Ported pending fixes from Xamarin.Forms

src/Compatibility/Core/src/Android/CollectionView/ItemContentView.cs

@@ -55,6 +55,7 @@ internal void Recycle()
 				RemoveView(Content.View);
 			}
 
+			Content?.Dispose();
 			Content = null;
 			_size = null;
 		}

src/Compatibility/Core/src/Android/Renderers/ListViewAdapter.cs

@@ -612,6 +612,10 @@ void OnDataChanged()
 				// we need to reset the ListView's adapter to reflect the changes on page B
 				// If there header and footer are present at the reset time of the adapter
 				// they will be DOUBLE added to the ViewGround (the ListView) causing indexes to be off by one. 
+
+				if (_realListView.IsDisposed())
+					return;
+
 				_realListView.RemoveHeaderView(HeaderView);
 				_realListView.RemoveFooterView(FooterView);
 				_realListView.Adapter = _realListView.Adapter;

src/Compatibility/Core/src/Android/VisualElementTracker.cs

@@ -412,8 +412,13 @@ void UpdateScale()
 			VisualElement view = _renderer.Element;
 			AView aview = _renderer.View;
 
-			aview.ScaleX = (float)view.Scale * (float)view.ScaleX;
-			aview.ScaleY = (float)view.Scale * (float)view.ScaleY;
+			var scale = view.Scale;
+
+			if (double.IsNaN(scale))
+				return;
+
+			aview.ScaleX = (float)scale * (float)view.ScaleX;
+			aview.ScaleY = (float)scale * (float)view.ScaleY;
 		}
 
 		[PortHandler]

src/Compatibility/Core/src/Windows/CellControl.cs

@@ -334,17 +334,10 @@ void SetCell(object newContext)
 			// If there is a ListView, load the Cell content from the ItemTemplate.
 			// Otherwise, the given Cell is already a templated Cell from a TableView.
 			ListView lv = _listView.Value;
+
 			if (lv != null)
 			{
-				// 🚀 If there is an old cell, check if it was a group header
-				// we need this later to know whether we can recycle this cell
-				bool? wasGroupHeader = null;
-				var oldCell = Cell;
-				if (oldCell != null)
-				{
-					wasGroupHeader = oldCell.GetIsGroupHeader<ItemsView<Cell>, Cell>();
-				}
-
+				Cell oldCell = Cell;
 				bool isGroupHeader = IsGroupHeader;
 				DataTemplate template = isGroupHeader ? lv.GroupHeaderTemplate : lv.ItemTemplate;
 				object bindingContext = newContext;
@@ -362,15 +355,8 @@ void SetCell(object newContext)
 						sameTemplate = oldTemplate == template;
 					}
 				}
-				// 🚀 if there is no datatemplateselector, we now verify if the old cell
-				// was a groupheader and whether the new one is as well.
-				// Again, this is only to verify we can reuse this cell
-				else if (wasGroupHeader.HasValue)
-				{
-					sameTemplate = wasGroupHeader == isGroupHeader;
-				}
 
-				// reuse cell
+				// Reuse cell
 				var canReuseCell = Cell != null && sameTemplate;
 
 				// 🚀 If we can reuse the cell, just reuse it...
@@ -407,7 +393,8 @@ void SetCell(object newContext)
 
 			if (Cell != cell)
 				Cell = cell;
-			// 🚀 even if the cell did not change, we **must** call SendDisappearing() and SendAppearing()
+
+			// 🚀 Even if the cell did not change, we **must** call SendDisappearing() and SendAppearing()
 			// because frameworks such as Reactive UI rely on this! (this.WhenActivated())
 			else if (Cell != null)
 			{

src/Compatibility/Core/src/Windows/FontImageSourceHandler.cs

@@ -35,7 +35,7 @@ public sealed class FontImageSourceHandler : IImageSourceHandler, IIconElementHa
 			{
 				FontFamily = GetFontSource(fontsource),
 				FontSize = (float)fontsource.Size,
-				HorizontalAlignment = CanvasHorizontalAlignment.Center,
+				HorizontalAlignment = CanvasHorizontalAlignment.Left,
 				VerticalAlignment = CanvasVerticalAlignment.Center,
 				Options = CanvasDrawTextOptions.Default
 			};
@@ -51,9 +51,7 @@ public sealed class FontImageSourceHandler : IImageSourceHandler, IIconElementHa
 					var iconcolor = (fontsource.Color != null ? fontsource.Color : Colors.White).ToWindowsColor();
 
