Add YogaKit Shared and iOS version

Summary:
Using shared code for reuse in other platforms based on iOS native implementation.

Adds YogaKit sample.

Adds YogaKit tests (same as objc).

```
YogaKitTest : 80 ms
Facebook.YogaKit.iOS.Tests.exe : 81 ms
Tests run: 11 Passed: 8 Inconclusive: 0 Failed: 3 Ignored: 1
```

Since we don't have extension properties we need to go with a extension method to get access to the YogaLayout .

I m also not sure this is leak free yet, would love some help with testing and feedback about view/node lifecycle
Closes https://github.com/facebook/yoga/pull/336

Reviewed By: splhack

Differential Revision: D4415027

Pulled By: emilsjolander

fbshipit-source-id: c88328212426c3200e6f0c48cda594cd2c432065

csharp/Facebook.YogaKit/Facebook.YogaKit.Shared.shproj

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <ProjectGuid>{A24B3BA6-3143-4FFF-B8B8-1EDF166F5F4A}</ProjectGuid>
+  </PropertyGroup>
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\CodeSharing\Microsoft.CodeSharing.Common.Default.props" />
+  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\CodeSharing\Microsoft.CodeSharing.Common.props" />
+  <Import Project="Facebook.YogaKit.projitems" Label="Shared" />
+  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\CodeSharing\Microsoft.CodeSharing.CSharp.targets" />
+</Project>

csharp/Facebook.YogaKit/Facebook.YogaKit.projitems

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
+    <HasSharedItems>true</HasSharedItems>
+    <SharedGUID>{A24B3BA6-3143-4FFF-B8B8-1EDF166F5F4A}</SharedGUID>
+  </PropertyGroup>
+  <PropertyGroup Label="Configuration">
+    <Import_RootNamespace>Facebook.YogaKit</Import_RootNamespace>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildThisFileDirectory)YogaLayout.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)IYogaLayout.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)YogaKit.cs" />
+  </ItemGroup>
+</Project>

csharp/Facebook.YogaKit/IYogaLayout.cs

@@ -0,0 +1,85 @@
+using System;
+using System.Drawing;
+using Facebook.Yoga;
+
+namespace Facebook.YogaKit
+{
+	public interface IYogaLayout : IDisposable
+	{
+		bool IsEnabled { get; set; }
+		bool IsIncludeInLayout { get; set; }
+
+		//YogaDirection Direction { get; set; }
+		YogaFlexDirection FlexDirection { get; set; }
+		YogaJustify JustifyContent { get; set; }
+		YogaAlign AlignContent { get; set; }
+		YogaAlign AlignSelf { get; set; }
+		YogaAlign AlignItems { get; set; }
+		YogaPositionType Position { get; set; }
+		YogaWrap FlexWrap { get; set; }
+		YogaOverflow Overflow { get; set; }
+
+
+		float FlexGrow { get; set; }
+		float FlexShrink { get; set; }
+		float FlexBasis { get; set; }
+
+		float Left { get; set; }
+		float Top { get; set; }
+		float Right { get; set; }
+		float Bottom { get; set; }
+		float Start { get; set; }
+		float End { get; set; }
+
+		float MarginLeft { get; set; }
+		float MarginTop { get; set; }
+		float MarginRight { get; set; }
+		float MarginBottom { get; set; }
+		float MarginStart { get; set; }
+		float MarginEnd { get; set; }
+		float MarginHorizontal { get; set; }
+		float MarginVertical { get; set; }
+		float Margin { get; set; }
+
+		float PaddingLeft { get; set; }
+		float PaddingTop { get; set; }
+		float PaddingRight { get; set; }
+		float PaddingBottom { get; set; }
+		float PaddingStart { get; set; }
+		float PaddingEnd { get; set; }
+		float PaddingHorizontal { get; set; }
+		float PaddingVertical { get; set; }
+		float Padding { get; set; }
+
+		float BorderLeftWidth { get; set; }
+		float BorderTopWidth { get; set; }
+		float BorderRightWidth { get; set; }
+		float BorderBottomWidth { get; set; }
+		float BorderStartWidth { get; set; }
+		float BorderEndWidth { get; set; }
+		float BorderWidth { get; set; }
+
+		float Width { get; set; }
+		float Height { get; set; }
+		float MinWidth { get; set; }
+		float MinHeight { get; set; }
+		float MaxWidth { get; set; }
+		float MaxHeight { get; set; }
+
+		// Yoga specific properties, not compatible with flexbox specification
+
+		// Returns the size of the view if no constraints were given. This could equivalent to calling [self sizeThatFits:CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX)];
+		SizeF IntrinsicSize { get; }
+		float AspectRatio { get; set; }
+		// Get the resolved direction of this node. This won't be YGDirectionInherit
+		YogaDirection ResolvedDirection { get; }
+		// Returns the number of children that are using Flexbox.
+		int NumberOfChildren { get; }
+		// Return a BOOL indiciating whether or not we this node contains any subviews that are included in Yoga's layout.
+		bool IsLeaf { get; }
+		// Perform a layout calculation and update the frames of the views in the hierarchy with the results
+		void ApplyLayout();
+		// Mark that a view's layout needs to be recalculated. Only works for leaf views.
+		void MarkDirty();
+	}
+}

csharp/Facebook.YogaKit/YogaKit.cs

@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+using Facebook.Yoga;
+
+namespace Facebook.YogaKit
+{
+	public static partial class YogaKit
+	{
+		internal static Dictionary<YogaNode, object> Bridges = new Dictionary<YogaNode, object>();
+	}
+}

