001 /* KeyEventDispatcher.java -- dispatches key events
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;
040
041 import java.awt.event.KeyEvent;
042
043 /**
044 * An instance of this interface coordinates with a KeyboardFocusManager to
045 * target and dispatch all key events. This allows retargeting, consuming,
046 * changing, or otherwise manipulating the key event before sending it on to
047 * a target.
048 *
049 * <p>By default, the KeyboardFocusManager is the sink for all key events not
050 * dispatched by other dispatchers. 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#addKeyEventDispatcher(KeyEventDispatcher)
055 * @see KeyboardFocusManager#removeKeyEventDispatcher(KeyEventDispatcher)
056 * @since 1.4
057 * @status updated to 1.4
058 */
059 public interface KeyEventDispatcher
060 {
061 /**
062 * Called by the KeyboardFocusManager to request that a key event be
063 * dispatched. The dispatcher is free to retarget the event, consume it,
064 * dispatch it, or make other changes. This is usually done to allow
065 * delivery of key events to objects other than the window in focus, such
066 * as for navigating non-focusable components. If this dispatcher chooses
067 * to dispatch the event itself, it should call <code>redispatchEvent</code>
068 * to avoid infinite recursion.
069 *
070 * <p>If the return value is false, the KeyEvent is passed to the next
071 * dispatcher in the chain, ending with the KeyboardFocusManager. If the
072 * return value is true, the event has been consumed (although it might
073 * have been ignored), and no further action will be taken on the event. Be
074 * sure to check whether the event was consumed before dispatching it
075 * further.
076 *
077 * @param e the key event
078 * @return true if the event has been consumed
079 * @see KeyboardFocusManager#redispatchEvent(Component, AWTEvent)
080 */
081 boolean dispatchKeyEvent(KeyEvent e);
082 } // interface KeyEventDispatcher