fix: Prevent Shapes (mapped to svg) to stoll the pointer events when …

…they are not visible

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

@@ -38,6 +38,15 @@ body {
   transform: translate(0, 0);
 }
 
+svg.uno-uielement {
+  /*
+    The SVG elements are not intended to be a touch target (they are only a holder collection of child shapes),
+    instead it's their child SvgElement that should be the target of the pointer.
+    This also ensure that we are HitTestVisible only for shapes that has a fill.
+  */
+  pointer-events: none;
+}
+
 .uno-frameworkelement.uno-clippedToBounds {
   /*
     This CSS class is applied when a control is a _clipping mode_:

src/Uno.UI/UI/Xaml/Shapes/Shape.wasm.cs

@@ -33,21 +33,6 @@ protected Shape() : base("svg", isSvg: true)
 			OnStretchUpdatedPartial();
 		}
 
-		private void OnSvgChildrenChanged(object sender, NotifyCollectionChangedEventArgs e)
-			=> OnChildrenChanged();
-
-		protected override void OnLoaded()
-		{
-			base.OnLoaded();
-			SvgChildren.CollectionChanged += OnSvgChildrenChanged;
-		}
-
-		protected override void OnUnloaded()
-		{
-			base.OnUnloaded();
-			SvgChildren.CollectionChanged -= OnSvgChildrenChanged;
-		}
-
 		protected void InitCommonShapeProperties() // Should be called from base class constructor
 		{
 			// Initialize
@@ -58,10 +43,6 @@ protected override void OnUnloaded()
 
 		protected abstract SvgElement GetMainSvgElement();
 
-		protected virtual void OnChildrenChanged()
-		{
-		}
-
 		partial void OnFillUpdatedPartial()
 		{
 			UpdateHitTest();
@@ -163,5 +144,11 @@ private UIElementCollection GetDefs()
 
 			return _defs.Defs;
 		}
+
+		private protected override void OnHitTestVisibilityChanged(HitTestVisibility oldValue, HitTestVisibility newValue)
+		{
+			// We don't invoke the base, so we stay at the default "pointer-events: none" defined in Uno.UI.css in class svg.uno-uielement.
+			// This is required to avoid this SVG element (which is actually only a collection) to stoll pointer events.
+		}
 	}
 }

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

@@ -202,7 +202,7 @@ internal void UpdateHitTest()
 			this.CoerceValue(HitTestVisibilityProperty);
 		}
 
-		private enum HitTestVisibility
+		private protected enum HitTestVisibility
 		{
 			/// <summary>
 			/// The element and its children can't be targeted by hit-testing.
@@ -280,27 +280,34 @@ private static object CoerceHitTestVisibility(DependencyObject dependencyObject,
 
 		private static void OnHitTestVisibilityChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
 		{
-			if (dependencyObject is UIElement element && args.NewValue is HitTestVisibility hitTestVisibility)
+			if (dependencyObject is UIElement element
+				&& args.OldValue is HitTestVisibility oldValue
+				&& args.NewValue is HitTestVisibility newValue)
 			{
-				if (hitTestVisibility == HitTestVisibility.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.
-					// This is aligned with HitTestVisibilityProperty's default value of Visible.
-					element.SetStyle("pointer-events", "auto");
-				}
-				else
-				{
-					// If HitTestVisibilityProperty is calculated to Invisible or Collapsed,
-					// we don't want to be the target of hit-testing and raise any pointer events.
-					// This is done by setting 'pointer-events' to 'none'.
-					element.SetStyle("pointer-events", "none");
-				}
-
-				if (FeatureConfiguration.UIElement.AssignDOMXamlProperties)
-				{
-					element.UpdateDOMProperties();
-				}
+				element.OnHitTestVisibilityChanged(oldValue, newValue);
+			}
+		}
+
+		private protected virtual void OnHitTestVisibilityChanged(HitTestVisibility oldValue, HitTestVisibility newValue)
+		{
+			if (newValue == HitTestVisibility.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.
+				// This is aligned with HitTestVisibilityProperty's default value of Visible.
+				SetStyle("pointer-events", "auto");
+			}
+			else
+			{
+				// If HitTestVisibilityProperty is calculated to Invisible or Collapsed,
+				// we don't want to be the target of hit-testing and raise any pointer events.
+				// This is done by setting 'pointer-events' to 'none'.
+				SetStyle("pointer-events", "none");
+			}
+
+			if (FeatureConfiguration.UIElement.AssignDOMXamlProperties)
+			{
+				UpdateDOMProperties();
 			}
 		}
 		#endregion