csharp/Facebook.YogaKit/YogaLayout.cs

@@ -0,0 +1,888 @@
+using System;
+using Facebook.Yoga;
+using System.Collections.Generic;
+using System.Drawing;
+#if __IOS__
+using NativeView = UIKit.UIView;
+#endif
+
+namespace Facebook.YogaKit
+{
+	public partial class YogaLayout : IYogaLayout
+	{
+		WeakReference<NativeView> _viewRef;
+		YogaNode _node;
+
+		internal YogaLayout(NativeView view)
+		{
+			_viewRef = new WeakReference<NativeView>(view);
+			_node = new YogaNode();
+			YogaKit.Bridges.Add(_node, view);
+
+			IsEnabled = false;
+			IsIncludeInLayout = true;
+		}
+
+		public new void MarkDirty()
+		{
+			if (IsLeaf)
+				_node.MarkDirty();
+		}
+
+		public bool IsLeaf
+		{
+			get
+			{
+				if (IsEnabled)
+				{
+					NativeView view = null;
+					if (_viewRef.TryGetTarget(out view))
+					{
+						foreach (NativeView subview in GetChildren(view))
+						{
+							var layout = subview.Yoga();
+							if (layout.IsEnabled && layout.IsIncludeInLayout)
+							{
+								return false;
+							}
+						}
+					}
+
+				}
+				return true;
+			}
+		}
+
+
+
+		public bool IsEnabled
+		{
+			get;
+			set;
+		}
+
+		public bool IsIncludeInLayout
+		{
+			get;
+			set;
+		}
+
+		public int NumberOfChildren => _node.Count;
+
+		public YogaDirection ResolvedDirection => _node.LayoutDirection;
+
+		public YogaFlexDirection FlexDirection
+		{
+			get
+			{
+				return _node.FlexDirection;
+			}
+
+			set
+			{
+				_node.FlexDirection = value;
+			}
+		}
+
+		public YogaAlign AlignItems
+		{
+			get
+			{
+				return _node.AlignItems;
+			}
+
+			set
+			{
+				_node.AlignItems = value;
+			}
+		}
+
+		public YogaJustify JustifyContent
+		{
+			get
+			{
+				return _node.JustifyContent;
+			}
+
+			set
+			{
+				_node.JustifyContent = value;
+			}
+		}
+
+		public YogaAlign AlignContent
+		{
+			get
+			{
+				return _node.AlignContent;
+			}
+
+			set
+			{
+				_node.AlignContent = value;
+			}
+		}
+
+		public YogaAlign AlignSelf
+		{
+			get
+			{
+				return _node.AlignSelf;
+			}
+
+			set
+			{
+				_node.AlignSelf = value;
+			}
+		}
+
+		public YogaPositionType Position
+		{
+			get
+			{
+				return _node.PositionType;
+			}
+
+			set
+			{
+				_node.PositionType = value;
+			}
+		}
+
+		public YogaWrap FlexWrap
+		{
+			get
+			{
+				return _node.Wrap;
+			}
+
+			set
+			{
+				_node.Wrap = value;
+			}
+		}
+
+		public YogaOverflow Overflow
+		{
+			get
+			{
+				return _node.Overflow;
+			}
+
+			set
+			{
+				_node.Overflow = value;
+			}
+		}
+
+		public float FlexGrow
+		{
+			get
+			{
+				return _node.FlexGrow;
+			}
+
+			set
+			{
+				_node.FlexGrow = value;
+			}
+		}
+
+		public float FlexShrink
+		{
+			get
+			{
+				return _node.FlexShrink;
+			}
+
+			set
+			{
+				_node.FlexShrink = value;
+			}
+		}
+
+		public float FlexBasis
+		{
+			get
+			{
+				return (float)_node.FlexBasis.Value;
+			}
+
+			set
+			{
+				_node.FlexBasis = value;
+			}
+		}
+
+		public float Left
+		{
+			get
+			{
+				return _node.Left.Value;
+			}
+
+			set
+			{
+				_node.Left = value;
+			}
+		}
+
+		public float Top
+		{
+			get
+			{
+				return _node.Top.Value;
+			}
+
+			set
+			{
+				_node.Top = value;
+			}
+		}
+
+		public float Right
+		{
+			get
+			{
+				return _node.Right.Value;
+			}
+
+			set
+			{
+				_node.Right = value;
+			}
+		}
+
+		public float Bottom
+		{
+			get
+			{
+				return _node.Bottom.Value;
+			}
+
+			set
+			{
+				_node.Bottom = value;
+			}
+		}
+
+		public float Start
+		{
+			get
+			{
+				return _node.Start.Value;
+			}
+
+			set
+			{
+				_node.Start = value;
+			}
+		}
+
+		public float End
+		{
+			get
+			{
+				return _node.End.Value;
+			}
+
+			set
+			{
+				_node.End = value;
+			}
+		}
+
+		public float MarginLeft
+		{
+			get
+			{
+				return _node.MarginLeft.Value;
+			}
+
+			set
+			{
+				_node.MarginLeft = value;
+			}
+		}
+
+		public float MarginTop
+		{
+			get
+			{
+				return _node.MarginTop.Value;
+			}
+
+			set
+			{
+				_node.MarginTop = value;
+			}
+		}
+
+		public float MarginRight
+		{
+			get
+			{
+				return _node.MarginRight.Value;
+			}
+
+			set
+			{
+				_node.MarginRight = value;
+			}
+		}
+
+		public float MarginBottom
+		{
+			get
+			{
+				return _node.MarginBottom.Value;
+			}
+
+			set
+			{
+				_node.MarginBottom = value;
+			}
+		}
+
+		public float MarginStart
+		{
+			get
+			{
+				return _node.MarginStart.Value;
+			}
+
+			set
+			{
+				_node.MarginStart = value;
+			}
+		}
+
+		public float MarginEnd
+		{
+			get
+			{
+				return _node.MarginEnd.Value;
+			}
+
+			set
+			{
+				_node.MarginEnd = value;
+			}
+		}
+
+		public float MarginHorizontal
+		{
+			get
+			{
+				return _node.MarginHorizontal.Value;
+			}
+
+			set
+			{
+				_node.MarginHorizontal = value;
+			}
+		}
+
+		public float MarginVertical
+		{
+			get
+			{
+				return _node.MarginVertical.Value;
+			}
+
+			set
+			{
+				_node.MarginVertical = value;
+			}
+		}
+
+		public float Margin
+		{
+			get
+			{
+				return _node.Margin.Value;
+			}
+
+			set
+			{
+				_node.Margin = value;
+			}
+		}
+
+		public float PaddingLeft
+		{
+			get
+			{
+				return _node.PaddingLeft.Value;
+			}
+
+			set
+			{
+				_node.PaddingLeft = value;
+			}
+		}
+
+		public float PaddingTop
+		{
+			get
+			{
+				return _node.PaddingTop.Value;
+			}
+
+			set
+			{
+				_node.PaddingTop = value;
+			}
+		}
+
+		public float PaddingRight
+		{
+			get
+			{
+				return _node.PaddingRight.Value;
+			}
+
+			set
+			{
+				_node.PaddingRight = value;
+			}
+		}
+
+		public float PaddingBottom
+		{
+			get
+			{
+				return _node.PaddingBottom.Value;
+			}
+
+			set
+			{
+				_node.PaddingBottom = value;
+			}
+		}
+
+		public float PaddingStart
+		{
+			get
+			{
+				return _node.PaddingStart.Value;
+			}
+
+			set
+			{
+				_node.PaddingStart = value;
+			}
+		}
+
+		public float PaddingEnd
+		{
+			get
+			{
+				return _node.PaddingEnd.Value;
+			}
+
+			set
+			{
+				_node.PaddingEnd = value;
+			}
+		}
+
+		public float PaddingHorizontal
+		{
+			get
+			{
+				return _node.PaddingHorizontal.Value;
+			}
+
+			set
+			{
+				_node.PaddingHorizontal = value;
+			}
+		}
+
+		public float PaddingVertical
+		{
+			get
+			{
+				return _node.PaddingVertical.Value;
+			}
+
+			set
+			{
+				_node.PaddingHorizontal = value;
+			}
+		}
+
+		public float Padding
+		{
+			get
+			{
+				return _node.Padding.Value;
+			}
+
+			set
+			{
+				_node.Padding = value;
+			}
+		}
+
+		public float BorderLeftWidth
+		{
+			get
+			{
+				return _node.BorderLeftWidth;
+			}
+
+			set
+			{
+				_node.BorderLeftWidth = value;
+			}
+		}
+
+		public float BorderTopWidth
+		{
+			get
+			{
+				return _node.BorderTopWidth;
+			}
+
+			set
+			{
+				_node.BorderTopWidth = value;
+			}
+		}
+
+		public float BorderRightWidth
+		{
+			get
+			{
+				return _node.BorderRightWidth;
+			}
+
+			set
+			{
+				_node.BorderRightWidth = value;
+			}
+		}
+
+		public float BorderBottomWidth
+		{
+			get
+			{
+				return _node.BorderBottomWidth;
+			}
+
+			set
+			{
+				_node.BorderBottomWidth = value;
+			}
+		}
+
+		public float BorderStartWidth
+		{
+			get
+			{
+				return _node.BorderStartWidth;
+			}
+
+			set
+			{
+				_node.BorderStartWidth = value;
+			}
+		}
+
+		public float BorderEndWidth
+		{
+			get
+			{
+				return _node.BorderEndWidth;
+			}
+
+			set
+			{
+				_node.BorderEndWidth = value;
+			}
+		}
+
+		public float BorderWidth
+		{
+			get
+			{
+				return _node.BorderWidth;
+			}
+
+			set
+			{
+				_node.BorderWidth = value;
+			}
+		}
+
+		public float Height
+		{
+			get
+			{
+				return _node.Height.Value;
+			}
+
+			set
+			{
+				_node.Height = value;
+			}
+		}
+
+		public float Width
+		{
+			get
+			{
+				return _node.Width.Value;
+			}
+
+			set
+			{
+				_node.Width = value;
+			}
+		}
+
+		public float MinWidth
+		{
+			get
+			{
+				return _node.MinWidth.Value;
+			}
+
+			set
+			{
+				_node.MinWidth = value;
+			}
+		}
+
+		public float MinHeight
+		{
+			get
+			{
+				return _node.MinHeight.Value;
+			}
+
+			set
+			{
+				_node.MinHeight = value;
+			}
+		}
+
+		public float MaxWidth
+		{
+			get
+			{
+				return _node.MaxWidth.Value;
+			}
+
+			set
+			{
+				_node.MaxWidth = value;
+			}
+		}
+
+		public float MaxHeight
+		{
+			get
+			{
+				return _node.MaxHeight.Value;
+			}
+
+			set
+			{
+				_node.MaxHeight = value;
+			}
+		}
+
+		public float AspectRatio
+		{
+			get
+			{
+				return _node.StyleAspectRatio;
+			}
+
+			set
+			{
+				_node.StyleAspectRatio = value;
+			}
+		}
+
+		public void ApplyLayout()
+		{
+			NativeView view = null;
+			if (_viewRef.TryGetTarget(out view))
+			{
+				float width = 0;
+				float height = 0;
+				GetWidthHeightOfNativeView(view, out width, out height);
+				CalculateLayoutWithSize(this, width, height);
+				ApplyLayoutToViewHierarchy(view);
+			}
+		}
+		public SizeF IntrinsicSize
+		{
+			get
+			{
+				return CalculateLayoutWithSize(this, float.NaN, float.NaN);
+			}
+		}
+
+		SizeF CalculateLayoutWithSize(YogaLayout layout, float width, float height)
+		{
+			//TODO : Check thread access 
+			if (!layout.IsEnabled)
+			{
+				System.Diagnostics.Debug.WriteLine("Doesn't use Yoga");
+			}
+			NativeView view = null;
+			if (_viewRef.TryGetTarget(out view))
+			{
+				AttachNodesFromViewHierachy(view);
+			}
+
+			var node = layout._node;
+
+			node.Width = width;
+			node.Height = height;
+			node.CalculateLayout();
+
+			return new SizeF { Width = node.LayoutWidth, Height = node.LayoutHeight };
+		}
+
+		static YogaSize MeasureView(YogaNode node, float width, YogaMeasureMode widthMode, float height, YogaMeasureMode heightMode)
+		{
+			var constrainedWidth = (widthMode == YogaMeasureMode.Undefined) ? float.MaxValue : width;
+			var constrainedHeight = (heightMode == YogaMeasureMode.Undefined) ? float.MaxValue : height;
+
+			NativeView view = null;
+			if (YogaKit.Bridges.ContainsKey(node))
+				view = YogaKit.Bridges[node] as NativeView;
+
+			float sizeThatFitsWidth = 0;
+			float sizeThatFitsHeight = 0;
+
+			MeasureNativeView(view, constrainedWidth, constrainedHeight, out sizeThatFitsWidth, out sizeThatFitsHeight);
+
+			var finalWidth = SanitizeMeasurement(constrainedWidth, sizeThatFitsWidth, widthMode);
+			var finalHeight = SanitizeMeasurement(constrainedHeight, sizeThatFitsHeight, heightMode);
+
+			return MeasureOutput.Make(finalWidth, finalHeight);
+		}
+
+		static float SanitizeMeasurement(float constrainedSize, float measuredSize, YogaMeasureMode measureMode)
+		{
+			float result;
+			if (measureMode == YogaMeasureMode.Exactly)
+			{
+				result = (float)constrainedSize;
+			}
+			else if (measureMode == YogaMeasureMode.AtMost)
+			{
+				result = (float)Math.Min(constrainedSize, measuredSize);
+			}
+			else {
+				result = (float)measuredSize;
+			}
+
+			return result;
+		}
+
+		static bool NodeHasExactSameChildren(YogaNode node, NativeView[] subviews)
+		{
+			if (node.Count != subviews.Length)
+				return false;
+			for (int i = 0; i < subviews.Length; i++)
+			{
+				YogaLayout yoga = subviews[i].Yoga() as YogaLayout;
+				if (node[i] != yoga._node)
+				{
+					return false;
+				}
+			}
+			return true;
+		}
+
+		static void AttachNodesFromViewHierachy(NativeView view)
+		{
+			YogaLayout yoga = view.Yoga() as YogaLayout;
+			var node = yoga._node;
+			// Only leaf nodes should have a measure function
+			if (yoga.IsLeaf)
+			{
+				RemoveAllChildren(node);
+				node.SetMeasureFunction(MeasureView);
+			}
+			else
+			{
+				node.SetMeasureFunction(null);
+				// Create a list of all the subviews that we are going to use for layout.
+				var subviewsToInclude = new List<NativeView>();
+				foreach (var subview in view.Subviews)
+				{
+					if (subview.Yoga().IsIncludeInLayout)
+					{
+						subviewsToInclude.Add(subview);
+					}
+				}
+
+				if (!NodeHasExactSameChildren(node, subviewsToInclude.ToArray()))
+				{
+					RemoveAllChildren(node);
+					for (int i = 0; i < subviewsToInclude.Count; i++)
+					{
+						YogaLayout yogaSubview = subviewsToInclude[i].Yoga() as YogaLayout;
+						node.Insert(i, yogaSubview._node);
+					}
+				}
+
+				foreach (var subView in subviewsToInclude)
+				{
+					AttachNodesFromViewHierachy(subView);
+				}
+			}
+		}
+
+		static void RemoveAllChildren(YogaNode node)
+		{
+			if (node == null)
+				return;
+
+			if (node.Count > 0)
+			{
+				node.Clear();
+			}
+		}
+
+		static double RoundPixelValue(float value)
+		{
+			float scale = NativePixelScale;
+
+			return Math.Round(value * scale) / scale;
+		}
+
+		static void ApplyLayoutToViewHierarchy(NativeView view)
+		{
+			//TODO : "Framesetting should only be done on the main thread."
+			YogaLayout yoga = view.Yoga() as YogaLayout;
+
+			if (!yoga.IsIncludeInLayout)
+				return;
+
+			var node = yoga._node;
+
+			ApplyLayoutToNativeView(view, node);
+
+			if (!yoga.IsLeaf)
+			{
+				for (int i = 0; i < view.Subviews.Length; i++)
+				{
+					ApplyLayoutToViewHierarchy(view.Subviews[i]);
+				}
+			}
+		}
+
+
+	}
+}
+

