Removes MeasureInvalidated virtual event from iOS Shell renderers

src/Controls/src/Core/Compatibility/Handlers/Shell/iOS/ShellFlyoutContentRenderer.cs

@@ -1,6 +1,10 @@
 #nullable disable
 using System;
 using System.ComponentModel;
+using CoreGraphics;
+using Microsoft.Maui.Controls.Platform;
+using Microsoft.Maui.Graphics;
+using ObjCRuntime;
 using UIKit;
 
 namespace Microsoft.Maui.Controls.Platform.Compatibility
@@ -131,11 +135,12 @@ void UpdateFlyoutFooter(View view)
 
 			if (_footer is not null)
 			{
-				_footerView = new ShellFlyoutFooterContainer(_footer);
+				_footerView = new UIContainerView(_footer);
 				_uIViews[FooterIndex] = _footerView;
 				AddViewInCorrectOrder(_footerView, previousIndex);
 
 				_footerView.ClipsToBounds = true;
+				_footerView.PlatformMeasureInvalidated += OnFooterMeasureInvalidated;
 			}
 
 			_tableViewController.FooterView = _footerView;
@@ -181,10 +186,45 @@ void AddViewInCorrectOrder(UIView newView, int previousIndex)
 			View.AddSubview(newView);
 		}
 
+		void OnFooterMeasureInvalidated(object sender, System.EventArgs e)
+		{
+			ReMeasureFooter();
+		}
+
+		void ReMeasureFooter()
+		{
+			var size = _footerView?.SizeThatFits(new CGSize(View.Frame.Width, double.PositiveInfinity));
+			if (size is not null)
+				UpdateFooterPosition(size.Value.Height);
+		}
+
+		void UpdateFooterPosition()
+		{
+			if (_footerView is null)
+				return;
+
+			if (double.IsNaN(_footerView.MeasuredHeight))
+				ReMeasureFooter();
+			else
+				UpdateFooterPosition((nfloat)_footerView.MeasuredHeight);
+		}
+
+		void UpdateFooterPosition(nfloat footerHeight)
+		{
+			if (_footerView is null && !nfloat.IsNaN(footerHeight))
+				return;
+
+			var footerWidth = View.Frame.Width;
+
+			_footerView.Frame = new CoreGraphics.CGRect(0, View.Frame.Height - footerHeight, footerWidth, footerHeight);
+
+			_tableViewController.LayoutParallax();
+		}
+
 		public override void ViewWillLayoutSubviews()
 		{
 			base.ViewWillLayoutSubviews();
-			_tableViewController.LayoutParallax();
+			UpdateFooterPosition();
 			UpdateFlyoutContent();
 		}
 
@@ -273,6 +313,11 @@ public override void ViewDidLayoutSubviews()
 			_bgImage.Frame = View.Bounds;
 		}
 
+		public override void LoadView()
+		{
+			View = new UIContainerViewContainer();
+		}
+
 		public override void ViewDidLoad()
 		{
 			base.ViewDidLoad();
@@ -317,7 +362,7 @@ void UpdateFlyoutContent()
 
 			_uIViews[ContentIndex] = _shellFlyoutContentManager.ContentView;
 			AddViewInCorrectOrder(_uIViews[ContentIndex], previousIndex);
-			_shellFlyoutContentManager.UpdateHeaderSize();
+			_shellFlyoutContentManager.UpdateLayout();
 		}
 
 		public override void ViewWillAppear(bool animated)

src/Controls/src/Core/Compatibility/Handlers/Shell/iOS/ShellFlyoutHeaderContainer.cs

@@ -34,21 +34,13 @@ public override Thickness Margin
 			}
 		}
 
-		public override void LayoutSubviews()
-		{
-			if (!UpdateSafeAreaMargin())
-				base.LayoutSubviews();
-
-			OnHeaderSizeChanged();
-		}
-
 		public override void SafeAreaInsetsDidChange()
 		{
 			UpdateSafeAreaMargin();
 			base.SafeAreaInsetsDidChange();
 		}
 
