[XamlC] support non-generic IMarkup on ABPs (#562)

* [XamlC] support custom markups on ABPs

* [XamlC] test for 47950

Xamarin.Forms.Build.Tasks/SetPropertiesVisitor.cs

@@ -94,9 +94,10 @@ namespace Xamarin.Forms.Build.Tasks
 			var localName = propertyName.LocalName;
 			TypeReference declaringTypeReference = null;
 			FieldReference bpRef = null;
+			var _ = false;
 			PropertyDefinition propertyRef = null;
 			if (parentNode is IElementNode && propertyName != XmlName.Empty) {
-				bpRef = GetBindablePropertyReference(Context.Variables [(IElementNode)parentNode], propertyName.NamespaceURI, ref localName, Context, node);
+				bpRef = GetBindablePropertyReference(Context.Variables [(IElementNode)parentNode], propertyName.NamespaceURI, ref localName, out _, Context, node);
 				propertyRef = Context.Variables [(IElementNode)parentNode].VariableType.GetProperty(pd => pd.Name == localName, out declaringTypeReference);
 			}
 			Context.IL.Append(ProvideValue(vardefref, Context, Module, node, bpRef:bpRef, propertyRef:propertyRef, propertyDeclaringTypeRef: declaringTypeReference));
@@ -675,7 +676,8 @@ namespace Xamarin.Forms.Build.Tasks
 		{
 			var module = context.Body.Method.Module;
 			var localName = propertyName.LocalName;
-			var bpRef = GetBindablePropertyReference(parent, propertyName.NamespaceURI, ref localName, context, iXmlLineInfo);
+			bool attached;
+			var bpRef = GetBindablePropertyReference(parent, propertyName.NamespaceURI, ref localName, out attached, context, iXmlLineInfo);
 
 			//If the target is an event, connect
 			if (CanConnectEvent(parent, localName))
@@ -690,7 +692,7 @@ namespace Xamarin.Forms.Build.Tasks
 				return SetBinding(parent, bpRef, valueNode as IElementNode, iXmlLineInfo, context);
 
 			//If it's a BP, SetValue ()
-			if (CanSetValue(bpRef, valueNode, iXmlLineInfo, context))
+			if (CanSetValue(bpRef, attached, valueNode, iXmlLineInfo, context))
 				return SetValue(parent, bpRef, valueNode, iXmlLineInfo, context);
 
 			//If it's a property, set it
@@ -704,14 +706,14 @@ namespace Xamarin.Forms.Build.Tasks
 			throw new XamlParseException($"No property, bindable property, or event found for '{localName}'", iXmlLineInfo);
 		}
 
-		static FieldReference GetBindablePropertyReference(VariableDefinition parent, string namespaceURI, ref string localName, ILContext context, IXmlLineInfo iXmlLineInfo)
+		static FieldReference GetBindablePropertyReference(VariableDefinition parent, string namespaceURI, ref string localName, out bool attached, ILContext context, IXmlLineInfo iXmlLineInfo)
 		{
 			var module = context.Body.Method.Module;
 			TypeReference declaringTypeReference;
 
 			//If it's an attached BP, update elementType and propertyName
 			var bpOwnerType = parent.VariableType;
-			GetNameAndTypeRef(ref bpOwnerType, namespaceURI, ref localName, context, iXmlLineInfo);
+			attached = GetNameAndTypeRef(ref bpOwnerType, namespaceURI, ref localName, context, iXmlLineInfo);
 			var name = $"{localName}Property";
 			FieldReference bpRef = bpOwnerType.GetField(fd => fd.Name == name &&
 														fd.IsStatic &&
@@ -832,7 +834,7 @@ namespace Xamarin.Forms.Build.Tasks
 			yield return Instruction.Create(OpCodes.Callvirt, module.Import(setBinding));
 		}
 
-		static bool CanSetValue(FieldReference bpRef, INode node, IXmlLineInfo iXmlLineInfo, ILContext context)
+		static bool CanSetValue(FieldReference bpRef, bool attached, INode node, IXmlLineInfo iXmlLineInfo, ILContext context)
 		{
 			var module = context.Body.Method.Module;
 
@@ -851,6 +853,10 @@ namespace Xamarin.Forms.Build.Tasks
 				return false;
 
 			var bpTypeRef = bpRef.GetBindablePropertyType(iXmlLineInfo, module);
+			// If it's an attached BP, there's no second chance to handle IMarkupExtensions, so we try here.
+			// Worst case scenario ? InvalidCastException at runtime
+			if (attached && varValue.VariableType.FullName == "System.Object") 
+				return true;
 			return varValue.VariableType.InheritsFromOrImplements(bpTypeRef);
 		}
 

Xamarin.Forms.Xaml.UnitTests/Issues/Bz47950.xaml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
+		xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+		xmlns:local="clr-namespace:Xamarin.Forms.Xaml.UnitTests"
+		x:Class="Xamarin.Forms.Xaml.UnitTests.Bz47950">
+	<ContentPage.Resources>
+		<ResourceDictionary>
+			<Color x:Key="MyColor">#c2d1d3</Color>
+		</ResourceDictionary>
+	</ContentPage.Resources>
+	<Label x:Name="label" local:Bz47950Behavior.ColorTest="{StaticResource MyColor}" />
+</ContentPage>

