Implement all permutations of InputTransparent and CascadeInputTransparent

src/Controls/samples/Controls.Sample/Pages/Core/InputTransparentPage.xaml

@@ -3,70 +3,100 @@
     xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
     xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
     x:Class="Maui.Controls.Sample.Pages.InputTransparentPage">
-	<ContentPage.Resources>
-		<ResourceDictionary>
+
+    <ContentPage.Resources>
+        <ResourceDictionary>
             <Style TargetType="Label">
             </Style>
-
             <Style TargetType="Button">
                 <!-- <Setter Property="Padding" Value="14,10" /> -->
-				<!-- <Setter Property="WidthRequest" Value="200"/> -->
+                <!-- <Setter Property="WidthRequest" Value="200"/> -->
             </Style>
         </ResourceDictionary>
-	</ContentPage.Resources>
-
-    <ContentPage.Content>
-		<ScrollView>
-			<VerticalStackLayout>
-				<Label Text="This Button has InputTransparent=false; it should be clickable."/>
-				<Button Text="Clickable" Clicked="ClickSuccess" HorizontalOptions="Center" />
-
-				<Label Margin="0,10,0,0" Text="This Button has InputTransparent=true; it should not be clickable."/>
-				<Button InputTransparent="True" Text="Not Clickable" Clicked="ClickFail" HorizontalOptions="Center" />
-
-				<Grid Margin="0,10,0,0" RowDefinitions="Auto, Auto">
-
-					<Label Text="This Button has InputTransparent=true; it should not be clickable. But the button hidden under it should be."/>
-
-					<Button	Grid.Row="1" Margin="2,2,0,0" InputTransparent="False" Text="Clickable" Clicked="ClickSuccess" 
-						HorizontalOptions="Center" />
-
-					<Button BackgroundColor="LightBlue"	Grid.Row="1" InputTransparent="True" Text="Not Clickable" Clicked="ClickFail"
-						HorizontalOptions="Center"/>
-
-				</Grid>
-
-				<Label Margin="0,10,0,0" Text="The Grid below has controls and an overlay layer with more controls."/>
-
-				<Grid>
-
-					<Grid Margin="10" HeightRequest="100" BackgroundColor="LightBlue">
-						<Button Text="Bottom Layer" Clicked="ClickSuccess" HorizontalOptions="Center" VerticalOptions="Center" />
-					</Grid>
-
-					<Grid HorizontalOptions="Fill" VerticalOptions="Fill" InputTransparent="True" CascadeInputTransparent="False">
-						<Button Text="Overlay BR" Clicked="ClickSuccess" HorizontalOptions="End" VerticalOptions="End" Margin="5" />
-						<Button Text="Overlay TL" Clicked="ClickSuccess" HorizontalOptions="Start" VerticalOptions="Start" Margin="5" />
-					</Grid>
-
-				</Grid>
-
-				<Label Margin="0,10,0,0" Text="The Grid below has controls an overlay with CascadeInputTransparent set to true; the overlay buttons should not be usable."/>
-
-				<Grid>
-
-					<Grid Margin="10" HeightRequest="100" BackgroundColor="LightBlue">
-						<Button Text="Bottom Layer" Clicked="ClickSuccess" HorizontalOptions="Center" VerticalOptions="Center" />
-					</Grid>
-
-					<Grid HorizontalOptions="Fill" VerticalOptions="Fill" InputTransparent="True" CascadeInputTransparent="True">
-						<Button Text="Overlay BR" Clicked="ClickFail" HorizontalOptions="End" VerticalOptions="End" Margin="5" />
-						<Button Text="Overlay TL" Clicked="ClickFail" HorizontalOptions="Start" VerticalOptions="Start" Margin="5" />
-					</Grid>
-
-				</Grid>
-
-			</VerticalStackLayout>
-		</ScrollView>
-    </ContentPage.Content>
+    </ContentPage.Resources>
+
+    <ScrollView>
+        <VerticalStackLayout>
+            <Label Text="This Button has InputTransparent=false; it should be clickable."/>
+            <Button Text="Clickable" Clicked="ClickSuccess" HorizontalOptions="Center" />
+
+            <Label Margin="0,10,0,0" Text="This Button has InputTransparent=true; it should not be clickable."/>
+            <Button InputTransparent="True" Text="Not Clickable" Clicked="ClickFail" HorizontalOptions="Center" />
+
+            <Label Margin="0,10,0,0" Text="This Button has InputTransparent=true; it should not be clickable. But the button hidden under it should be."/>
+            <Grid RowDefinitions="Auto" ColumnDefinitions="Auto">
+
+                <Button	InputTransparent="False" Text="Clickable" Clicked="ClickSuccess" Grid.Row="1" Margin="2,2,0,0" HorizontalOptions="Center" />
+
+                <Button InputTransparent="True" Text="Not Clickable" Clicked="ClickFail" BackgroundColor="LightBlue" Grid.Row="1" HorizontalOptions="Center" />
+
+            </Grid>
+
+            <Label Margin="0,10,0,0" Text="The Grid below has controls and an overlay layer with more controls."/>
+            <Grid>
+
+                <Grid Margin="10" HeightRequest="100" BackgroundColor="LightBlue">
+                    <Button Text="Bottom Layer" Clicked="ClickSuccess" HorizontalOptions="Center" VerticalOptions="Center" />