csharp/iOS/Facebook.YogaKit.iOS.Sample/AppDelegate.cs

@@ -0,0 +1,23 @@
+using Foundation;
+using UIKit;
+
+namespace Facebook.YogaKit.iOS.Sample
+{
+	[Register("AppDelegate")]
+	public class AppDelegate : UIApplicationDelegate
+	{
+		public override UIWindow Window
+		{
+			get;
+			set;
+		}
+
+		public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
+		{
+			return true;
+		}
+
+
+	}
+}
+

csharp/iOS/Facebook.YogaKit.iOS.Sample/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -0,0 +1,157 @@
+{
+  "images": [
+    {
+      "idiom": "iphone",
+      "size": "29x29",
+      "scale": "1x"
+    },
+    {
+      "idiom": "iphone",
+      "size": "29x29",
+      "scale": "2x"
+    },
+    {
+      "idiom": "iphone",
+      "size": "29x29",
+      "scale": "3x"
+    },
+    {
+      "idiom": "iphone",
+      "size": "40x40",
+      "scale": "2x"
+    },
+    {
+      "idiom": "iphone",
+      "size": "40x40",
+      "scale": "3x"
+    },
+    {
+      "idiom": "iphone",
+      "size": "57x57",
+      "scale": "1x"
+    },
+    {
+      "idiom": "iphone",
+      "size": "57x57",
+      "scale": "2x"
+    },
+    {
+      "idiom": "iphone",
+      "size": "60x60",
+      "scale": "2x"
+    },
+    {
+      "idiom": "iphone",
+      "size": "60x60",
+      "scale": "3x"
+    },
+    {
+      "idiom": "ipad",
+      "size": "29x29",
+      "scale": "1x"
+    },
+    {
+      "idiom": "ipad",
+      "size": "29x29",
+      "scale": "2x"
+    },
+    {
+      "idiom": "ipad",
+      "size": "40x40",
+      "scale": "1x"
+    },
+    {
+      "idiom": "ipad",
+      "size": "40x40",
+      "scale": "2x"
+    },
+    {
+      "idiom": "ipad",
+      "size": "50x50",
+      "scale": "1x"
+    },
+    {
+      "idiom": "ipad",
+      "size": "50x50",
+      "scale": "2x"
+    },
+    {
+      "idiom": "ipad",
+      "size": "72x72",
+      "scale": "1x"
+    },
+    {
+      "idiom": "ipad",
+      "size": "72x72",
+      "scale": "2x"
+    },
+    {
+      "idiom": "ipad",
+      "size": "76x76",
+      "scale": "1x"
+    },
+    {
+      "idiom": "ipad",
+      "size": "76x76",
+      "scale": "2x"
+    },
+    {
+      "size": "24x24",
+      "idiom": "watch",
+      "scale": "2x",
+      "role": "notificationCenter",
+      "subtype": "38mm"
+    },
+    {
+      "size": "27.5x27.5",
+      "idiom": "watch",
+      "scale": "2x",
+      "role": "notificationCenter",
+      "subtype": "42mm"
+    },
+    {
+      "size": "29x29",
+      "idiom": "watch",
+      "role": "companionSettings",
+      "scale": "2x"
+    },
+    {
+      "size": "29x29",
+      "idiom": "watch",
+      "role": "companionSettings",
+      "scale": "3x"
+    },
+    {
+      "size": "40x40",
+      "idiom": "watch",
+      "scale": "2x",
+      "role": "appLauncher",
+      "subtype": "38mm"
+    },
+    {
+      "size": "44x44",
+      "idiom": "watch",
+      "scale": "2x",
+      "role": "longLook",
+      "subtype": "42mm"
+    },
+    {
+      "size": "86x86",
+      "idiom": "watch",
+      "scale": "2x",
+      "role": "quickLook",
+      "subtype": "38mm"
+    },
+    {
+      "size": "98x98",
+      "idiom": "watch",
+      "scale": "2x",
+      "role": "quickLook",
+      "subtype": "42mm"
+    }
+  ],
+  "info": {
+    "version": 1,
+    "author": "xcode"
+  }
+}

csharp/iOS/Facebook.YogaKit.iOS.Sample/Assets.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

