perf: Skip ClearPointersStateIfNeeded during ctor

src/Uno.UI/UI/Xaml/FrameworkPropertyMetadata.cs

@@ -117,14 +117,24 @@ CoerceValueCallback coerceValueCallback
 		) : base(defaultValue, propertyChangedCallback, coerceValueCallback, null)
 		{
 		}
-		
+
 		internal FrameworkPropertyMetadata(
 			PropertyChangedCallback propertyChangedCallback,
 			CoerceValueCallback coerceValueCallback
 		) : base(propertyChangedCallback, coerceValueCallback)
 		{
 		}
-
+
+		internal FrameworkPropertyMetadata(
+			object defaultValue,
+			FrameworkPropertyMetadataOptions options,
+			BackingFieldUpdateCallback backingFieldUpdateCallback,
+			CoerceValueCallback coerceValueCallback
+		) : base(defaultValue: defaultValue, propertyChangedCallback: null, coerceValueCallback: coerceValueCallback, backingFieldUpdateCallback: backingFieldUpdateCallback)
+		{
+			Options = options.WithDefault();
+		}
+
 		internal FrameworkPropertyMetadata(
 			object defaultValue,
 			FrameworkPropertyMetadataOptions options,

src/Uno.UI/UI/Xaml/UIElement.Pointers.Managed.cs

@@ -20,6 +20,7 @@
 using Windows.UI.Xaml.Input;
 using Windows.UI.Xaml.Media;
 using Uno.UI;
+using Uno.UI.Xaml;
 
 namespace Windows.UI.Xaml
 {
@@ -274,7 +275,7 @@ private void ClearPressedState(PointerRoutedEventArgs routedArgs)
 				}
 			}
 
-			#region Helpers
+#region Helpers
 			private delegate void RaisePointerEventArgs(UIElement element, PointerRoutedEventArgs args, BubblingContext ctx);
 
 			private static readonly RaisePointerEventArgs Wheel = (elt, args, ctx) => elt.OnPointerWheel(args, ctx);
@@ -340,7 +341,7 @@ private static void RaiseUsingCaptures(RaisePointerEventArgs raise, UIElement or
 					raise(originalSource, routedArgs, BubblingContext.Bubble);
 				}
 			}
-			#endregion
+#endregion
 		}
 
 		// TODO Should be per CoreWindow
@@ -354,7 +355,7 @@ partial void InitializePointersPartial()
 			}
 		}
 
-		#region HitTestVisibility
+#region HitTestVisibility
 		internal void UpdateHitTest()
 		{
 			this.CoerceValue(HitTestVisibilityProperty);
@@ -366,27 +367,21 @@ internal void UpdateHitTest()
 		/// <remarks>
 		/// This property should never be directly set, and its value should always be calculated through coercion (see <see cref="CoerceHitTestVisibility(DependencyObject, object, bool)"/>.
 		/// </remarks>
-		private static readonly DependencyProperty HitTestVisibilityProperty =
-			DependencyProperty.Register(
-				"HitTestVisibility",
-				typeof(HitTestability),
-				typeof(UIElement),
-				new FrameworkPropertyMetadata(
-					HitTestability.Visible,
-					FrameworkPropertyMetadataOptions.Inherits,
-					coerceValueCallback: CoerceHitTestVisibility,
-					propertyChangedCallback: OnHitTestVisibilityChanged
-				)
-			);
+		[GeneratedDependencyProperty(DefaultValue = HitTestability.Collapsed, CoerceCallback = true, Options = FrameworkPropertyMetadataOptions.Inherits)]
+		internal static DependencyProperty HitTestVisibilityProperty { get; } = CreateHitTestVisibilityProperty();
+
+		internal HitTestability HitTestVisibility
+		{
+			get => GetHitTestVisibilityValue();
+			set => SetHitTestVisibilityValue(value);
+		}
 
 		/// <summary>
 		/// This calculates the final hit-test visibility of an element.
 		/// </summary>
 		/// <returns></returns>
-		private static object CoerceHitTestVisibility(DependencyObject dependencyObject, object baseValue)
+		private object CoerceHitTestVisibility(object baseValue)
 		{
-			var element = (UIElement)dependencyObject;
-
 			// The HitTestVisibilityProperty is never set directly. This means that baseValue is always the result of the parent's CoerceHitTestVisibility.
 			var baseHitTestVisibility = (HitTestability)baseValue;
 
