1 /*
   2  * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.java.accessibility.util;
  27 
  28 import java.awt.*;
  29 import java.util.EventListener;
  30 import javax.accessibility.*;
  31 
  32 
  33 /**
  34  * The GUIInitializedMulticaster class is used to maintain a list of
  35  * GUIInitializedListener classes.  It is intended to be used primarily
  36  * for internal support in the EventQueueMonitor class, and is not intended
  37  * to be used by classes outside the Java Accessibility Utility package.
  38  *
  39  * @see EventQueueMonitor
  40  * @see EventQueueMonitor#addGUIInitializedListener
  41  * @see EventQueueMonitor#removeGUIInitializedListener
  42  *
  43  */
  44 class GUIInitializedMulticaster
  45     extends AWTEventMulticaster implements GUIInitializedListener
  46 {
  47     protected GUIInitializedMulticaster(EventListener a, EventListener b) {
  48         super(a, b);
  49     }
  50 
  51     public void guiInitialized() {
  52         ((GUIInitializedListener)a).guiInitialized();
  53         ((GUIInitializedListener)b).guiInitialized();
  54     }
  55 
  56     public static GUIInitializedListener add(GUIInitializedListener a, GUIInitializedListener b) {
  57         return (GUIInitializedListener)addInternal(a, b);
  58     }
  59 
  60     public static GUIInitializedListener remove(GUIInitializedListener l, GUIInitializedListener oldl) {
  61         return (GUIInitializedListener)removeInternal(l, oldl);
  62     }
  63 
  64     protected static EventListener addInternal(EventListener a, EventListener b) {
  65         if (a == null)  return b;
  66         if (b == null)  return a;
  67         return new GUIInitializedMulticaster(a, b);
  68     }
  69 
  70     protected static EventListener removeInternal(EventListener l, EventListener oldl) {
  71         if (l == oldl || l == null) {
  72             return null;
  73         } else if (l instanceof GUIInitializedMulticaster) {
  74             return ((GUIInitializedMulticaster)l).remove(oldl);
  75         } else {
  76             return l;           // it's not here
  77         }
  78     }
  79 
  80 }