csharp/iOS/Facebook.YogaKit.iOS.Sample/Entitlements.plist

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+</dict>
+</plist>

csharp/iOS/Facebook.YogaKit.iOS.Sample/Facebook.YogaKit.iOS.Sample.csproj

@@ -0,0 +1,128 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">iPhoneSimulator</Platform>
+    <ProjectGuid>{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}</ProjectGuid>
+    <ProjectTypeGuids>{FEACFBD2-3405-455C-9665-78FE426C6842};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
+    <OutputType>Exe</OutputType>
+    <RootNamespace>Facebook.YogaKit.iOS.Sample</RootNamespace>
+    <AssemblyName>Facebook.YogaKit.iOS.Sample</AssemblyName>
+    <IPhoneResourcePrefix>Resources</IPhoneResourcePrefix>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|iPhoneSimulator' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\iPhoneSimulator\Debug</OutputPath>
+    <DefineConstants>DEBUG;ENABLE_TEST_CLOUD;__IOS__</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <CodesignKey>iPhone Developer</CodesignKey>
+    <MtouchDebug>true</MtouchDebug>
+    <MtouchFastDev>true</MtouchFastDev>
+    <MtouchProfiling>true</MtouchProfiling>
+    <MtouchUseSGen>true</MtouchUseSGen>
+    <MtouchUseRefCounting>true</MtouchUseRefCounting>
+    <IOSDebuggerPort>56768</IOSDebuggerPort>
+    <MtouchLink>None</MtouchLink>
+    <MtouchArch>x86_64</MtouchArch>
+    <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
+    <MtouchTlsProvider>Default</MtouchTlsProvider>
+    <DeviceSpecificBuild>false</DeviceSpecificBuild>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|iPhone' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\iPhone\Release</OutputPath>
+    <DefineConstants></DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <CodesignKey>iPhone Developer</CodesignKey>
+    <MtouchUseSGen>true</MtouchUseSGen>
+    <MtouchUseRefCounting>true</MtouchUseRefCounting>
+    <MtouchFloat32>true</MtouchFloat32>
+    <CodesignEntitlements>Entitlements.plist</CodesignEntitlements>
+    <MtouchLink>SdkOnly</MtouchLink>
+    <MtouchArch>ARMv7, ARM64</MtouchArch>
+    <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
+    <MtouchTlsProvider>Default</MtouchTlsProvider>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|iPhoneSimulator' ">
+    <DebugType></DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\iPhoneSimulator\Release</OutputPath>
+    <DefineConstants></DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <CodesignKey>iPhone Developer</CodesignKey>
+    <MtouchUseSGen>true</MtouchUseSGen>
+    <MtouchUseRefCounting>true</MtouchUseRefCounting>
+    <MtouchLink>None</MtouchLink>
+    <MtouchArch>x86_64</MtouchArch>
+    <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
+    <MtouchTlsProvider>Default</MtouchTlsProvider>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|iPhone' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\iPhone\Debug</OutputPath>
+    <DefineConstants>DEBUG;ENABLE_TEST_CLOUD;</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <CodesignKey>iPhone Developer</CodesignKey>
+    <DeviceSpecificBuild>true</DeviceSpecificBuild>
+    <MtouchDebug>true</MtouchDebug>
+    <MtouchFastDev>true</MtouchFastDev>
+    <MtouchProfiling>true</MtouchProfiling>
+    <MtouchUseSGen>true</MtouchUseSGen>
+    <MtouchUseRefCounting>true</MtouchUseRefCounting>
+    <MtouchFloat32>true</MtouchFloat32>
+    <CodesignEntitlements>Entitlements.plist</CodesignEntitlements>
+    <MtouchLink>SdkOnly</MtouchLink>
+    <MtouchArch>ARMv7, ARM64</MtouchArch>
+    <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
+    <MtouchTlsProvider>Default</MtouchTlsProvider>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Xml" />
+    <Reference Include="System.Core" />
+    <Reference Include="Xamarin.iOS" />
+  </ItemGroup>
+  <ItemGroup>
+    <ImageAsset Include="Assets.xcassets\AppIcon.appiconset\Contents.json" />
+    <ImageAsset Include="Assets.xcassets\Contents.json" />
+  </ItemGroup>
+  <ItemGroup>
+    <Folder Include="Resources\" />
+  </ItemGroup>
+  <ItemGroup>
+    <InterfaceDefinition Include="LaunchScreen.storyboard" />
+    <InterfaceDefinition Include="Main.storyboard" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="Info.plist" />
+    <None Include="Entitlements.plist" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Main.cs" />
+    <Compile Include="AppDelegate.cs" />
+    <Compile Include="ViewController.cs" />
+    <Compile Include="ViewController.designer.cs">
+      <DependentUpon>ViewController.cs</DependentUpon>
+    </Compile>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Facebook.YogaKit.iOS\Facebook.YogaKit.iOS.csproj">
+      <Project>{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}</Project>
+      <Name>Facebook.YogaKit.iOS</Name>
+    </ProjectReference>
+    <ProjectReference Include="..\Facebook.Yoga.iOS\Facebook.Yoga.iOS.csproj">
+      <Project>{128FB32A-C4A1-4363-BF06-0A36E700B7FA}</Project>
+      <Name>Facebook.Yoga.iOS</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
+</Project>

csharp/iOS/Facebook.YogaKit.iOS.Sample/Info.plist

@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>CFBundleName</key>
+    <string>Facebook.YogaKit.iOS.Sample</string>
+    <key>CFBundleIdentifier</key>
+    <string>com.xamarin.facebook-yogakit-ios-sample</string>
+    <key>CFBundleShortVersionString</key>
+    <string>1.0</string>
+    <key>CFBundleVersion</key>
+    <string>1.0</string>
+    <key>LSRequiresIPhoneOS</key>
+    <true/>
+    <key>MinimumOSVersion</key>
+    <string>10.2</string>
+    <key>UIDeviceFamily</key>
+    <array>
+        <integer>1</integer>
+        <integer>2</integer>
+    </array>
+    <key>UILaunchStoryboardName</key>
+    <string>LaunchScreen</string>
+    <key>UIMainStoryboardFile</key>
+    <string>Main</string>
+    <key>UIRequiredDeviceCapabilities</key>
+    <array>
+        <string>armv7</string>
+    </array>
+    <key>UISupportedInterfaceOrientations</key>
+    <array>
+        <string>UIInterfaceOrientationPortrait</string>
+        <string>UIInterfaceOrientationLandscapeLeft</string>
+        <string>UIInterfaceOrientationLandscapeRight</string>
+    </array>
+    <key>XSAppIconAssets</key>
+    <string>Assets.xcassets/AppIcon.appiconset</string>
+</dict>
+</plist>

csharp/iOS/Facebook.YogaKit.iOS.Sample/LaunchScreen.storyboard

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="9532" systemVersion="15D21" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES" initialViewController="01J-lp-oVM">
+    <dependencies>
+        <deployment identifier="iOS" />
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="9530" />
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="EHf-IW-A2E">
+            <objects>
+                <viewController id="01J-lp-oVM" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="Llm-lL-Icb" />
+                        <viewControllerLayoutGuide type="bottom" id="xb3-aO-Qok" />
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="Ze5-6b-2t3">
+                        <rect key="frame" x="0.0" y="0.0" width="600" height="600" />
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES" />
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite" />
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="iYj-Kq-Ea1" userLabel="First Responder" sceneMemberID="firstResponder" />
+            </objects>
+            <point key="canvasLocation" x="53" y="375" />
+        </scene>
+    </scenes>
+</document>

csharp/iOS/Facebook.YogaKit.iOS.Sample/Main.cs

@@ -0,0 +1,12 @@
+using UIKit;
+
+namespace Facebook.YogaKit.iOS.Sample
+{
+	public class Application
+	{
+		static void Main(string[] args)
+		{
+			UIApplication.Main(args, null, "AppDelegate");
+		}
+	}
+}

csharp/iOS/Facebook.YogaKit.iOS.Sample/Main.storyboard

@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="6211" systemVersion="14A298i" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" initialViewController="BYZ-38-t0r">
+    <dependencies>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="6204" />
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="tne-QT-ifu">
+            <objects>
+                <viewController id="BYZ-38-t0r" customClass="ViewController" customModuleProvider="" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="y3c-jy-aDJ" />
+                        <viewControllerLayoutGuide type="bottom" id="wfy-db-euE" />
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="8bC-Xf-vdC">
+                        <rect key="frame" x="0.0" y="0.0" width="600" height="600" />
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES" />
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite" />
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="dkx-z0-nzr" sceneMemberID="firstResponder" />
+            </objects>
+        </scene>
+    </scenes>
+</document>

csharp/iOS/Facebook.YogaKit.iOS.Sample/ViewController.cs

@@ -0,0 +1,54 @@
+using System;
+using CoreGraphics;
+using Facebook.Yoga;
+using UIKit;
+
+namespace Facebook.YogaKit.iOS.Sample
+{
+	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();
+			CreateViewHierarchy(View, View.Bounds.Size.Width, View.Bounds.Size.Height);
+		}
+
+		static void CreateViewHierarchy(UIView root, nfloat width, nfloat height)
+		{
+			root.BackgroundColor = UIColor.Red;
+			root.Yoga().IsEnabled = true;
+
+			root.Yoga().Width = (float)width;
+			root.Yoga().Height = (float)height;
+			root.Yoga().AlignItems = YogaAlign.Center;
+			root.Yoga().JustifyContent = YogaJustify.Center;
+
+			var child1 = new UIView { BackgroundColor = UIColor.Blue };
+			child1.Yoga().IsEnabled = true;
+			child1.Yoga().Width = 100;
+			child1.Yoga().Height = 100;
+
+			var child2 = new UIView
+			{
+				BackgroundColor = UIColor.Green,
+				Frame = new CGRect { Size = new CGSize(200, 100) }
+			};
+
+			var child3 = new UIView
+			{
+				BackgroundColor = UIColor.Yellow,
+				Frame = new CGRect { Size = new CGSize(100, 100) }
+			};
+
+			child2.AddSubview(child3);
+			root.AddSubview(child1);
+			root.AddSubview(child2);
+			root.Yoga().ApplyLayout();
+		}
+	}
+}

csharp/iOS/Facebook.YogaKit.iOS.Sample/ViewController.designer.cs

@@ -0,0 +1,17 @@
+//
+// This file has been generated automatically by MonoDevelop to store outlets and
+// actions made in the Xcode designer. If it is removed, they will be lost.
+// Manual changes to this file may not be handled correctly.
+//
+using Foundation;
+
+namespace Facebook.YogaKit.iOS.Sample
+{
+    [Register("ViewController")]
+    partial class ViewController
+    {
+        void ReleaseDesignerOutlets()
+        {
+        }
+    }
+}