-		bool UpdateSafeAreaMargin()
+		void UpdateSafeAreaMargin()
 		{
 			var safeArea = UIApplication.SharedApplication.GetSafeAreaInsetsForWindow();
 
@@ -64,12 +56,8 @@ bool UpdateSafeAreaMargin()
 						safeArea.Right,
 						safeArea.Bottom);
 
-				OnHeaderSizeChanged();
-				return true;
+				OnPlatformMeasureInvalidated();
 			}
-
-			return false;
-
 		}
 	}
 }

src/Controls/src/Core/Compatibility/Handlers/Shell/iOS/ShellFlyoutLayoutManager.cs

@@ -16,7 +16,7 @@ class ShellFlyoutLayoutManager
 		UIView _contentView;
 		UIScrollView ScrollView { get; set; }
 		UIContainerView _headerView;
-		UIView _footerView;
+		UIContainerView _footerView;
 		double _headerSize;
 		readonly IShellContext _context;
 		Action removeScrolledEvent;
@@ -142,7 +142,7 @@ private set
 					ScrollView.ContentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentBehavior.Never;
 				}
 
-				UpdateHeaderSize();
+				UpdateLayout();
 			}
 		}
 
@@ -155,40 +155,61 @@ public virtual UIContainerView HeaderView
 					return;
 
 				if (_headerView is not null)
-					_headerView.HeaderSizeChanged -= OnHeaderViewMeasureChanged;
+					_headerView.PlatformMeasureInvalidated -= OnHeaderViewMeasureChanged;
 
 				_headerView = value;
 
 				if (_headerView is not null)
-					_headerView.HeaderSizeChanged += OnHeaderViewMeasureChanged;
+					_headerView.PlatformMeasureInvalidated += OnHeaderViewMeasureChanged;
 
-				UpdateHeaderSize();
+				UpdateLayout();
 			}
 		}
 
-		public virtual UIView FooterView
+		public virtual UIContainerView FooterView
 		{
 			get => _footerView;
 			set
 			{
 				if (_footerView == value)
 					return;
 
+				if (_footerView is not null)
+					_footerView.PlatformMeasureInvalidated -= OnFooterViewMeasureChanged;
+
 				_footerView = value;
-				UpdateHeaderSize();
+
+				if (_footerView is not null)
+					_footerView.PlatformMeasureInvalidated += OnFooterViewMeasureChanged;
+
+				UpdateLayout();
 			}
 		}
 
+		void OnFooterViewMeasureChanged(object sender, EventArgs e)
+		{
+			if (FooterView is null || ContentView?.Superview is not { } flyoutView)
+				return;
+
+			var flyoutFrame = flyoutView.Frame;
+			var widthConstraint = flyoutFrame.Width;
+			var heightConstraint = flyoutFrame.Height;
+			var size = FooterView.SizeThatFits(new CGSize(widthConstraint, double.PositiveInfinity));
+			FooterView.Frame = new CGRect(0, heightConstraint - size.Height, widthConstraint, size.Height);
+
+			UpdateLayout();
+		}
+
 		void OnHeaderViewMeasureChanged(object sender, EventArgs e)
 		{
 			if (HeaderView is null || ContentView?.Superview is null)
 				return;
 
 			HeaderView.SizeThatFits(new CGSize(ContentView.Superview.Frame.Width, double.PositiveInfinity));
-			UpdateHeaderSize();
+			UpdateLayout();
 		}
 
-		internal void UpdateHeaderSize()
+		internal void UpdateLayout()
 		{
 			if (HeaderView is null || ContentView?.Superview is null)
 				return;
@@ -365,7 +386,7 @@ void OnShellPropertyChanged(object sender, PropertyChangedEventArgs e)
 
 		public void ViewDidLoad()
 		{
-			UpdateHeaderSize();
+			UpdateLayout();
 		}
 
 		public void OnScrolled(nfloat contentOffsetY)

src/Controls/src/Core/Compatibility/Handlers/Shell/iOS/ShellTableViewController.cs

