Merge pull request #12 from Sergio0694/feature/clip-to-bounds

Merge Sergio0694 code in my own branch

Microsoft.Toolkit.Uwp.UI/Extensions/UIElement/UIElementExtensions.cs

@@ -0,0 +1,56 @@
+// 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.Xaml;
+using Windows.UI.Xaml.Hosting;
+
+namespace Microsoft.Toolkit.Uwp.UI.Extensions
+{
+    /// <summary>
+    /// Provides attached dependency properties for the <see cref="Windows.UI.Xaml.UIElement"/>
+    /// </summary>
+    public static class UIElementExtensions
+    {
+        /// <summary>
+        /// Attached <see cref="DependencyProperty"/> that indicates whether or not the contents of the target <see cref="UIElement"/> should always be clipped to their parent's bounds.
+        /// </summary>
+        public static readonly DependencyProperty ClipToBoundsProperty = DependencyProperty.RegisterAttached("ClipToBounds", typeof(bool), typeof(UIElementExtensions), new PropertyMetadata(DependencyProperty.UnsetValue, OnClipToBoundsPropertyChanged));
+
+        /// <summary>
+        /// Gets the value of <see cref="ClipToBoundsProperty"/>
+        /// </summary>
+        /// <param name="element">The <see cref="UIElement"/> to read the property value from</param>
+        /// <returns>The <see cref="bool"/> associated with the <see cref="FrameworkElement"/></returns>.
+        public static bool GetClipToBounds(UIElement element)
+        {
+            return (bool)element.GetValue(ClipToBoundsProperty);
+        }
+
+        /// <summary>
+        /// Sets the value of <see cref="ClipToBoundsProperty"/>
+        /// </summary>
+        /// <param name="element">The <see cref="UIElement"/> to set the property to</param>
+        /// <param name="value">The new value of the attached property</param>
+        public static void SetClipToBounds(UIElement element, bool value)
+        {
+            element.SetValue(ClipToBoundsProperty, value);
+        }
+
+        private static void OnClipToBoundsPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+        {
+            var element = d as UIElement;
+
+            if (element is null)
+            {
+                return;
+            }
+
+            bool value = (bool)e.NewValue;
+
+            var visual = ElementCompositionPreview.GetElementVisual(element);
+
+            visual.Clip = value ? visual.Compositor.CreateInsetClip() : null;
+        }
+    }
+}