1 /*
2 * Copyright (c) 1997, 2014, 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 import sun.swing.SwingAccessor;
30
31 /**
32 * A KeyStroke represents a key action on the keyboard, or equivalent input
33 * device. KeyStrokes can correspond to only a press or release of a particular
34 * key, just as KEY_PRESSED and KEY_RELEASED KeyEvents do; alternately, they
35 * can correspond to typing a specific Java character, just as KEY_TYPED
36 * KeyEvents do. In all cases, KeyStrokes can specify modifiers (alt, shift,
37 * control, meta, altGraph, or a combination thereof) which must be present during the
38 * action for an exact match.
39 * <p>
40 * KeyStrokes are used to define high-level (semantic) action events. Instead
41 * of trapping every keystroke and throwing away the ones you are not
42 * interested in, those keystrokes you care about automatically initiate
43 * actions on the Components with which they are registered.
44 * <p>
45 * KeyStrokes are immutable, and are intended to be unique. Client code cannot
46 * create a KeyStroke; a variant of <code>getKeyStroke</code> must be used
47 * instead. These factory methods allow the KeyStroke implementation to cache
48 * and share instances efficiently.
49 * <p>
50 * <strong>Warning:</strong>
51 * Serialized objects of this class will not be compatible with
52 * future Swing releases. The current serialization support is
53 * appropriate for short term storage or RMI between applications running
54 * the same version of Swing. As of 1.4, support for long term storage
55 * of all JavaBeans
56 * has been added to the <code>java.beans</code> package.
57 * Please see {@link java.beans.XMLEncoder}.
58 *
59 * @see javax.swing.text.Keymap
60 * @see #getKeyStroke
61 *
62 * @author Arnaud Weber
63 * @author David Mendenhall
64 * @since 1.2
65 */
66 @SuppressWarnings("serial") // Same-version serialization only
67 public class KeyStroke extends AWTKeyStroke {
68
69 /**
70 * Serial Version ID.
71 */
72 private static final long serialVersionUID = -9060180771037902530L;
73
74 static {
75 SwingAccessor.setKeyStrokeAccessor(new SwingAccessor.KeyStrokeAccessor() {
76
77 @Override
78 public KeyStroke create() {
79 return new KeyStroke();
80 }
81 });
82 }
83
84 private KeyStroke() {
85 }
86 private KeyStroke(char keyChar, int keyCode, int modifiers,
87 boolean onKeyRelease) {
88 super(keyChar, keyCode, modifiers, onKeyRelease);
89 }
90
91 /**
92 * Returns a shared instance of a <code>KeyStroke</code>
93 * that represents a <code>KEY_TYPED</code> event for the
94 * specified character.
95 *
96 * @param keyChar the character value for a keyboard key
97 * @return a KeyStroke object for that key
98 */
99 public static KeyStroke getKeyStroke(char keyChar) {
100 synchronized (AWTKeyStroke.class) {
101 return (KeyStroke)getAWTKeyStroke(keyChar);
102 }
103 }
104
105 /**
106 * Returns an instance of a KeyStroke, specifying whether the key is
107 * considered to be activated when it is pressed or released. Unlike all
108 * other factory methods in this class, the instances returned by this
109 * method are not necessarily cached or shared.
110 *
111 * @param keyChar the character value for a keyboard key
112 * @param onKeyRelease <code>true</code> if this KeyStroke corresponds to a
113 * key release; <code>false</code> otherwise.
114 * @return a KeyStroke object for that key
115 * @deprecated use getKeyStroke(char)
116 */
117 @Deprecated
118 public static KeyStroke getKeyStroke(char keyChar, boolean onKeyRelease) {
119 return new KeyStroke(keyChar, KeyEvent.VK_UNDEFINED, 0, onKeyRelease);
120 }
121
122 /**
123 * Returns a shared instance of a {@code KeyStroke}
124 * that represents a {@code KEY_TYPED} event for the
125 * specified Character object and a
126 * set of modifiers. Note that the first parameter is of type Character
127 * rather than char. This is to avoid inadvertent clashes with calls to
128 * <code>getKeyStroke(int keyCode, int modifiers)</code>.
