Fix RTL on Labels with FormattedText and/or LineHeight (#13197) fixes #…

…3311 fixes #12473 fixes #8157

* Add Issue3311.cs

* Update Issue331.cs test file

* Fix RTL issue on FormattedText

* Add relevant RTL FormattedText test

* Update Issue3311.cs

* Add Issue12473

* Add BackgroundColor to test labels for clarit

* Add LabelTest for RTL Label with LineHeight

* Add missing closing EmbeddedResource tag

* Remove UITest template code

* Update RTL tests to be more thorough

* UpdateHorizontalTextAlignment on UpdateFormattedText

Fix RTL issue that arises when certain text properties are set on a Label w/ RTL and FormattedText (i.e. FontAttributes, FontSize, LineHeight, TextColor, TextTransform, etc)

* Remove TextType from tests

TextType on FormattedText labels causes app crash. This separate issue will be fixed in a follow-up PR

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue12473.xaml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<controls:TestContentPage
+    xmlns="http://xamarin.com/schemas/2014/forms"
+    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    xmlns:controls="clr-namespace:Xamarin.Forms.Controls"
+    x:Class="Xamarin.Forms.Controls.Issues.Issue12473">
+    <ScrollView Margin="20">
+        <StackLayout>
+            <Label Text="This test passes if all proceeding labels are properly right-aligned" FontSize="20" HorizontalTextAlignment="Center" />
+
+            <Label Text="This is a normal text label with RTL" FlowDirection="RightToLeft" BackgroundColor="Red"/>
+            <Label Text="This is a normal text label with RTL and LineHeight" FlowDirection="RightToLeft" LineHeight="3" BackgroundColor="Yellow"/>
+
+            <!--Test the same thing with Labels in an RTL language-->
+            <Label Text="هذا نص حشو عشوائي أتمنى ترجمته بشكل صحيح من الإنجليزية" FlowDirection="RightToLeft" BackgroundColor="Red"/>
+            <Label Text="هذا نص حشو عشوائي أتمنى ترجمته بشكل صحيح من الإنجليزية" FlowDirection="RightToLeft" LineHeight="3" BackgroundColor="Yellow"/>
+
+            <!--Test the same thing with Labels using both LTR and RTL languages-->
+            <Label Text="foo هذا نص حشو عشوائي أتمنى ترجمته بشكل صحيح من الإنجليزية" FlowDirection="RightToLeft" BackgroundColor="Red"/>
+            <Label Text="foo هذا نص حشو عشوائي أتمنى ترجمته بشكل صحيح من الإنجليزية" FlowDirection="RightToLeft" LineHeight="3" BackgroundColor="Yellow"/>
+        </StackLayout>
+    </ScrollView>
+</controls:TestContentPage>

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue12473.xaml.cs

@@ -0,0 +1,35 @@
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+using Xamarin.Forms.Xaml;
+
+#if UITEST
+using Xamarin.Forms.Core.UITests;
+using Xamarin.UITest;
+using NUnit.Framework;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+#if UITEST
+	[Category(UITestCategories.ManualReview)]
+#endif
+#if APP
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+#endif
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 12473, "iOS Label text alignment in RTL with LineHeight", PlatformAffected.iOS)]
+	public partial class Issue12473 : TestContentPage
+	{
+		public Issue12473()
+		{
+#if APP
+			InitializeComponent();
+#endif
+		}
+
+		protected override void Init()
+		{
+
+		}
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue3311.cs

@@ -0,0 +1,86 @@
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+#if UITEST
+using Xamarin.Forms.Core.UITests;
+using Xamarin.UITest;
+using NUnit.Framework;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+#if UITEST
+	[Category(UITestCategories.ManualReview)]
+#endif
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 3311, "RTL is not working for iOS Label with FormattedText", PlatformAffected.Default)]
+	public class Issue3311 : TestContentPage
+	{
+		protected override void Init()
+		{
+			var formattedString = new FormattedString();
+			formattedString.Spans.Add(new Span { Text = "RTL formatted text" });
+
+			Content = new StackLayout()
+			{
+				Margin = 20,
+
+				Children =
+				{
+					new Label()
+					{
+						AutomationId = "Issue3311Label",
+						Text = "This test passes if all proceeding labels are properly right-aligned",
+						HorizontalTextAlignment = TextAlignment.Center,
+						FontSize = 20
+					},
+					new Label()
+					{
+						AutomationId = "Issue3311NormalTextLabel",
+						Text = "RTL normal text",
+						FlowDirection = FlowDirection.RightToLeft,
+
+						BackgroundColor = Color.Red,
+						HeightRequest = 100,
+						LineBreakMode = LineBreakMode.WordWrap,
+						Margin = 20,
+						MaxLines = 1,
+						Opacity = 50,
+						Padding = 5,
+						TextDecorations = TextDecorations.Underline,
+						VerticalTextAlignment = TextAlignment.Center,
+						FontAttributes = FontAttributes.Bold,
+						FontSize = 20,
+						LineHeight = 3,
+						TextColor = Color.Blue,
+						TextTransform = TextTransform.Uppercase,
+						TextType = TextType.Html,
+						HorizontalTextAlignment = TextAlignment.Start
+					},
+					new Label()
+					{
+						AutomationId = "Issue3311FormattedTextLabel",
+						FormattedText = formattedString,
+						FlowDirection = FlowDirection.RightToLeft,
+
+						BackgroundColor = Color.Yellow,
+						HeightRequest = 100,
+						LineBreakMode = LineBreakMode.WordWrap,
+						Margin = 20,
+						MaxLines = 1,
+						Opacity = 50,
+						Padding = 5,
+						TextDecorations = TextDecorations.Underline,
+						VerticalTextAlignment = TextAlignment.Center,
+						FontAttributes = FontAttributes.Bold,
+						FontSize = 20,
+						LineHeight = 3,
+						TextColor = Color.Blue,
+						TextTransform = TextTransform.Uppercase,
+						HorizontalTextAlignment = TextAlignment.Start
+					}
+				}
+			};
+		}
+	}
+}

