[XamlC] Compile ContraintTypeConverters (#592)

* [XamlC] Compile ContraintTypeConverters

* fix error message

5 files changed, 45 insertions, 14 deletions

diff --git a/Xamarin.Forms.Build.Tasks/CompiledConverters/ConstraintTypeConverter.cs b/Xamarin.Forms.Build.Tasks/CompiledConverters/ConstraintTypeConverter.cs
new file mode 100644
index 00000000..18b1810c
--- /dev/null
+++ b/Xamarin.Forms.Build.Tasks/CompiledConverters/ConstraintTypeConverter.cs
@@ -0,0 +1,28 @@
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+using Xamarin.Forms.Xaml;
+
+namespace Xamarin.Forms.Core.XamlC
+{
+	class ConstraintTypeConverter : ICompiledTypeConverter
+	{
+		public IEnumerable<Instruction> ConvertFromString(string value, ModuleDefinition module, BaseNode node)
+		{
+			double size;
+
+			if (string.IsNullOrEmpty(value) || !double.TryParse(value, NumberStyles.Number, CultureInfo.InvariantCulture, out size))
+				throw new XamlParseException($"Cannot convert \"{value}\" into {typeof(Constraint)}", node);
+
+			yield return Instruction.Create(OpCodes.Ldc_R8, size);
+
+			var constantDef = module.Import(typeof(Constraint)).Resolve().Methods.FirstOrDefault(md => md.IsStatic && md.Name == "Constant");
+			var constantRef = module.Import(constantDef);
+			yield return Instruction.Create(OpCodes.Call, constantRef);
+		}
+	}
+}
diff --git a/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj b/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
index c845b597..9507ea3c 100644
--- a/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
+++ b/Xamarin.Forms.Build.Tasks/Xamarin.Forms.Build.Tasks.csproj
@@ -101,6 +101,7 @@
     <Compile Include="Logger.cs" />
     <Compile Include="XamlTask.cs" />
     <Compile Include="CompiledMarkupExtensions\ArrayExtension.cs" />
+    <Compile Include="CompiledConverters\ConstraintTypeConverter.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <Target Name="AfterBuild">
diff --git a/Xamarin.Forms.Core/ConstraintTypeConverter.cs b/Xamarin.Forms.Core/ConstraintTypeConverter.cs
index fb0be513..04f3519b 100644
--- a/Xamarin.Forms.Core/ConstraintTypeConverter.cs
+++ b/Xamarin.Forms.Core/ConstraintTypeConverter.cs
@@ -3,6 +3,7 @@ using System.Globalization;
 
 namespace Xamarin.Forms
 {
+	[Xaml.ProvideCompiled("Xamarin.Forms.Core.XamlC.ConstraintTypeConverter")]
 	public class ConstraintTypeConverter : TypeConverter
 	{
 		public override object ConvertFromInvariantString(string value)
diff --git a/Xamarin.Forms.Xaml.UnitTests/CompiledTypeConverter.xaml b/Xamarin.Forms.Xaml.UnitTests/CompiledTypeConverter.xaml
index 56d7e082..b1630646 100644
--- a/Xamarin.Forms.Xaml.UnitTests/CompiledTypeConverter.xaml
+++ b/Xamarin.Forms.Xaml.UnitTests/CompiledTypeConverter.xaml
@@ -1,9 +1,11 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.0" encoding="UTF-8"?>
 <ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
 			 xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
 			 x:Class="Xamarin.Forms.Xaml.UnitTests.CompiledTypeConverter"
 			 RectangleP="0,1,2,4"
 			 RectangleBP="4,8,16,32"
 			 BackgroundColor="Pink">
-	<Label HorizontalOptions="EndAndExpand" />
+	<Label x:Name="label"
+		HorizontalOptions="EndAndExpand"
+		RelativeLayout.XConstraint="2" />
 </ContentPage>
\ No newline at end of file
diff --git a/Xamarin.Forms.Xaml.UnitTests/CompiledTypeConverter.xaml.cs b/Xamarin.Forms.Xaml.UnitTests/CompiledTypeConverter.xaml.cs
index 092d67de..834a55c9 100644
--- a/Xamarin.Forms.Xaml.UnitTests/CompiledTypeConverter.xaml.cs
+++ b/Xamarin.Forms.Xaml.UnitTests/CompiledTypeConverter.xaml.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-
-using Xamarin.Forms;
-using NUnit.Framework;
+using NUnit.Framework;
 
 namespace Xamarin.Forms.Xaml.UnitTests
 {
@@ -31,14 +27,17 @@ namespace Xamarin.Forms.Xaml.UnitTests
 		[TestFixture]
 		public class Tests
 		{
-			[TestCase (false)]
-			[TestCase (true)]
-			public void CompiledTypeConverterAreInvoked (bool useCompiledXaml)
+			[TestCase(false)]
+			[TestCase(true)]
+			public void CompiledTypeConverterAreInvoked(bool useCompiledXaml)
 			{
-				var p = new CompiledTypeConverter (useCompiledXaml);
-				Assert.AreEqual (new Rectangle (0, 1, 2, 4), p.RectangleP);
-				Assert.AreEqual (new Rectangle (4, 8, 16, 32), p.RectangleBP);
-				Assert.AreEqual (Color.Pink, p.BackgroundColor);
+				var p = new CompiledTypeConverter(useCompiledXaml);
+				Assert.AreEqual(new Rectangle(0, 1, 2, 4), p.RectangleP);
+				Assert.AreEqual(new Rectangle(4, 8, 16, 32), p.RectangleBP);
+				Assert.AreEqual(Color.Pink, p.BackgroundColor);
+				Assert.AreEqual(LayoutOptions.EndAndExpand, p.label.GetValue(View.HorizontalOptionsProperty));
+				var xConstraint = RelativeLayout.GetXConstraint(p.label);
+				Assert.AreEqual(2, xConstraint.Compute(null));
 			}
 		}
 	}