//
// System.ComponentModel.EventHandlerList.cs
//
// Author:
// Miguel de Icaza (miguel@ximian.com)
// Gonzalo Paniagua Javier (gonzalo@ximian.com)
//
// (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;
#if NET_2_0
using System.Collections.Generic;
#endif
namespace System.ComponentModel{
internal class ListEntry {
public object key;
public Delegate value;
public ListEntry next;
}
// <summary>
// List of Event delegates.
// </summary>
//
// <remarks>
// Longer description
// </remarks>
public sealed class EventHandlerList : IDisposable
{
ListEntry entries;
Delegate null_entry;
public EventHandlerList ()
{
}
public Delegate this [object key] {
get {
if (key == null)
return null_entry;
ListEntry entry = FindEntry (key);
if (entry != null)
return entry.value;
else
return null;
}
set {
AddHandler (key, value);
}
}
public void AddHandler (object key, Delegate value)
{
if (key == null) {
null_entry = Delegate.Combine (null_entry, value);
return;
}
ListEntry entry = FindEntry (key);
if (entry == null) {
entry = new ListEntry ();
entry.key = key;
entry.value = null;
entry.next = entries;
entries = entry;
}
entry.value = Delegate.Combine (entry.value, value);
}
#if NET_2_0
public void AddHandlers (EventHandlerList listToAddFrom)
{
if (listToAddFrom == null)
return;
ListEntry entry = listToAddFrom.entries;
while (entry != null) {
AddHandler (entry.key, entry.value);
entry = entry.next;
}
}
#endif
public void RemoveHandler (object key, Delegate value)
{
if (key == null) {
null_entry = Delegate.Remove (null_entry, value);
return;
}
ListEntry entry = FindEntry (key);
if (entry == null)
return;
entry.value = Delegate.Remove (entry.value, value);
}
public void Dispose ()
{
entries = null;
}
private ListEntry FindEntry (object key)
{
ListEntry entry = entries;
while (entry != null) {
if (entry.key == key)
return entry;
entry = entry.next;
}
return null;
}
}
}
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