Entry and Editor RTL fixes (#10046) fixes #9022 fixes #5860 fixes #3359

* Use right alignment instead of natural for RTL Entry on iOS; fixes #9022
Fixes #3359;
Remove DetectFromContent as default alignment for UWP Editor; Fixes #5860

* Fix occasional ReusebindingInstance test failures due to GC

* Remove commented code

Xamarin.Forms.Core.UnitTests/BindingBaseUnitTests.cs

@@ -194,6 +194,8 @@ namespace Xamarin.Forms.Core.UnitTests
 			bindable2.BindingContext = new MockViewModel();
 			Assert.Throws<InvalidOperationException>(() => bindable2.SetBinding(property, binding),
 				"Binding allowed reapplication with a different context");
+
+			GC.KeepAlive(bindable);
 		}
 
 		[Test, Category("[Binding] Set Value")]

Xamarin.Forms.Platform.UAP.UnitTests/BackgroundColorTests.cs

@@ -7,7 +7,7 @@ using Windows.UI.Xaml.Media;
 using Xamarin.Forms.Platform.UWP;
 using WColor = Windows.UI.Color;
 
-namespace Xamarin.Forms.Platform.UAP.Tests
+namespace Xamarin.Forms.Platform.UAP.UnitTests
 {
 	[TestFixture]
 	public class BackgroundColorTests : PlatformTestFixture

Xamarin.Forms.Platform.UAP.UnitTests/FlowDirectionTests.cs

@@ -0,0 +1,104 @@
+using System.Threading.Tasks;
+using NUnit.Framework;
+using WTextAlignment = Windows.UI.Xaml.TextAlignment;
+using WFlowDirection = Windows.UI.Xaml.FlowDirection;
+using System;
+
+namespace Xamarin.Forms.Platform.UAP.UnitTests
+{
+	public class FlowDirectionTests : PlatformTestFixture
+	{
+		[TestCase(true, FlowDirection.LeftToRight, Category = "FlowDirection,Entry", ExpectedResult = WTextAlignment.Left)]
+		[TestCase(true, FlowDirection.RightToLeft, Category = "FlowDirection,Entry", ExpectedResult = WTextAlignment.Right)]
+		[TestCase(false, FlowDirection.LeftToRight, Category = "FlowDirection,Entry", ExpectedResult = WTextAlignment.Left)]
+		[TestCase(false, FlowDirection.RightToLeft, Category = "FlowDirection,Entry", ExpectedResult = WTextAlignment.Right)]
+		public async Task<WTextAlignment> EntryAlignmentMatchesFlowDirection(bool isExplicit, FlowDirection flowDirection)
+		{
+			var entry = new Entry { Text = "Checking flow direction", HorizontalTextAlignment = TextAlignment.Start };
+			var contentPage = new ContentPage { Title = "Flow Direction", Content = entry };
+
+			if (isExplicit)
+			{
+				entry.FlowDirection = flowDirection;
+			}
+			else
+			{
+				contentPage.FlowDirection = flowDirection;
+			}
+
+			var nativeAlignment = await Device.InvokeOnMainThreadAsync(() => {
+				if (!isExplicit)
+				{
+					GetRenderer(contentPage);
+				}
+				var textField = GetNativeControl(entry);
+				return textField.TextAlignment;
+			});
+
+			return nativeAlignment;
+		}
+
+		async Task<Tuple<WTextAlignment, WFlowDirection>> GetEditorAlignmentAndFlowDirection(bool isExplicit, FlowDirection flowDirection) 
+		{
+			var editor = new Editor { Text = " تسجيل الدخول" };
+			var contentPage = new ContentPage { Title = "Flow Direction", Content = editor };
+
+			if (isExplicit)
+			{
+				editor.FlowDirection = flowDirection;
+			}
+			else
+			{
+				contentPage.FlowDirection = flowDirection;
+			}
+
+			var (nativeAlignment, nativeFlowDirection) = await Device.InvokeOnMainThreadAsync(() => {
+				if (!isExplicit)
+				{
+					GetRenderer(contentPage);
+				}
+				var textField = GetNativeControl(editor);
+				return (textField.TextAlignment, textField.FlowDirection);
+			});
+
+			return new Tuple<WTextAlignment, WFlowDirection>(nativeAlignment, nativeFlowDirection);
+		}
+
+		// The Left TextAlignment seems counterintuitive, but for the Editor the FlowDirection
+		// is going to automatically handle the alignment anyway.
+		// The important thing is that the TextAlignment is *not* set to DetectFromContent,
+		// as that will override our FlowDirection settings if they don't agree
+
+		[Test, Category("Editor"), Category("FlowDirection")]
+		public async Task EditorAlignmentMatchesFlowDirectionRtlExplicit()
+		{
+			var results = await GetEditorAlignmentAndFlowDirection(true, FlowDirection.RightToLeft);
+			Assert.That(results.Item1, Is.EqualTo(WTextAlignment.Left));
+			Assert.That(results.Item2, Is.EqualTo(WFlowDirection.RightToLeft));
+		}
+
+		[Test, Category("Editor"), Category("FlowDirection")]
+		public async Task EditorAlignmentMatchesFlowDirectionLtrExplicit()
+		{
+			var results = await GetEditorAlignmentAndFlowDirection(true, FlowDirection.LeftToRight);
+			Assert.That(results.Item1, Is.EqualTo(WTextAlignment.Left));
+			Assert.That(results.Item2, Is.EqualTo(WFlowDirection.LeftToRight));
+		}
+
+		[Test, Category("Editor"), Category("FlowDirection")]
+		public async Task EditorAlignmentMatchesFlowDirectionRtlImplicit()
+		{
+			var results = await GetEditorAlignmentAndFlowDirection(false, FlowDirection.RightToLeft);
+			Assert.That(results.Item1, Is.EqualTo(WTextAlignment.Left));
+			Assert.That(results.Item2, Is.EqualTo(WFlowDirection.RightToLeft));
+		}
+
+		[Test, Category("Editor"), Category("FlowDirection")]
+		public async Task EditorAlignmentMatchesFlowDirectionLtrImplicit()
+		{
+			var results = await GetEditorAlignmentAndFlowDirection(false, FlowDirection.LeftToRight);
+			Assert.That(results.Item1, Is.EqualTo(WTextAlignment.Left));
+			Assert.That(results.Item2, Is.EqualTo(WFlowDirection.LeftToRight));
+		}
+	}
+}

