Add some initial helpers for the InputSimulator

Fix issue with UWP and WeakReference

common/CommunityToolkit.Labs.Tests.Shared/CommunityToolkit.Labs.Tests.Shared.projitems

@@ -18,6 +18,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)App.xaml.cs">
       <DependentUpon>App.xaml</DependentUpon>
     </Compile>
+    <Compile Include="$(MSBuildThisFileDirectory)Input\InputHelpers.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Input\InputSimulator.Bounds.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Log.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Input\InputSimulator.cs" />

common/CommunityToolkit.Labs.Tests.Shared/Input/InputHelpers.cs

@@ -0,0 +1,30 @@
+// 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.
+
+#if WINAPPSDK
+using MainWindow = Microsoft.UI.Xaml.Window;
+#else
+using MainWindow = Windows.UI.Xaml.Window;
+#endif
+
+namespace CommunityToolkit.Labs.Tests;
+
+public static class InputHelpers
+{
+    /// <summary>
+    /// Helper extension method to create a new <see cref="InputSimulator"/> chain for the current window.
+    /// </summary>
+    /// <param name="window"><see cref="Window"/> class for your application.</param>
+    /// <returns>A new <see cref="InputSimulator"/> instance for that window.</returns>
+    public static InputSimulator InjectInput(this MainWindow window)
+    {
+        return new InputSimulator(window);
+    }
+
+    public static Point CoordinatesToCenter(this UIElement parent, UIElement target)
+    {
+        var location = target.TransformToVisual(parent).TransformPoint(default(Point));
+        return new(location.X + target.ActualSize.X / 2, location.Y + target.ActualSize.Y / 2);
+    }
+}

common/CommunityToolkit.Labs.Tests.Shared/Input/InputSimulator.Bounds.cs

@@ -41,7 +41,7 @@ public partial class InputSimulator
         }
     }
 #else
-    private Rect Bounds => currentWindow.Bounds;
+    private Rect Bounds => _currentWindowRef.TryGetTarget(out Window window) ? window.Bounds : default;
 #endif
 
     private Point TranslatePointForWindow(Point point)

labs/SizerBase/tests/SizerBase.Tests/ExampleSizerBaseTestClass.cs

@@ -58,6 +58,21 @@ public partial class ExampleSizerBaseTestClass : VisualUITestBase
         Assert.AreEqual(200, propertySizer.Binding, "Property Sizer not at expected changed value.");
     }
 
+    [LabsUITestMethod]
+    public void PropertySizer_TestTouchDrag(PropertySizerTestInitialBinding testControl)
+    {
+        var propertySizer = testControl.FindDescendant<PropertySizer>();
+
+        Assert.IsNotNull(propertySizer, "Could not find PropertySizer control.");
+        Assert.IsNotNull(App.ContentRoot, "Could not find ContentRoot.");
+        // Set in XAML Page LINK: PropertySizerTestInitialBinding.xaml#L14
+        Assert.AreEqual(300, propertySizer.Binding, "Property Sizer not at expected initial value.");
+
+        var location = App.ContentRoot.CoordinatesToCenter(propertySizer);
+
+        App.CurrentWindow.InjectInput();
+    }
+
     [LabsUITestMethod]
     public async Task InputInjection_TestClickButton(TouchInjectionTest testControl)
     {
@@ -67,14 +82,14 @@ public partial class ExampleSizerBaseTestClass : VisualUITestBase
         Assert.IsFalse(testControl.WasButtonClicked, "Initial state unexpected. Button shouldn't be clicked yet.");
 
         // Get location to button.
-        var location = App.ContentRoot.CoordinatesTo(button); // TODO: Write a `CoordinatesToCenter` helper?
+        var location = App.ContentRoot!.CoordinatesToCenter(button); // TODO: Write a `CoordinatesToCenter` helper?
 
         // TODO: Make an extension method on window for this to be like: App.CurrentWindow.InjectInput()...
         InputSimulator sim = new(App.CurrentWindow);
 
         sim.StartTouch();
         // Offset location slightly to ensure we're inside the button.
-        var pointerId = sim.TouchDown(new Point(location.X + 25, location.Y + 25));
+        var pointerId = sim.TouchDown(new Point(location.X, location.Y));
         await Task.Delay(50);
         sim.TouchUp(pointerId);