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src/java.desktop/share/classes/java/awt/KeyEventDispatcher.java

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  45  * KeyboardFocusManager as a KeyEventDispatcher one or more times, this is
  46  * usually unnecessary and not recommended.)
  47  *
  48  * @author David Mendenhall
  49  *
  50  * @see KeyboardFocusManager#addKeyEventDispatcher
  51  * @see KeyboardFocusManager#removeKeyEventDispatcher
  52  * @since 1.4
  53  */
  54 @FunctionalInterface
  55 public interface KeyEventDispatcher {
  56 
  57     /**
  58      * This method is called by the current KeyboardFocusManager requesting
  59      * that this KeyEventDispatcher dispatch the specified event on its behalf.
  60      * This KeyEventDispatcher is free to retarget the event, consume it,
  61      * dispatch it itself, or make other changes. This capability is typically
  62      * used to deliver KeyEvents to Components other than the focus owner. This
  63      * can be useful when navigating children of non-focusable Windows in an
  64      * accessible environment, for example. Note that if a KeyEventDispatcher
  65      * dispatches the KeyEvent itself, it must use <code>redispatchEvent</code>
  66      * to prevent the current KeyboardFocusManager from recursively requesting
  67      * that this KeyEventDispatcher dispatch the event again.
  68      * <p>
  69      * If an implementation of this method returns <code>false</code>, then
  70      * the KeyEvent is passed to the next KeyEventDispatcher in the chain,
  71      * ending with the current KeyboardFocusManager. If an implementation
  72      * returns <code>true</code>, the KeyEvent is assumed to have been
  73      * dispatched (although this need not be the case), and the current
  74      * KeyboardFocusManager will take no further action with regard to the
  75      * KeyEvent. In such a case,
  76      * <code>KeyboardFocusManager.dispatchEvent</code> should return
  77      * <code>true</code> as well. If an implementation consumes the KeyEvent,
  78      * but returns <code>false</code>, the consumed event will still be passed
  79      * to the next KeyEventDispatcher in the chain. It is important for
  80      * developers to check whether the KeyEvent has been consumed before
  81      * dispatching it to a target. By default, the current KeyboardFocusManager
  82      * will not dispatch a consumed KeyEvent.
  83      *
  84      * @param e the KeyEvent to dispatch
  85      * @return <code>true</code> if the KeyboardFocusManager should take no
  86      *         further action with regard to the KeyEvent; <code>false</code>
  87      *         otherwise
  88      * @see KeyboardFocusManager#redispatchEvent
  89      */
  90     boolean dispatchKeyEvent(KeyEvent e);
  91 }


  45  * KeyboardFocusManager as a KeyEventDispatcher one or more times, this is
  46  * usually unnecessary and not recommended.)
  47  *
  48  * @author David Mendenhall
  49  *
  50  * @see KeyboardFocusManager#addKeyEventDispatcher
  51  * @see KeyboardFocusManager#removeKeyEventDispatcher
  52  * @since 1.4
  53  */
  54 @FunctionalInterface
  55 public interface KeyEventDispatcher {
  56 
  57     /**
  58      * This method is called by the current KeyboardFocusManager requesting
  59      * that this KeyEventDispatcher dispatch the specified event on its behalf.
  60      * This KeyEventDispatcher is free to retarget the event, consume it,
  61      * dispatch it itself, or make other changes. This capability is typically
  62      * used to deliver KeyEvents to Components other than the focus owner. This
  63      * can be useful when navigating children of non-focusable Windows in an
  64      * accessible environment, for example. Note that if a KeyEventDispatcher
  65      * dispatches the KeyEvent itself, it must use {@code redispatchEvent}
  66      * to prevent the current KeyboardFocusManager from recursively requesting
  67      * that this KeyEventDispatcher dispatch the event again.
  68      * <p>
  69      * If an implementation of this method returns {@code false}, then
  70      * the KeyEvent is passed to the next KeyEventDispatcher in the chain,
  71      * ending with the current KeyboardFocusManager. If an implementation
  72      * returns {@code true}, the KeyEvent is assumed to have been
  73      * dispatched (although this need not be the case), and the current
  74      * KeyboardFocusManager will take no further action with regard to the
  75      * KeyEvent. In such a case,
  76      * {@code KeyboardFocusManager.dispatchEvent} should return
  77      * {@code true} as well. If an implementation consumes the KeyEvent,
  78      * but returns {@code false}, the consumed event will still be passed
  79      * to the next KeyEventDispatcher in the chain. It is important for
  80      * developers to check whether the KeyEvent has been consumed before
  81      * dispatching it to a target. By default, the current KeyboardFocusManager
  82      * will not dispatch a consumed KeyEvent.
  83      *
  84      * @param e the KeyEvent to dispatch
  85      * @return {@code true} if the KeyboardFocusManager should take no
  86      *         further action with regard to the KeyEvent; {@code false}
  87      *         otherwise
  88      * @see KeyboardFocusManager#redispatchEvent
  89      */
  90     boolean dispatchKeyEvent(KeyEvent e);
  91 }
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