2 // System.ComponentModel.EventHandlerList.cs
5 // Miguel de Icaza (miguel@ximian.com)
6 // Gonzalo Paniagua Javier (gonzalo@ximian.com)
8 // (C) Ximian, Inc. http://www.ximian.com
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17 // permit persons to whom the Software is furnished to do so, subject to
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20 // The above copyright notice and this permission notice shall be
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33 using System.Collections;
35 namespace System.ComponentModel {
38 // List of Event delegates.
44 public sealed class EventHandlerList : IDisposable {
47 public EventHandlerList ()
52 public Delegate this [object key] {
54 ListNode entry = FindEntry (key);
55 return entry == null ? null : entry.value;
59 AddHandler (key, value);
63 public void AddHandler (object key, Delegate value)
65 ListNode entry = FindEntry (key);
67 head = new ListNode (key, value, head);
70 entry.value = Delegate.Combine (entry.value, value);
73 public void RemoveHandler (object key, Delegate value)
75 ListNode entry = FindEntry (key);
79 entry.value = Delegate.Remove (entry.value, value);
82 public void Dispose ()
86 private ListNode FindEntry (object key)
89 throw new ArgumentNullException ("key", "Attempted lookup for a null key.");
91 for (ListNode entry = head; entry != null; entry = entry.next)
98 private class ListNode
101 public Delegate value;
102 public ListNode next;
103 public ListNode (object key, Delegate value, ListNode next)
111 private ListNode head;