Reformat methods to original order

1 files changed, 207 insertions, 210 deletions

diff --git a/Xamarin.Forms.Platform.iOS/Renderers/CarouselViewRenderer.cs b/Xamarin.Forms.Platform.iOS/Renderers/CarouselViewRenderer.cs
index 26ef16cc..d07e9d8f 100644
--- a/Xamarin.Forms.Platform.iOS/Renderers/CarouselViewRenderer.cs
+++ b/Xamarin.Forms.Platform.iOS/Renderers/CarouselViewRenderer.cs
@@ -42,13 +42,16 @@ namespace Xamarin.Forms.Platform.iOS
 	/// </summary>
 	public class CarouselViewRenderer : ViewRenderer<CarouselView, UICollectionView>
 	{
+		#region Static Fields
 		const int DefaultMinimumDimension = 44;
 		static readonly UIColor DefaultBackgroundColor = UIColor.White;
+		#endregion
 
+		#region Fields
 		CarouselViewController.Layout _layout;
 		int _position;
-
-		CarouselViewController CarouselViewController { get; set; }
+		CarouselViewController _controller;
+		#endregion
 
 		new UIScrollView Control
 		{
@@ -58,32 +61,10 @@ namespace Xamarin.Forms.Platform.iOS
 				return base.Control;
 			}
 		}
-
 		ICarouselViewController Controller
 		{
 			get { return Element; }
 		}
-
-		public override SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint)
-		{
-			return Control.GetSizeRequest(widthConstraint, heightConstraint, DefaultMinimumDimension, DefaultMinimumDimension);
-		}
-
-		protected override void OnElementChanged(ElementChangedEventArgs<CarouselView> e)
-		{
-			base.OnElementChanged(e);
-			Initialize();
-		}
-
-		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
-		{
-			if (e.PropertyName == "Position")
-				// not ideal; the event is raised before the animation to move completes (or even starts)
-				ScrollToPosition(Element.Position);
-
-			base.OnElementPropertyChanged(sender, e);
-		}
-
 		void Initialize()
 		{
 			// cache hit? 
@@ -91,7 +72,13 @@ namespace Xamarin.Forms.Platform.iOS
 			if (carouselView != null)
 				return;
 
-			CarouselViewController = new CarouselViewController(this, _layout = new CarouselViewController.Layout(UICollectionViewScrollDirection.Horizontal), Element.Position);
+			_controller = new CarouselViewController(
+				renderer: this, 
+				layout: _layout = new CarouselViewController.Layout(
+					UICollectionViewScrollDirection.Horizontal
+				),
+				originPosition: Element.Position
+			);
 
 			// hook up on position changed event
 			// not ideal; the event is raised upon releasing the swipe instead of animation completion
@@ -101,15 +88,38 @@ namespace Xamarin.Forms.Platform.iOS
 			Element.CollectionChanged += OnCollectionChanged;
 
 			// populate cache
-			SetNativeControl(CarouselViewController.CollectionView);
+			SetNativeControl(_controller.CollectionView);
 		}
 
+		void OnItemChange(int position)
+		{
+			var item = Controller.GetItem(position);
+			Controller.SendSelectedItemChanged(item);
+		}
+		bool OnPositionChange(int position)
+		{
+			if (position == _position)
+				return false;
+
+			_position = position;
+
+			Controller.SendSelectedPositionChanged(position);
+			OnItemChange(position);
+			return true;
+		}
+		void ScrollToPosition(int position, bool animated = true)
+		{
+			if (!OnPositionChange(position))
+				return;
+
+			_controller.ScrollToPosition(position, animated);
+		}
 		void OnCollectionChanged(object source, NotifyCollectionChangedEventArgs e)
 		{
 			switch (e.Action)
 			{
 				case NotifyCollectionChangedAction.Add:
-					CarouselViewController.ReloadData();
+					_controller.ReloadData();
 
 					if (e.NewStartingIndex <= _position)
 						ShiftPosition(e.NewItems.Count);
@@ -119,7 +129,10 @@ namespace Xamarin.Forms.Platform.iOS
 				case NotifyCollectionChangedAction.Move:
 					for (var i = 0; i < e.NewItems.Count; i++)
 					{
-						CarouselViewController.MoveItem(e.OldStartingIndex + i, e.NewStartingIndex + i);
+						_controller.MoveItem(
+							oldPosition: e.OldStartingIndex + i,
+							newPosition: e.NewStartingIndex + i
+						);
 					}
 					break;
 