csharp/iOS/Facebook.YogaKit.iOS.Tests/Entitlements.plist

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+</dict>
+</plist>

csharp/iOS/Facebook.YogaKit.iOS.Tests/Facebook.YogaKit.iOS.Tests.csproj

@@ -0,0 +1,118 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">iPhoneSimulator</Platform>
+    <ProjectGuid>{238DB3A2-1182-4775-92BC-F62C885725D8}</ProjectGuid>
+    <ProjectTypeGuids>{FEACFBD2-3405-455C-9665-78FE426C6842};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
+    <OutputType>Exe</OutputType>
+    <RootNamespace>Facebook.YogaKit.iOS.Tests</RootNamespace>
+    <AssemblyName>Facebook.YogaKit.iOS.Tests</AssemblyName>
+    <IPhoneResourcePrefix>Resources</IPhoneResourcePrefix>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|iPhoneSimulator' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\iPhoneSimulator\Debug</OutputPath>
+    <DefineConstants>DEBUG;</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <CodesignKey>iPhone Developer</CodesignKey>
+    <MtouchDebug>true</MtouchDebug>
+    <MtouchFastDev>true</MtouchFastDev>
+    <MtouchProfiling>true</MtouchProfiling>
+    <MtouchUseSGen>true</MtouchUseSGen>
+    <MtouchUseRefCounting>true</MtouchUseRefCounting>
+    <IOSDebuggerPort>17481</IOSDebuggerPort>
+    <MtouchLink>None</MtouchLink>
+    <MtouchArch>x86_64</MtouchArch>
+    <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
+    <MtouchTlsProvider>Default</MtouchTlsProvider>
+    <DeviceSpecificBuild>false</DeviceSpecificBuild>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|iPhone' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\iPhone\Release</OutputPath>
+    <DefineConstants></DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <CodesignKey>iPhone Developer</CodesignKey>
+    <MtouchUseSGen>true</MtouchUseSGen>
+    <MtouchUseRefCounting>true</MtouchUseRefCounting>
+    <MtouchFloat32>true</MtouchFloat32>
+    <CodesignEntitlements>Entitlements.plist</CodesignEntitlements>
+    <MtouchLink>SdkOnly</MtouchLink>
+    <MtouchArch>ARMv7, ARM64</MtouchArch>
+    <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
+    <MtouchTlsProvider>Default</MtouchTlsProvider>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|iPhoneSimulator' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\iPhoneSimulator\Release</OutputPath>
+    <DefineConstants></DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <CodesignKey>iPhone Developer</CodesignKey>
+    <MtouchUseSGen>true</MtouchUseSGen>
+    <MtouchUseRefCounting>true</MtouchUseRefCounting>
+    <MtouchLink>None</MtouchLink>
+    <MtouchArch>x86_64</MtouchArch>
+    <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
+    <MtouchTlsProvider>Default</MtouchTlsProvider>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|iPhone' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\iPhone\Debug</OutputPath>
+    <DefineConstants>DEBUG;</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <CodesignKey>iPhone Developer</CodesignKey>
+    <DeviceSpecificBuild>true</DeviceSpecificBuild>
+    <MtouchDebug>true</MtouchDebug>
+    <MtouchFastDev>true</MtouchFastDev>
+    <MtouchProfiling>true</MtouchProfiling>
+    <MtouchUseSGen>true</MtouchUseSGen>
+    <MtouchUseRefCounting>true</MtouchUseRefCounting>
+    <MtouchFloat32>true</MtouchFloat32>
+    <CodesignEntitlements>Entitlements.plist</CodesignEntitlements>
+    <MtouchLink>SdkOnly</MtouchLink>
+    <MtouchArch>ARMv7, ARM64</MtouchArch>
+    <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
+    <MtouchTlsProvider>Default</MtouchTlsProvider>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Xml" />
+    <Reference Include="System.Core" />
+    <Reference Include="Xamarin.iOS" />
+    <Reference Include="MonoTouch.NUnitLite" />
+  </ItemGroup>
+  <ItemGroup>
+    <InterfaceDefinition Include="LaunchScreen.storyboard" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="Info.plist" />
+    <None Include="Entitlements.plist" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Main.cs" />
+    <Compile Include="UnitTestAppDelegate.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Facebook.YogaKit.iOS\Facebook.YogaKit.iOS.csproj">
+      <Project>{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}</Project>
+      <Name>Facebook.YogaKit.iOS</Name>
+    </ProjectReference>
+    <ProjectReference Include="..\Facebook.Yoga.iOS\Facebook.Yoga.iOS.csproj">
+      <Project>{128FB32A-C4A1-4363-BF06-0A36E700B7FA}</Project>
+      <Name>Facebook.Yoga.iOS</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="..\..\tests\Facebook.YogaKit.Shared.Tests\Facebook.YogaKit.Shared.Tests.projitems" Label="Shared" Condition="Exists('..\..\tests\Facebook.YogaKit.Shared.Tests\Facebook.YogaKit.Shared.Tests.projitems')" />
+  <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
+</Project>

csharp/iOS/Facebook.YogaKit.iOS.Tests/Info.plist

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"[]>
+<plist version="1.0">
+    <dict>
+        <key>CFBundleName</key>
+        <string>Facebook.YogaKit.iOS.Tests</string>
+        <key>CFBundleIdentifier</key>
+        <string>com.xamarin.facebook-yogakit-ios-tests</string>
+        <key>CFBundleShortVersionString</key>
+        <string>1.0</string>
+        <key>CFBundleVersion</key>
+        <string>1.0</string>
+        <key>LSRequiresIPhoneOS</key>
+        <true />
+        <key>MinimumOSVersion</key>
+        <string>10.2</string>
+        <key>UIDeviceFamily</key>
+        <array>
+            <integer>1</integer>
+            <integer>2</integer>
+        </array>
+        <key>UISupportedInterfaceOrientations</key>
+        <array>
+            <string>UIInterfaceOrientationPortrait</string>
+            <string>UIInterfaceOrientationLandscapeLeft</string>
+            <string>UIInterfaceOrientationLandscapeRight</string>
+        </array>
+        <key>UILaunchStoryboardName</key>
+        <string>LaunchScreen</string>
+        <key>NSAppTransportSecurity</key>
+        <dict>
+            <key>NSAllowsArbitraryLoads</key>
+            <true />
+        </dict>
+    </dict>
+</plist>

csharp/iOS/Facebook.YogaKit.iOS.Tests/LaunchScreen.storyboard

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="9532" systemVersion="15D21" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES" initialViewController="01J-lp-oVM">
+    <dependencies>
+        <deployment identifier="iOS" />
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="9530" />
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="EHf-IW-A2E">
+            <objects>
+                <viewController id="01J-lp-oVM" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="Llm-lL-Icb" />
+                        <viewControllerLayoutGuide type="bottom" id="xb3-aO-Qok" />
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="Ze5-6b-2t3">
+                        <rect key="frame" x="0.0" y="0.0" width="600" height="600" />
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES" />
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite" />
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="iYj-Kq-Ea1" userLabel="First Responder" sceneMemberID="firstResponder" />
+            </objects>
+            <point key="canvasLocation" x="53" y="375" />
+        </scene>
+    </scenes>
+</document>

csharp/iOS/Facebook.YogaKit.iOS.Tests/Main.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Linq;
+using System.Collections.Generic;
+
+using Foundation;
+using UIKit;
+
+namespace Facebook.YogaKit.iOS.Tests
+{
+    public class Application
+    {
+        // This is the main entry point of the application.
+        static void Main(string[] args)
+        {
+            // if you want to use a different Application Delegate class from "UnitTestAppDelegate"
+            // you can specify it here.
+            UIApplication.Main(args, null, "UnitTestAppDelegate");
+        }
+    }
+}

csharp/iOS/Facebook.YogaKit.iOS.Tests/UnitTestAppDelegate.cs

@@ -0,0 +1,45 @@
+using System;
+using System.Linq;
+using System.Collections.Generic;
+
+using Foundation;
+using UIKit;
+using MonoTouch.NUnit.UI;
+
+namespace Facebook.YogaKit.iOS.Tests
+{
+    // The UIApplicationDelegate for the application. This class is responsible for launching the 
+    // User Interface of the application, as well as listening (and optionally responding) to 
+    // application events from iOS.
+    [Register("UnitTestAppDelegate")]
+    public partial class UnitTestAppDelegate : UIApplicationDelegate
+    {
+        // class-level declarations
+        UIWindow window;
+        TouchRunner runner;
+
+        //
+        // This method is invoked when the application has loaded and is ready to run. In this 
+        // method you should instantiate the window, load the UI into it and then make the window
+        // visible.
+        //
+        // You have 17 seconds to return from this method, or iOS will terminate your application.
+        //
+        public override bool FinishedLaunching(UIApplication app, NSDictionary options)
+        {
+            // create a new window instance based on the screen size
+            window = new UIWindow(UIScreen.MainScreen.Bounds);
+            runner = new TouchRunner(window);
+
+            // register every tests included in the main application/assembly
+            runner.Add(System.Reflection.Assembly.GetExecutingAssembly());
+
+            window.RootViewController = new UINavigationController(runner.GetViewController());
+
+            // make the window visible
+            window.MakeKeyAndVisible();
+
+            return true;
+        }
+    }
+}

