// ==++==
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--==
 
/*============================================================
**
** Class:  ComEventsInfo
**
** Purpose: part of ComEventHelpers APIs which allow binding 
** managed delegates to COM's connection point based events.
**
** Date:  April 2008
**/
 
 
namespace System.Runtime.InteropServices {
 
    using System;
    using ComTypes = System.Runtime.InteropServices.ComTypes;
 
    // see code:ComEventsHelper#ComEventsArchitecture
    [System.Security.SecurityCritical]
    internal class ComEventsInfo {
 
 
#region fields
 
        private ComEventsSink _sinks;
        private object _rcw;
 
#endregion
 
 
#region ctor/dtor
 
        ComEventsInfo(object rcw) {
            _rcw = rcw;
        }
 
        [System.Security.SecuritySafeCritical]
        ~ComEventsInfo() {
            // see code:ComEventsHelper#ComEventsFinalization
            _sinks = ComEventsSink.RemoveAll(_sinks);
        }
 
#endregion
 
 
#region static methods
 
        [System.Security.SecurityCritical]
        internal static ComEventsInfo Find(object rcw) {
            return (ComEventsInfo)Marshal.GetComObjectData(rcw, typeof(ComEventsInfo));
        }
 
        // it is caller's responsibility to call this method under lock(rcw)
        [System.Security.SecurityCritical]
        internal static ComEventsInfo FromObject(object rcw) {
            ComEventsInfo eventsInfo = Find(rcw);
            if (eventsInfo == null) {
                eventsInfo = new ComEventsInfo(rcw);
                Marshal.SetComObjectData(rcw, typeof(ComEventsInfo), eventsInfo);
            }
            return eventsInfo;
        }
 
#endregion
 
 
#region internal methods
 
        internal ComEventsSink FindSink(ref Guid iid) {
            return ComEventsSink.Find(_sinks, ref iid);
        }
 
        // it is caller's responsibility to call this method under lock(rcw)
        internal ComEventsSink AddSink(ref Guid iid) {
            ComEventsSink sink = new ComEventsSink(_rcw, iid);
            _sinks = ComEventsSink.Add(_sinks, sink);
 
            return _sinks;
        }
 
        // it is caller's responsibility to call this method under lock(rcw)
        [System.Security.SecurityCritical]
        internal ComEventsSink RemoveSink(ComEventsSink sink) {
            _sinks = ComEventsSink.Remove(_sinks, sink);
            return _sinks;
        }
 
#endregion
 
    }
}