@@ -129,7 +142,9 @@ namespace Xamarin.Forms.Platform.iOS
 
 					if (e.OldStartingIndex == _position)
 					{
-						CarouselViewController.DeleteItems(Enumerable.Range(e.OldStartingIndex, e.OldItems.Count));
+						_controller.DeleteItems(
+							Enumerable.Range(e.OldStartingIndex, e.OldItems.Count)
+						);
 						if (_position == Element.Count)
 							_position--;
 						OnItemChange(_position);
@@ -137,7 +152,7 @@ namespace Xamarin.Forms.Platform.iOS
 
 					else
 					{
-						CarouselViewController.ReloadData();
+						_controller.ReloadData();
 
 						if (e.OldStartingIndex < _position)
 							ShiftPosition(-e.OldItems.Count);
@@ -146,44 +161,19 @@ namespace Xamarin.Forms.Platform.iOS
 					break;
 
 				case NotifyCollectionChangedAction.Replace:
-					CarouselViewController.ReloadItems(Enumerable.Range(e.OldStartingIndex, e.OldItems.Count));
+					_controller.ReloadItems(
+						Enumerable.Range(e.OldStartingIndex, e.OldItems.Count)
+					);
 					break;
 
 				case NotifyCollectionChangedAction.Reset:
-					CarouselViewController.ReloadData();
+					_controller.ReloadData();
 					break;
 
 				default:
 					throw new Exception();
 			}
 		}
-
-		void OnItemChange(int position)
-		{
-			var item = Controller.GetItem(position);
-			Controller.SendSelectedItemChanged(item);
-		}
-
-		bool OnPositionChange(int position)
-		{
-			if (position == _position)
-				return false;
-
-			_position = position;
-
-			Controller.SendSelectedPositionChanged(position);
-			OnItemChange(position);
-			return true;
-		}
-
-		void ScrollToPosition(int position, bool animated = true)
-		{
-			if (!OnPositionChange(position))
-				return;
-
-			CarouselViewController.ScrollToPosition(position, animated);
-		}
-
 		void ShiftPosition(int offset)
 		{
 			// By default the position remains the same which causes an animation in the case
@@ -191,126 +181,29 @@ namespace Xamarin.Forms.Platform.iOS
 			// Android behavior whereby the item remains the same and the position changes.
 			ScrollToPosition(_position + offset, false);
 		}
-	}
-
-	internal sealed class CarouselViewController : UICollectionViewController
-	{
-		readonly Dictionary<object, int> _typeIdByType;
-		UICollectionViewLayout _layout;
-		int _nextItemTypeId;
-		int _originPosition;
-
-		public Action<int> OnBind;
-		public Action<int> OnSwipeTargetChosen;
 
