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Java > Open Source Codes > org > lobobrowser > util > EventDispatch


1 /*
2     GNU LESSER GENERAL PUBLIC LICENSE
3     Copyright (C) 2006 The Lobo Project
4
5     This library is free software; you can redistribute it and/or
6     modify it under the terms of the GNU Lesser General Public
7     License as published by the Free Software Foundation; either
8     version 2.1 of the License, or (at your option) any later version.
9
10     This library is distributed in the hope that it will be useful,
11     but WITHOUT ANY WARRANTY; without even the implied warranty of
12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13     Lesser General Public License for more details.
14
15     You should have received a copy of the GNU Lesser General Public
16     License along with this library; if not, write to the Free Software
17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18
19     Contact info: xamjadmin@users.sourceforge.net
20 */
21 /*
22  * Created on Mar 19, 2005
23  */
24 package org.lobobrowser.util;
25
26 import java.util.*;
27
28 /**
29  * @author J. H. S.
30  */
31 public class EventDispatch {
32     private Collection listeners;
33     
34     public EventDispatch() {
35     }
36     
37     public Collection createListenerCollection() {
38         return new LinkedList();
39     }
40     
41     public final void addListener(GenericEventListener listener) {
42         synchronized(this) {
43             if(this.listeners == null) {
44                 this.listeners = this.createListenerCollection();
45             }
46             this.listeners.add(listener);
47         }
48     }
49     
50     public final void removeListener(GenericEventListener listener) {
51         synchronized(this) {
52             if(this.listeners != null) {
53                 this.listeners.remove(listener);
54             }
55         }
56     }
57     
58     public final void fireEvent(EventObject event) {
59         GenericEventListener[] larray = null;
60         synchronized(this) {
61             if(this.listeners != null) {
62                 larray = (GenericEventListener[]) this.listeners.toArray(GenericEventListener.EMPTY_ARRAY);
63             }
64         }
65         if(larray != null) {
66             for(int i = 0; i < larray.length; i++) {
67                 // Call holding no locks
68 larray[i].processEvent(event);
69             }
70         }
71     }
72 }
73
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