perf: Misc performance improvements

src/Uno.UI.Runtime.Skia.Gtk/Input/GtkCorePointerInputSource.cs

@@ -507,7 +507,7 @@ private static PointerDeviceType GetDeviceType(Gdk.Device sourceDevice)
 	}
 
 	private static bool IsPressed(ModifierType state, ModifierType mask, PointerUpdateKind update, PointerUpdateKind pressed, PointerUpdateKind released)
-		=> update == pressed || (state.HasFlag(mask) && update != released);
+		=> update == pressed || (((state & mask) != 0) && update != released);
 	#endregion
 
 	private void RaisePointerEntered(PointerEventArgs ptArgs, [CallerMemberName] string caller = "")

src/Uno.UI/UI/Xaml/Controls/Control/Control.cs

@@ -330,127 +330,127 @@ private void SubscribeToOverridenRoutedEvents()
 
 			var implementedEvents = GetImplementedRoutedEventsForType(GetType());
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.PointerPressed))
+			if ((implementedEvents & RoutedEventFlag.PointerPressed) != 0)
 			{
 				PointerPressed += OnPointerPressedHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.PointerReleased))
+			if ((implementedEvents & RoutedEventFlag.PointerReleased) != 0)
 			{
 				PointerReleased += OnPointerReleasedHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.PointerMoved))
+			if ((implementedEvents & RoutedEventFlag.PointerMoved) != 0)
 			{
 				PointerMoved += OnPointerMovedHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.PointerEntered))
+			if ((implementedEvents & RoutedEventFlag.PointerEntered) != 0)
 			{
 				PointerEntered += OnPointerEnteredHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.PointerExited))
+			if ((implementedEvents & RoutedEventFlag.PointerExited) != 0)
 			{
 				PointerExited += OnPointerExitedHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.PointerCanceled))
+			if ((implementedEvents & RoutedEventFlag.PointerCanceled) != 0)
 			{
 				PointerCanceled += OnPointerCanceledHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.PointerCaptureLost))
+			if ((implementedEvents & RoutedEventFlag.PointerCaptureLost) != 0)
 			{
 				PointerCaptureLost += OnPointerCaptureLostHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.PointerWheelChanged))
+			if ((implementedEvents & RoutedEventFlag.PointerWheelChanged) != 0)
 			{
 				PointerWheelChanged += OnPointerWheelChangedHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.ManipulationStarting))
+			if ((implementedEvents & RoutedEventFlag.ManipulationStarting) != 0)
 			{
 				ManipulationStarting += OnManipulationStartingHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.ManipulationStarted))
+			if ((implementedEvents & RoutedEventFlag.ManipulationStarted) != 0)
 			{
 				ManipulationStarted += OnManipulationStartedHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.ManipulationDelta))
+			if ((implementedEvents & RoutedEventFlag.ManipulationDelta) != 0)
 			{
 				ManipulationDelta += OnManipulationDeltaHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.ManipulationInertiaStarting))
+			if ((implementedEvents & RoutedEventFlag.ManipulationInertiaStarting) != 0)
 			{
 				ManipulationInertiaStarting += OnManipulationInertiaStartingHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.ManipulationCompleted))
+			if ((implementedEvents & RoutedEventFlag.ManipulationCompleted) != 0)
 			{
 				ManipulationCompleted += OnManipulationCompletedHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.Tapped))
+			if ((implementedEvents & RoutedEventFlag.Tapped) != 0)
 			{
 				Tapped += OnTappedHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.DoubleTapped))
+			if ((implementedEvents & RoutedEventFlag.DoubleTapped) != 0)
 			{
 				DoubleTapped += OnDoubleTappedHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.RightTapped))
+			if ((implementedEvents & RoutedEventFlag.RightTapped) != 0)
 			{
 				RightTapped += OnRightTappedHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.DragEnter))
+			if ((implementedEvents & RoutedEventFlag.DragEnter) != 0)
 			{
 				DragEnter += OnDragEnterHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.DragOver))
+			if ((implementedEvents & RoutedEventFlag.DragOver) != 0)
 			{
 				DragOver += OnDragOverHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.DragLeave))
+			if ((implementedEvents & RoutedEventFlag.DragLeave) != 0)
 			{
 				DragLeave += OnDragLeaveHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.Drop))
+			if ((implementedEvents & RoutedEventFlag.Drop) != 0)
 			{
 				Drop += OnDropHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.Holding))
+			if ((implementedEvents & RoutedEventFlag.Holding) != 0)
 			{
 				Holding += OnHoldingHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.KeyDown))
+			if ((implementedEvents & RoutedEventFlag.KeyDown) != 0)
 			{
 				KeyDown += OnKeyDownHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.KeyUp))
+			if ((implementedEvents & RoutedEventFlag.KeyUp) != 0)
 			{
 				KeyUp += OnKeyUpHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.GotFocus))
+			if ((implementedEvents & RoutedEventFlag.GotFocus) != 0)
 			{
 				GotFocus += OnGotFocusHandler;
 			}
 
