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 TopLevelWindowMulticaster class is used to maintain a list of
  35  * TopLevelWindowListener 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#addTopLevelWindowListener
  41  * @see EventQueueMonitor#removeTopLevelWindowListener
  42  *
  43  */
  44 @jdk.Exported(false)
  45 public class TopLevelWindowMulticaster
  46     extends AWTEventMulticaster implements TopLevelWindowListener
  47 {
  48     protected TopLevelWindowMulticaster(EventListener a, EventListener b) {
  49         super(a, b);
  50     }
  51 
  52     public void topLevelWindowCreated(Window w) {
  53         ((TopLevelWindowListener)a).topLevelWindowCreated(w);
  54         ((TopLevelWindowListener)b).topLevelWindowCreated(w);
  55     }
  56 
  57     public void topLevelWindowDestroyed(Window w) {
  58         ((TopLevelWindowListener)a).topLevelWindowDestroyed(w);
  59         ((TopLevelWindowListener)b).topLevelWindowDestroyed(w);
  60     }
  61 
  62     public static TopLevelWindowListener add(TopLevelWindowListener a, TopLevelWindowListener b) {
  63         return (TopLevelWindowListener)addInternal(a, b);
  64     }
  65 
  66     public static TopLevelWindowListener remove(TopLevelWindowListener l, TopLevelWindowListener oldl) {
  67         return (TopLevelWindowListener)removeInternal(l, oldl);
  68     }
  69 
  70     protected static EventListener addInternal(EventListener a, EventListener b) {
  71         if (a == null)  return b;
  72         if (b == null)  return a;
  73         return new TopLevelWindowMulticaster(a, b);
  74     }
  75 
  76     protected static EventListener removeInternal(EventListener l, EventListener oldl) {
  77         if (l == oldl || l == null) {
  78             return null;
  79         } else if (l instanceof TopLevelWindowMulticaster) {
  80             return ((TopLevelWindowMulticaster)l).remove(oldl);
  81         } else {
  82             return l;           // it's not here
  83         }
  84     }
  85 
  86 }