-		public CarouselViewController(CarouselViewRenderer renderer, UICollectionViewLayout layout, int originPosition) : base(layout)
-		{
-			Renderer = renderer;
-			_typeIdByType = new Dictionary<object, int>();
-			_nextItemTypeId = 0;
-			_layout = layout;
-			_originPosition = originPosition;
-		}
-
-		ICarouselViewController Controller
-		{
-			get { return Element; }
-		}
-
-		CarouselView Element
-		{
-			get { return Renderer.Element; }
-		}
-
-		CarouselViewRenderer Renderer { get; }
-
-		public void DeleteItems(IEnumerable<int> positions)
-		{
-			var indices = positions.Select(o => NSIndexPath.FromRowSection(o, 0)).ToArray();
-			CollectionView.DeleteItems(indices);
-		}
-
-		public override UICollectionViewCell GetCell(UICollectionView collectionView, NSIndexPath indexPath)
-		{
-			var index = indexPath.Row;
-
-			if (_originPosition != 0)
-				index = _originPosition;
-
-			var item = Controller.GetItem(index);
-			var itemType = Controller.GetItemType(item);
-
-			var itemTypeId = default(int);
-			if (!_typeIdByType.TryGetValue(itemType, out itemTypeId))
-			{
-				_typeIdByType[itemType] = itemTypeId = _nextItemTypeId++;
-				CollectionView.RegisterClassForCell(typeof(Cell), itemTypeId.ToString());
-			}
-
-			var cell = (Cell)CollectionView.DequeueReusableCell(itemTypeId.ToString(), indexPath);
-			cell.Initialize(Element, itemType, item, index);
-
-			// a semantically weak approach to OnAppearing; decided not to expose as such
-			if (cell.OnBind == null)
-				cell.OnBind += o => OnBind?.Invoke(o);
-
-			return cell;
-		}
-
-		public override nint GetItemsCount(UICollectionView collectionView, nint section)
-		{
-			var result = Element.Count;
-			return result;
-		}
-
-		public void MoveItem(int oldPosition, int newPosition)
-		{
-			base.MoveItem(CollectionView, NSIndexPath.FromRowSection(oldPosition, 0), NSIndexPath.FromRowSection(newPosition, 0));
-		}
-
-		public override nint NumberOfSections(UICollectionView collectionView)
-		{
-			return 1;
-		}
-
-		public void ReloadData() => CollectionView.ReloadData();
-
-		public void ReloadItems(IEnumerable<int> positions)
-		{
-			var indices = positions.Select(o => NSIndexPath.FromRowSection(o, 0)).ToArray();
-			CollectionView.ReloadItems(indices);
-		}
-
-		public void ScrollToPosition(int position, bool animated = true)
-		{
-			CollectionView.ScrollToItem(NSIndexPath.FromRowSection(position, 0), UICollectionViewScrollPosition.CenteredHorizontally, animated);
-		}
-
-		public override void ViewDidLoad()
+		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
-			base.ViewDidLoad();
+			if (e.PropertyName == "Position")
+				// not ideal; the event is raised before the animation to move completes (or even starts)
+				ScrollToPosition(Element.Position);
 
-			CollectionView.PagingEnabled = true;
-			CollectionView.BackgroundColor = UIColor.Clear;
+			base.OnElementPropertyChanged(sender, e);
 		}
-
-		public override void WillDisplayCell(UICollectionView collectionView, UICollectionViewCell cell, NSIndexPath indexPath)
+		protected override void OnElementChanged(ElementChangedEventArgs<CarouselView> e)
 		{
-			if (_originPosition == 0)
-				return;
-
-			// Ideally position zero would not be rendered in memory however it is.
-			// Thankfully, position zero is not displyed; position originPosition is rendered and displayed.
-			ScrollToPosition(_originPosition, false);
-			_originPosition = 0;
+			base.OnElementChanged(e);
+			Initialize();
 		}
 
-		[Export("collectionView:layout:sizeForItemAtIndexPath:")]
-		SizeF GetSizeForItem(UICollectionView collectionView, UICollectionViewLayout layout, NSIndexPath indexPath)
+		public override SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint)
 		{
-			return collectionView.Frame.Size;
+			return Control.GetSizeRequest(widthConstraint, heightConstraint, DefaultMinimumDimension, DefaultMinimumDimension);
 		}
+	}
 
+	internal sealed class CarouselViewController : UICollectionViewController
+	{
 		internal new sealed class Layout : UICollectionViewFlowLayout
 		{
 			static readonly nfloat ZeroMinimumInteritemSpacing = 0;
@@ -318,8 +211,6 @@ namespace Xamarin.Forms.Platform.iOS
 
 			int _width;
 
-			public Action<int> OnSwipeOffsetChosen;
-
 			public Layout(UICollectionViewScrollDirection scrollDirection)
 			{
 				ScrollDirection = scrollDirection;
@@ -327,31 +218,16 @@ namespace Xamarin.Forms.Platform.iOS
 				MinimumLineSpacing = ZeroMinimumLineSpacing;
 			}
 
