/IronPython_Main/Runtime/Microsoft.Dynamic/ComInterop/TypeLibMetaObject.cs

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

 *

 * Copyright (c) Microsoft Corporation. 

 *

 * This source code is subject to terms and conditions of the Apache License, Version 2.0. A 

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

 * you cannot locate the  Apache License, Version 2.0, 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 Apache License, Version 2.0.

 *

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

 *

 *

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



#if !SILVERLIGHT

#if !CLR2

using System.Linq.Expressions;

#else

using Microsoft.Scripting.Ast;

#endif



using System.Collections.Generic;

using System.Dynamic;

using AstUtils = Microsoft.Scripting.Ast.Utils;



namespace Microsoft.Scripting.ComInterop {



    internal class TypeLibMetaObject : DynamicMetaObject {

        private readonly ComTypeLibDesc _lib;



        internal TypeLibMetaObject(Expression expression, ComTypeLibDesc lib)

            : base(expression, BindingRestrictions.Empty, lib) {

            _lib = lib;

        }



        private DynamicMetaObject TryBindGetMember(string name) {

            if (_lib.HasMember(name)) {

                BindingRestrictions restrictions =

                    BindingRestrictions.GetTypeRestriction(

                        Expression, typeof(ComTypeLibDesc)

                    ).Merge(

                        BindingRestrictions.GetExpressionRestriction(

                            Expression.Equal(

                                Expression.Property(

                                    AstUtils.Convert(

                                        Expression, typeof(ComTypeLibDesc)

                                    ),

                                    typeof(ComTypeLibDesc).GetProperty("Guid")

                                ),

                                AstUtils.Constant(_lib.Guid)

                            )

                        )

                    );



                return new DynamicMetaObject(

                    AstUtils.Constant(

                        ((ComTypeLibDesc)Value).GetTypeLibObjectDesc(name)

                    ),

                    restrictions

                );

            }



            return null;

        }



        public override DynamicMetaObject BindGetMember(GetMemberBinder binder) {

            return TryBindGetMember(binder.Name) ?? base.BindGetMember(binder);

        }



        public override DynamicMetaObject BindInvokeMember(InvokeMemberBinder binder, DynamicMetaObject[] args) {

            var result = TryBindGetMember(binder.Name);

            if (result != null) {

                return binder.FallbackInvoke(result, args, null);

            }



            return base.BindInvokeMember(binder, args);

        }



        public override IEnumerable<string> GetDynamicMemberNames() {

            return _lib.GetMemberNames();

        }

    }

}



#endif