129 *
130 * The modifiers consist of any combination of following:<ul>
131 * <li>java.awt.event.InputEvent.SHIFT_DOWN_MASK
132 * <li>java.awt.event.InputEvent.CTRL_DOWN_MASK
133 * <li>java.awt.event.InputEvent.META_DOWN_MASK
134 * <li>java.awt.event.InputEvent.ALT_DOWN_MASK
135 * <li>java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK
136 * </ul>
137 * The old modifiers listed below also can be used, but they are
138 * mapped to _DOWN_ modifiers. <ul>
139 * <li>java.awt.event.InputEvent.SHIFT_MASK
140 * <li>java.awt.event.InputEvent.CTRL_MASK
141 * <li>java.awt.event.InputEvent.META_MASK
142 * <li>java.awt.event.InputEvent.ALT_MASK
143 * <li>java.awt.event.InputEvent.ALT_GRAPH_MASK
144 * </ul>
145 * also can be used, but they are mapped to _DOWN_ modifiers.
146 *
147 * Since these numbers are all different powers of two, any combination of
148 * them is an integer in which each bit represents a different modifier
149 * key. Use 0 to specify no modifiers.
150 *
151 * @param keyChar the Character object for a keyboard character
152 * @param modifiers a bitwise-ored combination of any modifiers
153 * @return an KeyStroke object for that key
154 * @throws IllegalArgumentException if keyChar is null
155 *
156 * @see java.awt.event.InputEvent
157 * @since 1.3
158 */
159 public static KeyStroke getKeyStroke(Character keyChar, int modifiers) {
160 synchronized (AWTKeyStroke.class) {
161 return (KeyStroke)getAWTKeyStroke(keyChar, modifiers);
162 }
163 }
164
165 /**
166 * Returns a shared instance of a KeyStroke, given a numeric key code and a
167 * set of modifiers, specifying whether the key is activated when it is
168 * pressed or released.
169 * <p>
170 * The "virtual key" constants defined in java.awt.event.KeyEvent can be
171 * used to specify the key code. For example:<ul>
172 * <li>java.awt.event.KeyEvent.VK_ENTER
173 * <li>java.awt.event.KeyEvent.VK_TAB
174 * <li>java.awt.event.KeyEvent.VK_SPACE
175 * </ul>
176 * Alternatively, the key code may be obtained by calling
177 * <code>java.awt.event.KeyEvent.getExtendedKeyCodeForChar</code>.
178 *
179 * The modifiers consist of any combination of:<ul>
180 * <li>java.awt.event.InputEvent.SHIFT_DOWN_MASK
181 * <li>java.awt.event.InputEvent.CTRL_DOWN_MASK
182 * <li>java.awt.event.InputEvent.META_DOWN_MASK
183 * <li>java.awt.event.InputEvent.ALT_DOWN_MASK
184 * <li>java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK
185 * </ul>
186 * The old modifiers <ul>
187 * <li>java.awt.event.InputEvent.SHIFT_MASK
188 * <li>java.awt.event.InputEvent.CTRL_MASK
189 * <li>java.awt.event.InputEvent.META_MASK
190 * <li>java.awt.event.InputEvent.ALT_MASK
191 * <li>java.awt.event.InputEvent.ALT_GRAPH_MASK
192 * </ul>
193 * also can be used, but they are mapped to _DOWN_ modifiers.
194 *
195 * Since these numbers are all different powers of two, any combination of
196 * them is an integer in which each bit represents a different modifier
197 * key. Use 0 to specify no modifiers.
198 *
199 * @param keyCode an int specifying the numeric code for a keyboard key
200 * @param modifiers a bitwise-ored combination of any modifiers
201 * @param onKeyRelease <code>true</code> if the KeyStroke should represent
202 * a key release; <code>false</code> otherwise.
203 * @return a KeyStroke object for that key
204 *
205 * @see java.awt.event.KeyEvent
206 * @see java.awt.event.InputEvent
207 */
208 public static KeyStroke getKeyStroke(int keyCode, int modifiers,
209 boolean onKeyRelease) {
210 synchronized (AWTKeyStroke.class) {
211 return (KeyStroke)getAWTKeyStroke(keyCode, modifiers,
212 onKeyRelease);
213 }
214 }
215
216 /**
217 * Returns a shared instance of a KeyStroke, given a numeric key code and a
218 * set of modifiers. The returned KeyStroke will correspond to a key press.
219 * <p>
220 * The "virtual key" constants defined in java.awt.event.KeyEvent can be
221 * used to specify the key code. For example:<ul>
222 * <li>java.awt.event.KeyEvent.VK_ENTER
223 * <li>java.awt.event.KeyEvent.VK_TAB
224 * <li>java.awt.event.KeyEvent.VK_SPACE
225 * </ul>
226 * Alternatively, the key code may be obtained by calling
227 * <code>java.awt.event.KeyEvent.getExtendedKeyCodeForChar</code>.
