Merge branch 'main' into user/arcadiog/shorterExpressionStrings

Author: arcadiogarcia

Microsoft.Toolkit.Uwp.UI.Controls.Core/DropShadowPanel/DropShadowPanel.cs

@@ -4,7 +4,6 @@
 
 using System;
 using System.Numerics;
-using System.Threading.Tasks;
 using Windows.UI;
 using Windows.UI.Composition;
 using Windows.UI.Xaml;
@@ -168,7 +167,13 @@ private void UpdateShadowMask()
             {
                 CompositionBrush mask = null;
 
-                if (Content is Image)
+                // We check for IAlphaMaskProvider first, to ensure that we use the custom
+                // alpha mask even if Content happens to extend any of the other classes
+                if (Content is IAlphaMaskProvider maskedControl)
+                {
+                    mask = maskedControl.GetAlphaMask();
+                }
+                else if (Content is Image)
                 {
                     mask = ((Image)Content).GetAlphaMask();
                 }

Microsoft.Toolkit.Uwp.UI/Helpers/IAlphaMaskProvider.cs

@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Windows.UI.Composition;
+
+namespace Microsoft.Toolkit.Uwp.UI
+{
+    /// <summary>
+    /// Any user control can implement this interface to provide a custom alpha mask to it's parent DropShadowPanel
+    /// </summary>
+    public interface IAlphaMaskProvider
+    {
+        /// <summary>
+        /// This method should return the appropiate alpha mask to be used in the shadow of this control
+        /// </summary>
+        /// <returns>The alpha mask as a composition brush</returns>
+        CompositionBrush GetAlphaMask();
+    }
+}

ReadMe.md

@@ -5,7 +5,7 @@ The Windows Community Toolkit is a collection of helper functions, custom contro
 | Target | Branch | Status | Recommended package version |
 | ------ | ------ | ------ | ------ |
 | Production | rel/7.0.2 | [![Build Status](https://dev.azure.com/dotnet/CommunityToolkit/_apis/build/status/Toolkit-CI?branchName=rel/7.0.2)](https://dev.azure.com/dotnet/CommunityToolkit/_build/latest?definitionId=10&branchName=rel/7.0.2) | [![NuGet](https://img.shields.io/nuget/v/Microsoft.Toolkit.Uwp.svg)](https://www.nuget.org/profiles/Microsoft.Toolkit) |
-| Pre-release beta testing | main | [![Build Status](https://dev.azure.com/dotnet/CommunityToolkit/_apis/build/status/Toolkit-CI?branchName=main)](https://dev.azure.com/dotnet/CommunityToolkit/_build/latest?definitionId=10) | [![DevOps](https://vsrm.dev.azure.com/dotnet/_apis/public/Release/badge/696bc9fd-f160-4e97-a1bd-7cbbb3b58f66/1/1)](https://dev.azure.com/dotnet/CommunityToolkit/_packaging?_a=feed&feed=WindowsCommunityToolkit-MainLatest) |
+| Pre-release beta testing | main | [![Build Status](https://dev.azure.com/dotnet/CommunityToolkit/_apis/build/status/Toolkit-CI?branchName=main)](https://dev.azure.com/dotnet/CommunityToolkit/_build/latest?definitionId=10) | [![DevOps](https://vsrm.dev.azure.com/dotnet/_apis/public/Release/badge/696bc9fd-f160-4e97-a1bd-7cbbb3b58f66/1/1)](https://dev.azure.com/dotnet/CommunityToolkit/_packaging?_a=feed&feed=CommunityToolkit-MainLatest) |
 
 ## Getting Started :raised_hands:
 Please read the [Getting Started with the Windows Community Toolkit](https://docs.microsoft.com/windows/communitytoolkit/getting-started) page for more detailed information about using the toolkit.