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

@@ -1689,6 +1689,11 @@
     <Compile Include="$(MSBuildThisFileDirectory)Issue8988.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue12084.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue12512.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue3311.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue12473.xaml.cs">
+      <DependentUpon>Issue12473.xaml</DependentUpon>
+      <SubType>Code</SubType>
+    </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Issue12809.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue11969.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue11381.xaml.cs" />
@@ -2076,6 +2081,9 @@
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue12084.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue12473.xaml">
+      <SubType>Designer</SubType>
+    </EmbeddedResource>
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue12809.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>

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

@@ -0,0 +1,76 @@
+using System.Threading.Tasks;
+using NUnit.Framework;
+using UIKit;
+
+namespace Xamarin.Forms.Platform.iOS.UnitTests
+{
+	[TestFixture]
+	public class LabelTests : PlatformTestFixture
+	{
+		[Test, Category("Label"), Category("RTL"), Category("FormattedText")]
+		[Description("RTL should work on Label with FormattedText")]
+		public async Task RTLWorksOnLabelWithFormattedText()
+		{
+			var formattedString = new FormattedString();
+			formattedString.Spans.Add(new Span { Text = "Label with RTL and FormattedText" });
+			var label = new Label { FormattedText = formattedString };
+			label.FlowDirection = FlowDirection.RightToLeft;
+			var expected = UITextAlignment.Right;
+			var actual = await GetControlProperty(label, uiLabel =>
+			{
+				label.BackgroundColor = Color.Yellow;
+				label.HeightRequest = 50;
+				label.LineBreakMode = LineBreakMode.WordWrap;
+				label.Margin = 20;
+				label.MaxLines = 1;
+				label.Opacity = 50;
+				label.Padding = 5;
+				label.TextDecorations = TextDecorations.Underline;
+
+				label.FontAttributes = FontAttributes.Bold;
+				label.FontSize = 20;
+				label.LineHeight = 3;
+				label.TextColor = Color.Blue;
+				label.TextTransform = TextTransform.Uppercase;
+				label.HorizontalTextAlignment = TextAlignment.Start;
+				label.VerticalTextAlignment = TextAlignment.Center;
+
+				return uiLabel.TextAlignment;
+			});
+			Assert.That(actual, Is.EqualTo(expected));
+		}
+
+		[Test, Category("Label"), Category("RTL"), Category("LineHeight")]
+		[Description("RTL should work on Label with LineHeight")]
+		public async Task RTLWorksOnLabelWithLineHeight()
+		{
+			var label = new Label { Text = "Label with RTL and LineHeight" };
+			label.FlowDirection = FlowDirection.RightToLeft;
+			label.LineHeight = 3;
+			var expected = UITextAlignment.Right;
+			var actual = await GetControlProperty(label, uiLabel =>
+			{
+				label.BackgroundColor = Color.Yellow;
+				label.HeightRequest = 50;
+				label.LineBreakMode = LineBreakMode.WordWrap;
+				label.Margin = 20;
+				label.MaxLines = 1;
+				label.Opacity = 50;
+				label.Padding = 5;
+				label.TextDecorations = TextDecorations.Underline;
+
+				label.FontAttributes = FontAttributes.Bold;
+				label.FontSize = 20;
+				label.LineHeight = 3;
+				label.TextColor = Color.Blue;
+				label.TextTransform = TextTransform.Uppercase;
+				label.TextType = TextType.Html;
+				label.HorizontalTextAlignment = TextAlignment.Start;
+				label.VerticalTextAlignment = TextAlignment.Center;
+
+				return uiLabel.TextAlignment;
+			});
+			Assert.That(actual, Is.EqualTo(expected));
+		}
+	}
+}

Xamarin.Forms.Platform.iOS.UnitTests/Xamarin.Forms.Platform.iOS.UnitTests.csproj

@@ -69,6 +69,7 @@
     <Compile Include="BackgroundTests.cs" />
     <Compile Include="TimePickerTests.cs" />
     <Compile Include="TransformationTests.cs" />
+    <Compile Include="LabelTests.cs" />
     <Compile Include="ShapeTests.cs" />
   </ItemGroup>
   <ItemGroup>

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

@@ -173,14 +173,14 @@ protected override void OnElementChanged(ElementChangedEventArgs<Label> e)
 				}
 
 				UpdateLineBreakMode();
-				UpdateHorizontalTextAlignment();
 				UpdateText();
 				UpdateTextDecorations();
 				UpdateTextColor();
 				UpdateFont();
 				UpdateMaxLines();
 				UpdateCharacterSpacing();
 				UpdatePadding();
+				UpdateHorizontalTextAlignment();
 			}
 
 			base.OnElementChanged(e);
@@ -466,6 +466,8 @@ void UpdateFormattedText()
 			Control.AttributedStringValue = _formatted.ToAttributed(Element, Element.TextColor, Element.HorizontalTextAlignment, Element.LineHeight);
 #endif
 			_perfectSizeValid = false;
+
+			UpdateHorizontalTextAlignment();
 		}
 
 		void UpdateTextHtml()