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| 1 | /* | ||
| 2 | * Copyright (c) 1995, 2008, 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 | |||
| 26 | package java.awt; | ||
| 27 | |||
| 28 | import java.awt.peer.ButtonPeer; | ||
| 29 | import java.util.EventListener; | ||
| 30 | import java.awt.event.*; | ||
| 31 | import java.io.ObjectOutputStream; | ||
| 32 | import java.io.ObjectInputStream; | ||
| 33 | import java.io.IOException; | ||
| 34 | import javax.accessibility.*; | ||
| 35 | |||
| 36 | /** | ||
| 37 | * This class creates a labeled button. The application can cause | ||
| 38 | * some action to happen when the button is pushed. This image | ||
| 39 | * depicts three views of a "<code>Quit</code>" button as it appears | ||
| 40 | * under the Solaris operating system: | ||
| 41 | * <p> | ||
| 42 | * <img src="doc-files/Button-1.gif" alt="The following context describes the graphic" | ||
| 43 | * ALIGN=center HSPACE=10 VSPACE=7> | ||
| 44 | * <p> | ||
| 45 | * The first view shows the button as it appears normally. | ||
| 46 | * The second view shows the button | ||
| 47 | * when it has input focus. Its outline is darkened to let the | ||
| 48 | * user know that it is an active object. The third view shows the | ||
| 49 | * button when the user clicks the mouse over the button, and thus | ||
| 50 | * requests that an action be performed. | ||
| 51 | * <p> | ||
| 52 | * The gesture of clicking on a button with the mouse | ||
| 53 | * is associated with one instance of <code>ActionEvent</code>, | ||
| 54 | * which is sent out when the mouse is both pressed and released | ||
| 55 | * over the button. If an application is interested in knowing | ||
| 56 | * when the button has been pressed but not released, as a separate | ||
| 57 | * gesture, it can specialize <code>processMouseEvent</code>, | ||
| 58 | * or it can register itself as a listener for mouse events by | ||
| 59 | * calling <code>addMouseListener</code>. Both of these methods are | ||
| 60 | * defined by <code>Component</code>, the abstract superclass of | ||
| 61 | * all components. | ||
| 62 | * <p> | ||
| 63 | * When a button is pressed and released, AWT sends an instance | ||
| 64 | * of <code>ActionEvent</code> to the button, by calling | ||
| 65 | * <code>processEvent</code> on the button. The button's | ||
| 66 | * <code>processEvent</code> method receives all events | ||
| 67 | * for the button; it passes an action event along by | ||
| 68 | * calling its own <code>processActionEvent</code> method. | ||
| 69 | * The latter method passes the action event on to any action | ||
| 70 | * listeners that have registered an interest in action | ||
| 71 | * events generated by this button. | ||
| 72 | * <p> | ||
| 73 | * If an application wants to perform some action based on | ||
| 74 | * a button being pressed and released, it should implement | ||
| 75 | * <code>ActionListener</code> and register the new listener | ||
| 76 | * to receive events from this button, by calling the button's | ||
| 77 | * <code>addActionListener</code> method. The application can | ||
| 78 | * make use of the button's action command as a messaging protocol. | ||
| 79 | * | ||
| 80 | * @author Sami Shaio | ||
| 81 | * @see java.awt.event.ActionEvent | ||
| 82 | * @see java.awt.event.ActionListener | ||
| 83 | * @see java.awt.Component#processMouseEvent | ||
| 84 | * @see java.awt.Component#addMouseListener | ||
| 85 | * @since JDK1.0 | ||
| 86 | */ | ||
| 87 | public class Button extends Component implements Accessible { | ||
| 88 | |||
| 89 | /** | ||
| 90 | * The button's label. This value may be null. | ||
| 91 | * @serial | ||
| 92 | * @see #getLabel() | ||
| 93 | * @see #setLabel(String) | ||
| 94 | */ | ||
| 95 | String label; | ||
| 96 | |||
| 97 | /** | ||
| 98 | * The action to be performed once a button has been | ||
| 99 | * pressed. This value may be null. | ||
| 100 | * @serial | ||
| 101 | * @see #getActionCommand() | ||
| 102 | * @see #setActionCommand(String) | ||
| 103 | */ | ||
| 104 | String actionCommand; | ||
| 105 | |||
| 106 | transient ActionListener actionListener; | ||
| 107 | |||
| 108 | private static final String base = "button"; | ||
| 109 | private static int nameCounter = 0; | ||
| 110 | |||
| 111 | /* | ||
| 112 | * JDK 1.1 serialVersionUID | ||
| 113 | */ | ||
| 114 | private static final long serialVersionUID = -8774683716313001058L; | ||
| 115 | |||
| 116 | |||
| 117 | static { | ||
| 118 | /* ensure that the necessary native libraries are loaded */ | ||
