1 /*
2 * Copyright (c) 1997, 2009, 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 javax.swing;
26
27 import java.awt.AWTKeyStroke;
28 import java.awt.event.KeyEvent;
29
30 /**
31 * A KeyStroke represents a key action on the keyboard, or equivalent input
32 * device. KeyStrokes can correspond to only a press or release of a particular
33 * key, just as KEY_PRESSED and KEY_RELEASED KeyEvents do; alternately, they
34 * can correspond to typing a specific Java character, just as KEY_TYPED
35 * KeyEvents do. In all cases, KeyStrokes can specify modifiers (alt, shift,
36 * control, meta, altGraph, or a combination thereof) which must be present during the
37 * action for an exact match.
38 * <p>
39 * KeyStrokes are used to define high-level (semantic) action events. Instead
40 * of trapping every keystroke and throwing away the ones you are not
41 * interested in, those keystrokes you care about automatically initiate
42 * actions on the Components with which they are registered.
43 * <p>
44 * KeyStrokes are immutable, and are intended to be unique. Client code cannot
45 * create a KeyStroke; a variant of <code>getKeyStroke</code> must be used
46 * instead. These factory methods allow the KeyStroke implementation to cache
47 * and share instances efficiently.
48 * <p>
49 * <strong>Warning:</strong>
50 * Serialized objects of this class will not be compatible with
51 * future Swing releases. The current serialization support is
52 * appropriate for short term storage or RMI between applications running
53 * the same version of Swing. As of 1.4, support for long term storage
54 * of all JavaBeans™
55 * has been added to the <code>java.beans</code> package.
56 * Please see {@link java.beans.XMLEncoder}.
57 *
58 * @see javax.swing.text.Keymap
59 * @see #getKeyStroke
60 *
61 * @author Arnaud Weber
62 * @author David Mendenhall
63 */
64 public class KeyStroke extends AWTKeyStroke {
65
66 /**
67 * Serial Version ID.
68 */
69 private static final long serialVersionUID = -9060180771037902530L;
70
71 private KeyStroke() {
72 }
73 private KeyStroke(char keyChar, int keyCode, int modifiers,
74 boolean onKeyRelease) {
75 super(keyChar, keyCode, modifiers, onKeyRelease);
76 }
77
78 /**
79 * Returns a shared instance of a <code>KeyStroke</code>
80 * that represents a <code>KEY_TYPED</code> event for the
81 * specified character.
82 *
83 * @param keyChar the character value for a keyboard key
84 * @return a KeyStroke object for that key
85 */
86 public static KeyStroke getKeyStroke(char keyChar) {
87 synchronized (AWTKeyStroke.class) {
88 registerSubclass(KeyStroke.class);
89 return (KeyStroke)getAWTKeyStroke(keyChar);
90 }
91 }
92
93 /**
94 * Returns an instance of a KeyStroke, specifying whether the key is
95 * considered to be activated when it is pressed or released. Unlike all
96 * other factory methods in this class, the instances returned by this
97 * method are not necessarily cached or shared.
98 *
99 * @param keyChar the character value for a keyboard key
100 * @param onKeyRelease <code>true</code> if this KeyStroke corresponds to a
101 * key release; <code>false</code> otherwise.
102 * @return a KeyStroke object for that key
103 * @deprecated use getKeyStroke(char)
104 */
105 @Deprecated
106 public static KeyStroke getKeyStroke(char keyChar, boolean onKeyRelease) {
107 return new KeyStroke(keyChar, KeyEvent.VK_UNDEFINED, 0, onKeyRelease);
108 }
109
110 /**
111 * Returns a shared instance of a {@code KeyStroke}
112 * that represents a {@code KEY_TYPED} event for the
113 * specified Character object and a
114 * set of modifiers. Note that the first parameter is of type Character
115 * rather than char. This is to avoid inadvertent clashes with calls to
116 * <code>getKeyStroke(int keyCode, int modifiers)</code>.
117 *
118 * The modifiers consist of any combination of following:<ul>
119 * <li>java.awt.event.InputEvent.SHIFT_DOWN_MASK
120 * <li>java.awt.event.InputEvent.CTRL_DOWN_MASK
121 * <li>java.awt.event.InputEvent.META_DOWN_MASK
122 * <li>java.awt.event.InputEvent.ALT_DOWN_MASK
123 * <li>java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK
124 * </ul>
125 * The old modifiers listed below also can be used, but they are
126 * mapped to _DOWN_ modifiers. <ul>
127 * <li>java.awt.event.InputEvent.SHIFT_MASK
128 * <li>java.awt.event.InputEvent.CTRL_MASK
129 * <li>java.awt.event.InputEvent.META_MASK
130 * <li>java.awt.event.InputEvent.ALT_MASK
131 * <li>java.awt.event.InputEvent.ALT_GRAPH_MASK
132 * </ul>
133 * also can be used, but they are mapped to _DOWN_ modifiers.