-			if (implementedEvents.HasFlag(RoutedEventFlag.LostFocus))
+			if ((implementedEvents & RoutedEventFlag.LostFocus) != 0)
 			{
 				LostFocus += OnLostFocusHandler;
 			}

src/Uno.UI/UI/Xaml/Media/VisualTreeHelper.cs

@@ -6,21 +6,15 @@
 using System.Diagnostics;
 using System.Linq;
 using System.Numerics;
-using System.Runtime.CompilerServices;
-using System.Text;
+using Uno.Collections;
+using Uno.Extensions;
+
 using Uno.UI;
+using Uno.UI.Extensions;
+using Uno.UI.Xaml.Core;
 using Windows.Foundation;
-using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
-using Uno.Extensions;
-using Uno.Disposables;
-using Windows.Globalization.DateTimeFormatting;
-using Windows.UI.Core;
-using Uno.Foundation.Logging;
-using Uno.UI.Extensions;
 using Windows.UI.Xaml.Controls.Primitives;
-using Uno.UI.Xaml.Core;
-using Uno.UI.DataBinding;
 using WinUICoreServices = Uno.UI.Xaml.Core.CoreServices;
 
 #if __IOS__
@@ -67,19 +61,26 @@ public static IEnumerable<UIElement> FindElementsInHostCoordinates(Point interse
 					yield return subtree;
 				}
 
-				foreach (var child in subtree.GetChildren().OfType<UIElement>())
+				foreach (var uiElement in subtree.GetChildren())
 				{
+#if __ANDROID__ || __IOS__ || __MACOS__
+					// On Wasm and Skia, child is always UIElement.
+					if (uiElement is not UIElement)
+					{
+						continue;
+					}
+#endif
 					var canTest = includeAllElements
-						|| (child.IsHitTestVisible && child.IsViewHit());
+						|| (uiElement.IsHitTestVisible && uiElement.IsViewHit());
 
-					if (child is UIElement uiElement && canTest)
+					if (canTest)
 					{
 						if (IsElementIntersecting(intersectingPoint, uiElement))
 						{
 							yield return uiElement;
 						}
 
-						foreach (var subChild in FindElementsInHostCoordinates(intersectingPoint, child, includeAllElements))
+						foreach (var subChild in FindElementsInHostCoordinates(intersectingPoint, uiElement, includeAllElements))
 						{
 							yield return subChild;
 						}
@@ -111,7 +112,6 @@ public static IEnumerable<UIElement> FindElementsInHostCoordinates(Rect intersec
 #else
 			return (reference as UIElement)?
 				.GetChildren()
-				.OfType<DependencyObject>()
 				.ElementAtOrDefault(childIndex);
 #endif
 		}
@@ -126,7 +126,6 @@ public static int GetChildrenCount(DependencyObject reference)
 #else
 			return (reference as UIElement)?
 				.GetChildren()
-				.OfType<DependencyObject>()
 				.Count() ?? 0;
 #endif
 		}
@@ -284,7 +283,7 @@ internal static void AddChild(UIElement view, UIElement child)
 			view.AddView(child);
 #elif __IOS__ || __MACOS__
 			view.AddSubview(child);
-#elif UNO_REFERENCE_API
+#elif __CROSSRUNTIME__
 			view.AddChild(child);
 #elif IS_UNIT_TESTS
 			if (view is FrameworkElement fe)
@@ -309,7 +308,7 @@ internal static void RemoveChild(UIElement view, UIElement child)
 			{
 				child.RemoveFromSuperview();
 			}
-#elif UNO_REFERENCE_API
+#elif __CROSSRUNTIME__
 			view.RemoveChild(child);
 #else
 			throw new NotImplementedException("AddChild not implemented on this platform.");
@@ -333,7 +332,7 @@ internal static IReadOnlyList<_View> ClearChildren(UIElement view)
 			children.ForEach(v => v.RemoveFromSuperview());
 
 			return children;
-#elif UNO_REFERENCE_API
+#elif __CROSSRUNTIME__
 			var children = GetChildren<_View>(view).ToList();
 			view.ClearChildren();
 
@@ -343,11 +342,7 @@ internal static IReadOnlyList<_View> ClearChildren(UIElement view)
 #endif
 		}
 
