KeyEventPostProcessor.java 3.5 KB

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  1. /* KeyEventPostProcessor.java -- performs actions after a key event dispatch
  2. Copyright (C) 2002 Free Software Foundation, Inc.
  3. This file is part of GNU Classpath.
  4. GNU Classpath is free software; you can redistribute it and/or modify
  5. it under the terms of the GNU General Public License as published by
  6. the Free Software Foundation; either version 2, or (at your option)
  7. any later version.
  8. GNU Classpath is distributed in the hope that it will be useful, but
  9. WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. General Public License for more details.
  12. You should have received a copy of the GNU General Public License
  13. along with GNU Classpath; see the file COPYING. If not, write to the
  14. Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  15. 02111-1307 USA.
  16. Linking this library statically or dynamically with other modules is
  17. making a combined work based on this library. Thus, the terms and
  18. conditions of the GNU General Public License cover the whole
  19. combination.
  20. As a special exception, the copyright holders of this library give you
  21. permission to link this library with independent modules to produce an
  22. executable, regardless of the license terms of these independent
  23. modules, and to copy and distribute the resulting executable under
  24. terms of your choice, provided that you also meet, for each linked
  25. independent module, the terms and conditions of the license of that
  26. module. An independent module is a module which is not derived from
  27. or based on this library. If you modify this library, you may extend
  28. this exception to your version of the library, but you are not
  29. obligated to do so. If you do not wish to do so, delete this
  30. exception statement from your version. */
  31. package java.awt;
  32. import java.awt.event.KeyEvent;
  33. /**
  34. * An instance of this interface coordinates with a KeyboardFocusManager to
  35. * target and dispatch all key events that are otherwise unconsumed. This
  36. * allows events which take place when nothing has focus to still operate,
  37. * such as menu keyboard shortcuts.
  38. *
  39. * <p>By default, the KeyboardFocusManager is the sink for all key events not
  40. * post-processed elsewhere. Therefore, it is unnecessary for the user
  41. * to register the focus manager as a dispatcher.
  42. *
  43. * @author Eric Blake <ebb9@email.byu.edu>
  44. * @see KeyboardFocusManager#addKeyEventPostProcessor(KeyEventPostProcessor)
  45. * @see KeyboardFocusManager#removeKeyEventPostProcessor(KeyEventPostProcessor)
  46. * @since 1.4
  47. * @status updated to 1.4
  48. */
  49. public interface KeyEventPostProcessor
  50. {
  51. /**
  52. * Called by the KeyboardFocusManager to request that a key event be
  53. * post-processed. Typically, the event has already been dispatched and
  54. * handled, unless no object has focus. Thus, this allows global event
  55. * handling for things like menu shortcuts. If this post-processor chooses
  56. * to dispatch the event, it should call <code>redispatchEvent</code>
  57. * to avoid infinite recursion.
  58. *
  59. * <p>If the return value is false, the KeyEvent is passed to the next
  60. * dispatcher in the chain, ending with the KeyboardFocusManager. If the
  61. * return value is true, the event has been consumed (although it might
  62. * have been ignored), and no further action will be taken on the event. Be
  63. * sure to check whether the event was consumed before dispatching it
  64. * further.
  65. *
  66. * @param e the key event
  67. * @return true if the event has been consumed
  68. * @see KeyboardFocusManager#redispatchEvent(Component, AWTEvent)
  69. */
  70. boolean postProcessKeyEvent(KeyEvent e);
  71. } // interface KeyEventPostProcessor