01: /*
02: *
03: * Copyright 1990-2006 Sun Microsystems, Inc. All Rights Reserved.
04: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
05: *
06: * This program is free software; you can redistribute it and/or
07: * modify it under the terms of the GNU General Public License version
08: * 2 only, as published by the Free Software Foundation.
09: *
10: * This program is distributed in the hope that it will be useful, but
11: * WITHOUT ANY WARRANTY; without even the implied warranty of
12: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13: * General Public License version 2 for more details (a copy is
14: * included at /legal/license.txt).
15: *
16: * You should have received a copy of the GNU General Public License
17: * version 2 along with this work; if not, write to the Free Software
18: * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19: * 02110-1301 USA
20: *
21: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
22: * Clara, CA 95054 or visit www.sun.com if you need additional
23: * information or have any questions.
24: */
25: package java.awt;
26:
27: import java.awt.event.KeyEvent;
28:
29: /**
30: * A KeyEventPostProcessor cooperates with the current KeyboardFocusManager
31: * in the final resolution of all unconsumed KeyEvents. KeyEventPostProcessors
32: * registered with the current KeyboardFocusManager will receive KeyEvents
33: * after the KeyEvents have been dispatched to and handled by their targets.
34: * KeyEvents that would have been otherwise discarded because no Component in
35: * the application currently owns the focus will also be forwarded to
36: * registered KeyEventPostProcessors. This will allow applications to implement
37: * features that require global KeyEvent post-handling, such as menu shortcuts.
38: * <p>
39: * Note that the KeyboardFocusManager itself implements KeyEventPostProcessor.
40: * By default, the current KeyboardFocusManager will be the final
41: * KeyEventPostProcessor in the chain. The current KeyboardFocusManager cannot
42: * be completely deregistered as a KeyEventPostProcessor. However, if a
43: * KeyEventPostProcessor reports that no further post-processing of the
44: * KeyEvent should take place, the AWT will consider the event fully handled
45: * and will take no additional action with regard to the event. (While it is
46: * possible for client code to register the current KeyboardFocusManager as
47: * a KeyEventPostProcessor one or more times, this is usually unnecessary and
48: * not recommended.)
49: *
50: * @author David Mendenhall
51: * @version 1.4, 01/23/03
52: *
53: * @see KeyboardFocusManager#addKeyEventPostProcessor
54: * @see KeyboardFocusManager#removeKeyEventPostProcessor
55: * @since 1.4
56: */
57: public interface KeyEventPostProcessor {
58: /**
59: * This method is called by the current KeyboardFocusManager, requesting
60: * that this KeyEventPostProcessor perform any necessary post-processing
61: * which should be part of the KeyEvent's final resolution. At the time
62: * this method is invoked, typically the KeyEvent has already been
63: * dispatched to and handled by its target. However, if no Component in
64: * the application currently owns the focus, then the KeyEvent has not
65: * been dispatched to any Component. Typically, KeyEvent post-processing
66: * will be used to implement features which require global KeyEvent
67: * post-handling, such as menu shortcuts. Note that if a
68: * KeyEventPostProcessor wishes to dispatch the KeyEvent, it must use
69: * <code>redispatchEvent</code> to prevent the AWT from recursively
70: * requesting that this KeyEventPostProcessor perform post-processing
71: * of the event again.
72: * <p>
73: * If an implementation of this method returns <code>false</code>, then the
74: * KeyEvent is passed to the next KeyEventPostProcessor in the chain,
75: * ending with the current KeyboardFocusManager. If an implementation
76: * returns <code>true</code>, the KeyEvent is assumed to have been fully
77: * handled (although this need not be the case), and the AWT will take no
78: * further action with regard to the KeyEvent. If an implementation
79: * consumes the KeyEvent but returns <code>false</code>, the consumed
80: * event will still be passed to the next KeyEventPostProcessor in the
81: * chain. It is important for developers to check whether the KeyEvent has
82: * been consumed before performing any post-processing of the KeyEvent. By
83: * default, the current KeyboardFocusManager will perform no post-
84: * processing in response to a consumed KeyEvent.
85: *
86: * @param e the KeyEvent to post-process
87: * @return <code>true</code> if the AWT should take no further action with
88: * regard to the KeyEvent; <code>false</code> otherwise
89: * @see KeyboardFocusManager#redispatchEvent
90: */
91: boolean postProcessKeyEvent(KeyEvent e);
92: }
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