Fixed [iOS] Fix CarouselViewRemoveAt so that it's passing on both CV1…

… and CV2 sets of handlers (#25919) * Fixed [iOS] Fix CarouselViewRemoveAt so that it's passing on both CV1 and CV2 sets of handlers * modified code changes * Fixed [iOS] Fix CarouselViewRemoveAt so that it's passing on both CV1 and CV2 sets of handlers * modified code changes * Fixed test case failure
dotnet · Dec 11, 2024 · eeaf57b · eeaf57b
1 parent 07f41ae
commit eeaf57b
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Showing 2 changed files with 55 additions and 24 deletions.
diff --git a/src/Controls/src/Core/Handlers/Items/iOS/CarouselViewController.cs b/src/Controls/src/Core/Handlers/Items/iOS/CarouselViewController.cs
@@ -3,8 +3,10 @@
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Diagnostics.CodeAnalysis;
+using System.Threading.Tasks;
 using CoreGraphics;
 using Foundation;
+using Microsoft.Maui.ApplicationModel;
 using Microsoft.Maui.Devices;
 using ObjCRuntime;
 using UIKit;
@@ -104,7 +106,7 @@ public override void ViewWillLayoutSubviews()
 			UpdateVisualStates();
 		}
 
-		public override void ViewDidLayoutSubviews()
+		public override async void ViewDidLayoutSubviews()
 		{
 			base.ViewDidLayoutSubviews();
 
@@ -122,7 +124,7 @@ public override void ViewDidLayoutSubviews()
 			}
 			else
 			{
-				UpdateInitialPosition();
+				await UpdateInitialPosition();
 			}
 			_isRotating = false;
 		}
@@ -203,10 +205,11 @@ protected override void CacheCellAttributes(NSIndexPath indexPath, CGSize size)
 			base.CacheCellAttributes(NSIndexPath.FromItemSection(itemIndex, 0), size);
 		}
 
-		private protected override void AttachingToWindow()
+		private protected override async void AttachingToWindow()
 		{
 			base.AttachingToWindow();
 			Setup(ItemsView);
+			await UpdateInitialPosition();
 		}
 
 		private protected override void DetachingFromWindow()
@@ -220,7 +223,7 @@ private protected override void DetachingFromWindow()
 		void TearDown(CarouselView carouselView)
 		{
 			_oldViews = null;
-
+			InitialPositionSet = false;
 			carouselView.Scrolled -= CarouselViewScrolled;
 			DeviceDisplay.MainDisplayInfoChanged -= OnDisplayInfoChanged;
 
@@ -446,7 +449,7 @@ void ScrollToPosition(int goToPosition, int carouselPosition, bool animate, bool
 
 		void SetPosition(int position)
 		{
-			if (position == -1 || ItemsView is not CarouselView carousel)
+			if (!InitialPositionSet || position == -1 || ItemsView is not CarouselView carousel)
 			{
 				return;
 			}
@@ -478,6 +481,9 @@ void SetCurrentItem(int carouselPosition)
 
 		internal void UpdateFromCurrentItem()
 		{
+			if (!InitialPositionSet)
+				return;
+
 			if (ItemsView is not CarouselView carousel)
 			{
 				return;
@@ -497,6 +503,11 @@ internal void UpdateFromCurrentItem()
 
 		internal void UpdateFromPosition()
 		{
+			if (!InitialPositionSet)
+			{
+				return;
+			}
+
 			if (ItemsView is not CarouselView carousel)
 			{
 				return;
@@ -520,8 +531,12 @@ internal void UpdateFromPosition()
 			SetCurrentItem(carouselPosition);
 		}
 
-		void UpdateInitialPosition()
+		async Task UpdateInitialPosition()
 		{
+			if (ItemsView is not CarouselView carousel)
+			{
+				return;
+			}
 			var itemsCount = ItemsSource?.ItemCount;
 
 			if (itemsCount == 0)
@@ -531,28 +546,44 @@ void UpdateInitialPosition()
 
 			if (!InitialPositionSet)
 			{
-				if (ItemsView is not CarouselView carousel)
-				{
-					return;
-				}
-
-				InitialPositionSet = true;
-
 				int position = carousel.Position;
 				var currentItem = carousel.CurrentItem;
+
 				if (currentItem != null)
 				{
-					position = ItemsSource.GetIndexForItem(currentItem).Row;
-				}
-				else
-				{
-					SetCurrentItem(position);
-				}
+					// Sometimes the item could be just being removed while we navigate back to the CarouselView
+					var positionCurrentItem = ItemsSource.GetIndexForItem(currentItem).Row;
+					if (positionCurrentItem != -1)
+					{
+						position = positionCurrentItem;
+					}
+				}				
 
-				carousel.ScrollTo(position, -1, Microsoft.Maui.Controls.ScrollToPosition.Center, false);
+				await Task.Delay(100).ContinueWith((t) =>
+				{
+					MainThread.BeginInvokeOnMainThread(() =>
+					{
+						if (!IsViewLoaded)
+						{
+							return;
+						}
+
+						InitialPositionSet = true;
+
+						if (ItemsSource is null || ItemsSource.ItemCount == 0)
+						{
+							return;
+						}
+
+
+						carousel.ScrollTo(position, -1, Microsoft.Maui.Controls.ScrollToPosition.Center, false);
+
+						SetCurrentItem(position);
+						UpdateVisualStates();
+					});
+
+				});
 			}
-
-			UpdateVisualStates();
 		}
 
 		void UpdateVisualStates()

diff --git a/src/Controls/tests/TestCases.HostApp/Issues/CarouselViewRemoveAt.cs b/src/Controls/tests/TestCases.HostApp/Issues/CarouselViewRemoveAt.cs
@@ -6,7 +6,7 @@ namespace Maui.Controls.Sample.Issues
 	[Issue(IssueTracker.None, 10300, "ObservableCollection.RemoveAt(index) with a valid index raises ArgumentOutOfRangeException", PlatformAffected.iOS)]
 	public class CarouselViewRemoveAt : ContentPage
 	{
-		readonly CarouselView2 _carousel;
+		readonly CarouselView _carousel;
 
 		public class ModalPage : ContentPage
 		{
@@ -47,7 +47,7 @@ public CarouselViewRemoveAt()
 				new ModelCarouselViewRemoveAt("8", Colors.IndianRed),
 				new ModelCarouselViewRemoveAt("9", Colors.Khaki),
 			});
-			_carousel = new CarouselView2
+			_carousel = new CarouselView
 			{
 				ItemTemplate = new DataTemplate(() =>
 			{