Initial import

1 files changed, 179 insertions, 0 deletions

diff --git a/Xamarin.Forms.Platform.iOS/VisualElementPackager.cs b/Xamarin.Forms.Platform.iOS/VisualElementPackager.cs
new file mode 100644
index 00000000..7f511d9d
--- /dev/null
+++ b/Xamarin.Forms.Platform.iOS/VisualElementPackager.cs
@@ -0,0 +1,179 @@
+using System;
+#if __UNIFIED__
+using UIKit;
+
+#else
+using MonoTouch.UIKit;
+#endif
+
+namespace Xamarin.Forms.Platform.iOS
+{
+	public class VisualElementPackager : IDisposable
+	{
+		VisualElement _element;
+
+		bool _isDisposed;
+
+		public VisualElementPackager(IVisualElementRenderer renderer)
+		{
+			if (renderer == null)
+				throw new ArgumentNullException("renderer");
+
+			Renderer = renderer;
+			renderer.ElementChanged += OnRendererElementChanged;
+			SetElement(null, renderer.Element);
+		}
+
+		protected IVisualElementRenderer Renderer { get; set; }
+
+		public void Dispose()
+		{
+			Dispose(true);
+		}
+
+		public void Load()
+		{
+			for (var i = 0; i < Renderer.Element.LogicalChildren.Count; i++)
+			{
+				var child = Renderer.Element.LogicalChildren[i] as VisualElement;
+				if (child != null)
+					OnChildAdded(child);
+			}
+		}
+
+		protected virtual void Dispose(bool disposing)
+		{
+			if (_isDisposed)
+				return;
+
+			if (disposing)
+			{
+				SetElement(_element, null);
+				if (Renderer != null)
+				{
+					Renderer.ElementChanged -= OnRendererElementChanged;
+					Renderer = null;
+				}
+			}
+
+			_isDisposed = true;
+		}
+
+		protected virtual void OnChildAdded(VisualElement view)
+		{
+			if (_isDisposed)
+				return;
+
+			var viewRenderer = Platform.CreateRenderer(view);
+			Platform.SetRenderer(view, viewRenderer);
+
+			var uiview = Renderer.NativeView;
+			uiview.AddSubview(viewRenderer.NativeView);
+
+			if (Renderer.ViewController != null && viewRenderer.ViewController != null)
+				Renderer.ViewController.AddChildViewController(viewRenderer.ViewController);
+
+			EnsureChildrenOrder();
+		}
+
+		protected virtual void OnChildRemoved(VisualElement view)
+		{
+			var viewRenderer = Platform.GetRenderer(view);
+			if (viewRenderer == null || viewRenderer.NativeView == null)
+				return;
+
+			viewRenderer.NativeView.RemoveFromSuperview();
+
+			if (Renderer.ViewController != null && viewRenderer.ViewController != null)
+				viewRenderer.ViewController.RemoveFromParentViewController();
+		}
+
+		void EnsureChildrenOrder()
+		{
+			if (Renderer.Element.LogicalChildren.Count == 0)
+				return;
+
+			for (var z = 0; z < Renderer.Element.LogicalChildren.Count; z++)
+			{
+				var child = Renderer.Element.LogicalChildren[z] as VisualElement;
+				if (child == null)
+					continue;
+				var childRenderer = Platform.GetRenderer(child);
+
+				if (childRenderer == null)
+					continue;
+
+				var nativeControl = childRenderer.NativeView;
+
+				Renderer.NativeView.BringSubviewToFront(nativeControl);
+				nativeControl.Layer.ZPosition = z * 1000;
+			}
+		}
+
+		void OnChildAdded(object sender, ElementEventArgs e)
+		{
+			var view = e.Element as VisualElement;
+			if (view != null)
+				OnChildAdded(view);
+		}
+
+		void OnChildRemoved(object sender, ElementEventArgs e)
+		{
+			var view = e.Element as VisualElement;
+			if (view != null)
+				OnChildRemoved(view);
+		}
+
+		void OnRendererElementChanged(object sender, VisualElementChangedEventArgs args)
+		{
+			if (args.NewElement == _element)
+				return;
+
+			SetElement(_element, args.NewElement);
+		}
+
+		void SetElement(VisualElement oldElement, VisualElement newElement)
+		{
+			if (oldElement == newElement)
+				return;
+
+			if (oldElement != null)
+			{
+				oldElement.ChildAdded -= OnChildAdded;
+				oldElement.ChildRemoved -= OnChildRemoved;
+				oldElement.ChildrenReordered -= UpdateChildrenOrder;
+
+				if (newElement != null)
+				{
+					var pool = new RendererPool(Renderer, oldElement);
+					pool.UpdateNewElement(newElement);
+
+					EnsureChildrenOrder();
+				}
+				else
+				{
+					for (var i = 0; i < oldElement.LogicalChildren.Count; i++)
+					{
+						var child = oldElement.LogicalChildren[i] as VisualElement;
+						if (child != null)
+							OnChildRemoved(child);
+					}
+				}
+			}
+
+			_element = newElement;
+
+			if (newElement != null)
+			{
+				newElement.ChildAdded += OnChildAdded;
+				newElement.ChildRemoved += OnChildRemoved;
+				newElement.ChildrenReordered += UpdateChildrenOrder;
+			}
+		}
+
+		void UpdateChildrenOrder(object sender, EventArgs e)
+		{
+			EnsureChildrenOrder();
+		}
+	}
+}
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