingDropTarget = dropTargetAttributes?.IndexPath;
-				if (dropTargetAttributes != null)
+				if (dropTargetAttributes is not null)
 				{
 					var preDragDraggedFrame = draggedAttributes.Frame;
 

src/Uno.UI/UI/Xaml/Controls/ListViewBase/VirtualizingPanelLayout.managed.cs

@@ -1062,6 +1062,13 @@ internal void UpdateReorderingItem(Point location, FrameworkElement element, obj
 			LightRefresh();
 		}
 
+		internal void CleanupReordering()
+		{
+			_pendingReorder = null;
+
+			LightRefresh();
+		}
+
 		internal Uno.UI.IndexPath? CompleteReorderingItem(FrameworkElement element, object item)
 		{
 			var updatedIndex = default(Uno.UI.IndexPath?);