Add basic Xamarin.iOS support

csharp/Facebook.Yoga/ios/Facebook.Yoga.iOS.Test/ViewController.cs

@@ -0,0 +1,101 @@
+using System;
+using CoreGraphics;
+using Foundation;
+using UIKit;
+
+namespace Facebook.Yoga.iOS.Test
+{
+
+	public static class UIViewYogaExtensions
+	{
+		public static void ApplyYogaLayout(this UIView view, YogaNode n)
+		{
+			view.Frame = new CGRect(n.LayoutX, n.LayoutY, n.LayoutWidth, n.LayoutHeight);
+			// This assumes your YogaNode and NSView children were inserted in same order
+			for (int i = 0; i < n.Count; ++i)
+			{
+				YogaNode childNode = n[i];
+				view.Subviews[i].Frame = new CGRect(childNode.LayoutX, childNode.LayoutY, childNode.LayoutWidth, childNode.LayoutHeight);
+			}
+		}
+	}
+
+	public partial class ViewController : UIViewController
+	{
+		protected ViewController(IntPtr handle) : base(handle)
+		{
+			// Note: this .ctor should not contain any initialization logic.
+		}
+
+		public override void ViewDidLoad()
+		{
+			base.ViewDidLoad();
+			UIImage image = FromUrl("https://placehold.it/50x50");
+
+			UIView root = CreateViewHierarchy(image);
+
+			var rootNode = CalculateLayout(image.Size);
+
+			root.ApplyYogaLayout(rootNode);
+
+			View.AddSubview(root);
+
+		}
+		static UIImage FromUrl(string uri)
+		{
+			using (var url = new NSUrl(uri))
+			using (var data = NSData.FromUrl(url))
+				return UIImage.LoadFromData(data);
+		}
+		static UIView CreateViewHierarchy(UIImage image)
+		{
+			var root = new UIView();
+			UIImageView imageView = new UIImageView()
+			{
+				Image = image
+			};
+			root.AddSubview(imageView);
+
+			UITextField text = new UITextField()
+			{
+				Text = "Hello World",
+			};
+			root.AddSubview(text);
+			return root;
+		}
+
+		static YogaNode CalculateLayout(CGSize imageSize)
+		{
+			var rootNode = new YogaNode()
+			{
+				Width = 400,
+				Height = 120,
+				FlexDirection = YogaFlexDirection.Row
+			};
+			rootNode.SetPadding(YogaEdge.All, 20);
+
+			var imageNode = new YogaNode()
+			{
+				Width = (float)imageSize.Width,
+			};
+			imageNode.SetMargin(YogaEdge.End, 20);
+
+			var textNode = new YogaNode()
+			{
+				AlignSelf = YogaAlign.Center,
+				FlexGrow = 1,
+			};
+			rootNode.Insert(0, imageNode);
+			rootNode.Insert(1, textNode);
+			rootNode.CalculateLayout();
+
+			return rootNode;
+		}
+
+		public override void DidReceiveMemoryWarning()
+		{
+			base.DidReceiveMemoryWarning();
+			// Release any cached data, images, etc that aren't in use.
+		}
+	}
+}