001/* KeyEventPostProcessor.java -- performs actions after a key event dispatch
002   Copyright (C) 2002, 2005  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package java.awt;
040
041import java.awt.event.KeyEvent;
042
043/**
044 * An instance of this interface coordinates with a KeyboardFocusManager to
045 * target and dispatch all key events that are otherwise unconsumed. This
046 * allows events which take place when nothing has focus to still operate,
047 * such as menu keyboard shortcuts.
048 *
049 * <p>By default, the KeyboardFocusManager is the sink for all key events not
050 * post-processed elsewhere. Therefore, it is unnecessary for the user
051 * to register the focus manager as a dispatcher.
052 *
053 * @author Eric Blake (ebb9@email.byu.edu)
054 * @see KeyboardFocusManager#addKeyEventPostProcessor(KeyEventPostProcessor)
055 * @see KeyboardFocusManager#removeKeyEventPostProcessor(KeyEventPostProcessor)
056 * @since 1.4
057 * @status updated to 1.4
058 */
059public interface KeyEventPostProcessor
060{
061  /**
062   * Called by the KeyboardFocusManager to request that a key event be
063   * post-processed. Typically, the event has already been dispatched and
064   * handled, unless no object has focus. Thus, this allows global event
065   * handling for things like menu shortcuts. If this post-processor chooses
066   * to dispatch the event, it should call <code>redispatchEvent</code>
067   * to avoid infinite recursion.
068   *
069   * <p>If the return value is false, the KeyEvent is passed to the next
070   * dispatcher in the chain, ending with the KeyboardFocusManager. If the
071   * return value is true, the event has been consumed (although it might
072   * have been ignored), and no further action will be taken on the event. Be
073   * sure to check whether the event was consumed before dispatching it
074   * further.
075   *
076   * @param e the key event
077   * @return true if the event has been consumed
078   * @see KeyboardFocusManager#redispatchEvent(Component, AWTEvent)
079   */
080  boolean postProcessKeyEvent(KeyEvent e);
081} // interface KeyEventPostProcessor