Add extension methods for ScaleXTo and ScaleYTo (#8007) fixes #8004

* Add extension methods for ScaleXTo and ScaleYTo

* Updated sample with small description

* Updated test

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue8004.cs

@@ -0,0 +1,92 @@
+using System;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+using System.Threading.Tasks;
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+#if UITEST
+	[Category(UITestCategories.Animation)]
+#endif
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 8004, "Add a ScaleXTo and ScaleYTo animation extension method", PlatformAffected.All)]
+	public class Issue8004 : TestContentPage
+	{
+		BoxView _boxView;
+		const string AnimateBoxViewButton = "AnimateBoxViewButton";
+		const string BoxToScale = "BoxToScale";
+
+		protected override void Init()
+		{
+			var label = new Label
+			{
+				Text = "Click the button below to animate the BoxView using individual ScaleXTo and ScaleYTo extension methods.",
+				TextColor = Color.Black
+			};
+
+			var button = new Button
+			{
+				AutomationId = AnimateBoxViewButton,
+				Text = "Animate BoxView",
+				BackgroundColor = Color.Black,
+				TextColor = Color.White,
+				VerticalOptions = LayoutOptions.EndAndExpand
+			};
+
+			button.Clicked += AnimateButton_Clicked;
+
+			_boxView = new BoxView
+			{
+				AutomationId = BoxToScale,
+				BackgroundColor = Color.Blue,
+				WidthRequest = 200,
+				HeightRequest = 100,
+				HorizontalOptions = LayoutOptions.Center
+			};
+
+			var grid = new Grid();
+
+			Grid.SetRow(label, 0);
+			Grid.SetRow(_boxView, 1);
+			Grid.SetRow(button, 2);
+
+			grid.Children.Add(label);
+			grid.Children.Add(_boxView);
+			grid.Children.Add(button);
+
+			Content = grid;
+		}
+
+		void AnimateButton_Clicked(object sender, EventArgs e)
+		{
+			_boxView.ScaleYTo(2, 250, Easing.CubicInOut);
+			_boxView.ScaleXTo(1.5, 400, Easing.BounceOut);
+		}
+
+#if UITEST
+		[Test]
+		public async Task AnimateScaleOfBoxView()
+		{
+			RunningApp.Screenshot("Small blue box");
+
+			// Check the box and button elements.
+			RunningApp.WaitForElement(q => q.Marked(BoxToScale));
+			RunningApp.WaitForElement(q => q.Marked(AnimateBoxViewButton));
+
+			// Tap the button.
+			RunningApp.Tap(q => q.Marked(AnimateBoxViewButton));
+
+			// Wait for animation to finish.
+			await Task.Delay(500);
+			   
+			RunningApp.Screenshot("Bigger blue box");
+		}
+#endif
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/TestPages/TestPages.cs

@@ -89,7 +89,7 @@ namespace Xamarin.Forms.Controls
 			}
 
 			// Running on the simulator
-			//var app = ConfigureApp.iOS
+			// var app = ConfigureApp.iOS
 			//				  .PreferIdeSettings()
 			//		  		  .AppBundle("../../../Xamarin.Forms.ControlGallery.iOS/bin/iPhoneSimulator/Debug/XamarinFormsControlGalleryiOS.app")
 			//				  .Debug()

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems

@@ -1118,6 +1118,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Issue6127.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue7283.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue5395.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue8004.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue7898.cs" />
   </ItemGroup>
   <ItemGroup>

Xamarin.Forms.Core/ViewExtensions.cs

@@ -15,6 +15,8 @@ namespace Xamarin.Forms
 			view.AbortAnimation(nameof(RotateYTo));
 			view.AbortAnimation(nameof(RotateXTo));
 			view.AbortAnimation(nameof(ScaleTo));
+			view.AbortAnimation(nameof(ScaleXTo));
+			view.AbortAnimation(nameof(ScaleYTo));
 			view.AbortAnimation(nameof(FadeTo));
 		}
 
@@ -116,6 +118,22 @@ namespace Xamarin.Forms
 			return AnimateTo(view, view.Scale, scale, nameof(ScaleTo), (v, value) => v.Scale = value, length, easing);
 		}
 
+		public static Task<bool> ScaleXTo(this VisualElement view, double scale, uint length = 250, Easing easing = null)
+		{
+			if (view == null)
+				throw new ArgumentNullException(nameof(view));
+
+			return AnimateTo(view, view.ScaleX, scale, nameof(ScaleXTo), (v, value) => v.ScaleX = value, length, easing);
+		}
+
+		public static Task<bool> ScaleYTo(this VisualElement view, double scale, uint length = 250, Easing easing = null)
+		{
+			if (view == null)
+				throw new ArgumentNullException(nameof(view));
+
+			return AnimateTo(view, view.ScaleY, scale, nameof(ScaleYTo), (v, value) => v.ScaleY = value, length, easing);
+		}
+
 		public static Task<bool> TranslateTo(this VisualElement view, double x, double y, uint length = 250, Easing easing = null)
 		{
 			if (view == null)