1 files changed, 72 insertions, 0 deletions
diff --git a/Xamarin.Forms.Platform.iOS/NativeViewWrapperRenderer.cs b/Xamarin.Forms.Platform.iOS/NativeViewWrapperRenderer.cs
new file mode 100644
index 00000000..3d3e6868
--- /dev/null
+++ b/Xamarin.Forms.Platform.iOS/NativeViewWrapperRenderer.cs
@@ -0,0 +1,72 @@
+using System.Collections.Generic;
+#if __UNIFIED__
+using CoreGraphics;
+using UIKit;
+
+#else
+using MonoTouch.UIKit;
+#endif
+
+#if !__UNIFIED__
+	// Save ourselves a ton of ugly ifdefs below
+using CGSize = System.Drawing.SizeF;
+#endif
+
+namespace Xamarin.Forms.Platform.iOS
+{
+	public class NativeViewWrapperRenderer : ViewRenderer<NativeViewWrapper, UIView>
+	{
+		public override SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint)
+		{
+			if (Element?.GetDesiredSizeDelegate == null)
+				return base.GetDesiredSize(widthConstraint, heightConstraint);
+
+			// The user has specified a different implementation of GetDesiredSize
+			var result = Element.GetDesiredSizeDelegate(this, widthConstraint, heightConstraint);
+
+			// If the GetDesiredSize delegate returns a SizeRequest, we use it; if it returns null,
+			// fall back to the default implementation
+			return result ?? base.GetDesiredSize(widthConstraint, heightConstraint);
+		}
+
+		public override void LayoutSubviews()
+		{
+			if (Element?.LayoutSubViews == null)
+			{
+				Element?.InvalidateMeasure(InvalidationTrigger.MeasureChanged);
+				base.LayoutSubviews();
+				return;
+			}
+
+			// The user has specified a different implementation of LayoutSubviews
+			var handled = Element.LayoutSubViews();
+
+			if (!handled)
+			{
+				// If the delegate wasn't able to handle the request, fall back to the default implementation
+				base.LayoutSubviews();
+			}
+		}
+
+		public override CGSize SizeThatFits(CGSize size)
+		{
+			if (Element?.SizeThatFitsDelegate == null)
+				return base.SizeThatFits(size);
+
+			// The user has specified a different implementation of SizeThatFits
+			var result = Element.SizeThatFitsDelegate(size);
+
+			// If the delegate returns a value, we use it; 
+			// if it returns null, fall back to the default implementation
+			return result ?? base.SizeThatFits(size);
+		}
+
+		protected override void OnElementChanged(ElementChangedEventArgs<NativeViewWrapper> e)
+		{
+			base.OnElementChanged(e);
+
+			if (e.OldElement == null)
+				SetNativeControl(Element.NativeView);
+		}
+	}
+}
+\ No newline at end of file