001    /* AWTEventListenerProxy.java -- wrapper/filter for AWTEventListener
002       Copyright (C) 2002, 2005  Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.awt.event;
040    
041    import java.awt.AWTEvent;
042    import java.awt.Toolkit;
043    import java.util.EventListenerProxy;
044    
045    /**
046     * This class allows adding an AWTEventListener which only pays attention to
047     * a specific event mask.
048     *
049     * @author Eric Blake (ebb9@email.byu.edu)
050     * @see Toolkit
051     * @see EventListenerProxy
052     * @since 1.4
053     * @status updated to 1.4
054     */
055    public class AWTEventListenerProxy extends EventListenerProxy
056      implements AWTEventListener
057    {
058      /** The event mask. */
059      private final long mask;
060    
061      /**
062       * Construct an AWT Event Listener which only listens to events in the given
063       * mask, passing the work on to the real listener.
064       *
065       * @param eventMask the mask of events to listen to
066       * @param listener the wrapped listener
067       */
068      public AWTEventListenerProxy(long eventMask, AWTEventListener listener)
069      {
070        super(listener);
071        mask = eventMask;
072      }
073    
074      /**
075       * Forwards events on to the delegate.
076       *
077       * @param event the to forward to the delagate listener
078       *
079       * @throws NullPointerException if the delegate this was created with is null
080       */
081      public void eventDispatched(AWTEvent event)
082      {
083        ((AWTEventListener) getListener()).eventDispatched(event);
084      }
085    
086      /**
087       * This returns the event mask associated with this listener.
088       *
089       * @return the event mask
090       */
091      public long getEventMask()
092      {
093        return mask;
094      }
095    } // class AWTEventListenerProxy