-		internal static readonly GetHitTestability DefaultGetTestability;
-		static VisualTreeHelper()
-		{
-			DefaultGetTestability = elt => (elt.GetHitTestVisibility(), DefaultGetTestability!);
-		}
+		internal static readonly GetHitTestability DefaultGetTestability = elt => (elt.GetHitTestVisibility(), DefaultGetTestability!);
 
 		internal static (UIElement? element, Branch? stale) HitTest(
 			Point position,
@@ -375,8 +370,7 @@ private static (UIElement? element, Branch? stale) SearchDownForTopMostElementAt
 			Point posRelToParent,
 			UIElement element,
 			GetHitTestability getVisibility,
-			StalePredicate? isStale = null,
-			Func<IEnumerable<UIElement>, IEnumerable<UIElement>>? childrenFilter = null)
+			StalePredicate? isStale = null)
 		{
 			var stale = default(Branch?);
 			HitTestability elementHitTestVisibility;
@@ -464,9 +458,19 @@ private static (UIElement? element, Branch? stale) SearchDownForTopMostElementAt
 			}
 
 			// Validate if any child is an acceptable target
-			var children = childrenFilter is null ? GetManagedVisualChildren(element) : childrenFilter(GetManagedVisualChildren(element));
-			using var child = children.Reverse().GetEnumerator();
+			var children = GetManagedVisualChildren(element);
+
 			var isChildStale = isStale;
+
+			using var child = children
+#if __IOS__ || __MACOS__ || __ANDROID__
+				.Reverse().GetEnumerator();
+#else
+				// On Skia and Wasm, we can get concrete data structure (MaterializableList in this case) instead of IEnumerable<T>.
+				// It has an efficient "ReverseEnumerator". This will also avoid the boxing allocations of the enumerator when it's a struct.
+				.GetReverseEnumerator();
+#endif
+
 			while (child.MoveNext())
 			{
 				var childResult = SearchDownForTopMostElementAt(posRelToElement, child.Current!, getVisibility, isChildStale);
@@ -571,8 +575,16 @@ internal static UIElement SearchDownForLeaf(UIElement root, StalePredicate predi
 
 		private static UIElement SearchDownForLeafCore(UIElement root, StalePredicate predicate)
 		{
-			foreach (var child in GetManagedVisualChildren(root).Reverse())
+			using var enumerator = GetManagedVisualChildren(root)
+#if __IOS__ || __MACOS__ || __ANDROID__
+				.Reverse().GetEnumerator();
+#else
+				.GetReverseEnumerator();
+#endif
+
+			while (enumerator.MoveNext())
 			{
+				var child = enumerator.Current;
 #if TRACE_HIT_TESTING
 				SET_TRACE_SUBJECT(child);
 #endif
@@ -653,8 +665,8 @@ internal static IEnumerable<UIElement> GetManagedVisualChildren(_ViewGroup view)
 			}
 		}
 #else
-		internal static IEnumerable<UIElement> GetManagedVisualChildren(_View view)
-			=> view.GetChildren().OfType<UIElement>();
+		internal static MaterializableList<UIElement> GetManagedVisualChildren(_View view)
+			=> view._children;
 #endif
 		#endregion
 

src/Uno.UI/UI/Xaml/UIElement.RoutedEvents.cs

@@ -684,7 +684,7 @@ internal bool RaiseEvent(RoutedEvent routedEvent, RoutedEventArgs args, Bubbling
 
 			// [3] Any local handlers?
 			var isHandled = IsHandled(args);
-			if (!ctx.Mode.HasFlag(BubblingMode.IgnoreElement)
+			if (!ctx.ModeHasFlag(BubblingMode.IgnoreElement)
 				&& !ctx.IsInternal
 				&& _eventHandlerStore.TryGetValue(routedEvent, out var handlers)
 				&& handlers.Any())
@@ -719,7 +719,7 @@ internal bool RaiseEvent(RoutedEvent routedEvent, RoutedEventArgs args, Bubbling
 				}
 			}
 
-			if (routedEvent.IsTunnelingEvent || ctx.Mode.HasFlag(BubblingMode.IgnoreParents) || ctx.Root == this)
+			if (routedEvent.IsTunnelingEvent || ctx.ModeHasFlag(BubblingMode.IgnoreParents) || ctx.Root == this)
 			{
 				return isHandled;
 			}
@@ -885,6 +885,9 @@ public static BubblingContext BubbleUpTo(UIElement root)
 			public BubblingContext WithMode(BubblingMode mode)
 				=> this with { Mode = mode };
 
+			public bool ModeHasFlag(BubblingMode flag)
+				=> (Mode & flag) != 0;
+
 			public override string ToString()
 				=> $"{Mode}{(IsInternal ? " *internal*" : "")}{(Root is { } r ? $" up to {Root.GetDebugName()}" : "")}";
 		}

src/Uno.UI/UI/Xaml/UIElement.skia.cs

@@ -226,8 +226,6 @@ private void InnerRemoveChild(UIElement child)
 
 		internal UIElement FindFirstChild() => _children.FirstOrDefault();
 
-		partial void InitializeCapture();
-
 		internal bool IsPointerCaptured { get; set; }
 
 		public virtual IEnumerable<UIElement> GetChildren() => _children;