Xamarin.Forms.Platform.UAP.UnitTests/IsEnabledTests.cs

@@ -2,7 +2,7 @@
 using System.Threading.Tasks;
 using NUnit.Framework;
 
-namespace Xamarin.Forms.Platform.UAP.Tests
+namespace Xamarin.Forms.Platform.UAP.UnitTests
 {
 	[TestFixture]
 	public class IsEnabledTests : PlatformTestFixture 

Xamarin.Forms.Platform.UAP.UnitTests/PlatformTestFixture.cs

@@ -5,7 +5,7 @@ using NUnit.Framework;
 using Windows.UI.Xaml.Controls;
 using Xamarin.Forms.Platform.UWP;
 
-namespace Xamarin.Forms.Platform.UAP.Tests
+namespace Xamarin.Forms.Platform.UAP.UnitTests
 {
 	public class PlatformTestFixture
 	{

Xamarin.Forms.Platform.UAP.UnitTests/RendererTests.cs

@@ -1,7 +1,7 @@
 using System.Threading.Tasks;
 using NUnit.Framework;
 
-namespace Xamarin.Forms.Platform.UAP.Tests
+namespace Xamarin.Forms.Platform.UAP.UnitTests
 {
 	[TestFixture]
 	public class RendererTests : PlatformTestFixture

Xamarin.Forms.Platform.UAP.UnitTests/RotationTests.cs

@@ -5,7 +5,7 @@ using NUnit.Framework;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Media;
 
-namespace Xamarin.Forms.Platform.UAP.Tests
+namespace Xamarin.Forms.Platform.UAP.UnitTests
 {
 	[TestFixture]
 	public class RotationTests : PlatformTestFixture 

Xamarin.Forms.Platform.UAP.UnitTests/ScaleTests.cs

@@ -5,7 +5,7 @@ using NUnit.Framework;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Media;
 
-namespace Xamarin.Forms.Platform.UAP.Tests
+namespace Xamarin.Forms.Platform.UAP.UnitTests
 {
 	[TestFixture]
 	public class ScaleTests : PlatformTestFixture

