/*

 * Copyright 2001 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package java.awt;

import java.awt.event.KeyEvent;

/**

 * A KeyEventPostProcessor cooperates with the current KeyboardFocusManager

 * in the final resolution of all unconsumed KeyEvents. KeyEventPostProcessors

 * registered with the current KeyboardFocusManager will receive KeyEvents

 * after the KeyEvents have been dispatched to and handled by their targets.

 * KeyEvents that would have been otherwise discarded because no Component in

 * the application currently owns the focus will also be forwarded to

 * registered KeyEventPostProcessors. This will allow applications to implement

 * features that require global KeyEvent post-handling, such as menu shortcuts.

 * <p>

 * Note that the KeyboardFocusManager itself implements KeyEventPostProcessor.

 * By default, the current KeyboardFocusManager will be the final

 * KeyEventPostProcessor in the chain. The current KeyboardFocusManager cannot

 * be completely deregistered as a KeyEventPostProcessor. However, if a

 * KeyEventPostProcessor reports that no further post-processing of the

 * KeyEvent should take place, the AWT will consider the event fully handled

 * and will take no additional action with regard to the event. (While it is

 * possible for client code to register the current KeyboardFocusManager as

 * a KeyEventPostProcessor one or more times, this is usually unnecessary and

 * not recommended.)

 *

 * @author David Mendenhall

 *

 * @see KeyboardFocusManager#addKeyEventPostProcessor

 * @see KeyboardFocusManager#removeKeyEventPostProcessor

 * @since 1.4

 */

public interface KeyEventPostProcessor {

    /**

     * This method is called by the current KeyboardFocusManager, requesting

     * that this KeyEventPostProcessor perform any necessary post-processing

     * which should be part of the KeyEvent's final resolution. At the time

     * this method is invoked, typically the KeyEvent has already been

     * dispatched to and handled by its target. However, if no Component in

     * the application currently owns the focus, then the KeyEvent has not

     * been dispatched to any Component. Typically, KeyEvent post-processing

     * will be used to implement features which require global KeyEvent

     * post-handling, such as menu shortcuts. Note that if a

     * KeyEventPostProcessor wishes to dispatch the KeyEvent, it must use

     * <code>redispatchEvent</code> to prevent the AWT from recursively

     * requesting that this KeyEventPostProcessor perform post-processing

     * of the event again.

     * <p>

     * If an implementation of this method returns <code>false</code>, then the

     * KeyEvent is passed to the next KeyEventPostProcessor in the chain,

     * ending with the current KeyboardFocusManager. If an implementation

     * returns <code>true</code>, the KeyEvent is assumed to have been fully

     * handled (although this need not be the case), and the AWT will take no

     * further action with regard to the KeyEvent. If an implementation

     * consumes the KeyEvent but returns <code>false</code>, the consumed

     * event will still be passed to the next KeyEventPostProcessor in the

     * chain. It is important for developers to check whether the KeyEvent has

     * been consumed before performing any post-processing of the KeyEvent. By

     * default, the current KeyboardFocusManager will perform no post-

     * processing in response to a consumed KeyEvent.

     *

     * @param e the KeyEvent to post-process

     * @return <code>true</code> if the AWT should take no further action with

     *         regard to the KeyEvent; <code>false</code> otherwise

     * @see KeyboardFocusManager#redispatchEvent

     */

    boolean postProcessKeyEvent(KeyEvent e);

}