Source for java.awt.KeyEventPostProcessor

   1: /* KeyEventPostProcessor.java -- performs actions after a key event dispatch
   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., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 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 that are otherwise unconsumed. This
  46:  * allows events which take place when nothing has focus to still operate,
  47:  * such as menu keyboard shortcuts.
  48:  *
  49:  * <p>By default, the KeyboardFocusManager is the sink for all key events not
  50:  * post-processed elsewhere. 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#addKeyEventPostProcessor(KeyEventPostProcessor)
  55:  * @see KeyboardFocusManager#removeKeyEventPostProcessor(KeyEventPostProcessor)
  56:  * @since 1.4
  57:  * @status updated to 1.4
  58:  */
  59: public interface KeyEventPostProcessor
  60: {
  61:   /**
  62:    * Called by the KeyboardFocusManager to request that a key event be
  63:    * post-processed. Typically, the event has already been dispatched and
  64:    * handled, unless no object has focus. Thus, this allows global event
  65:    * handling for things like menu shortcuts. If this post-processor chooses
  66:    * to dispatch the event, it should call <code>redispatchEvent</code>
  67:    * to avoid infinite recursion.
  68:    *
  69:    * <p>If the return value is false, the KeyEvent is passed to the next
  70:    * dispatcher in the chain, ending with the KeyboardFocusManager. If the
  71:    * return value is true, the event has been consumed (although it might
  72:    * have been ignored), and no further action will be taken on the event. Be
  73:    * sure to check whether the event was consumed before dispatching it
  74:    * further.
  75:    *
  76:    * @param e the key event
  77:    * @return true if the event has been consumed
  78:    * @see KeyboardFocusManager#redispatchEvent(Component, AWTEvent)
  79:    */
  80:   boolean postProcessKeyEvent(KeyEvent e);
  81: } // interface KeyEventPostProcessor