csharp/iOS/Facebook.YogaKit.iOS.sln

@@ -0,0 +1,84 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 2012
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Shared", "Shared", "{9FB621AA-66DD-46F1-8B10-94F508272A8D}"
+EndProject
+Project("{D954291E-2A0B-460D-934E-DC6B0785DB48}") = "Facebook.YogaKit.Shared", "..\Facebook.YogaKit\Facebook.YogaKit.Shared.shproj", "{A24B3BA6-3143-4FFF-B8B8-1EDF166F5F4A}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Facebook.YogaKit.iOS", "Facebook.YogaKit.iOS\Facebook.YogaKit.iOS.csproj", "{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Facebook.YogaKit.iOS.Sample", "Facebook.YogaKit.iOS.Sample\Facebook.YogaKit.iOS.Sample.csproj", "{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}"
+EndProject
+Project("{D954291E-2A0B-460D-934E-DC6B0785DB48}") = "Facebook.Yoga.Shared", "..\Facebook.Yoga\Facebook.Yoga.Shared.shproj", "{91C42D32-291D-4B72-90B4-551663D60B8B}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Facebook.Yoga.iOS", "Facebook.Yoga.iOS\Facebook.Yoga.iOS.csproj", "{128FB32A-C4A1-4363-BF06-0A36E700B7FA}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Facebook.YogaKit.iOS.Tests", "Facebook.YogaKit.iOS.Tests\Facebook.YogaKit.iOS.Tests.csproj", "{238DB3A2-1182-4775-92BC-F62C885725D8}"
+EndProject
+Project("{D954291E-2A0B-460D-934E-DC6B0785DB48}") = "Facebook.YogaKit.Shared.Tests", "..\tests\Facebook.YogaKit.Shared.Tests\Facebook.YogaKit.Shared.Tests.shproj", "{63AB08F4-4F7C-42B7-A20F-D84204D0D3CE}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+		Debug|iPhoneSimulator = Debug|iPhoneSimulator
+		Release|iPhone = Release|iPhone
+		Release|iPhoneSimulator = Release|iPhoneSimulator
+		Debug|iPhone = Debug|iPhone
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Debug|iPhoneSimulator.ActiveCfg = Debug|Any CPU
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Debug|iPhoneSimulator.Build.0 = Debug|Any CPU
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Release|iPhone.ActiveCfg = Release|Any CPU
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Release|iPhone.Build.0 = Release|Any CPU
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Release|iPhoneSimulator.ActiveCfg = Release|Any CPU
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Release|iPhoneSimulator.Build.0 = Release|Any CPU
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Debug|iPhone.ActiveCfg = Debug|Any CPU
+		{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}.Debug|iPhone.Build.0 = Debug|Any CPU
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Debug|Any CPU.ActiveCfg = Debug|iPhoneSimulator
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Debug|Any CPU.Build.0 = Debug|iPhoneSimulator
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Release|Any CPU.ActiveCfg = Release|iPhone
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Release|Any CPU.Build.0 = Release|iPhone
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Debug|iPhoneSimulator.ActiveCfg = Debug|iPhoneSimulator
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Debug|iPhoneSimulator.Build.0 = Debug|iPhoneSimulator
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Release|iPhone.ActiveCfg = Release|iPhone
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Release|iPhone.Build.0 = Release|iPhone
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Release|iPhoneSimulator.ActiveCfg = Release|iPhoneSimulator
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Release|iPhoneSimulator.Build.0 = Release|iPhoneSimulator
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Debug|iPhone.ActiveCfg = Debug|iPhone
+		{6A094B74-FA9A-4E49-A8E1-F450A04E3E5B}.Debug|iPhone.Build.0 = Debug|iPhone
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Release|Any CPU.Build.0 = Release|Any CPU
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Debug|iPhoneSimulator.ActiveCfg = Debug|Any CPU
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Debug|iPhoneSimulator.Build.0 = Debug|Any CPU
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Release|iPhone.ActiveCfg = Release|Any CPU
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Release|iPhone.Build.0 = Release|Any CPU
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Release|iPhoneSimulator.ActiveCfg = Release|Any CPU
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Release|iPhoneSimulator.Build.0 = Release|Any CPU
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Debug|iPhone.ActiveCfg = Debug|Any CPU
+		{128FB32A-C4A1-4363-BF06-0A36E700B7FA}.Debug|iPhone.Build.0 = Debug|Any CPU
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Debug|Any CPU.ActiveCfg = Debug|iPhoneSimulator
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Debug|Any CPU.Build.0 = Debug|iPhoneSimulator
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Release|Any CPU.ActiveCfg = Release|iPhone
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Release|Any CPU.Build.0 = Release|iPhone
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Debug|iPhoneSimulator.ActiveCfg = Debug|iPhoneSimulator
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Debug|iPhoneSimulator.Build.0 = Debug|iPhoneSimulator
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Release|iPhone.ActiveCfg = Release|iPhone
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Release|iPhone.Build.0 = Release|iPhone
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Release|iPhoneSimulator.ActiveCfg = Release|iPhoneSimulator
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Release|iPhoneSimulator.Build.0 = Release|iPhoneSimulator
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Debug|iPhone.ActiveCfg = Debug|iPhone
+		{238DB3A2-1182-4775-92BC-F62C885725D8}.Debug|iPhone.Build.0 = Debug|iPhone
+	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{A24B3BA6-3143-4FFF-B8B8-1EDF166F5F4A} = {9FB621AA-66DD-46F1-8B10-94F508272A8D}
+		{91C42D32-291D-4B72-90B4-551663D60B8B} = {9FB621AA-66DD-46F1-8B10-94F508272A8D}
+		{63AB08F4-4F7C-42B7-A20F-D84204D0D3CE} = {9FB621AA-66DD-46F1-8B10-94F508272A8D}
+	EndGlobalSection
+EndGlobal

csharp/iOS/Facebook.YogaKit.iOS/Facebook.YogaKit.iOS.csproj

@@ -0,0 +1,69 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{0C38AA9D-3178-4B43-9C3B-3C97A90FB1B0}</ProjectGuid>
+    <ProjectTypeGuids>{FEACFBD2-3405-455C-9665-78FE426C6842};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
+    <OutputType>Library</OutputType>
+    <RootNamespace>Facebook.YogaKit.iOS</RootNamespace>
+    <AssemblyName>Facebook.YogaKit.iOS</AssemblyName>
+    <IPhoneResourcePrefix>Resources</IPhoneResourcePrefix>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug</OutputPath>
+    <DefineConstants>DEBUG;__IOS__</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <CodesignKey>iPhone Developer</CodesignKey>
+    <MtouchDebug>true</MtouchDebug>
+    <MtouchFastDev>true</MtouchFastDev>
+    <MtouchProfiling>true</MtouchProfiling>
+    <MtouchUseSGen>true</MtouchUseSGen>
+    <MtouchUseRefCounting>true</MtouchUseRefCounting>
+    <IOSDebuggerPort>53781</IOSDebuggerPort>
+    <DeviceSpecificBuild>false</DeviceSpecificBuild>
+    <MtouchLink>SdkOnly</MtouchLink>
+    <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
+    <MtouchTlsProvider>Default</MtouchTlsProvider>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release</OutputPath>
+    <DefineConstants></DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <CodesignKey>iPhone Developer</CodesignKey>
+    <MtouchUseSGen>true</MtouchUseSGen>
+    <MtouchUseRefCounting>true</MtouchUseRefCounting>
+    <MtouchLink>SdkOnly</MtouchLink>
+    <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
+    <MtouchTlsProvider>Default</MtouchTlsProvider>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Xml" />
+    <Reference Include="System.Core" />
+    <Reference Include="Xamarin.iOS" />
+  </ItemGroup>
+  <ItemGroup>
+    <Folder Include="Resources\" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="YogaLayout.cs" />
+    <Compile Include="YogaKit.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Facebook.Yoga.iOS\Facebook.Yoga.iOS.csproj">
+      <Project>{128FB32A-C4A1-4363-BF06-0A36E700B7FA}</Project>
+      <Name>Facebook.Yoga.iOS</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="..\..\Facebook.YogaKit\Facebook.YogaKit.projitems" Label="Shared" Condition="Exists('..\..\Facebook.YogaKit\Facebook.YogaKit.projitems')" />
+  <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
+</Project>

csharp/iOS/Facebook.YogaKit.iOS/Properties/AssemblyInfo.cs

@@ -0,0 +1,26 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+
+// Information about this assembly is defined by the following attributes. 
+// Change them to the values specific to your project.
+
+[assembly: AssemblyTitle("Facebook.YogaKit.iOS")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("")]
+[assembly: AssemblyCopyright("rmarinho")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// The assembly version has the format "{Major}.{Minor}.{Build}.{Revision}".
+// The form "{Major}.{Minor}.*" will automatically update the build and revision,
+// and "{Major}.{Minor}.{Build}.*" will update just the revision.
+
+[assembly: AssemblyVersion("1.0.*")]
+
+// The following attributes are used to specify the signing key for the assembly, 
+// if desired. See the Mono documentation for more information about signing.
+
+//[assembly: AssemblyDelaySign(false)]
+//[assembly: AssemblyKeyFile("")]

csharp/iOS/Facebook.YogaKit.iOS/YogaKit.cs

@@ -0,0 +1,43 @@
+using System;
+using System.Runtime.InteropServices;
+using Foundation;
+using UIKit;
+
+namespace Facebook.YogaKit
+{
+	public static partial class YogaKit
+	{
+		static NSString YogaNodeKey = new NSString("YogaNode");
+
+		public static IYogaLayout Yoga(this UIView view)
+		{
+			return YogaLayoutNative(view);
+		}
+
+		static IYogaLayout YogaLayoutNative(UIView view)
+		{
+			var yoga = ObjCRuntime.Runtime.GetNSObject(objc_getAssociatedObject(view.Handle, YogaNodeKey.Handle)) as YogaLayout;
+			if (yoga == null)
+			{
+				yoga = new YogaLayout(view);
+				objc_setAssociatedObject(view.Handle, YogaNodeKey.Handle, yoga.Handle, AssociationPolicy.RETAIN_NONATOMIC);
+			}
+			return yoga;
+		}
+
+		[DllImport("/usr/lib/libobjc.dylib")]
+		static extern void objc_setAssociatedObject(IntPtr @object, IntPtr key, IntPtr value, AssociationPolicy policy);
+
+		[DllImport("/usr/lib/libobjc.dylib")]
+		static extern IntPtr objc_getAssociatedObject(IntPtr @object, IntPtr key);
+
+		enum AssociationPolicy
+		{
+			ASSIGN = 0,
+			RETAIN_NONATOMIC = 1,
+			COPY_NONATOMIC = 3,
+			RETAIN = 01401,
+			COPY = 01403,
+		}
+	}
+}