| 119 | Toolkit.loadLibraries(); | ||
| 120 | if (!GraphicsEnvironment.isHeadless()) { | ||
| 121 | initIDs(); | ||
| 122 | } | ||
| 123 | } | ||
| 124 | |||
| 125 | /** | ||
| 126 | * Initialize JNI field and method IDs for fields that may be | ||
| 127 | * accessed from C. | ||
| 128 | */ | ||
| 129 | private static native void initIDs(); | ||
| 130 | |||
| 131 | /** | ||
| 132 | * Constructs a button with an empty string for its label. | ||
| 133 | * | ||
| 134 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() | ||
| 135 | * returns true | ||
| 136 | * @see java.awt.GraphicsEnvironment#isHeadless | ||
| 137 | */ | ||
| 138 | public Button() throws HeadlessException { | ||
| 139 | this(""); | ||
| 140 | } | ||
| 141 | |||
| 142 | /** | ||
| 143 | * Constructs a button with the specified label. | ||
| 144 | * | ||
| 145 | * @param label a string label for the button, or | ||
| 146 | * <code>null</code> for no label | ||
| 147 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() | ||
| 148 | * returns true | ||
| 149 | * @see java.awt.GraphicsEnvironment#isHeadless | ||
| 150 | */ | ||
| 151 | public Button(String label) throws HeadlessException { | ||
| 152 | GraphicsEnvironment.checkHeadless(); | ||
| 153 | this.label = label; | ||
| 154 | } | ||
| 155 | |||
| 156 | /** | ||
| 157 | * Construct a name for this component. Called by getName() when the | ||
| 158 | * name is null. | ||
| 159 | */ | ||
| 160 | String constructComponentName() { | ||
| 161 | synchronized (Button.class) { | ||
| 162 | return base + nameCounter++; | ||
| 163 | } | ||
| 164 | } | ||
| 165 | |||
| 166 | /** | ||
| 167 | * Creates the peer of the button. The button's peer allows the | ||
| 168 | * application to change the look of the button without changing | ||
| 169 | * its functionality. | ||
| 170 | * | ||
| 171 | * @see java.awt.Toolkit#createButton(java.awt.Button) | ||
| 172 | * @see java.awt.Component#getToolkit() | ||
| 173 | */ | ||
| 174 | public void addNotify() { | ||
| 175 | synchronized(getTreeLock()) { | ||
| 176 | if (peer == null) | ||
| 177 | peer = getToolkit().createButton(this); | ||
| 178 | super.addNotify(); | ||
| 179 | } | ||
| 180 | } | ||
| 181 | |||
| 182 | /** | ||
| 183 | * Gets the label of this button. | ||
| 184 | * | ||
| 185 | * @return the button's label, or <code>null</code> | ||
| 186 | * if the button has no label. | ||
| 187 | * @see java.awt.Button#setLabel | ||
| 188 | */ | ||
| 189 | public String getLabel() { | ||
| 190 | return label; | ||
| 191 | } | ||
| 192 | |||
| 193 | /** | ||
| 194 | * Sets the button's label to be the specified string. | ||
| 195 | * | ||
| 196 | * @param label the new label, or <code>null</code> | ||
| 197 | * if the button has no label. | ||
| 198 | * @see java.awt.Button#getLabel | ||
| 199 | */ | ||
| 200 | public void setLabel(String label) { | ||
| 201 | boolean testvalid = false; | ||
| 202 | |||
| 203 | synchronized (this) { | ||
| 204 | if (label != this.label && (this.label == null || | ||
| 205 | !this.label.equals(label))) { | ||
| 206 | this.label = label; | ||
| 207 | ButtonPeer peer = (ButtonPeer)this.peer; | ||
| 208 | if (peer != null) { | ||
| 209 | peer.setLabel(label); | ||
| 210 | } | ||
| 211 | testvalid = true; | ||
| 212 | } | ||
| 213 | } | ||
| 214 | |||
| 215 | // This could change the preferred size of the Component. | ||
| 216 | if (testvalid) { | ||
| 217 | invalidateIfValid(); | ||
| 218 | } | ||
| 219 | } | ||
| 220 | |||
| 221 | /** | ||
| 222 | * Sets the command name for the action event fired | ||
| 223 | * by this button. By default this action command is | ||
| 224 | * set to match the label of the button. | ||
| 225 | * | ||
| 226 | * @param command a string used to set the button's | ||
| 227 | * action command. | ||
| 228 | * If the string is <code>null</code> then the action command | ||
| 229 | * is set to match the label of the button. | ||
| 230 | * @see java.awt.event.ActionEvent | ||
| 231 | * @since JDK1.1 | ||
| 232 | */ | ||
| 233 | public void setActionCommand(String command) { | ||
| 234 | actionCommand = command; | ||
| 235 | } | ||
| 236 | |||
| 237 | /** | ||
| 238 | * Returns the command name of the action event fired by this button. | ||
| 239 | * If the command name is <code>null</code> (default) then this method | ||
| 240 | * returns the label of the button. | ||
| 241 | */ | ||
| 242 | public String getActionCommand() { | ||
| 243 | return (actionCommand == null? label : actionCommand); | ||
| 244 | } | ||
| 245 | |||
