Initial import

1 files changed, 298 insertions, 0 deletions

diff --git a/Xamarin.Forms.Platform.iOS/ContextScrollViewDelegate.cs b/Xamarin.Forms.Platform.iOS/ContextScrollViewDelegate.cs
new file mode 100644
index 00000000..47ce0714
--- /dev/null
+++ b/Xamarin.Forms.Platform.iOS/ContextScrollViewDelegate.cs
@@ -0,0 +1,298 @@
+using System;
+using System.Drawing;
+using System.Collections.Generic;
+#if __UNIFIED__
+using UIKit;
+using Foundation;
+#else
+using MonoTouch.UIKit;
+using MonoTouch.Foundation;
+#endif
+#if __UNIFIED__
+using NSAction = System.Action;
+using RectangleF = CoreGraphics.CGRect;
+using SizeF = CoreGraphics.CGSize;
+using PointF = CoreGraphics.CGPoint;
+
+#else
+using nfloat=System.Single;
+using nint=System.Int32;
+#endif
+
+namespace Xamarin.Forms.Platform.iOS
+{
+	internal class iOS7ButtonContainer : UIView
+	{
+		readonly nfloat _buttonWidth;
+
+		public iOS7ButtonContainer(nfloat buttonWidth) : base(new RectangleF(0, 0, 0, 0))
+		{
+			_buttonWidth = buttonWidth;
+			ClipsToBounds = true;
+		}
+
+		public override void LayoutSubviews()
+		{
+			var width = Frame.Width;
+			nfloat takenSpace = 0;
+
+			for (var i = 0; i < Subviews.Length; i++)
+			{
+				var view = Subviews[i];
+
+				var pos = Subviews.Length - i;
+				var x = width - _buttonWidth * pos;
+				view.Frame = new RectangleF(x, 0, view.Frame.Width, view.Frame.Height);
+
+				takenSpace += view.Frame.Width;
+			}
+		}
+	}
+
+	internal class ContextScrollViewDelegate : UIScrollViewDelegate
+	{
+		readonly nfloat _finalButtonSize;
+		UIView _backgroundView;
+		List<UIButton> _buttons;
+		UITapGestureRecognizer _closer;
+		UIView _container;
+		GlobalCloseContextGestureRecognizer _globalCloser;
+
+		bool _isDisposed;
+
+		UITableView _table;
+
+		public ContextScrollViewDelegate(UIView container, List<UIButton> buttons, bool isOpen)
+		{
+			IsOpen = isOpen;
+			_container = container;
+			_buttons = buttons;
+
+			for (var i = 0; i < buttons.Count; i++)
+			{
+				var b = buttons[i];
+				b.Hidden = !isOpen;
+
+				ButtonsWidth += b.Frame.Width;
+				_finalButtonSize = b.Frame.Width;
+			}
+		}
+
+		public nfloat ButtonsWidth { get; }
+
+		public Action ClosedCallback { get; set; }
+
+		public bool IsOpen { get; private set; }
+
+		public override void DraggingStarted(UIScrollView scrollView)
+		{
+			if (!IsOpen)
+				SetButtonsShowing(true);
+
+			var cell = GetContextCell(scrollView);
+			if (!cell.Selected)
+				return;
+
+			if (!IsOpen)
+				RemoveHighlight(scrollView);
+		}
+
+		public void PrepareForDeselect(UIScrollView scrollView)
+		{
+			RestoreHighlight(scrollView);
+		}
+
+		public override void Scrolled(UIScrollView scrollView)
+		{
+			var width = _finalButtonSize;
+			var count = _buttons.Count;
+
+			if (!UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
+				_container.Frame = new RectangleF(scrollView.Frame.Width, 0, scrollView.ContentOffset.X, scrollView.Frame.Height);
+			else
+			{
+				var ioffset = scrollView.ContentOffset.X / (float)count;
+
+				if (ioffset > width)
+					width = ioffset + 1;
+
+				for (var i = count - 1; i >= 0; i--)
+				{
+					var b = _buttons[i];
+					var rect = b.Frame;
+					b.Frame = new RectangleF(scrollView.Frame.Width + (count - (i + 1)) * ioffset, 0, width, rect.Height);
+				}
+			}
+
+			if (scrollView.ContentOffset.X == 0)
+			{
+				IsOpen = false;
+				SetButtonsShowing(false);
+				RestoreHighlight(scrollView);
+
+				ClearCloserRecognizer(scrollView);
+
+				if (ClosedCallback != null)
+					ClosedCallback();
+			}
+		}
+
+		public void Unhook(UIScrollView scrollView)
+		{
+			RestoreHighlight(scrollView);
+			ClearCloserRecognizer(scrollView);
+		}
+
