/IronPython_2_0/Src/Microsoft.Scripting.Core/Com/ComMetaObject.cs

/* ****************************************************************************

 *

 * Copyright (c) Microsoft Corporation. 

 *

 * This source code is subject to terms and conditions of the Microsoft Public License. A 

 * copy of the license can be found in the License.html file at the root of this distribution. If 

 * you cannot locate the  Microsoft Public License, please send an email to 

 * dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound 

 * by the terms of the Microsoft Public License.

 *

 * You must not remove this notice, or any other, from this software.

 *

 *

 * ***************************************************************************/

using System; using Microsoft;





#if !SILVERLIGHT



using Microsoft.Linq.Expressions;

using Microsoft.Scripting.Actions;

using Microsoft.Scripting.Utils;



namespace Microsoft.Scripting.Com {

    internal class ComMetaObject : MetaObject {

        internal ComMetaObject(Expression expression, Restrictions restrictions, object arg)

            : base(expression, restrictions, arg) {

        }



        #region MetaObject



        public override MetaObject Call(CallAction action, MetaObject[] args) {

            ContractUtils.RequiresNotNull(action, "action");

            return action.Defer(args.AddFirst(WrapSelf()));

        }



        public override MetaObject Convert(ConvertAction action) {

            ContractUtils.RequiresNotNull(action, "action");

            return action.Defer(WrapSelf());

        }



        public override MetaObject Create(CreateAction action, MetaObject[] args) {

            ContractUtils.RequiresNotNull(action, "action");

            return action.Defer(args.AddFirst(WrapSelf()));

        }



        public override MetaObject DeleteMember(DeleteMemberAction action) {

            ContractUtils.RequiresNotNull(action, "action");

            return action.Defer(WrapSelf());

        }



        public override MetaObject GetMember(GetMemberAction action) {

            ContractUtils.RequiresNotNull(action, "action");

            return action.Defer(WrapSelf());

        }



        public override MetaObject Invoke(InvokeAction action, MetaObject[] args) {

            ContractUtils.RequiresNotNull(action, "action");

            return action.Defer(args.AddFirst(WrapSelf()));

        }



        public override MetaObject Operation(OperationAction action, MetaObject[] args) {

            ContractUtils.RequiresNotNull(action, "action");

            return action.Defer(args.AddFirst(WrapSelf()));

        }



        public override MetaObject SetMember(SetMemberAction action, MetaObject value) {

            ContractUtils.RequiresNotNull(action, "action");

            return action.Defer(WrapSelf(), value);

        }



        #endregion



        private MetaObject WrapSelf() {

            return new MetaObject(

                Expression.Call(

                    typeof(ComObject).GetMethod("ObjectToComObject"),

                    Expression.ConvertHelper(Expression, typeof(object))

                ),

                Restrictions.ExpressionRestriction(

                    Expression.AndAlso(

                        Expression.NotEqual(

                            Expression.ConvertHelper(Expression, typeof(object)),

                            Expression.Null()

                        ),

                        Expression.Call(

                            typeof(System.Runtime.InteropServices.Marshal).GetMethod("IsComObject"),

                            Expression.ConvertHelper(Expression, typeof(object))

                        )

                    )

                )

            );

        }



        internal static MetaObject GetComMetaObject(Expression expression, object arg) {

            return new ComMetaObject(expression, Restrictions.Empty, arg);

        }



        private static readonly Type ComObjectType = typeof(object).Assembly.GetType("System.__ComObject");



        internal static bool IsComObject(object obj) {

            // we can't use System.Runtime.InteropServices.Marshal.IsComObject(obj) since it doesn't work in partial trust

            return obj != null && ComObjectType.IsAssignableFrom(obj.GetType());

        }

    }

}



#endif