Xamarin.Forms.Platform.UAP.UnitTests/Xamarin.Forms.Platform.UAP.UnitTests.csproj

@@ -123,6 +123,7 @@
     <Compile Include="BackgroundColorTests.cs" />
     <Compile Include="ColorTests.cs" />
     <Compile Include="EmbeddingTests.cs" />
+    <Compile Include="FlowDirectionTests.cs" />
     <Compile Include="IsEnabledTests.cs" />
     <Compile Include="PlatformTestFixture.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />

Xamarin.Forms.Platform.UAP/EditorRenderer.cs

@@ -50,6 +50,10 @@ namespace Xamarin.Forms.Platform.UWP
 					// color stuff, then the underlying textbox should just use the Forms VSM states
 					textBox.UseFormsVsm = e.NewElement.HasVisualStateGroups()
 						|| !e.NewElement.OnThisPlatform().GetIsLegacyColorModeEnabled();
+
+					// The default is DetectFromContent, which we don't want because it can
+					// override the FlowDirection settings. 
+					textBox.TextAlignment = Windows.UI.Xaml.TextAlignment.Left;
 				}
 
 				UpdateText();
@@ -57,7 +61,6 @@ namespace Xamarin.Forms.Platform.UWP
 				UpdateTextColor();
 				UpdateCharacterSpacing();
 				UpdateFont();
-				UpdateTextAlignment();
 				UpdateFlowDirection();
 				UpdateMaxLength();
 				UpdateDetectReadingOrderFromContent();
@@ -122,7 +125,6 @@ namespace Xamarin.Forms.Platform.UWP
 			}
 			else if (e.PropertyName == VisualElement.FlowDirectionProperty.PropertyName)
 			{
-				UpdateTextAlignment();
 				UpdateFlowDirection();
 			}
 			else if (e.PropertyName == InputView.MaxLengthProperty.PropertyName)
@@ -177,7 +179,6 @@ namespace Xamarin.Forms.Platform.UWP
 			Element.SetValueCore(Editor.TextProperty, Control.Text);
 		}
 
-
 		public override SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint)
 		{
 			FormsTextBox child = Control;
@@ -255,6 +256,7 @@ namespace Xamarin.Forms.Platform.UWP
 		{
 			Control.CharacterSpacing = Element.CharacterSpacing.ToEm();
 		}
+	
 		void UpdateText()
 		{
 			string newText = Element.Text ?? "";
@@ -268,11 +270,6 @@ namespace Xamarin.Forms.Platform.UWP
 			Control.SelectionStart = Control.Text.Length;
 		}
 
-		void UpdateTextAlignment()
-		{
-			Control.UpdateTextAlignment(Element);
-		}
-
 		void UpdateTextColor()
 		{
 			Color textColor = Element.TextColor;

Xamarin.Forms.Platform.UAP/FlowDirectionExtensions.cs

@@ -1,8 +1,5 @@
 using Windows.UI.Xaml;
 using WFlowDirection = Windows.UI.Xaml.FlowDirection;
-using WTextAlignment = Windows.UI.Xaml.TextAlignment;
-using Windows.UI.Xaml.Controls;
-
 
 namespace Xamarin.Forms.Platform.UWP
 {
@@ -12,22 +9,11 @@ namespace Xamarin.Forms.Platform.UWP
 		{
 			if (controller == null || control == null)
 				return;
-
+				
 			if (controller.EffectiveFlowDirection.IsRightToLeft())
 				control.FlowDirection = WFlowDirection.RightToLeft;
 			else if (controller.EffectiveFlowDirection.IsLeftToRight())
 				control.FlowDirection = WFlowDirection.LeftToRight;
 		}
-
-		internal static void UpdateTextAlignment(this TextBox control, IVisualElementController controller)
-		{
-			if (controller == null || control == null)
-				return;
-
-			if (controller.EffectiveFlowDirection.IsRightToLeft())
-				control.TextAlignment = WTextAlignment.Right;
-			else if (controller.EffectiveFlowDirection.IsLeftToRight())
-				control.TextAlignment = WTextAlignment.Left;
-		}
 	}
 }

