libjava/java/awt/KeyEventDispatcher.java

   1 /* KeyEventDispatcher.java -- dispatches key events
   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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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;
  40
  41 import java.awt.event.KeyEvent;
  42
  43 /**
  44  * An instance of this interface coordinates with a KeyboardFocusManager to
  45  * target and dispatch all key events. This allows retargeting, consuming,
  46  * changing, or otherwise manipulating the key event before sending it on to
  47  * a target.
  48  *
  49  * <p>By default, the KeyboardFocusManager is the sink for all key events not
  50  * dispatched by other dispatchers. Therefore, it is unnecessary for the user
  51  * to register the focus manager as a dispatcher.
  52  *
  53  * @author Eric Blake (ebb9@email.byu.edu)
  54  * @see KeyboardFocusManager#addKeyEventDispatcher(KeyEventDispatcher)
  55  * @see KeyboardFocusManager#removeKeyEventDispatcher(KeyEventDispatcher)
  56  * @since 1.4
  57  * @status updated to 1.4
  58  */
  59 public interface KeyEventDispatcher
  60 {
  61   /**
  62    * Called by the KeyboardFocusManager to request that a key event be
  63    * dispatched. The dispatcher is free to retarget the event, consume it,
  64    * dispatch it, or make other changes. This is usually done to allow
  65    * delivery of key events to objects other than the window in focus, such
  66    * as for navigating non-focusable components. If this dispatcher chooses
  67    * to dispatch the event itself, it should call <code>redispatchEvent</code>
  68    * to avoid infinite recursion.
  69    *
  70    * <p>If the return value is false, the KeyEvent is passed to the next
  71    * dispatcher in the chain, ending with the KeyboardFocusManager. If the
  72    * return value is true, the event has been consumed (although it might
  73    * have been ignored), and no further action will be taken on the event. Be
  74    * sure to check whether the event was consumed before dispatching it
  75    * further.
  76    *
  77    * @param e the key event
  78    * @return true if the event has been consumed
  79    * @see KeyboardFocusManager#redispatchEvent(Component, AWTEvent)
  80    */
  81   boolean dispatchKeyEvent(KeyEvent e);
  82 } // interface KeyEventDispatcher