+		public override void WillEndDragging(UIScrollView scrollView, PointF velocity, ref PointF targetContentOffset)
+		{
+			var width = ButtonsWidth;
+			var x = targetContentOffset.X;
+			var parentThreshold = scrollView.Frame.Width * .4f;
+			var contentThreshold = width * .8f;
+
+			if (x >= parentThreshold || x >= contentThreshold)
+			{
+				IsOpen = true;
+				targetContentOffset = new PointF(width, 0);
+				RemoveHighlight(scrollView);
+
+				if (_globalCloser == null)
+				{
+					UIView view = scrollView;
+					while (view.Superview != null)
+					{
+						view = view.Superview;
+
+						NSAction close = () =>
+						{
+							if (UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
+								RestoreHighlight(scrollView);
+
+							IsOpen = false;
+							scrollView.SetContentOffset(new PointF(0, 0), true);
+
+							ClearCloserRecognizer(scrollView);
+						};
+
+						var table = view as UITableView;
+						if (table != null)
+						{
+							_table = table;
+							_globalCloser = new GlobalCloseContextGestureRecognizer(scrollView, _buttons, close);
+							_globalCloser.ShouldRecognizeSimultaneously = (recognizer, r) => r == _table.PanGestureRecognizer;
+							table.AddGestureRecognizer(_globalCloser);
+
+							_closer = new UITapGestureRecognizer(close);
+							var cell = GetContextCell(scrollView);
+							cell.ContentCell.AddGestureRecognizer(_closer);
+						}
+					}
+				}
+			}
+			else
+			{
+				ClearCloserRecognizer(scrollView);
+
+				IsOpen = false;
+				targetContentOffset = new PointF(0, 0);
+
+				if (UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
+					RestoreHighlight(scrollView);
+			}
+		}
+
+		protected override void Dispose(bool disposing)
+		{
+			if (_isDisposed)
+				return;
+
+			_isDisposed = true;
+
+			if (disposing)
+			{
+				ClosedCallback = null;
+
+				_table = null;
+				_backgroundView = null;
+				_container = null;
+
+				_buttons = null;
+			}
+
+			base.Dispose(disposing);
+		}
+
+		void ClearCloserRecognizer(UIScrollView scrollView)
+		{
+			if (_globalCloser == null)
+				return;
+
+			var cell = GetContextCell(scrollView);
+			cell.ContentCell.RemoveGestureRecognizer(_closer);
+			_closer.Dispose();
+			_closer = null;
+
+			_table.RemoveGestureRecognizer(_globalCloser);
+			_table = null;
+			_globalCloser.Dispose();
+			_globalCloser = null;
+		}
+
+		ContextActionsCell GetContextCell(UIScrollView scrollView)
+		{
+			var view = scrollView.Superview.Superview;
+			var cell = view as ContextActionsCell;
+			while (view.Superview != null)
+			{
+				cell = view as ContextActionsCell;
+				if (cell != null)
+					break;
+
+				view = view.Superview;
+			}
+
+			return cell;
+		}
+
+		void RemoveHighlight(UIScrollView scrollView)
+		{
+			var subviews = scrollView.Superview.Superview.Subviews;
+
+			var count = 0;
+			for (var i = 0; i < subviews.Length; i++)
+			{
+				var s = subviews[i];
+				if (s.Frame.Height > 1)
+					count++;
+			}
+
+			if (count <= 1)
+				return;
+
+			_backgroundView = subviews[0];
+			_backgroundView.RemoveFromSuperview();
+
+			var cell = GetContextCell(scrollView);
+			cell.SelectionStyle = UITableViewCellSelectionStyle.None;
+		}
+
+		void RestoreHighlight(UIScrollView scrollView)
+		{
+			if (_backgroundView == null)
+				return;
+
+			var cell = GetContextCell(scrollView);
+			cell.SelectionStyle = UITableViewCellSelectionStyle.Default;
+			cell.SetSelected(true, false);
+
+			scrollView.Superview.Superview.InsertSubview(_backgroundView, 0);
+			_backgroundView = null;
+		}
+
+		void SetButtonsShowing(bool show)
+		{
+			for (var i = 0; i < _buttons.Count; i++)
+				_buttons[i].Hidden = !show;
+		}
+	}
+}
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