[iOS] ScrollView content offset RTL - fix

src/Controls/tests/TestCases.HostApp/Issues/Issue29458.xaml

@@ -0,0 +1,109 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+			 xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+			 xmlns:local="clr-namespace:Maui.Controls.Sample.Issues"
+			 x:Class="Maui.Controls.Sample.Issues.Issue29458">
+	<VerticalStackLayout>
+
+		<ScrollView
+			AutomationId="RTLScrollView"
+			x:Name="RTLScrollView"
+			Orientation="Horizontal"
+			FlowDirection="RightToLeft">
+			<HorizontalStackLayout>
+
+				<Border BackgroundColor="Red"
+						HeightRequest="48"
+						WidthRequest="200">
+					<Label Text="Tab1"
+						   HorizontalOptions="Center"
+						   VerticalOptions="Center"/>
+				</Border>
+
+				<Border BackgroundColor="Blue"
+						HeightRequest="48"
+						WidthRequest="200">
+					<Label Text="Tab2"
+						   HorizontalOptions="Center"
+						   VerticalOptions="Center"/>
+				</Border>
+
+				<Border BackgroundColor="Red"
+						HeightRequest="48"
+						WidthRequest="200">
+					<Label Text="Tab3"
+						   HorizontalOptions="Center"
+						   VerticalOptions="Center"/>
+				</Border>
+
+				<Border BackgroundColor="Blue"
+						HeightRequest="48"
+						WidthRequest="200">
+					<Label Text="Tab4"
+						   HorizontalOptions="Center"
+						   VerticalOptions="Center"/>
+				</Border>
+
+
+				<Border BackgroundColor="Red"
+						HeightRequest="48"
+						WidthRequest="200">
+					<Label Text="Tab5"
+						   AutomationId="Tab5RTL"
+						   HorizontalOptions="Center"
+						   VerticalOptions="Center"/>
+				</Border>
+			</HorizontalStackLayout>
+		</ScrollView>
+
+		<ScrollView
+			AutomationId="LTRScrollView"
+			x:Name="LTRScrollView"
+			Orientation="Horizontal"
+			FlowDirection="LeftToRight">
+			<HorizontalStackLayout>
+
+				<Border BackgroundColor="Red"
+						HeightRequest="48"
+						WidthRequest="200">
+					<Label Text="Tab1"
+						   HorizontalOptions="Center"
+						   VerticalOptions="Center"/>
+				</Border>
+
+				<Border BackgroundColor="Blue"
+						HeightRequest="48"
+						WidthRequest="200">
+					<Label Text="Tab2"
+						   HorizontalOptions="Center"
+						   VerticalOptions="Center"/>
+				</Border>
+
+				<Border BackgroundColor="Red"
+						HeightRequest="48"
+						WidthRequest="200">
+					<Label Text="Tab3"
+						   HorizontalOptions="Center"
+						   VerticalOptions="Center"/>
+				</Border>
+
+				<Border BackgroundColor="Blue"
+						HeightRequest="48"
+						WidthRequest="200">
+					<Label Text="Tab4"
+						   HorizontalOptions="Center"
+						   VerticalOptions="Center"/>
+				</Border>
+
+				<Border BackgroundColor="Red"
+						HeightRequest="48"
+						WidthRequest="200">
+					<Label Text="Tab5"
+						   AutomationId="Tab5LTR"
+						   HorizontalOptions="Center"
+						   VerticalOptions="Center"/>
+				</Border>
+			</HorizontalStackLayout>
+		</ScrollView>
+	</VerticalStackLayout>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue29458.xaml.cs

@@ -0,0 +1,10 @@
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 29458, "ScrollView content offset shifts unexpectedly when FlowDirection is set to RightToLeft")]
+public partial class Issue29458 : ContentPage
+{
+	public Issue29458()
+	{
+		InitializeComponent();
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue29458.cs

@@ -0,0 +1,28 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue29458 : _IssuesUITest
+{
+	public Issue29458(TestDevice testDevice) : base(testDevice)
+	{
+	}
+
+	public override string Issue => "ScrollView content offset shifts unexpectedly when FlowDirection is set to RightToLeft";
+
+	[Test]
+	[Category(UITestCategories.ScrollView)]
+	public void ScrollViewShouldWorkInRTL()
+	{
+		App.WaitForElement("RTLScrollView");
+		for (int i = 0; i < 3; i++)
+		{
+			App.ScrollLeft("RTLScrollView");
+			App.ScrollRight("LTRScrollView");
+		}
+		App.WaitForElement("Tab5RTL");
+		App.WaitForElement("Tab5LTR");
+	}
+}

src/Core/src/Platform/iOS/MauiScrollView.cs

@@ -51,6 +51,20 @@ public override void LayoutSubviews()
 				var crossPlatformContentSize = crossPlatformLayout.CrossPlatformArrange(new Rect(new Point(), crossPlatformBounds));
 				var contentSize = crossPlatformContentSize.ToCGSize();
 
+				// For Right-To-Left (RTL) layouts, we need to adjust the content arrangement and offset
+				// to ensure the content is correctly aligned and scrolled. This involves a second layout
+				// arrangement with an adjusted starting point and recalculating the content offset.
+				if (EffectiveUserInterfaceLayoutDirection == UIUserInterfaceLayoutDirection.RightToLeft)
+				{
+					var horizontalOffset = contentSize.Width - crossPlatformBounds.Width;
+					crossPlatformLayout.CrossPlatformArrange(new Rect(new Point(-horizontalOffset, 0), crossPlatformBounds));
+					ContentOffset = new CGPoint(horizontalOffset, 0);
+				}
+				else
+				{
+					ContentOffset = CGPoint.Empty;
+				}
+
 				// When the content size changes, we need to adjust the scrollable area size so that the content can fit in it.
 				if (ContentSize != contentSize)
 				{