+                </Grid>
+
+                <Grid InputTransparent="True" CascadeInputTransparent="False" HorizontalOptions="Fill" VerticalOptions="Fill">
+                    <Button Text="Overlay BR" Clicked="ClickSuccess" HorizontalOptions="End" VerticalOptions="End" Margin="5" />
+                    <Button Text="Overlay TL" Clicked="ClickSuccess" HorizontalOptions="Start" VerticalOptions="Start" Margin="5" />
+                </Grid>
+
+            </Grid>
+
+            <Label Margin="0,10,0,0" Text="The Grid below has controls an overlay with CascadeInputTransparent set to true; the overlay buttons should not be usable."/>
+            <Grid>
+
+                <Grid Margin="10" HeightRequest="100" BackgroundColor="LightBlue">
+                    <Button Text="Bottom Layer" Clicked="ClickSuccess" HorizontalOptions="Center" VerticalOptions="Center" />
+                </Grid>
+
+                <Grid HorizontalOptions="Fill" VerticalOptions="Fill" InputTransparent="True" CascadeInputTransparent="True">
+                    <Button Text="Overlay BR" Clicked="ClickFail" HorizontalOptions="End" VerticalOptions="End" Margin="5" />
+                    <Button Text="Overlay TL" Clicked="ClickFail" HorizontalOptions="Start" VerticalOptions="Start" Margin="5" />
+                </Grid>
+
+            </Grid>
+
+            <Label Margin="0,10,0,0" Text="The Grid below has a 'Test Button' that is controlled by the switches."/>
+            <VerticalStackLayout>
+
+                <Grid Margin="10" HeightRequest="100" BackgroundColor="LightBlue">
+
+                    <Grid x:Name="rootLayout">
+                        <Grid x:Name="nestedLayout">
+                            <Button x:Name="testButton" Text="Test Button" Clicked="ClickSuccess" HorizontalOptions="Center" VerticalOptions="Center" />
+                        </Grid>
+                    </Grid>
+                </Grid>
+
+                <Grid ColumnDefinitions="Auto,Auto,Auto,Auto,Auto,2" RowDefinitions="Auto,Auto,Auto" ColumnSpacing="12" RowSpacing="6" Margin="10,0,10,0">
+                    <!-- root -->
+                    <Label Grid.Row="0" Grid.Column="0" Text="Root" VerticalOptions="Center" FontAttributes="Bold" />
+                    <Label Grid.Row="0" Grid.Column="1" Text="Transparent" VerticalOptions="Center" />
+                    <Switch Grid.Row="0" Grid.Column="2" IsToggled="{Binding InputTransparent, Source={Reference rootLayout}, Mode=OneWayToSource}" VerticalOptions="Center" />
+                    <Label Grid.Row="0" Grid.Column="3" Text="Cascade" VerticalOptions="Center" />
+                    <Switch Grid.Row="0" Grid.Column="4" IsToggled="{Binding CascadeInputTransparent, Source={Reference rootLayout}, Mode=OneWayToSource}" VerticalOptions="Center" />
+                    <BoxView Grid.Row="0" Grid.Column="5" Color="Green" WidthRequest="2" HorizontalOptions="End" IsVisible="{Binding InputTransparent, Source={Reference rootLayout}, Mode=OneWay}" />
+                    <!-- nested -->
+                    <Label Grid.Row="1" Grid.Column="0" Text="Nested" VerticalOptions="Center" FontAttributes="Bold" />
+                    <Label Grid.Row="1" Grid.Column="1" Text="Transparent" VerticalOptions="Center" />
+                    <Switch Grid.Row="1" Grid.Column="2" IsToggled="{Binding InputTransparent, Source={Reference nestedLayout}, Mode=OneWayToSource}" VerticalOptions="Center" />
+                    <Label Grid.Row="1" Grid.Column="3" Text="Cascade" VerticalOptions="Center" />
+                    <Switch Grid.Row="1" Grid.Column="4" IsToggled="{Binding CascadeInputTransparent, Source={Reference nestedLayout}, Mode=OneWayToSource}" VerticalOptions="Center" />
+                    <BoxView Grid.Row="1" Grid.Column="5" Color="Green" WidthRequest="2" HorizontalOptions="End" IsVisible="{Binding InputTransparent, Source={Reference nestedLayout}, Mode=OneWay}" />
+                    <!-- button -->
+                    <Label Grid.Row="2" Grid.Column="0" Text="Button" VerticalOptions="Center" FontAttributes="Bold" />
+                    <Label Grid.Row="2" Grid.Column="1" Text="Transparent" VerticalOptions="Center" />
+                    <Switch Grid.Row="2" Grid.Column="2" IsToggled="{Binding InputTransparent, Source={Reference testButton}, Mode=OneWayToSource}" VerticalOptions="Center" />
+                    <BoxView Grid.Row="2" Grid.Column="5" Color="Green" WidthRequest="2" HorizontalOptions="End" IsVisible="{Binding InputTransparent, Source={Reference testButton}, Mode=OneWay}" />
+                </Grid>
+
+            </VerticalStackLayout>
+
+        </VerticalStackLayout>
+    </ScrollView>
+
 </ContentPage>