csharp/iOS/Facebook.YogaKit.iOS/YogaLayout.cs

@@ -0,0 +1,52 @@
+using System.Collections.Generic;
+using CoreGraphics;
+using Facebook.Yoga;
+using Foundation;
+using UIKit;
+
+namespace Facebook.YogaKit
+{
+	public partial class YogaLayout : NSObject
+	{
+		static IEnumerable<UIView> GetChildren(UIView view) => view.Subviews;
+
+		static void MeasureNativeView(UIView view, float constrainedWidth, float constrainedHeight, out float sizeThatFitsWidth, out float sizeThatFitsHeight)
+		{
+			var sizeThatFits = view.SizeThatFits(new CGSize(constrainedWidth, constrainedHeight));
+			sizeThatFitsWidth = (float)sizeThatFits.Width;
+			sizeThatFitsHeight = (float)sizeThatFits.Height;
+		}
+
+		static void GetWidthHeightOfNativeView(UIView view, out float width, out float height)
+		{
+			width = (float)view.Bounds.Width;
+			height = (float)view.Bounds.Height;
+		}
+
+		static float NativePixelScale => (float)UIScreen.MainScreen.Scale;
+
+
+		static void ApplyLayoutToNativeView(UIView view, YogaNode node)
+		{
+			var topLeft = new CGPoint(node.LayoutX, node.LayoutY);
+			var bottomRight = new CGPoint(topLeft.X + node.LayoutWidth, topLeft.Y + node.LayoutHeight);
+			view.Frame = new CGRect(RoundPixelValue((float)topLeft.X), RoundPixelValue((float)topLeft.Y), RoundPixelValue((float)bottomRight.X) - RoundPixelValue((float)topLeft.X), RoundPixelValue((float)bottomRight.Y) - RoundPixelValue((float)topLeft.Y));
+		}
+
+		bool _disposed;
+		protected override void Dispose(bool disposing)
+		{
+			if (disposing && !_disposed)
+			{
+				_disposed = true;
+				if (YogaKit.Bridges.ContainsKey(_node))
+				{
+					YogaKit.Bridges.Remove(_node);
+				}
+				_node = null;
+				_viewRef = null;
+			}
+			base.Dispose(disposing);
+		}
+	}
+}

csharp/tests/Facebook.YogaKit.Shared.Tests/Facebook.YogaKit.Shared.Tests.projitems

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
+    <HasSharedItems>true</HasSharedItems>
+    <SharedGUID>{63AB08F4-4F7C-42B7-A20F-D84204D0D3CE}</SharedGUID>
+  </PropertyGroup>
+  <PropertyGroup Label="Configuration">
+    <Import_RootNamespace>Facebook.YogaKit.Shared.Tests</Import_RootNamespace>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildThisFileDirectory)YogaKitTest.cs" />
+  </ItemGroup>
+</Project>

csharp/tests/Facebook.YogaKit.Shared.Tests/Facebook.YogaKit.Shared.Tests.shproj

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <ProjectGuid>{63AB08F4-4F7C-42B7-A20F-D84204D0D3CE}</ProjectGuid>
+  </PropertyGroup>
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\CodeSharing\Microsoft.CodeSharing.Common.Default.props" />
+  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\CodeSharing\Microsoft.CodeSharing.Common.props" />
+  <Import Project="Facebook.YogaKit.Shared.Tests.projitems" Label="Shared" />
+  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\CodeSharing\Microsoft.CodeSharing.CSharp.targets" />
+</Project>

