libjava/classpath/java/awt/event/AWTEventListenerProxy.java

   1 /* AWTEventListenerProxy.java -- wrapper/filter for AWTEventListener
   2    Copyright (C) 2002, 2005  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.awt.event;
  40
  41 import java.awt.AWTEvent;
  42 import java.awt.Toolkit;
  43 import java.util.EventListenerProxy;
  44
  45 /**
  46  * This class allows adding an AWTEventListener which only pays attention to
  47  * a specific event mask.
  48  *
  49  * @author Eric Blake (ebb9@email.byu.edu)
  50  * @see Toolkit
  51  * @see EventListenerProxy
  52  * @since 1.4
  53  * @status updated to 1.4
  54  */
  55 public class AWTEventListenerProxy extends EventListenerProxy
  56   implements AWTEventListener
  57 {
  58   /** The event mask. */
  59   private final long mask;
  60
  61   /**
  62    * Construct an AWT Event Listener which only listens to events in the given
  63    * mask, passing the work on to the real listener.
  64    *
  65    * @param eventMask the mask of events to listen to
  66    * @param listener the wrapped listener
  67    */
  68   public AWTEventListenerProxy(long eventMask, AWTEventListener listener)
  69   {
  70     super(listener);
  71     mask = eventMask;
  72   }
  73
  74   /**
  75    * Forwards events on to the delegate.
  76    *
  77    * @param event the to forward to the delagate listener
  78    *
  79    * @throws NullPointerException if the delegate this was created with is null
  80    */
  81   public void eventDispatched(AWTEvent event)
  82   {
  83     ((AWTEventListener) getListener()).eventDispatched(event);
  84   }
  85
  86   /**
  87    * This returns the event mask associated with this listener.
  88    *
  89    * @return the event mask
  90    */
  91   public long getEventMask()
  92   {
  93     return mask;
  94   }
  95 } // class AWTEventListenerProxy