 					// offset by 1 as we added a 1 inset
-					var x = (float)layout.DrawBounds.X * -1;
-
-					ds.DrawTextLayout(layout, x, 1f, iconcolor);
+					ds.DrawTextLayout(layout, 1f, 1f, iconcolor);
 				}
 
 				return Task.FromResult((UI.Xaml.Media.ImageSource)imageSource);

src/Compatibility/Core/src/iOS/CollectionView/ItemsViewController.cs

@@ -19,7 +19,7 @@ public abstract class ItemsViewController<TItemsView> : UICollectionViewControll
 		public TItemsView ItemsView { get; }
 		protected ItemsViewLayout ItemsViewLayout { get; set; }
 		bool _initialized;
-		bool _isEmpty;
+		bool _isEmpty = true;
 		bool _emptyViewDisplayed;
 		bool _disposed;
 
@@ -212,6 +212,7 @@ public virtual void UpdateItemsSource()
 		{
 			_measurementCells.Clear();
 			ItemsViewLayout?.ClearCellSizeCache();
+			ItemsSource?.Dispose();
 			ItemsSource = CreateItemsViewSource();
 			CollectionView.ReloadData();
 			CollectionView.CollectionViewLayout.InvalidateLayout();
@@ -470,7 +471,14 @@ void AlignEmptyView()
 				return;
 			}
 
-			if (CollectionView.EffectiveUserInterfaceLayoutDirection == UIUserInterfaceLayoutDirection.RightToLeft)
+			bool isRtl;
+
+			if (PlatformVersion.IsAtLeast(10))
+				isRtl = CollectionView.EffectiveUserInterfaceLayoutDirection == UIUserInterfaceLayoutDirection.RightToLeft;
+			else
+				isRtl = CollectionView.SemanticContentAttribute == UISemanticContentAttribute.ForceRightToLeft;
+
+			if (isRtl)
 			{
 				if (_emptyUIView.Transform.A == -1)
 				{
@@ -621,6 +629,7 @@ internal protected virtual void UpdateVisibility()
 			{
 				if (CollectionView.Hidden)
 				{
+					CollectionView.ReloadData();
 					CollectionView.Hidden = false;
 					Layout.InvalidateLayout();
 					CollectionView.LayoutIfNeeded();

src/Compatibility/Core/src/iOS/CollectionView/ObservableItemsSource.cs

@@ -106,7 +106,8 @@ void CollectionChanged(object sender, NotifyCollectionChangedEventArgs args)
 		void CollectionChanged(NotifyCollectionChangedEventArgs args)
 		{
 			// Force UICollectionView to get the internal accounting straight 
-			CollectionView.NumberOfItemsInSection(_section);
+			if (!CollectionView.Hidden)
+				CollectionView.NumberOfItemsInSection(_section);
 
 			switch (args.Action)
 			{

src/Compatibility/Core/src/iOS/CollectionView/TemplatedCell.cs

@@ -172,6 +172,8 @@ void SetRenderer(IVisualElementRenderer renderer)
 
 			InitializeContentConstraints(nativeView);
 
+			UpdateVisualStates();
+
 			renderer.Element.MeasureInvalidated += MeasureInvalidated;
 		}
 
@@ -236,14 +238,7 @@ public override bool Selected
 			{
 				base.Selected = value;
 
-				var element = VisualElementRenderer?.Element;
-
-				if (element != null)
-				{
-					VisualStateManager.GoToState(element, value
-						? VisualStateManager.CommonStates.Selected
-						: VisualStateManager.CommonStates.Normal);
-				}
+				UpdateVisualStates();
 			}
 		}
 
@@ -293,5 +288,17 @@ bool SizesAreSame(CGSize preferredSize, Size elementSize)
 
 			return true;
 		}
+
+		void UpdateVisualStates()
+		{
+			var element = VisualElementRenderer?.Element;
+
+			if (element != null)
+			{
+				VisualStateManager.GoToState(element, Selected
+					? VisualStateManager.CommonStates.Selected
+					: VisualStateManager.CommonStates.Normal);
+			}
+		}
 	}
 }