csharp/tests/Facebook.YogaKit.Shared.Tests/YogaKitTest.cs

@@ -0,0 +1,369 @@
+using System.Drawing;
+using Facebook.Yoga;
+using NUnit.Framework;
+using System;
+#if __IOS__
+using NativeView = UIKit.UIView;
+using CoreGraphics;
+#endif
+
+namespace Facebook.YogaKit
+{
+	[TestFixture]
+	public class YogaKitTest
+	{
+		[Test]
+		public void TestUsesYoga()
+		{
+			var view = new NativeView();
+			Assert.False(view.Yoga().IsEnabled);
+			view.Yoga().IsEnabled = true;
+			Assert.True(view.Yoga().IsEnabled);
+			view.Yoga().IsEnabled = false;
+			Assert.False(view.Yoga().IsEnabled);
+		}
+
+		[Test]
+		public void TestSizeThatFitsAsserts()
+		{
+			var view = new NativeView();
+			Assert.Ignore("Not implemented yet");
+			//  dispatch_sync(dispatch_queue_create("com.facebook.Yoga.testing", DISPATCH_QUEUE_SERIAL), ^(void){
+			//    XCTAssertThrows(view.yoga.intrinsicSize);
+			//  });
+		}
+
+		[Test]
+		public void TestSizeThatFitsSmoke()
+		{
+			var container = new NativeView();
+			container.Yoga().IsEnabled = true;
+			container.Yoga().FlexDirection = YogaFlexDirection.Row;
+			container.Yoga().AlignItems = YogaAlign.FlexStart;
+
+			var longTextLabel = new UIKit.UILabel();
+			longTextLabel.Text = @"This is a very very very very very very very very long piece of text.";
+			longTextLabel.LineBreakMode = UIKit.UILineBreakMode.TailTruncation;
+			longTextLabel.Lines = 1;
+			longTextLabel.Yoga().IsEnabled = true;
+			longTextLabel.Yoga().FlexShrink = 1;
+			container.AddSubview(longTextLabel);
+
+			var textBadgeView = new NativeView();
+			textBadgeView.Yoga().IsEnabled = true;
+			textBadgeView.Yoga().MarginLeft = 3.0f;
+			textBadgeView.Yoga().Width = 10;
+			textBadgeView.Yoga().Height = 10;
+			container.AddSubview(textBadgeView);
+
+			var containerSize = container.Yoga().IntrinsicSize;
+			Assert.True(new SizeF(514, 21) == containerSize, $"Size is actually {containerSize})");
+		}
+
+		[Test]
+		public void TestThatMarkingLeafsAsDirtyWillTriggerASizeRecalculation()
+		{
+			var container = new NativeView(new CGRect(0, 0, 500, 500));
+			container.Yoga().IsEnabled = true;
+			container.Yoga().FlexDirection = YogaFlexDirection.Row;
+			container.Yoga().AlignItems = YogaAlign.FlexStart;
+
+			var label = new UIKit.UILabel();
+			label.Text = @"This is a short text.";
+			label.Lines = 1;
+			label.Yoga().IsEnabled = true;
+			container.AddSubview(label);
+
+			container.Yoga().ApplyLayout();
+			Assert.True(new SizeF(146, 21) == label.Bounds.Size, $"Size is actually {label.Bounds.Size})");
+
+			label.Text = @"This is a slightly longer text.";
+			label.Yoga().MarkDirty();
+
+			container.Yoga().ApplyLayout();
+			Assert.True(new SizeF(213, 21) == label.Bounds.Size, $"Size is actually {label.Bounds.Size})");
+		}
+
+		[Test]
+		public void TestFrameAndOriginPlacement()
+		{
+			var containerSize = new SizeF(320, 50);
+
+			var container = new NativeView(new CGRect(0, 0, containerSize.Width, containerSize.Height));
+			container.Yoga().IsEnabled = true;
+			container.Yoga().FlexDirection = YogaFlexDirection.Row;
+
+			for (int i = 0; i < 3; i++)
+			{
+				var subview = new NativeView();
+				subview.Yoga().IsEnabled = true;
+				subview.Yoga().FlexGrow = 1;
+				container.AddSubview(subview);
+			}
+			container.Yoga().ApplyLayout();
+
+			Assert.False(CGRect.Intersect(container.Subviews[0].Frame, container.Subviews[1].Frame) == CGRect.Empty);
+			Assert.False(CGRect.Intersect(container.Subviews[1].Frame, container.Subviews[2].Frame) == CGRect.Empty);
+			Assert.False(CGRect.Intersect(container.Subviews[0].Frame, container.Subviews[2].Frame) == CGRect.Empty);
+
+			float totalWidth = 0;
+			foreach (var view in container.Subviews)
+				totalWidth += (float)view.Bounds.Size.Width;
+
+			Assert.AreEqual(containerSize.Width, totalWidth, $"The container's width is {containerSize.Width}, the subviews take up {totalWidth}");
+		}
+
+
+		[Test]
+		public void TestThatLayoutIsCorrectWhenWeSwapViewOrder()
+		{
+			var containerSize = new SizeF(300, 50);
+
+			var container = new NativeView(new CGRect(0, 0, containerSize.Width, containerSize.Height));
+			container.Yoga().IsEnabled = true;
+			container.Yoga().FlexDirection = YogaFlexDirection.Row;
+
+			var subview1 = new NativeView();
+			subview1.Yoga().IsEnabled = true;
+			subview1.Yoga().FlexGrow = 1;
+			container.AddSubview(subview1);
+
+			var subview2 = new NativeView();
+			subview2.Yoga().IsEnabled = true;
+			subview2.Yoga().FlexGrow = 1;
+			container.AddSubview(subview2);
+
+			var subview3 = new NativeView();
+			subview3.Yoga().IsEnabled = true;
+			subview3.Yoga().FlexGrow = 1;
+			container.AddSubview(subview3);
+
+			container.Yoga().ApplyLayout();
+
+			Assert.True(subview1.Frame == new CGRect(0, 0, 100, 50));
+			Assert.True(subview2.Frame == new CGRect(100, 0, 100, 50), $"It's actually {subview2.Frame}");
+			Assert.True(subview3.Frame == new CGRect(200, 0, 100, 50));
+
+			container.ExchangeSubview(2, 0);
+			subview2.Yoga().IsIncludeInLayout = false;
+			container.Yoga().ApplyLayout();
+
+			Assert.True(subview3.Frame == new CGRect(0, 0, 150, 50));
+			Assert.True(subview1.Frame == new CGRect(150, 0, 150, 50));
+			//// this frame shouldn't have been modified since last time.
+			Assert.True(subview2.Frame == new CGRect(100, 0, 100, 50));
+		}
+
+		[Test]
+		public void TestThatWeRespectIncludeInLayoutFlag()
+		{
+			var containerSize = new SizeF(300, 50);
+
+			var container = new NativeView(new CGRect(0, 0, containerSize.Width, containerSize.Height));
+			container.Yoga().IsEnabled = true;
+			container.Yoga().FlexDirection = YogaFlexDirection.Row;
+
+			var subview1 = new NativeView();
+			subview1.Yoga().IsEnabled = true;
+			subview1.Yoga().FlexGrow = 1;
+			container.AddSubview(subview1);
+
+			var subview2 = new NativeView();
+			subview2.Yoga().IsEnabled = true;
+			subview2.Yoga().FlexGrow = 1;
+			container.AddSubview(subview2);
+
+			var subview3 = new NativeView();
+			subview3.Yoga().IsEnabled = true;
+			subview3.Yoga().FlexGrow = 1;
+			container.AddSubview(subview3);
+
+			container.Yoga().ApplyLayout();
+
+			foreach (var view in container.Subviews)
+			{
+				Assert.True(new CGSize(100, 50) == view.Bounds.Size, $"Actual size is {view.Bounds.Size}");
+			}
+
+			subview3.Yoga().IsIncludeInLayout = false;
+			container.Yoga().ApplyLayout();
+			Assert.True(subview1.Frame.Size == new CGSize(150, 50), $"Actual size is {subview1.Frame.Size}");
+			Assert.True(subview2.Frame.Size == new CGSize(150, 50), $"Actual size is {subview2.Frame.Size}");
+			//// We don't set the frame to zero, so, it should be set to what it was previously at.
+			Assert.True(subview3.Frame.Size == new CGSize(100, 50), $"Actual size is {subview3.Frame.Size}");
+		}
+
+		[Test]
+		public void TestThatNumberOfChildrenIsCorrectWhenWeIgnoreSubviews()
+		{
+			var container = new NativeView();
+			container.Yoga().IsEnabled = true;
+			container.Yoga().FlexDirection = YogaFlexDirection.Row;
+
+			var subview1 = new NativeView();
+			subview1.Yoga().IsEnabled = true;
+			subview1.Yoga().IsIncludeInLayout = false;
+			container.AddSubview(subview1);
+
+			var subview2 = new NativeView();
+			subview2.Yoga().IsEnabled = true;
+			subview2.Yoga().IsIncludeInLayout = false;
+			container.AddSubview(subview2);
+
+			var subview3 = new NativeView();
+			subview3.Yoga().IsEnabled = true;
+			subview3.Yoga().IsIncludeInLayout = true;
+			container.AddSubview(subview3);
+
+			container.Yoga().ApplyLayout();
+			Assert.AreEqual(1, container.Yoga().NumberOfChildren);
+
+			subview2.Yoga().IsIncludeInLayout = true;
+			container.Yoga().ApplyLayout();
+			Assert.AreEqual(2, container.Yoga().NumberOfChildren);
+		}
+
+		[Test]
+		public void TestThatViewNotIncludedInFirstLayoutPassAreIncludedInSecond()
+		{
+			var containerSize = new SizeF(300, 50);
+
+			var container = new NativeView(new CGRect(0, 0, containerSize.Width, containerSize.Height));
+			container.Yoga().IsEnabled = true;
+			container.Yoga().FlexDirection = YogaFlexDirection.Row;
+
+			var subview1 = new NativeView();
+			subview1.Yoga().IsEnabled = true;
+			subview1.Yoga().FlexGrow = 1;
+			container.AddSubview(subview1);
+
+			var subview2 = new NativeView();
+			subview2.Yoga().IsEnabled = true;
+			subview2.Yoga().FlexGrow = 1;
+			container.AddSubview(subview2);
+
+			var subview3 = new NativeView();
+			subview3.Yoga().IsEnabled = true;
+			subview3.Yoga().FlexGrow = 1;
+			subview3.Yoga().IsIncludeInLayout = false;
+			container.AddSubview(subview3);
+
+			container.Yoga().ApplyLayout();
+
+			Assert.True(subview1.Frame.Size == new CGSize(150, 50), $"Actual size is {subview1.Frame.Size}");
+			Assert.True(subview2.Frame.Size == new CGSize(150, 50), $"Actual size is {subview2.Frame.Size}");
+			Assert.True(subview3.Frame.Size == CGSize.Empty, $"Actual size is {subview3.Frame.Size}");
+
+			subview3.Yoga().IsIncludeInLayout = true;
+			container.Yoga().ApplyLayout();
+
+			foreach (var view in container.Subviews)
+			{
+				Assert.True(new CGSize(100, 50) == view.Bounds.Size, $"Actual size is {view.Bounds.Size}");
+			}
+		}
+
+		[Test]
+		public void TestYogaIsLeafFlag()
+		{
+			var view = new NativeView();
+			Assert.True(view.Yoga().IsLeaf);
+
+			for (int i = 0; i < 10; i++)
+			{
+				var subView = new NativeView();
+				view.AddSubview(subView);
+			}
+			Assert.True(view.Yoga().IsLeaf);
+			view.Yoga().IsEnabled = true;
+			view.Yoga().Width = 50.0f;
+			Assert.True(view.Yoga().IsLeaf);
+
+			var subView1 = view.Subviews[0];
+			subView1.Yoga().IsEnabled = true;
+			subView1.Yoga().Width = 50.0f;
+			Assert.False(view.Yoga().IsLeaf);
+		}
+
+		[Test]
+		public void TestThatWeCorrectlyAttachNestedViews()
+		{
+			var containerSize = new SizeF(300, 50);
+
+			var container = new NativeView(new CGRect(0, 0, containerSize.Width, containerSize.Height));
+			container.Yoga().IsEnabled = true;
+			container.Yoga().FlexDirection = YogaFlexDirection.Column;
+
+			var subview1 = new NativeView();
+			subview1.Yoga().IsEnabled = true;
+			subview1.Yoga().Width = 100;
+			subview1.Yoga().FlexGrow = 1;
+			subview1.Yoga().FlexDirection = YogaFlexDirection.Column;
+			container.AddSubview(subview1);
+
+			var subview2 = new NativeView();
+			subview2.Yoga().IsEnabled = true;
+			subview2.Yoga().Width = 150;
+			subview2.Yoga().FlexGrow = 1;
+			subview2.Yoga().FlexDirection = YogaFlexDirection.Column;
+			container.AddSubview(subview2);
+
+			foreach (var view in new NativeView[] { subview1, subview2 })
+			{
+				var someView = new NativeView();
+				someView.Yoga().IsEnabled = true;
+				someView.Yoga().FlexGrow = 1;
+				view.AddSubview(someView);
+			}
+			container.Yoga().ApplyLayout();
+
+			// Add the same amount of new views, reapply layout.
+			foreach (var view in new NativeView[] { subview1, subview2 })
+			{
+				var someView = new NativeView();
+				someView.Yoga().IsEnabled = true;
+				someView.Yoga().FlexGrow = 1;
+				view.AddSubview(someView);
+			}
+			container.Yoga().ApplyLayout();
+
+			Assert.True(new CGSize(100, 25) == subview1.Bounds.Size, $"Actual size is {subview1.Bounds.Size}");
+			foreach (var subview in subview1.Subviews)
+			{
+				var subviewSize = subview.Bounds.Size;
+				Assert.False(subviewSize.IsEmpty);
+				Assert.False(nfloat.IsNaN(subviewSize.Height));
+				Assert.False(nfloat.IsNaN(subviewSize.Width));
+			}
+
+			Assert.True(new CGSize(150, 25) == subview2.Bounds.Size, $"Actual size is {subview2.Bounds.Size}");
+			foreach (var subview in subview2.Subviews)
+			{
+				var subviewSize = subview.Bounds.Size;
+				Assert.False(subviewSize.IsEmpty);
+				Assert.False(nfloat.IsNaN(subviewSize.Height));
+				Assert.False(nfloat.IsNaN(subviewSize.Width));
+			}
+		}
+
+		[Test]
+		public void TestThatANonLeafNodeCanBecomeALeafNode()
+		{
+			var containerSize = new SizeF(300, 50);
+
+			var container = new NativeView(new CGRect(0, 0, containerSize.Width, containerSize.Height));
+			container.Yoga().IsEnabled = true;
+
+			var subview1 = new NativeView();
+			subview1.Yoga().IsEnabled = true;
+			container.AddSubview(subview1);
+
+			var subview2 = new NativeView();
+			subview2.Yoga().IsEnabled = true;
+			container.AddSubview(subview2);
+			container.Yoga().ApplyLayout();
+			subview2.RemoveFromSuperview();
+			container.Yoga().ApplyLayout();
+		}
+	}
+}