134 *
135 * Since these numbers are all different powers of two, any combination of
136 * them is an integer in which each bit represents a different modifier
137 * key. Use 0 to specify no modifiers.
138 *
139 * @param keyChar the Character object for a keyboard character
140 * @param modifiers a bitwise-ored combination of any modifiers
141 * @return an KeyStroke object for that key
142 * @throws IllegalArgumentException if keyChar is null
143 *
144 * @see java.awt.event.InputEvent
145 * @since 1.3
146 */
147 public static KeyStroke getKeyStroke(Character keyChar, int modifiers) {
148 synchronized (AWTKeyStroke.class) {
149 registerSubclass(KeyStroke.class);
150 return (KeyStroke)getAWTKeyStroke(keyChar, modifiers);
151 }
152 }
153
154 /**
155 * Returns a shared instance of a KeyStroke, given a numeric key code and a
156 * set of modifiers, specifying whether the key is activated when it is
157 * pressed or released.
158 * <p>
159 * The "virtual key" constants defined in java.awt.event.KeyEvent can be
160 * used to specify the key code. For example:<ul>
161 * <li>java.awt.event.KeyEvent.VK_ENTER
162 * <li>java.awt.event.KeyEvent.VK_TAB
163 * <li>java.awt.event.KeyEvent.VK_SPACE
164 * </ul>
165 * Alternatively, the key code may be obtained by calling
166 * <code>java.awt.event.KeyEvent.getExtendedKeyCodeForChar</code>.
167 *
168 * The modifiers consist of any combination of:<ul>
169 * <li>java.awt.event.InputEvent.SHIFT_DOWN_MASK
170 * <li>java.awt.event.InputEvent.CTRL_DOWN_MASK
171 * <li>java.awt.event.InputEvent.META_DOWN_MASK
172 * <li>java.awt.event.InputEvent.ALT_DOWN_MASK
173 * <li>java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK
174 * </ul>
175 * The old modifiers <ul>
176 * <li>java.awt.event.InputEvent.SHIFT_MASK
177 * <li>java.awt.event.InputEvent.CTRL_MASK
178 * <li>java.awt.event.InputEvent.META_MASK
179 * <li>java.awt.event.InputEvent.ALT_MASK
180 * <li>java.awt.event.InputEvent.ALT_GRAPH_MASK
181 * </ul>
182 * also can be used, but they are mapped to _DOWN_ modifiers.
183 *
184 * Since these numbers are all different powers of two, any combination of
185 * them is an integer in which each bit represents a different modifier
186 * key. Use 0 to specify no modifiers.
187 *
188 * @param keyCode an int specifying the numeric code for a keyboard key
189 * @param modifiers a bitwise-ored combination of any modifiers
190 * @param onKeyRelease <code>true</code> if the KeyStroke should represent
191 * a key release; <code>false</code> otherwise.
192 * @return a KeyStroke object for that key
193 *
194 * @see java.awt.event.KeyEvent
195 * @see java.awt.event.InputEvent
196 */
197 public static KeyStroke getKeyStroke(int keyCode, int modifiers,
198 boolean onKeyRelease) {
199 synchronized (AWTKeyStroke.class) {
200 registerSubclass(KeyStroke.class);
201 return (KeyStroke)getAWTKeyStroke(keyCode, modifiers,
202 onKeyRelease);
203 }
204 }
205
206 /**
207 * Returns a shared instance of a KeyStroke, given a numeric key code and a
208 * set of modifiers. The returned KeyStroke will correspond to a key press.
209 * <p>
210 * The "virtual key" constants defined in java.awt.event.KeyEvent can be
211 * used to specify the key code. For example:<ul>
212 * <li>java.awt.event.KeyEvent.VK_ENTER
213 * <li>java.awt.event.KeyEvent.VK_TAB
214 * <li>java.awt.event.KeyEvent.VK_SPACE
215 * </ul>
216 * Alternatively, the key code may be obtained by calling
217 * <code>java.awt.event.KeyEvent.getExtendedKeyCodeForChar</code>.