-			public override SizeF CollectionViewContentSize
+			public Action<int> OnSwipeOffsetChosen;
+
+			public override UICollectionViewLayoutAttributes InitialLayoutAttributesForAppearingItem(NSIndexPath itemIndexPath)
 			{
-				get
-				{
-					var result = base.CollectionViewContentSize;
-					return result;
-				}
+				return base.InitialLayoutAttributesForAppearingItem(itemIndexPath);
 			}
-
 			public override UICollectionViewLayoutAttributes FinalLayoutAttributesForDisappearingItem(NSIndexPath itemIndexPath)
 			{
 				return base.FinalLayoutAttributesForDisappearingItem(itemIndexPath);
 			}
-
-			public override NSIndexPath GetTargetIndexPathForInteractivelyMovingItem(NSIndexPath previousIndexPath, PointF position)
-			{
-				var result = base.GetTargetIndexPathForInteractivelyMovingItem(previousIndexPath, position);
-				return result;
-			}
-
-			public override UICollectionViewLayoutAttributes InitialLayoutAttributesForAppearingItem(NSIndexPath itemIndexPath)
-			{
-				return base.InitialLayoutAttributesForAppearingItem(itemIndexPath);
-			}
-
 			public override UICollectionViewLayoutAttributes[] LayoutAttributesForElementsInRect(RectangleF rect)
 			{
 				// couldn't figure a way to use these values to compute when an element appeared to disappeared. YMMV
@@ -371,26 +247,35 @@ namespace Xamarin.Forms.Platform.iOS
 				}
 				return result;
 			}
-
-			public override bool ShouldInvalidateLayoutForBoundsChange(RectangleF newBounds)
+			public override SizeF CollectionViewContentSize
 			{
-				return true;
+				get
+				{
+					var result = base.CollectionViewContentSize;
+					return result;
+				}
 			}
-
-			public override PointF TargetContentOffset(PointF proposedContentOffset, PointF scrollingVelocity)
+			public override NSIndexPath GetTargetIndexPathForInteractivelyMovingItem(NSIndexPath previousIndexPath, PointF position)
 			{
-				var result = base.TargetContentOffset(proposedContentOffset, scrollingVelocity);
-				OnSwipeOffsetChosen?.Invoke((int)result.X / _width);
+				var result = base.GetTargetIndexPathForInteractivelyMovingItem(previousIndexPath, position);
 				return result;
 			}
-
 			public override PointF TargetContentOffsetForProposedContentOffset(PointF proposedContentOffset)
 			{
 				var result = base.TargetContentOffsetForProposedContentOffset(proposedContentOffset);
 				return result;
 			}
+			public override PointF TargetContentOffset(PointF proposedContentOffset, PointF scrollingVelocity)
+			{
+				var result = base.TargetContentOffset(proposedContentOffset, scrollingVelocity);
+				OnSwipeOffsetChosen?.Invoke((int)result.X / _width);
+				return result;
+			}
+			public override bool ShouldInvalidateLayoutForBoundsChange(RectangleF newBounds)
+			{
+				return true;
+			}
 		}
-
 		sealed class Cell : UICollectionViewCell
 		{
 			IItemViewController _controller;
@@ -398,19 +283,21 @@ namespace Xamarin.Forms.Platform.iOS
 			IVisualElementRenderer _renderer;
 			View _view;
 
-			public Action<int> OnBind;
-
 			[Export("initWithFrame:")]
 			internal Cell(RectangleF frame) : base(frame)
 			{
 				_position = -1;
 			}
 
-			public override void LayoutSubviews()
+			void Bind(object item, int position)
 			{
-				base.LayoutSubviews();
+				//if (position != this.position)
+				//	controller.SendPositionDisappearing (this.position);
 
-				_renderer.Element.Layout(new Rectangle(0, 0, ContentView.Frame.Width, ContentView.Frame.Height));
+				_position = position;
+				OnBind?.Invoke(position);
+
+				_controller.BindView(_view, item);
 			}
 
 			internal void Initialize(IItemViewController controller, object itemType, object item, int position)
@@ -439,16 +326,126 @@ namespace Xamarin.Forms.Platform.iOS
 					Bind(item, position);
 			}
 
-			void Bind(object item, int position)
+			public Action<int> OnBind;
+
+			public override void LayoutSubviews()
 			{
-				//if (position != this.position)
-				//	controller.SendPositionDisappearing (this.position);
+				base.LayoutSubviews();
 
-				_position = position;
-				OnBind?.Invoke(position);
+				_renderer.Element.Layout(new Rectangle(0, 0, ContentView.Frame.Width, ContentView.Frame.Height));
+			}
+		}
 