@@ -399,15 +394,15 @@ private static object CoerceHitTestVisibility(DependencyObject dependencyObject,
 			// If we're not locally hit-test visible, visible, or enabled, we should be collapsed. Our children will be collapsed as well.
 			if (
 #if !__MACOS__
-				!element.IsLoaded ||
+				!IsLoaded ||
 #endif
-				!element.IsHitTestVisible || element.Visibility != Visibility.Visible || !element.IsEnabledOverride())
+				!IsHitTestVisible || Visibility != Visibility.Visible || !IsEnabledOverride())
 			{
 				return HitTestability.Collapsed;
 			}
 
 			// If we're not hit (usually means we don't have a Background/Fill), we're invisible. Our children will be visible or not, depending on their state.
-			if (!element.IsViewHit())
+			if (!IsViewHit())
 			{
 				return HitTestability.Invisible;
 			}
@@ -416,10 +411,20 @@ private static object CoerceHitTestVisibility(DependencyObject dependencyObject,
 			return HitTestability.Visible;
 		}
 
-		private static void OnHitTestVisibilityChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
+		internal void SetHitTestVisibilityForRoot()
 		{
+			// Root element must be visible to hit testing, regardless of the other properties values.
+			// The default value of HitTestVisibility is collapsed to avoid spending time coercing to a
+			// Collapsed.
+			HitTestVisibility = HitTestability.Visible;
 		}
-		#endregion
+
+		internal void ClearHitTestVisibilityForRoot()
+		{
+			this.ClearValue(HitTestVisibilityProperty);
+		}
+
+#endregion
 
 		partial void CapturePointerNative(Pointer pointer)
 			=> CoreWindow.GetForCurrentThread()!.SetPointerCapture();

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

@@ -218,7 +218,7 @@ private void InitializePointers()
 		internal HitTestability GetHitTestVisibility()
 		{
 #if __WASM__ || __SKIA__
-			return (HitTestability)this.GetValue(HitTestVisibilityProperty);
+			return HitTestVisibility;
 #else
 			// This is a coalesced HitTestVisible and should be unified with it
 			// We should follow the WASM way and unify it on all platforms!

src/Uno.UI/UI/Xaml/UIElement.Pointers.wasm.cs

@@ -265,33 +265,21 @@ internal void UpdateHitTest()
 			this.CoerceValue(HitTestVisibilityProperty);
 		}
 
-		/// <summary>
-		/// Represents the final calculated hit-test visibility of the element.
-		/// </summary>
-		/// <remarks>
-		/// This property should never be directly set, and its value should always be calculated through coercion (see <see cref="CoerceHitTestVisibility(DependencyObject, object, bool)"/>.
-		/// </remarks>
-		private static DependencyProperty HitTestVisibilityProperty { get ; } =
-			DependencyProperty.Register(
-				"HitTestVisibility",
-				typeof(HitTestability),
-				typeof(UIElement),
-				new FrameworkPropertyMetadata(
-					HitTestability.Visible,
-					FrameworkPropertyMetadataOptions.Inherits,
-					coerceValueCallback: (s, e) => CoerceHitTestVisibility(s, e),
-					propertyChangedCallback: (s, e) => OnHitTestVisibilityChanged(s, e)
-				)
-			);
+		[GeneratedDependencyProperty(DefaultValue = HitTestability.Collapsed, ChangedCallback = true, CoerceCallback = true, Options = FrameworkPropertyMetadataOptions.Inherits)]
+		internal static DependencyProperty HitTestVisibilityProperty { get; } = CreateHitTestVisibilityProperty();
+
+		internal HitTestability HitTestVisibility
+		{
+			get => GetHitTestVisibilityValue();
+			set => SetHitTestVisibilityValue(value);
+		}
 
 		/// <summary>
 		/// This calculates the final hit-test visibility of an element.
 		/// </summary>
 		/// <returns></returns>
-		private static object CoerceHitTestVisibility(DependencyObject dependencyObject, object baseValue)
+		private object CoerceHitTestVisibility(object baseValue)
 		{
-			var element = (UIElement)dependencyObject;
-
 			// The HitTestVisibilityProperty is never set directly. This means that baseValue is always the result of the parent's CoerceHitTestVisibility.
 			var baseHitTestVisibility = (HitTestability)baseValue;
 
@@ -302,13 +290,13 @@ private static object CoerceHitTestVisibility(DependencyObject dependencyObject,
 			}
 
