1 /* 2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package java.awt; 26 27 import java.awt.event.KeyEvent; 28 29 30 /** 31 * A KeyEventPostProcessor cooperates with the current KeyboardFocusManager 32 * in the final resolution of all unconsumed KeyEvents. KeyEventPostProcessors 33 * registered with the current KeyboardFocusManager will receive KeyEvents 34 * after the KeyEvents have been dispatched to and handled by their targets. 35 * KeyEvents that would have been otherwise discarded because no Component in 36 * the application currently owns the focus will also be forwarded to 37 * registered KeyEventPostProcessors. This will allow applications to implement 38 * features that require global KeyEvent post-handling, such as menu shortcuts. 39 * <p> 40 * Note that the KeyboardFocusManager itself implements KeyEventPostProcessor. 41 * By default, the current KeyboardFocusManager will be the final 42 * KeyEventPostProcessor in the chain. The current KeyboardFocusManager cannot 43 * be completely deregistered as a KeyEventPostProcessor. However, if a 44 * KeyEventPostProcessor reports that no further post-processing of the 45 * KeyEvent should take place, the AWT will consider the event fully handled 46 * and will take no additional action with regard to the event. (While it is 47 * possible for client code to register the current KeyboardFocusManager as 48 * a KeyEventPostProcessor one or more times, this is usually unnecessary and 49 * not recommended.) 50 * 51 * @author David Mendenhall 52 * 53 * @see KeyboardFocusManager#addKeyEventPostProcessor 54 * @see KeyboardFocusManager#removeKeyEventPostProcessor 55 * @since 1.4 56 */ 57 @FunctionalInterface 58 public interface KeyEventPostProcessor { 59 60 /** 61 * This method is called by the current KeyboardFocusManager, requesting 62 * that this KeyEventPostProcessor perform any necessary post-processing 63 * which should be part of the KeyEvent's final resolution. At the time 64 * this method is invoked, typically the KeyEvent has already been 65 * dispatched to and handled by its target. However, if no Component in 66 * the application currently owns the focus, then the KeyEvent has not 67 * been dispatched to any Component. Typically, KeyEvent post-processing 68 * will be used to implement features which require global KeyEvent 69 * post-handling, such as menu shortcuts. Note that if a 70 * KeyEventPostProcessor wishes to dispatch the KeyEvent, it must use 71 * {@code redispatchEvent} to prevent the AWT from recursively 72 * requesting that this KeyEventPostProcessor perform post-processing 73 * of the event again. 74 * <p> 75 * If an implementation of this method returns {@code false}, then the 76 * KeyEvent is passed to the next KeyEventPostProcessor in the chain, 77 * ending with the current KeyboardFocusManager. If an implementation 78 * returns {@code true}, the KeyEvent is assumed to have been fully 79 * handled (although this need not be the case), and the AWT will take no 80 * further action with regard to the KeyEvent. If an implementation 81 * consumes the KeyEvent but returns {@code false}, the consumed 82 * event will still be passed to the next KeyEventPostProcessor in the 83 * chain. It is important for developers to check whether the KeyEvent has 84 * been consumed before performing any post-processing of the KeyEvent. By 85 * default, the current KeyboardFocusManager will perform no post- 86 * processing in response to a consumed KeyEvent. 87 * 88 * @param e the KeyEvent to post-process 89 * @return {@code true} if the AWT should take no further action with 90 * regard to the KeyEvent; {@code false} otherwise 91 * @see KeyboardFocusManager#redispatchEvent 92 */ 93 boolean postProcessKeyEvent(KeyEvent e); 94 } --- EOF ---