@@ -51,10 +51,11 @@ public virtual UIContainerView HeaderView
 			set => ShellFlyoutContentManager.HeaderView = value;
 		}
 
+		// TODO: .NET10 change to UIContainerView
 		public virtual UIView FooterView
 		{
 			get => ShellFlyoutContentManager.FooterView;
-			set => ShellFlyoutContentManager.FooterView = value;
+			set => ShellFlyoutContentManager.FooterView = value as UIContainerView;
 		}
 
 		protected ShellTableViewSource CreateShellTableViewSource()

src/Controls/src/Core/Compatibility/Handlers/Shell/iOS/ShellTableViewSource.cs

@@ -178,16 +178,10 @@ public override UITableViewCell GetCell(UITableView tableView, NSIndexPath index
 			_cells[context] = cell;
 			cell.TableView = tableView;
 			cell.IndexPath = indexPath;
-			cell.ViewMeasureInvalidated += OnViewMeasureInvalidated;
 
 			return cell;
 		}
 
-		void OnViewMeasureInvalidated(UIContainerCell cell)
-		{
-			cell.ReloadRow();
-		}
-
 		public override nfloat GetHeightForFooter(UITableView tableView, nint section)
 		{
 			if (section < Groups.Count - 1)

src/Controls/src/Core/Compatibility/Handlers/Shell/iOS/UIContainerCell.cs

@@ -6,19 +6,17 @@
 
 namespace Microsoft.Maui.Controls.Platform.Compatibility
 {
-	public class UIContainerCell : UITableViewCell
+	public class UIContainerCell : UITableViewCell, IPlatformMeasureInvalidationController
 	{
 		IPlatformViewHandler _renderer;
 		object _bindingContext;
 
-		internal Action<UIContainerCell> ViewMeasureInvalidated { get; set; }
 		internal NSIndexPath IndexPath { get; set; }
 		internal UITableView TableView { get; set; }
 
 		internal UIContainerCell(string cellId, View view, Shell shell, object context) : base(UITableViewCellStyle.Default, cellId)
 		{
 			View = view;
-			View.MeasureInvalidated += MeasureInvalidated;
 			SelectionStyle = UITableViewCellSelectionStyle.None;
 
 			_renderer = (IPlatformViewHandler)view.Handler;
@@ -43,16 +41,20 @@ internal UIContainerCell(string cellId, View view, Shell shell, object context)
 				shell.AddLogicalChild(View);
 		}
 
-		public UIContainerCell(string cellId, View view) : this(cellId, view, null, null)
+		void IPlatformMeasureInvalidationController.InvalidateAncestorsMeasuresWhenMovedToWindow()
 		{
 		}
 
-		void MeasureInvalidated(object sender, System.EventArgs e)
+		void IPlatformMeasureInvalidationController.InvalidateMeasure(bool isPropagating)
 		{
-			if (View == null || TableView == null)
-				return;
+			if (isPropagating)
+			{
+				ReloadRow();
+			}
+		}
 
-			ViewMeasureInvalidated?.Invoke(this);
+		public UIContainerCell(string cellId, View view) : this(cellId, view, null, null)
+		{
 		}
 
 		internal void ReloadRow()
@@ -62,8 +64,6 @@ internal void ReloadRow()
 
 		internal void Disconnect(Shell shell = null, bool keepRenderer = false)
 		{
-			ViewMeasureInvalidated = null;
-			View.MeasureInvalidated -= MeasureInvalidated;
 			if (_bindingContext != null && _bindingContext is BaseShellItem baseShell)
 				baseShell.PropertyChanged -= OnElementPropertyChanged;