 			// If we're not locally hit-test visible, visible, or enabled, we should be collapsed. Our children will be collapsed as well.
-			if (!element.IsLoaded || !element.IsHitTestVisible || element.Visibility != Visibility.Visible || !element.IsEnabledOverride())
+			if (!IsLoaded || !IsHitTestVisible || Visibility != Visibility.Visible || !IsEnabledOverride())
 			{
 				return HitTestability.Collapsed;
 			}
 
 			// If we're not hit (usually means we don't have a Background/Fill), we're invisible. Our children will be visible or not, depending on their state.
-			if (!element.IsViewHit())
+			if (!IsViewHit())
 			{
 				return HitTestability.Invisible;
 			}
@@ -317,19 +305,14 @@ private static object CoerceHitTestVisibility(DependencyObject dependencyObject,
 			return HitTestability.Visible;
 		}
 
-		private static void OnHitTestVisibilityChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
+		private protected virtual void OnHitTestVisibilityChanged(HitTestability oldValue, HitTestability newValue)
 		{
-			if (dependencyObject is UIElement element
-				&& args.OldValue is HitTestability oldValue
-				&& args.NewValue is HitTestability newValue)
-			{
-				element.OnHitTestVisibilityChanged(oldValue, newValue);
-			}
+			ApplyHitTestVisibility(newValue);
 		}
 
-		private protected virtual void OnHitTestVisibilityChanged(HitTestability oldValue, HitTestability newValue)
+		private void ApplyHitTestVisibility(HitTestability value)
 		{
-			if (newValue == HitTestability.Visible)
+			if (value == HitTestability.Visible)
 			{
 				// By default, elements have 'pointer-event' set to 'auto' (see Uno.UI.css .uno-uielement class).
 				// This means that they can be the target of hit-testing and will raise pointer events when interacted with.
@@ -349,6 +332,20 @@ private protected virtual void OnHitTestVisibilityChanged(HitTestability oldValu
 				UpdateDOMProperties();
 			}
 		}
+
+		internal void SetHitTestVisibilityForRoot()
+		{
+			// Root element must be visible to hit testing, regardless of the other properties values.
+			// The default value of HitTestVisibility is collapsed to avoid spending time coercing to a
+			// Collapsed.
+			HitTestVisibility = HitTestability.Visible;
+		}
+
+		internal void ClearHitTestVisibilityForRoot()
+		{
+			this.ClearValue(HitTestVisibilityProperty);
+		}
+
 		#endregion
 
 		// TODO: This should be marshaled instead of being parsed! https://github.com/unoplatform/uno/issues/2116

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

@@ -56,10 +56,16 @@ internal static void LoadingRootElement(UIElement visualTreeRoot)
 			=> visualTreeRoot.OnElementLoading(1);
 
 		internal static void RootElementLoaded(UIElement visualTreeRoot)
-			=> visualTreeRoot.OnElementLoaded();
+		{
+			visualTreeRoot.SetHitTestVisibilityForRoot();
+			visualTreeRoot.OnElementLoaded();
+		}
 
 		internal static void RootElementUnloaded(UIElement visualTreeRoot)
-			=> visualTreeRoot.OnElementUnloaded();
+		{
+			visualTreeRoot.ClearHitTestVisibilityForRoot();
+			visualTreeRoot.OnElementUnloaded();
+		}
 
 		// Overloads for the FrameworkElement to raise the events
 		// (Load/Unload is actually a concept of the FwElement, but it's easier to handle it directly from the UIElement)

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

@@ -43,5 +43,10 @@ public UIElement()
 		protected virtual void OnVisibilityChanged(Visibility oldValue, Visibility newVisibility)
 		{
 		}
+
+
+		internal void SetHitTestVisibilityForRoot() => throw new NotSupportedException("Reference assembly");
+
+		internal void ClearHitTestVisibilityForRoot() => throw new NotSupportedException("Reference assembly");
 	}
 }

src/Uno.UI/WasmCSS/Uno.UI.css

@@ -20,14 +20,17 @@ body {
   position: absolute;
   display: inline;
   outline: none;
-  pointer-events: auto;
+  /*
+      Disable pointer events by default to match HitTestVisibilityProperty
+      default value
+  */
+  pointer-events: none;
   /*
     Padding & margin are required for measure/arrange to behave well:
     margin & padding are calculated through Xaml elements.
   */
   margin: 0 !important;
   padding: 0;
-
   line-height: normal;
   -webkit-box-sizing: border-box !important;
   -moz-box-sizing: border-box !important;