[Testing] Add UITest for Issue30147 on iOS (#30506)

* fix added

* Revert "fix added"

This reverts commit 138797f.

* test case added

* test sample modified

* test sample updated

* affected platform changed

* sample changes added

Author: devanathan-vaithiyanathan

src/Controls/tests/TestCases.HostApp/Issues/Issue30147.cs

@@ -0,0 +1,166 @@
+#if IOS
+using UIKit;
+using CoreGraphics;
+using Microsoft.Maui.Handlers;
+#endif
+
+namespace Maui.Controls.Sample.Issues;
+
+
+[Issue(IssueTracker.Github, 30147, "MauiScrollView resets ContentOffset on first layout pass", PlatformAffected.iOS)]
+public class Issue30147 : ContentPage
+{
+    Issue30147CustomScrollView myScroll;
+    Label offsetLabel;
+
+    public Issue30147()
+    {
+        Title = "Issue 30147";
+        
+        // Create the Label to display scroll offset
+        offsetLabel = new Label
+        {
+            Text = "0",
+			AutomationId = "OffsetLabel",
+            FontSize = 18
+        };
+        
+        // Create Header with offset display
+        var headerLayout = new HorizontalStackLayout
+        {
+            Padding = new Thickness(20),
+            BackgroundColor = Colors.LightGray,
+            Children =
+            {
+                new Label
+                {
+                    Text = "Offset: X = ",
+                    FontSize = 18
+                },
+                offsetLabel
+            }
+        };
+        
+        // Create the CustomScrollView
+        myScroll = new Issue30147CustomScrollView
+        {
+            Orientation = ScrollOrientation.Horizontal
+        };
+        
+        // Add the event handler for offset changes
+        myScroll.OffsetChanged += (s, e) =>
+        {
+            offsetLabel.Text = e.X.ToString();
+        };
+        
+        // Create the content for the scroll view
+        var scrollContent = new StackLayout();
+        scrollContent.Add(new BoxView { Color = Colors.Red, HeightRequest = 300, WidthRequest = 2000 });
+        
+        myScroll.Content = scrollContent;
+        
+        // Create the Grid layout
+        var grid = new Grid
+        {
+            RowDefinitions =
+            {
+                new RowDefinition { Height = GridLength.Auto },
+                new RowDefinition { Height = GridLength.Star }
+            }
+        };
+        
+        grid.Add(headerLayout, 0, 0);
+        grid.Add(myScroll, 0, 1);
+        
+        // Set the page content
+        Content = grid;
+    }
+}
+
+public class Issue30147ScrollOffsetChangedEventArgs : EventArgs
+{
+	public double X { get; }
+	public double Y { get; }
+
+	public Issue30147ScrollOffsetChangedEventArgs(double x, double y)
+	{
+		X = x;
+		Y = y;
+	}
+}
+
+// Custom ScrollView class for tracking offset changes
+public class Issue30147CustomScrollView : ScrollView
+{
+    public event EventHandler<Issue30147ScrollOffsetChangedEventArgs> OffsetChanged;
+
+    // Raise the event from platform-specific code
+    internal void RaiseOffsetChanged(double x, double y)
+    {
+        OffsetChanged?.Invoke(this, new Issue30147ScrollOffsetChangedEventArgs(x, y));
+    }
+}
+
+#if IOS
+public class Issue30147CustomMauiScrollView : Microsoft.Maui.Platform.MauiScrollView
+{
+    CGPoint _previousOffset = new(-1, -1);
+    Issue30147CustomScrollView _virtualView;
+
+    public Issue30147CustomMauiScrollView(Issue30147CustomScrollView virtualView)
+    {
+        _virtualView = virtualView;
+    }
+
+    public override void SetContentOffset(CGPoint contentOffset, bool animated)
+    {
+        base.SetContentOffset(contentOffset, animated);
+        NotifyOffsetChanged(contentOffset);
+    }
+
+    public override CGPoint ContentOffset 
+    {
+        get => base.ContentOffset;
+        set 
+        {
+            base.ContentOffset = value;
+            NotifyOffsetChanged(value);
+        }
+    }
+
+    void NotifyOffsetChanged(CGPoint offset)
+    {
+        if (_previousOffset.X != offset.X || _previousOffset.Y != offset.Y)
+        {
+            _previousOffset = offset;
+            _virtualView?.RaiseOffsetChanged(offset.X, offset.Y);
+        }
+    }
+}
+
+public class Issue30147CustomScrollViewHandler : ScrollViewHandler
+{
+    bool _initialOffsetApplied = false;
+    
+    protected override UIScrollView CreatePlatformView()
+    {
+        if (VirtualView is Issue30147CustomScrollView customScrollView)
+        {
+            return new Issue30147CustomMauiScrollView(customScrollView);
+        }
+
+        return base.CreatePlatformView();
+    }
+
+    public override void PlatformArrange(Rect frame)
+    {
+        base.PlatformArrange(frame);
+        
+        if (!_initialOffsetApplied)
+        {
+            PlatformView.ContentOffset = new CGPoint(500, 0);
+            _initialOffsetApplied = true;
+        }
+    } 
+}
+#endif

src/Controls/tests/TestCases.HostApp/MauiProgram.cs

@@ -50,6 +50,9 @@ public static MauiApp CreateMauiApp()
 				handlers.AddHandler(typeof(UITestEditor), typeof(UITestEditorHandler));
 				handlers.AddHandler(typeof(UITestEntry), typeof(UITestEntryHandler));
 				handlers.AddHandler(typeof(UITestSearchBar), typeof(UITestSearchBarHandler));
+#endif
+#if IOS
+				handlers.AddHandler(typeof(Issue30147CustomScrollView), typeof(Issue30147CustomScrollViewHandler));
 #endif
 			});
 

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue30147.cs

@@ -0,0 +1,24 @@
+#if IOS  // The issue is specific to iOS, so restricting other platforms
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue30147 : _IssuesUITest
+{
+	public override string Issue => "MauiScrollView resets ContentOffset on first layout pass";
+
+	public Issue30147(TestDevice device)
+	: base(device)
+	{ }
+
+	[Test]
+	[Category(UITestCategories.ScrollView)]
+	public void VerifyScrollViewContentOffsetValue()
+	{
+		App.WaitForElement("OffsetLabel");
+		Assert.That(App.FindElement("OffsetLabel").GetText(), Is.EqualTo("500"));
+	}
+}
+#endif