Showing the changes to java/pkg/java/awt/KeyEventPostProcessor.java (1 of 18352 files). Show all
Unified · Split
| @@ -0,0 +1,93 @@ | ||
| 1 | +/* | |
| 2 | + * Copyright (c) 2001, 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 | +public interface KeyEventPostProcessor { | |
| 58 | + | |
| 59 | + /** | |
| 60 | + * This method is called by the current KeyboardFocusManager, requesting | |
| 61 | + * that this KeyEventPostProcessor perform any necessary post-processing | |
| 62 | + * which should be part of the KeyEvent's final resolution. At the time | |
| 63 | + * this method is invoked, typically the KeyEvent has already been | |
| 64 | + * dispatched to and handled by its target. However, if no Component in | |
| 65 | + * the application currently owns the focus, then the KeyEvent has not | |
| 66 | + * been dispatched to any Component. Typically, KeyEvent post-processing | |
| 67 | + * will be used to implement features which require global KeyEvent | |
| 68 | + * post-handling, such as menu shortcuts. Note that if a | |
| 69 | + * KeyEventPostProcessor wishes to dispatch the KeyEvent, it must use | |
| 70 | + * <code>redispatchEvent</code> to prevent the AWT from recursively | |
| 71 | + * requesting that this KeyEventPostProcessor perform post-processing | |
| 72 | + * of the event again. | |
| 73 | + * <p> | |
| 74 | + * If an implementation of this method returns <code>false</code>, then the | |
| 75 | + * KeyEvent is passed to the next KeyEventPostProcessor in the chain, | |
| 76 | + * ending with the current KeyboardFocusManager. If an implementation | |
| 77 | + * returns <code>true</code>, the KeyEvent is assumed to have been fully | |
| 78 | + * handled (although this need not be the case), and the AWT will take no | |
| 79 | + * further action with regard to the KeyEvent. If an implementation | |
| 80 | + * consumes the KeyEvent but returns <code>false</code>, the consumed | |
| 81 | + * event will still be passed to the next KeyEventPostProcessor in the | |
| 82 | + * chain. It is important for developers to check whether the KeyEvent has | |
| 83 | + * been consumed before performing any post-processing of the KeyEvent. By | |
| 84 | + * default, the current KeyboardFocusManager will perform no post- | |
| 85 | + * processing in response to a consumed KeyEvent. | |
| 86 | + * | |
| 87 | + * @param e the KeyEvent to post-process | |
| 88 | + * @return <code>true</code> if the AWT should take no further action with | |
| 89 | + * regard to the KeyEvent; <code>false</code> otherwise | |
| 90 | + * @see KeyboardFocusManager#redispatchEvent | |
| 91 | + */ | |
| 92 | + boolean postProcessKeyEvent(KeyEvent e); | |
| 93 | +} | |