mono/mcs/class/System/System.ComponentModel/EventHandlerList.cs

//
// System.ComponentModel.EventHandlerList.cs
//
// Author:
//   Miguel de Icaza ([email protected])
//   Gonzalo Paniagua Javier ([email protected])
//
// (C) Ximian, Inc.  http://www.ximian.com
//

//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Collections;

namespace System.ComponentModel {

	// <summary>
	//   List of Event delegates.
	// </summary>
	//
	// <remarks>
	//   Longer description
	// </remarks>
	public sealed class EventHandlerList : IDisposable {
		Hashtable table;
		
		public EventHandlerList ()
		{
		}

		public Delegate this [object key] {
			get {
				if (table == null)
					return null;

				return table [key] as Delegate;
			}

			set {
				AddHandler (key, value);
			}
		}

		public void AddHandler (object key, Delegate value)
		{
			if (table == null)
				table = new Hashtable ();

			Delegate prev = table [key] as Delegate;
			prev = Delegate.Combine (prev, value);
			table [key] = prev;
		}

		public void RemoveHandler (object key, Delegate value)
		{
			if (table == null)
				return;

			Delegate prev = table [key] as Delegate;
			prev = Delegate.Remove (prev, value);
			table [key] = prev;
		}

		public void Dispose ()
		{
			table = null;
		}
	}
	
}