src/Compatibility/Core/src/iOS/Renderers/ImageAnimationHelper.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Text;
 using System.Threading;
@@ -52,9 +53,9 @@ public void AddFrameData(int index, CGImageSource imageSource)
 				using (var delayTimeValue = gifImageProperties?.ValueForKey(ImageIO.CGImageProperties.GIFDelayTime))
 				{
 					if (unclampedDelayTimeValue != null)
-						double.TryParse(unclampedDelayTimeValue.ToString(), out delayTime);
+						double.TryParse(unclampedDelayTimeValue.ToString(), NumberStyles.Any, CultureInfo.InvariantCulture, out delayTime);
 					else if (delayTimeValue != null)
-						double.TryParse(delayTimeValue.ToString(), out delayTime);
+						double.TryParse(delayTimeValue.ToString(), NumberStyles.Any, CultureInfo.InvariantCulture, out delayTime);
 
 					// Frame delay compability adjustment.
 					if (delayTime <= 0.02f)

src/Compatibility/Core/src/iOS/Renderers/ListViewRenderer.cs

@@ -274,6 +274,9 @@ protected override void OnElementChanged(ElementChangedEventArgs<ListView> e)
 					}
 					_tableViewController = new FormsUITableViewController(e.NewElement, _usingLargeTitles);
 					SetNativeControl(_tableViewController.TableView);
+
+					if (Forms.IsiOS15OrNewer)
+						_tableViewController.TableView.SectionHeaderTopPadding = new nfloat(0);
 
 					_backgroundUIView = _tableViewController.TableView.BackgroundView;
 

src/Controls/src/Core/Compatibility/Handlers/ListView/Android/ListViewAdapter.cs

@@ -617,6 +617,10 @@ void OnDataChanged()
 				// we need to reset the ListView's adapter to reflect the changes on page B
 				// If there header and footer are present at the reset time of the adapter
 				// they will be DOUBLE added to the ViewGround (the ListView) causing indexes to be off by one. 
+
+				if (_realListView.IsDisposed())
+					return;
+
 				_realListView.RemoveHeaderView(HeaderView);
 				_realListView.RemoveFooterView(FooterView);
 				_realListView.Adapter = _realListView.Adapter;

src/Controls/src/Core/Compatibility/Handlers/ListView/Android/ListViewRenderer.cs

@@ -440,14 +440,27 @@ void UpdateIsRefreshing(bool isInitialValue = false)
 					});
 				}
 				else
-					_refresh.Refreshing = isRefreshing;
+					_refresh.Refreshing = isRefreshing; 
+
+				// Allow to disable SwipeToRefresh layout AFTER refresh is done
+				UpdateIsSwipeToRefreshEnabled();
 			}
 		}
 
 		void UpdateIsSwipeToRefreshEnabled()
 		{
 			if (_refresh != null)
-				_refresh.Enabled = Element.IsPullToRefreshEnabled && (Element as IListViewController).RefreshAllowed;
+			{
+				var isEnabled = Element.IsPullToRefreshEnabled && (Element as IListViewController).RefreshAllowed;
+				_refresh.Post(() =>
+				{
+					// NOTE: only disable while NOT refreshing, otherwise Command bindings CanExecute behavior will effectively
+					// cancel refresh animation. If not possible right now we will be called by UpdateIsRefreshing().
+					// For details see https://github.com/xamarin/Xamarin.Forms/issues/8384
+					if (isEnabled || !_refresh.Refreshing)
+						_refresh.Enabled = isEnabled;
+				});
+			}
 		}
 
 		void UpdateFastScrollEnabled()

src/Controls/src/Core/Compatibility/Handlers/ListView/Windows/CellControl.cs

@@ -330,17 +330,10 @@ void SetCell(object newContext)
 			// If there is a ListView, load the Cell content from the ItemTemplate.
 			// Otherwise, the given Cell is already a templated Cell from a TableView.
 			ListView lv = _listView.Value;
+
 			if (lv != null)
 			{
-				// 🚀 If there is an old cell, check if it was a group header
-				// we need this later to know whether we can recycle this cell
-				bool? wasGroupHeader = null;
-				var oldCell = Cell;
-				if (oldCell != null)
-				{
-					wasGroupHeader = oldCell.GetIsGroupHeader<ItemsView<Cell>, Cell>();
-				}
-
+				Cell oldCell = Cell;
 				bool isGroupHeader = IsGroupHeader;
 				DataTemplate template = isGroupHeader ? lv.GroupHeaderTemplate : lv.ItemTemplate;
 				object bindingContext = newContext;
@@ -358,15 +351,8 @@ void SetCell(object newContext)
 						sameTemplate = oldTemplate == template;
 					}
 				}
-				// 🚀 if there is no datatemplateselector, we now verify if the old cell
-				// was a groupheader and whether the new one is as well.
-				// Again, this is only to verify we can reuse this cell
-				else if (wasGroupHeader.HasValue)
-				{
-					sameTemplate = wasGroupHeader == isGroupHeader;
-				}
 