218 *
219 * The modifiers consist of any combination of:<ul>
220 * <li>java.awt.event.InputEvent.SHIFT_DOWN_MASK
221 * <li>java.awt.event.InputEvent.CTRL_DOWN_MASK
222 * <li>java.awt.event.InputEvent.META_DOWN_MASK
223 * <li>java.awt.event.InputEvent.ALT_DOWN_MASK
224 * <li>java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK
225 * </ul>
226 * The old modifiers <ul>
227 * <li>java.awt.event.InputEvent.SHIFT_MASK
228 * <li>java.awt.event.InputEvent.CTRL_MASK
229 * <li>java.awt.event.InputEvent.META_MASK
230 * <li>java.awt.event.InputEvent.ALT_MASK
231 * <li>java.awt.event.InputEvent.ALT_GRAPH_MASK
232 * </ul>
233 * also can be used, but they are mapped to _DOWN_ modifiers.
234 *
235 * Since these numbers are all different powers of two, any combination of
236 * them is an integer in which each bit represents a different modifier
237 * key. Use 0 to specify no modifiers.
238 *
239 * @param keyCode an int specifying the numeric code for a keyboard key
240 * @param modifiers a bitwise-ored combination of any modifiers
241 * @return a KeyStroke object for that key
242 *
243 * @see java.awt.event.KeyEvent
244 * @see java.awt.event.InputEvent
245 */
246 public static KeyStroke getKeyStroke(int keyCode, int modifiers) {
247 synchronized (AWTKeyStroke.class) {
248 registerSubclass(KeyStroke.class);
249 return (KeyStroke)getAWTKeyStroke(keyCode, modifiers);
250 }
251 }
252
253 /**
254 * Returns a KeyStroke which represents the stroke which generated a given
255 * KeyEvent.
256 * <p>
257 * This method obtains the keyChar from a KeyTyped event, and the keyCode
258 * from a KeyPressed or KeyReleased event. The KeyEvent modifiers are
259 * obtained for all three types of KeyEvent.
260 *
261 * @param anEvent the KeyEvent from which to obtain the KeyStroke
262 * @throws NullPointerException if <code>anEvent</code> is null
263 * @return the KeyStroke that precipitated the event
264 */
265 public static KeyStroke getKeyStrokeForEvent(KeyEvent anEvent) {
266 synchronized (AWTKeyStroke.class) {
267 registerSubclass(KeyStroke.class);
268 return (KeyStroke)getAWTKeyStrokeForEvent(anEvent);
269 }
270 }
271
272 /**
273 * Parses a string and returns a <code>KeyStroke</code>.
274 * The string must have the following syntax:
275 * <pre>
276 * <modifiers>* (<typedID> | <pressedReleasedID>)
277 *
278 * modifiers := shift | control | ctrl | meta | alt | altGraph
279 * typedID := typed <typedKey>
280 * typedKey := string of length 1 giving Unicode character.
281 * pressedReleasedID := (pressed | released) key
282 * key := KeyEvent key code name, i.e. the name following "VK_".
283 * </pre>
284 * If typed, pressed or released is not specified, pressed is assumed. Here
285 * are some examples:
286 * <pre>
287 * "INSERT" => getKeyStroke(KeyEvent.VK_INSERT, 0);
288 * "control DELETE" => getKeyStroke(KeyEvent.VK_DELETE, InputEvent.CTRL_MASK);
289 * "alt shift X" => getKeyStroke(KeyEvent.VK_X, InputEvent.ALT_MASK | InputEvent.SHIFT_MASK);
290 * "alt shift released X" => getKeyStroke(KeyEvent.VK_X, InputEvent.ALT_MASK | InputEvent.SHIFT_MASK, true);
291 * "typed a" => getKeyStroke('a');
292 * </pre>
293 *
294 * In order to maintain backward-compatibility, specifying a null String,
295 * or a String which is formatted incorrectly, returns null.
296 *
297 * @param s a String formatted as described above
298 * @return a KeyStroke object for that String, or null if the specified
299 * String is null, or is formatted incorrectly
300 *
301 * @see java.awt.event.KeyEvent
302 */
303 public static KeyStroke getKeyStroke(String s) {
304 if (s == null || s.length() == 0) {
305 return null;
306 }
307 synchronized (AWTKeyStroke.class) {
308 registerSubclass(KeyStroke.class);
309 try {
310 return (KeyStroke)getAWTKeyStroke(s);
311 } catch (IllegalArgumentException e) {
312 return null;
313 }
314 }
315 }
316 }