src/Controls/src/Core/IInputTransparentContainerElement.cs

@@ -0,0 +1,14 @@
+#nullable disable
+
+namespace Microsoft.Maui.Controls
+{
+	// There are 2 Layout types: Controls and Compatibility
+	interface IInputTransparentContainerElement
+	{
+		bool InputTransparent { get; }
+
+		bool CascadeInputTransparent { get; }
+
+		Element Parent { get; }
+	}
+}

src/Controls/src/Core/Layout.cs

@@ -63,7 +63,7 @@ Size ILayoutManager.ArrangeChildren(Rect bounds)
 		}
 	}
 
-	public abstract class Layout : View, ILayout, ILayoutController, IPaddingElement, IView, IVisualTreeElement
+	public abstract class Layout : View, ILayout, ILayoutController, IPaddingElement, IView, IVisualTreeElement, IInputTransparentContainerElement
 	{
 		/// <summary>Bindable property for <see cref="IsClippedToBounds"/>.</summary>
 		public static readonly BindableProperty IsClippedToBoundsProperty =
@@ -72,7 +72,8 @@ public abstract class Layout : View, ILayout, ILayoutController, IPaddingElement
 
 		/// <summary>Bindable property for <see cref="CascadeInputTransparent"/>.</summary>
 		public static readonly BindableProperty CascadeInputTransparentProperty =
-			BindableProperty.Create(nameof(CascadeInputTransparent), typeof(bool), typeof(Layout), true);
+			BindableProperty.Create(nameof(CascadeInputTransparent), typeof(bool), typeof(Layout), true,
+				propertyChanged: OnCascadeInputTransparentPropertyChanged);
 
 		/// <summary>Bindable property for <see cref="Padding"/>.</summary>
 		public static readonly BindableProperty PaddingProperty = PaddingElement.PaddingProperty;
@@ -518,5 +519,15 @@ public Size CrossPlatformArrange(Rect bounds)
 
 			return Frame.Size;
 		}
+
+		static void OnCascadeInputTransparentPropertyChanged(BindableObject bindable, object oldValue, object newValue)
+		{
+			// We only need to update if the cascade changes anything, namely when InputTransparent=true.
+			// When InputTransparent=false, then the cascade property has no effect.
+			if (bindable is Layout layout && layout.InputTransparent)
+			{
+				layout.RefreshInputTransparentProperty();
+			}
+		}
 	}
 }

src/Controls/src/Core/Layout/Layout.Android.cs

@@ -7,31 +7,8 @@ namespace Microsoft.Maui.Controls
 {
 	public partial class Layout
 	{
-		public static void MapInputTransparent(LayoutHandler handler, Layout layout) =>
-			UpdateInputTransparent(handler, layout);
+		public static void MapInputTransparent(LayoutHandler handler, Layout layout) { }
 