-				_controller.BindView(_view, item);
+		readonly Dictionary<object, int> _typeIdByType;
+		UICollectionViewLayout _layout;
+		CarouselViewRenderer _renderer;
+		int _nextItemTypeId;
+		int _originPosition;
+
+		public Action<int> OnBind;
+		public Action<int> OnSwipeTargetChosen;
+
+		public CarouselViewController(CarouselViewRenderer renderer, UICollectionViewLayout layout, int originPosition) : base(layout)
+		{
+			_renderer = renderer;
+			_typeIdByType = new Dictionary<object, int>();
+			_nextItemTypeId = 0;
+			_layout = layout;
+			_originPosition = originPosition;
+		}
+
+		CarouselViewRenderer Renderer => _renderer;
+		CarouselView Element => _renderer.Element;
+		ICarouselViewController Controller => Element;
+
+		[Export("collectionView:layout:sizeForItemAtIndexPath:")]
+		SizeF GetSizeForItem(
+			UICollectionView collectionView,
+			UICollectionViewLayout layout, 
+			NSIndexPath indexPath)
+		{
+			return collectionView.Frame.Size;
+		}
+
+		public override void WillDisplayCell(UICollectionView collectionView, UICollectionViewCell cell, NSIndexPath indexPath)
+		{
+			if (_originPosition == 0)
+				return;
+
+			// Ideally position zero would not be rendered in memory however it is.
+			// Thankfully, position zero is not displyed; position originPosition is rendered and displayed.
+			ScrollToPosition(_originPosition, false);
+			_originPosition = 0;
+		}
+		public override nint NumberOfSections(UICollectionView collectionView)
+		{
+			return 1;
+		}
+		public override void ViewDidLoad()
+		{
+			base.ViewDidLoad();
+
+			CollectionView.PagingEnabled = true;
+			CollectionView.BackgroundColor = UIColor.Clear;
+		}
+		public override nint GetItemsCount(UICollectionView collectionView, nint section)
+		{
+			var result = Element.Count;
+			return result;
+		}
+		public override UICollectionViewCell GetCell(UICollectionView collectionView, NSIndexPath indexPath)
+		{
+			var index = indexPath.Row;
+
+			if (_originPosition != 0)
+				index = _originPosition;
+
+			var item = Controller.GetItem(index);
+			var itemType = Controller.GetItemType(item);
+
+			var itemTypeId = default(int);
+			if (!_typeIdByType.TryGetValue(itemType, out itemTypeId))
+			{
+				_typeIdByType[itemType] = itemTypeId = _nextItemTypeId++;
+				CollectionView.RegisterClassForCell(typeof(Cell), itemTypeId.ToString());
 			}
+
+			var cell = (Cell)CollectionView.DequeueReusableCell(itemTypeId.ToString(), indexPath);
+			cell.Initialize(Element, itemType, item, index);
+
+			// a semantically weak approach to OnAppearing; decided not to expose as such
+			if (cell.OnBind == null)
+				cell.OnBind += o => OnBind?.Invoke(o);
+
+			return cell;
+		}
+
+		public void ReloadData() => CollectionView.ReloadData();
+		public void ReloadItems(IEnumerable<int> positions)
+		{
+			var indices = positions.Select(o => NSIndexPath.FromRowSection(o, 0)).ToArray();
+			CollectionView.ReloadItems(indices);
+		}
+		public void DeleteItems(IEnumerable<int> positions)
+		{
+			var indices = positions.Select(o => NSIndexPath.FromRowSection(o, 0)).ToArray();
+			CollectionView.DeleteItems(indices);
+		}
+		public void MoveItem(int oldPosition, int newPosition)
+		{
+			base.MoveItem(
+				CollectionView, 
+				NSIndexPath.FromRowSection(oldPosition, 0), 
+				NSIndexPath.FromRowSection(newPosition, 0)
+			);
+		}
+		public void ScrollToPosition(int position, bool animated = true)
+		{
+			CollectionView.ScrollToItem(
+				indexPath: NSIndexPath.FromRowSection(position, 0), 
+				scrollPosition: UICollectionViewScrollPosition.CenteredHorizontally, 
+				animated: animated
+			);
 		}
 	}
 }
\ No newline at end of file