Bind RadioButton default template root properties to RadioButton's pr… (#12742) fixes #12345

* Bind RadioButton default template root properties to RadioButton's properties
Fixes #12345

* Revert project file changes

Xamarin.Forms.Core.UnitTests/RadioButtonTemplateTests.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections;
+using NUnit.Framework;
+
+namespace Xamarin.Forms.Core.UnitTests
+{
+	[TestFixture(Category = "RadioButton")]
+	public class RadioButtonTemplateTests : BaseTestFixture
+	{
+		class FrameStyleCases : IEnumerable
+		{
+			public IEnumerator GetEnumerator()
+			{
+				yield return new object[] { Frame.VerticalOptionsProperty, LayoutOptions.End };
+				yield return new object[] { Frame.HorizontalOptionsProperty, LayoutOptions.End };
+				yield return new object[] { Frame.BackgroundColorProperty, Color.Red };
+				yield return new object[] { Frame.BorderColorProperty, Color.Magenta };
+				yield return new object[] { Frame.MarginProperty, new Thickness(1, 2, 3, 4) };
+				yield return new object[] { Frame.OpacityProperty, 0.67 };
+				yield return new object[] { Frame.RotationProperty, 0.3 };
+				yield return new object[] { Frame.ScaleProperty, 0.8 };
+				yield return new object[] { Frame.ScaleXProperty, 0.9 };
+				yield return new object[] { Frame.ScaleYProperty, 0.95 };
+				yield return new object[] { Frame.TranslationXProperty, 123 };
+				yield return new object[] { Frame.TranslationYProperty, 321 };
+			}
+		}
+
+		[TestCaseSource(typeof(FrameStyleCases))]
+		[Description("Frame Style properties should not affect RadioButton")]
+		public void RadioButtonIgnoresFrameStyleProperties(BindableProperty property, object value)
+		{
+			var implicitFrameStyle = new Style(typeof(Frame));
+			implicitFrameStyle.Setters.Add(new Setter() { Property = property, Value = value });
+
+			var page = new ContentPage();
+			page.Resources.Add(implicitFrameStyle);
+
+			var radioButton = new RadioButton() { ControlTemplate = RadioButton.DefaultTemplate };
+			page.Content = radioButton;
+
+			var root = (radioButton as IControlTemplated)?.TemplateRoot as Frame;
+
+			Assert.IsNotNull(root);
+			Assert.That(root.GetValue(property), Is.Not.EqualTo(value), $"{property.PropertyName} should be ignored.");
+		}
+
+		class RadioButtonStyleCases : IEnumerable
+		{
+			public IEnumerator GetEnumerator()
+			{
+				yield return new object[] { RadioButton.VerticalOptionsProperty, LayoutOptions.End };
+				yield return new object[] { RadioButton.HorizontalOptionsProperty, LayoutOptions.End };
+				yield return new object[] { RadioButton.BackgroundColorProperty, Color.Red };
+				yield return new object[] { RadioButton.MarginProperty, new Thickness(1, 2, 3, 4) };
+				yield return new object[] { RadioButton.OpacityProperty, 0.67 };
+				yield return new object[] { RadioButton.RotationProperty, 0.3 };
+				yield return new object[] { RadioButton.ScaleProperty, 0.8};
+				yield return new object[] { RadioButton.ScaleXProperty, 0.9 };
+				yield return new object[] { RadioButton.ScaleYProperty, 0.95 };
+				yield return new object[] { RadioButton.TranslationXProperty, 123 };
+				yield return new object[] { RadioButton.TranslationYProperty, 321 };
+			}
+		}
+
+		[TestCaseSource(typeof(RadioButtonStyleCases))]
+		[Description("RadioButton Style properties should affect RadioButton")]
+		public void RadioButtonStyleSetsPropertyOnTemplateRoot(BindableProperty property, object value)
+		{
+			var radioButtonStyle = new Style(typeof(RadioButton));
+			radioButtonStyle.Setters.Add(new Setter() { Property = property, Value = value });
+
+			var radioButton = new RadioButton() { ControlTemplate = RadioButton.DefaultTemplate, Style = radioButtonStyle };
+
+			var root = (radioButton as IControlTemplated)?.TemplateRoot as Frame;
+
+			Assert.IsNotNull(root);
+			Assert.That(root.GetValue(property), Is.EqualTo(value), $"{property.PropertyName} should match.");
+		}
+	}
+}

Xamarin.Forms.Core.UnitTests/Xamarin.Forms.Core.UnitTests.csproj

@@ -289,4 +289,4 @@
     <Copy SourceFiles="@(_NUnitTestAdapterFiles)" DestinationFolder="$(SolutionDir)packages\NUnitTestAdapter.AnyVersion\tools\%(RecursiveDir)" ContinueOnError="true" Retries="0" />
     <Copy SourceFiles="@(_NUnitTestAdapterFiles)" DestinationFolder="$(SolutionDir)packages\NUnitTestAdapter.AnyVersion\build\%(RecursiveDir)" ContinueOnError="true" Retries="0" />
   </Target>
-</Project>
+</Project>

Xamarin.Forms.Core/RadioButton.cs

@@ -417,18 +417,27 @@ namespace Xamarin.Forms
 			IsChecked = true;
 		}
 
+		static void BindToTemplatedParent(BindableObject bindableObject, params BindableProperty[] properties)
+		{
+			foreach (var property in properties)
+			{
+				bindableObject.SetBinding(property, new Binding(property.PropertyName,
+					source: RelativeBindingSource.TemplatedParent));
+			}
+		}
+
 		static View BuildDefaultTemplate()
 		{
 			var frame = new Frame
 			{
 				HasShadow = false,
-				BackgroundColor = Color.Transparent,
-				VerticalOptions = LayoutOptions.Start,
-				HorizontalOptions = LayoutOptions.Start,
-				Margin = new Thickness(6),
-				Padding = new Thickness(0)
+				Padding = 6
 			};
 
+			BindToTemplatedParent(frame, BackgroundColorProperty, Frame.BorderColorProperty, HorizontalOptionsProperty,
+				MarginProperty, OpacityProperty, RotationProperty, ScaleProperty, ScaleXProperty, ScaleYProperty, 
+				TranslationYProperty, TranslationXProperty, VerticalOptionsProperty);
+	
 			var grid = new Grid
 			{
 				RowSpacing = 0,