228 *
229 * The modifiers consist of any combination of:<ul>
230 * <li>java.awt.event.InputEvent.SHIFT_DOWN_MASK
231 * <li>java.awt.event.InputEvent.CTRL_DOWN_MASK
232 * <li>java.awt.event.InputEvent.META_DOWN_MASK
233 * <li>java.awt.event.InputEvent.ALT_DOWN_MASK
234 * <li>java.awt.event.InputEvent.ALT_GRAPH_DOWN_MASK
235 * </ul>
236 * The old modifiers <ul>
237 * <li>java.awt.event.InputEvent.SHIFT_MASK
238 * <li>java.awt.event.InputEvent.CTRL_MASK
239 * <li>java.awt.event.InputEvent.META_MASK
240 * <li>java.awt.event.InputEvent.ALT_MASK
241 * <li>java.awt.event.InputEvent.ALT_GRAPH_MASK
242 * </ul>
243 * also can be used, but they are mapped to _DOWN_ modifiers.
244 *
245 * Since these numbers are all different powers of two, any combination of
246 * them is an integer in which each bit represents a different modifier
247 * key. Use 0 to specify no modifiers.
248 *
249 * @param keyCode an int specifying the numeric code for a keyboard key
250 * @param modifiers a bitwise-ored combination of any modifiers
251 * @return a KeyStroke object for that key
252 *
253 * @see java.awt.event.KeyEvent
254 * @see java.awt.event.InputEvent
255 */
256 public static KeyStroke getKeyStroke(int keyCode, int modifiers) {
257 synchronized (AWTKeyStroke.class) {
258 return (KeyStroke)getAWTKeyStroke(keyCode, modifiers);
259 }
260 }
261
262 /**
263 * Returns a KeyStroke which represents the stroke which generated a given
264 * KeyEvent.
265 * <p>
266 * This method obtains the keyChar from a KeyTyped event, and the keyCode
267 * from a KeyPressed or KeyReleased event. The KeyEvent modifiers are
268 * obtained for all three types of KeyEvent.
269 *
270 * @param anEvent the KeyEvent from which to obtain the KeyStroke
271 * @throws NullPointerException if <code>anEvent</code> is null
272 * @return the KeyStroke that precipitated the event
273 */
274 public static KeyStroke getKeyStrokeForEvent(KeyEvent anEvent) {
275 synchronized (AWTKeyStroke.class) {
276 return (KeyStroke)getAWTKeyStrokeForEvent(anEvent);
277 }
278 }
279
280 /**
281 * Parses a string and returns a <code>KeyStroke</code>.
282 * The string must have the following syntax:
283 * <pre>
284 * <modifiers>* (<typedID> | <pressedReleasedID>)
285 *
286 * modifiers := shift | control | ctrl | meta | alt | altGraph
287 * typedID := typed <typedKey>
288 * typedKey := string of length 1 giving Unicode character.
289 * pressedReleasedID := (pressed | released) key
290 * key := KeyEvent key code name, i.e. the name following "VK_".
291 * </pre>
292 * If typed, pressed or released is not specified, pressed is assumed. Here
293 * are some examples:
294 * <pre>
295 * "INSERT" => getKeyStroke(KeyEvent.VK_INSERT, 0);
296 * "control DELETE" => getKeyStroke(KeyEvent.VK_DELETE, InputEvent.CTRL_MASK);
297 * "alt shift X" => getKeyStroke(KeyEvent.VK_X, InputEvent.ALT_MASK | InputEvent.SHIFT_MASK);
298 * "alt shift released X" => getKeyStroke(KeyEvent.VK_X, InputEvent.ALT_MASK | InputEvent.SHIFT_MASK, true);
299 * "typed a" => getKeyStroke('a');
300 * </pre>
301 *
302 * In order to maintain backward-compatibility, specifying a null String,
303 * or a String which is formatted incorrectly, returns null.
304 *
305 * @param s a String formatted as described above
306 * @return a KeyStroke object for that String, or null if the specified
307 * String is null, or is formatted incorrectly
308 *
309 * @see java.awt.event.KeyEvent
310 */
311 public static KeyStroke getKeyStroke(String s) {
312 if (s == null || s.length() == 0) {
313 return null;
314 }
315 synchronized (AWTKeyStroke.class) {
316 try {
317 return (KeyStroke)getAWTKeyStroke(s);
318 } catch (IllegalArgumentException e) {
319 return null;
320 }
321 }
322 }
323 }