Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Activities/System/Activities/XamlIntegration/FuncFactory.cs

@@ -0,0 +1,137 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//-----------------------------------------------------------------------------
+
+namespace System.Activities.XamlIntegration
+{
+    using System;
+    using System.Collections.Generic;
+    using System.ComponentModel;
+    using System.Reflection;
+    using System.Runtime;
+    using System.Windows.Markup;
+    using System.Xaml;
+
+    abstract class FuncFactory
+    {
+        public static Func<object> CreateFunc(XamlReader reader, Type returnType)
+        {
+            FuncFactory factory = CreateFactory(null, reader, returnType);
+            return factory.GetFunc();
+        }
+
+        public static Func<T> CreateFunc<T>(XamlReader reader) where T : class
+        {
+            FuncFactory<T> factory = new FuncFactory<T>(null, reader);
+            return factory.GetTypedFunc();
+        }
+
+        internal IList<NamespaceDeclaration> ParentNamespaces
+        {
+            get;
+            set;
+        }
+
+        internal XamlNodeList Nodes
+        {
+            get;
+            set;
+        }
+
+        // Back-compat switch: we don't want to copy parent settings on Activity/DynamicActivity
+        internal bool IgnoreParentSettings
+        {
+            get;
+            set;
+        }
+
+        internal abstract Func<object> GetFunc();
+
+        internal static FuncFactory CreateFactory(XamlReader xamlReader, IServiceProvider context)
+        {
+            IXamlObjectWriterFactory objectWriterFactory = context.GetService(typeof(IXamlObjectWriterFactory)) as IXamlObjectWriterFactory;
+            IProvideValueTarget provideValueService = context.GetService(typeof(IProvideValueTarget)) as IProvideValueTarget;
+
+            Type propertyType = null;
+            //
+            // IProvideValueTarget.TargetProperty can return DP, Attached Property or MemberInfo for clr property
+            // In this case it should always be a regular clr property here - we are always targeting Activity.Body.
+            PropertyInfo propertyInfo = provideValueService.TargetProperty as PropertyInfo;
+
+            if (propertyInfo != null)
+            {
+                propertyType = propertyInfo.PropertyType;
+            }
+
+            FuncFactory funcFactory = CreateFactory(objectWriterFactory, xamlReader, propertyType.GetGenericArguments());
+            return funcFactory;
+        }
+
+        // Back-compat workaround: returnType should only be a single value. But in 4.0 we didn't
+        // validate this; we just passed the array in to MakeGenericType, which would throw if there
+        // were multiple values. To preserve the same exception, we allow passing in an array here.
+        static FuncFactory CreateFactory(IXamlObjectWriterFactory objectWriterFactory, XamlReader xamlReader, params Type[] returnType)
+        {
+            Type closedType = typeof(FuncFactory<>).MakeGenericType(returnType);
+            return (FuncFactory)Activator.CreateInstance(closedType, objectWriterFactory, xamlReader);
+        }
+    }
+
+    class FuncFactory<T> : FuncFactory where T : class
+    {
+        IXamlObjectWriterFactory objectWriterFactory;
+
+        public FuncFactory(IXamlObjectWriterFactory objectWriterFactory, XamlReader reader)
+        {
+            this.objectWriterFactory = objectWriterFactory;
+            this.Nodes = new XamlNodeList(reader.SchemaContext);
+            XamlServices.Transform(reader, this.Nodes.Writer);
+        }
+
+        internal T Evaluate()
+        {
+            XamlObjectWriter writer = GetWriter();
+            XamlServices.Transform(this.Nodes.GetReader(), writer);
+            return (T)writer.Result;
+        }
+
+        internal override Func<object> GetFunc()
+        {
+            return (Func<T>)Evaluate;
+        }
+
+        internal Func<T> GetTypedFunc()
+        {
+            return Evaluate;
+        }
+
+        XamlObjectWriter GetWriter()
+        {
+            if (this.objectWriterFactory != null)
+            {
+                return this.objectWriterFactory.GetXamlObjectWriter(GetObjectWriterSettings());
+            }
+            else
+            {
+                return new XamlObjectWriter(this.Nodes.Writer.SchemaContext);
+            }
+        }
+
+        XamlObjectWriterSettings GetObjectWriterSettings()
+        {
+            if (IgnoreParentSettings)
+            {
+                return new XamlObjectWriterSettings();
+            }
+            XamlObjectWriterSettings result = new XamlObjectWriterSettings(this.objectWriterFactory.GetParentSettings());
+            // The delegate settings are already stripped by XOW. Some other settings don't make sense to copy.
+            result.ExternalNameScope = null;
+            result.RegisterNamesOnExternalNamescope = false;
+            result.RootObjectInstance = null;
+            result.SkipProvideValueOnRoot = false;
+            return result;
+        }
+    }
+}
+
+