Xamarin.Forms.Platform.iOS.UnitTests/FlowDirectionTests.cs

@@ -1,12 +1,13 @@
-using NUnit.Framework;
+using System.Threading.Tasks;
+using NUnit.Framework;
 using UIKit;
 
 namespace Xamarin.Forms.Platform.iOS.UnitTests
 {
 	[TestFixture]
-	public class FlowDirectionTests
+	public class FlowDirectionTests : PlatformTestFixture
 	{
-		[Test]
+		[Test, Category("FlowDirection")]
 		public void FlowDirectionConversion() 
 		{
 			var ltr = UIUserInterfaceLayoutDirection.LeftToRight.ToFlowDirection();
@@ -15,5 +16,65 @@ namespace Xamarin.Forms.Platform.iOS.UnitTests
 			var rtl = UIUserInterfaceLayoutDirection.RightToLeft.ToFlowDirection();
 			Assert.That(rtl, Is.EqualTo(FlowDirection.RightToLeft));
 		}
+
+		[TestCase(true, FlowDirection.LeftToRight, Category = "FlowDirection,Entry", ExpectedResult = UITextAlignment.Left)]
+		[TestCase(true, FlowDirection.RightToLeft, Category = "FlowDirection,Entry", ExpectedResult = UITextAlignment.Right)]
+		[TestCase(false, FlowDirection.LeftToRight, Category = "FlowDirection,Entry", ExpectedResult = UITextAlignment.Left)]
+		[TestCase(false, FlowDirection.RightToLeft, Category = "FlowDirection,Entry", ExpectedResult = UITextAlignment.Right)]
+		public async Task<UITextAlignment> EntryAlignmentMatchesFlowDirection(bool isExplicit, FlowDirection flowDirection) 
+		{
+			var entry = new Entry { Text = "Checking flow direction", HorizontalTextAlignment = TextAlignment.Start };
+			var contentPage = new ContentPage { Title = "Flow Direction", Content = entry };
+
+			if (isExplicit)
+			{
+				entry.FlowDirection = flowDirection;
+			}
+			else
+			{
+				contentPage.FlowDirection = flowDirection;
+			}
+
+			var nativeAlignment = await Device.InvokeOnMainThreadAsync(() => {
+				if (!isExplicit)
+				{
+					GetRenderer(contentPage);
+				}
+				var textField = GetNativeControl(entry);
+				return textField.TextAlignment;
+			});
+
+			return nativeAlignment;
+		}
+
+		[TestCase(true, FlowDirection.LeftToRight, Category = "FlowDirection,Entry", ExpectedResult = UITextAlignment.Left)]
+		[TestCase(true, FlowDirection.RightToLeft, Category = "FlowDirection,Entry", ExpectedResult = UITextAlignment.Right)]
+		[TestCase(false, FlowDirection.LeftToRight, Category = "FlowDirection,Entry", ExpectedResult = UITextAlignment.Left)]
+		[TestCase(false, FlowDirection.RightToLeft, Category = "FlowDirection,Entry", ExpectedResult = UITextAlignment.Right)]
+		public async Task<UITextAlignment> EditorAlignmentMatchesFlowDirection(bool isExplicit, FlowDirection flowDirection)
+		{
+			var editor = new Editor { Text = "Checking flow direction" };
+			var contentPage = new ContentPage { Title = "Flow Direction", Content = editor };
+
+			if (isExplicit)
+			{
+				editor.FlowDirection = flowDirection;
+			}
+			else
+			{
+				contentPage.FlowDirection = flowDirection;
+			}
+
+			var nativeAlignment = await Device.InvokeOnMainThreadAsync(() => {
+				if (!isExplicit)
+				{
+					GetRenderer(contentPage);
+				}
+				var textField = GetNativeControl(editor);
+				return textField.TextAlignment;
+			});
+
+			return nativeAlignment;
+		}
 	}
 }

Xamarin.Forms.Platform.iOS/Renderers/AlignmentExtensions.cs

@@ -21,7 +21,7 @@ namespace Xamarin.Forms.Platform.iOS
 					if (isLtr)
 						return UITextAlignment.Left;
 					else
-						return UITextAlignment.Natural;
+						return UITextAlignment.Right;
 			}
 		}
 

Xamarin.Forms.Platform.iOS/Renderers/EntryRenderer.cs

@@ -355,6 +355,7 @@ namespace Xamarin.Forms.Platform.iOS
 
 			UpdateAttributedPlaceholder(Control.AttributedPlaceholder.AddCharacterSpacing(Element.Placeholder, Element.CharacterSpacing));
 		}
+
 		protected virtual void UpdateAttributedPlaceholder(NSAttributedString nsAttributedString) =>
 			Control.AttributedPlaceholder = nsAttributedString;