-		public static void MapInputTransparent(ILayoutHandler handler, Layout layout) =>
-			UpdateInputTransparent(handler, layout);
-
-		static void MapInputTransparent(IViewHandler handler, IView layout) =>
-			UpdateInputTransparent(handler, layout);
-
-		static void UpdateInputTransparent(IViewHandler handler, IView layout)
-		{
-			if (handler is ILayoutHandler layoutHandler && layout is Layout controlsLayout)
-			{
-				if (layoutHandler.PlatformView is LayoutViewGroup layoutViewGroup)
-				{
-					// Handle input transparent for this view
-					layoutViewGroup.InputTransparent = layout.InputTransparent;
-				}
-
-				controlsLayout.UpdateDescendantInputTransparent();
-			}
-			else
-			{
-				ControlsVisualElementMapper.UpdateProperty(handler, layout, nameof(IView.InputTransparent));
-			}
-		}
+		public static void MapInputTransparent(ILayoutHandler handler, Layout layout) { }
 	}
 }

src/Controls/src/Core/Layout/Layout.Mapper.cs

@@ -15,8 +15,6 @@ public abstract partial class Layout
 
 		public static IPropertyMapper<IView, IViewHandler> ControlsLayoutMapper = new PropertyMapper<IView, IViewHandler>(ControlsVisualElementMapper)
 		{
-			[nameof(CascadeInputTransparent)] = MapInputTransparent,
-			[nameof(IView.InputTransparent)] = MapInputTransparent,
 		};
 	}
 }

src/Controls/src/Core/Layout/Layout.Tizen.cs

@@ -3,36 +3,8 @@ namespace Microsoft.Maui.Controls
 {
 	public partial class Layout
 	{
-		public static void MapInputTransparent(LayoutHandler handler, Layout layout) =>
-			UpdateInputTransparent(handler, layout);
+		public static void MapInputTransparent(LayoutHandler handler, Layout layout) { }
 
-		public static void MapInputTransparent(ILayoutHandler handler, Layout layout) =>
-			UpdateInputTransparent(handler, layout);
-
-		static void MapInputTransparent(IViewHandler handler, IView layout) =>
-			UpdateInputTransparent(handler, layout);
-
-		static void UpdateInputTransparent(IViewHandler handler, IView view)
-		{
-			if (handler.PlatformView is not Microsoft.Maui.Platform.LayoutViewGroup platformView ||
-				view is not Layout layout)
-			{
-				return;
-			}
-
-			if (layout.CascadeInputTransparent)
-			{
-				// Sensitive property on NUI View was false, disabled all touch event including children
-				platformView.Sensitive = !layout.InputTransparent;
-				platformView.InputTransparent = false;
-			}
-			else
-			{
-				// InputTransparent property on LayoutViewGroup was false,
-				// Only LayoutViewGroup event was disabled but children are allowed
-				platformView.InputTransparent = layout.InputTransparent;
-				platformView.Sensitive = true;
-			}
-		}
+		public static void MapInputTransparent(ILayoutHandler handler, Layout layout) { }
 	}
 }

src/Controls/src/Core/Layout/Layout.Windows.cs

@@ -5,26 +5,8 @@ namespace Microsoft.Maui.Controls
 {
 	public partial class Layout
 	{
-		public static void MapInputTransparent(LayoutHandler handler, Layout layout) =>
-			UpdateInputTransparent(handler, layout);
+		public static void MapInputTransparent(LayoutHandler handler, Layout layout) { }
 
-		public static void MapInputTransparent(ILayoutHandler handler, Layout layout) =>
-			UpdateInputTransparent(handler, layout);
-
-		static void MapInputTransparent(IViewHandler handler, IView layout) =>
-			UpdateInputTransparent(handler, layout);
-
-		static void UpdateInputTransparent(IViewHandler handler, IView layout)
-		{
-			if (handler is ILayoutHandler layoutHandler && layout is Layout controlsLayout)
-			{
-				layoutHandler.PlatformView?.UpdateInputTransparent(layoutHandler, controlsLayout);
-				controlsLayout.UpdateDescendantInputTransparent();
-			}
-			else
-			{
-				ControlsVisualElementMapper.UpdateProperty(handler, layout, nameof(IView.InputTransparent));
-			}
-		}
+		public static void MapInputTransparent(ILayoutHandler handler, Layout layout) { }
 	}
 }