[iOS/MacCatalyst] Fix CollectionView ScrollTo for horizontal layouts

src/Controls/src/Core/Handlers/Items2/ItemsViewHandler2.iOS.cs

@@ -146,7 +146,8 @@ protected virtual void ScrollToRequested(object sender, ScrollToRequestEventArgs
 					return;
 				}
 
-				var position = Items.ScrollToPositionExtensions.ToCollectionViewScrollPosition(args.ScrollToPosition, UICollectionViewScrollDirection.Vertical);
+				var scrollDirection = Controller.GetScrollDirection();
+				var position = Items.ScrollToPositionExtensions.ToCollectionViewScrollPosition(args.ScrollToPosition, scrollDirection);
 
 				Controller.CollectionView.ScrollToItem(indexPath,
 					position, args.IsAnimated);

src/Controls/tests/TestCases.HostApp/Issues/Issue33852.cs

@@ -0,0 +1,85 @@
+using System.Collections.ObjectModel;
+
+namespace Maui.Controls.Sample.Issues;
+
+[Issue(IssueTracker.Github, 33852, "CollectionView ScrollTo does not work with horizontal layout", PlatformAffected.iOS | PlatformAffected.macOS)]
+public class Issue33852 : ContentPage
+{
+	public ObservableCollection<string> Items { get; set; }
+	private Label _indexLabel;
+	private CollectionView2 _collectionView;
+	public Issue33852()
+	{
+		Items = new ObservableCollection<string>();
+		for (int i = 0; i <= 50; i++)
+		{
+			Items.Add($"Item_{i}");
+		}
+
+		_indexLabel = new Label
+		{
+			AutomationId = "IndexLabel",
+			Text = "ItemIndex: 0"
+		};
+
+		var scrollToButton = new Button
+		{
+			AutomationId = "ScrollToButton",
+			Text = "Scroll to Item 15",
+			WidthRequest = 150
+		};
+		scrollToButton.Clicked += OnScrollToButtonClicked;
+
+		_collectionView = new CollectionView2
+		{
+			AutomationId = "TestCollectionView",
+			ItemsSource = Items,
+			HeightRequest = 600,
+			ItemsLayout = new LinearItemsLayout(ItemsLayoutOrientation.Horizontal)
+			{
+				ItemSpacing = 10
+			},
+			ItemTemplate = new DataTemplate(() =>
+			{
+				var label = new Label();
+				label.SetBinding(Label.TextProperty, ".");
+				return new Border
+				{
+					Margin = new Thickness(5),
+					Padding = new Thickness(10),
+					Stroke = Colors.Gray,
+					Content = label
+				};
+			})
+		};
+
+		_collectionView.Scrolled += OnCollectionViewScrolled;
+
+		Content = new StackLayout
+		{
+			Children =
+			{
+				_indexLabel,
+				 scrollToButton,
+				_collectionView
+			}
+		};
+	}
+
+	private void OnCollectionViewScrolled(object sender, ItemsViewScrolledEventArgs e)
+	{
+		if (e.FirstVisibleItemIndex > 0)
+		{
+			_indexLabel.Text = $"The CollectionView is scrolled";
+		}
+		else
+		{
+			_indexLabel.Text = "The CollectionView does not scroll";
+		}
+	}
+
+	private void OnScrollToButtonClicked(object sender, EventArgs e)
+	{
+		_collectionView.ScrollTo(15, position: ScrollToPosition.Start, animate: true);
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue33852.cs

@@ -0,0 +1,24 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues;
+
+public class Issue33852 : _IssuesUITest
+{
+    public Issue33852(TestDevice testDevice) : base(testDevice)
+    {
+    }
+
+    public override string Issue => "CollectionView ScrollTo does not work with horizontal layout";
+
+    [Test]
+    [Category(UITestCategories.CollectionView)]
+    public void ProgrammaticScrollToWorksWithHorizontalLayout()
+    {
+        App.WaitForElement("ScrollToButton");
+        App.Tap("ScrollToButton");
+        var firstIndexText = App.FindElement("IndexLabel").GetText();
+        Assert.That(firstIndexText, Is.EqualTo("The CollectionView is scrolled"));
+    }
+}