Xamarin.Forms.Xaml.UnitTests/Issues/Bz47950.xaml.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using NUnit.Framework;
+using Xamarin.Forms;
+
+namespace Xamarin.Forms.Xaml.UnitTests
+{
+	public class Bz47950Behavior : Behavior<View>
+	{
+		public static readonly BindableProperty ColorTestProperty =
+			BindableProperty.CreateAttached("ColorTest", typeof(Color), typeof(View), default(Color));
+
+		public static Color GetColorTest(BindableObject bindable) => (Color)bindable.GetValue(ColorTestProperty);
+		public static void SetColorTest(BindableObject bindable, Color value) => bindable.SetValue(ColorTestProperty, value);
+	}
+
+	public partial class Bz47950 : ContentPage
+	{
+		public Bz47950()
+		{
+			InitializeComponent();
+		}
+
+		public Bz47950(bool useCompiledXaml)
+		{
+			//this stub will be replaced at compile time
+		}
+
+		[TestFixture]
+		class Tests
+		{
+			[TestCase(true)]
+			[TestCase(false)]
+			public void BehaviorAndStaticResource(bool useCompiledXaml)
+			{
+				var page = new Bz47950(useCompiledXaml);
+			}
+		}
+	}
+}

Xamarin.Forms.Xaml.UnitTests/Issues/Unreported004.xaml.cs

@@ -43,7 +43,7 @@ namespace Xamarin.Forms.Xaml.UnitTests
 			[TestCase(true), TestCase(false)]
 			public void MultipleGetMethodsAllowed(bool useCompiledXaml)
 			{
-				var page = new Unreported004();
+				var page = new Unreported004(useCompiledXaml);
 				Assert.NotNull(page.label);
 				Assert.AreEqual("foo", GetSomeProperty(page.label));
 			}

Xamarin.Forms.Xaml.UnitTests/Issues/Unreported005.xaml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
+		xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+		xmlns:local="clr-namespace:Xamarin.Forms.Xaml.UnitTests"
+		x:Class="Xamarin.Forms.Xaml.UnitTests.Unreported005">
+	<RelativeLayout>
+		<Label x:Name="before" />
+		<Button x:Name="after"
+				RelativeLayout.XConstraint="{local:Unreported005RelativeToViewHorizontal ElementName=before, Constant=105}" />
+    
+	</RelativeLayout>
+</ContentPage>

Xamarin.Forms.Xaml.UnitTests/Issues/Unreported005.xaml.cs

@@ -0,0 +1,78 @@
+using System;
+using NUnit.Framework;
+
+namespace Xamarin.Forms.Xaml.UnitTests
+{
+	public abstract class Unreported005RelativeToView : IMarkupExtension
+	{
+		protected Unreported005RelativeToView()
+		{
+			Factor = 1;
+		}
+
+		public string ElementName { get; set; }
+
+		public double Factor { get; set; }
+
+		public double Constant { get; set; }
+
+		public object ProvideValue(IServiceProvider serviceProvider)
+		{
+			var element = new ReferenceExtension { Name = ElementName }.ProvideValue(serviceProvider) as View;
+			if (element != null) {
+				var result = Constraint.RelativeToView(element, (layout, view) => DeterminePosition(view) + Constant);
+				return result;
+			}
+			return null;
+		}
+
+		protected virtual double DeterminePosition(VisualElement view)
+		{
+			var result = DetermineStart(view) + DetermineExtent(view) * Factor;
+			return result;
+		}
+
+		protected abstract double DetermineExtent(VisualElement view);
+
+		protected abstract double DetermineStart(VisualElement view);
+	}
+
+	public class Unreported005RelativeToViewHorizontal : Unreported005RelativeToView
+	{
+		protected override double DetermineExtent(VisualElement view)
+		{
+			return view.Width;
+		}
+
+		protected override double DetermineStart(VisualElement view)
+		{
+			return view.X;
+		}
+	}
+
+	//[XamlCompilation(XamlCompilationOptions.Skip)]
+	public partial class Unreported005 : ContentPage
+	{
+		public Unreported005()
+		{
+			InitializeComponent();
+		}
+
+		public Unreported005(bool useCompiledXaml)
+		{
+			//this stub will be replaced at compile time
+		}
+
+		[TestFixture]
+		class Tests
+		{
+			[TestCase(true), TestCase(false)]
+			public void CustomMarkupExtensionWorks(bool useCompiledXaml)
+			{
+				var page = new Unreported005(useCompiledXaml);
+				Assert.That(RelativeLayout.GetXConstraint(page.after), Is.TypeOf<Constraint>());
+				Assert.NotNull(RelativeLayout.GetXConstraint(page.after));
+			}
+		}
+	}
+}

Xamarin.Forms.Xaml.UnitTests/Xamarin.Forms.Xaml.UnitTests.csproj

@@ -373,6 +373,12 @@
     <Compile Include="BindingsCompiler.xaml.cs">
       <DependentUpon>BindingsCompiler.xaml</DependentUpon>
     </Compile>
+    <Compile Include="Issues\Unreported005.xaml.cs">
+      <DependentUpon>Unreported005.xaml</DependentUpon>
+    </Compile>
+    <Compile Include="Issues\Bz47950.xaml.cs">
+      <DependentUpon>Bz47950.xaml</DependentUpon>
+    </Compile>
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <Import Project="..\.nuspec\Xamarin.Forms.Debug.targets" />
@@ -667,6 +673,12 @@
     <EmbeddedResource Include="BindingsCompiler.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Include="Issues\Unreported005.xaml">
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
+    <EmbeddedResource Include="Issues\Bz47950.xaml">
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
   </ItemGroup>
   <ItemGroup>
     <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />