001 /* KeyEventPostProcessor.java -- performs actions after a key event dispatch
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
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013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
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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
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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 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 */
059 public 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