-				// reuse cell
+				// Reuse cell
 				var canReuseCell = Cell != null && sameTemplate;
 
 				// 🚀 If we can reuse the cell, just reuse it...
@@ -403,7 +389,8 @@ void SetCell(object newContext)
 
 			if (Cell != cell)
 				Cell = cell;
-			// 🚀 even if the cell did not change, we **must** call SendDisappearing() and SendAppearing()
+
+			// 🚀 Even if the cell did not change, we **must** call SendDisappearing() and SendAppearing()
 			// because frameworks such as Reactive UI rely on this! (this.WhenActivated())
 			else if (Cell != null)
 			{

src/Controls/src/Core/Compatibility/Handlers/ListView/iOS/ListViewRenderer.cs

@@ -228,6 +228,9 @@ protected override void OnElementChanged(ElementChangedEventArgs<ListView> e)
 					}
 					_tableViewController = new FormsUITableViewController(e.NewElement, _usingLargeTitles);
 					SetNativeControl(_tableViewController.TableView);
+
+					if (PlatformVersion.IsAtLeast(15))
+						_tableViewController.TableView.SectionHeaderTopPadding = new nfloat(0);
 
 					_backgroundUIView = _tableViewController.TableView.BackgroundView;
 

src/Controls/src/Core/Compatibility/Handlers/Shell/Android/ShellContentFragment.cs

@@ -173,6 +173,8 @@ void Destroy()
 
 				if (_root is ViewGroup vg)
 					vg.RemoveView(_shellPageContainer);
+
+				_shellPageContainer.Dispose();
 			}
 
 			_root?.Dispose();
@@ -186,6 +188,7 @@ void Destroy()
 			_root = null;
 			_viewhandler = null;
 			_shellContent = null;
+			_shellPageContainer = null;
 		}
 
 		protected override void Dispose(bool disposing)

src/Controls/src/Core/Compatibility/Handlers/Shell/Android/ShellToolbarTracker.cs

@@ -185,7 +185,10 @@ protected override void Dispose(bool disposing)
 				_currentMenuItems?.Clear();
 				_currentToolbarItems?.Clear();
 
+				_drawerLayout.RemoveDrawerListener(_drawerToggle);
 				_drawerToggle?.Dispose();
+
+				_toolbar.RemoveAllViews();
 			}
 
 			_currentMenuItems = null;

src/Controls/src/Core/Handlers/Items/iOS/ItemsViewController.cs

@@ -18,7 +18,7 @@ public abstract class ItemsViewController<TItemsView> : UICollectionViewControll
 		public TItemsView ItemsView { get; }
 		protected ItemsViewLayout ItemsViewLayout { get; set; }
 		bool _initialized;
-		bool _isEmpty;
+		bool _isEmpty = true;
 		bool _emptyViewDisplayed;
 		bool _disposed;
 
@@ -211,6 +211,7 @@ public virtual void UpdateItemsSource()
 		{
 			_measurementCells.Clear();
 			ItemsViewLayout?.ClearCellSizeCache();
+			ItemsSource?.Dispose();
 			ItemsSource = CreateItemsViewSource();
 			CollectionView.ReloadData();
 			CollectionView.CollectionViewLayout.InvalidateLayout();
@@ -472,7 +473,14 @@ void AlignEmptyView()
 				return;
 			}
 
-			if (CollectionView.EffectiveUserInterfaceLayoutDirection == UIUserInterfaceLayoutDirection.RightToLeft)
+			bool isRtl;
+
+			if (PlatformVersion.IsAtLeast(10))
+				isRtl = CollectionView.EffectiveUserInterfaceLayoutDirection == UIUserInterfaceLayoutDirection.RightToLeft;
+			else
+				isRtl = CollectionView.SemanticContentAttribute == UISemanticContentAttribute.ForceRightToLeft;
+
+			if (isRtl)
 			{
 				if (_emptyUIView.Transform.A == -1)
 				{