| 246 | /** | ||
| 247 | * Adds the specified action listener to receive action events from | ||
| 248 | * this button. Action events occur when a user presses or releases | ||
| 249 | * the mouse over this button. | ||
| 250 | * If l is null, no exception is thrown and no action is performed. | ||
| 251 | * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" | ||
| 252 | * >AWT Threading Issues</a> for details on AWT's threading model. | ||
| 253 | * | ||
| 254 | * @param l the action listener | ||
| 255 | * @see #removeActionListener | ||
| 256 | * @see #getActionListeners | ||
| 257 | * @see java.awt.event.ActionListener | ||
| 258 | * @since JDK1.1 | ||
| 259 | */ | ||
| 260 | public synchronized void addActionListener(ActionListener l) { | ||
| 261 | if (l == null) { | ||
| 262 | return; | ||
| 263 | } | ||
| 264 | actionListener = AWTEventMulticaster.add(actionListener, l); | ||
| 265 | newEventsOnly = true; | ||
| 266 | } | ||
| 267 | |||
| 268 | /** | ||
| 269 | * Removes the specified action listener so that it no longer | ||
| 270 | * receives action events from this button. Action events occur | ||
| 271 | * when a user presses or releases the mouse over this button. | ||
| 272 | * If l is null, no exception is thrown and no action is performed. | ||
| 273 | * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" | ||
| 274 | * >AWT Threading Issues</a> for details on AWT's threading model. | ||
| 275 | * | ||
| 276 | * @param l the action listener | ||
| 277 | * @see #addActionListener | ||
| 278 | * @see #getActionListeners | ||
| 279 | * @see java.awt.event.ActionListener | ||
| 280 | * @since JDK1.1 | ||
| 281 | */ | ||
| 282 | public synchronized void removeActionListener(ActionListener l) { | ||
| 283 | if (l == null) { | ||
| 284 | return; | ||
| 285 | } | ||
| 286 | actionListener = AWTEventMulticaster.remove(actionListener, l); | ||
| 287 | } | ||
| 288 | |||
| 289 | /** | ||
| 290 | * Returns an array of all the action listeners | ||
| 291 | * registered on this button. | ||
| 292 | * | ||
| 293 | * @return all of this button's <code>ActionListener</code>s | ||
| 294 | * or an empty array if no action | ||
| 295 | * listeners are currently registered | ||
| 296 | * | ||
| 297 | * @see #addActionListener | ||
| 298 | * @see #removeActionListener | ||
| 299 | * @see java.awt.event.ActionListener | ||
| 300 | * @since 1.4 | ||
| 301 | */ | ||
| 302 | public synchronized ActionListener[] getActionListeners() { | ||
| 303 | return (ActionListener[]) (getListeners(ActionListener.class)); | ||
| 304 | } | ||
| 305 | |||
| 306 | /** | ||
| 307 | * Returns an array of all the objects currently registered | ||
| 308 | * as <code><em>Foo</em>Listener</code>s | ||
| 309 | * upon this <code>Button</code>. | ||
| 310 | * <code><em>Foo</em>Listener</code>s are registered using the | ||
| 311 | * <code>add<em>Foo</em>Listener</code> method. | ||
| 312 | * | ||
| 313 | * <p> | ||
| 314 | * You can specify the <code>listenerType</code> argument | ||
| 315 | * with a class literal, such as | ||
| 316 | * <code><em>Foo</em>Listener.class</code>. | ||
| 317 | * For example, you can query a | ||
| 318 | * <code>Button</code> <code>b</code> | ||
| 319 | * for its action listeners with the following code: | ||
| 320 | * | ||
| 321 | * <pre>ActionListener[] als = (ActionListener[])(b.getListeners(ActionListener.class));</pre> | ||
| 322 | * | ||
| 323 | * If no such listeners exist, this method returns an empty array. | ||
| 324 | * | ||
| 325 | * @param listenerType the type of listeners requested; this parameter | ||
| 326 | * should specify an interface that descends from | ||
| 327 | * <code>java.util.EventListener</code> | ||
| 328 | * @return an array of all objects registered as | ||
| 329 | * <code><em>Foo</em>Listener</code>s on this button, | ||
| 330 | * or an empty array if no such | ||
| 331 | * listeners have been added | ||
| 332 | * @exception ClassCastException if <code>listenerType</code> | ||
| 333 | * doesn't specify a class or interface that implements | ||
| 334 | * <code>java.util.EventListener</code> | ||
| 335 | * | ||
| 336 | * @see #getActionListeners | ||
| 337 | * @since 1.3 | ||
| 338 | */ | ||
| 339 | public <T extends EventListener> T[] getListeners(Class<T> listenerType) { | ||
| 340 | EventListener l = null; | ||
| 341 | if (listenerType == ActionListener.class) { | ||
| 342 | l = actionListener; | ||
| 343 | } else { | ||
| 344 | return super.getListeners(listenerType); | ||
| 345 | } | ||
| 346 | return AWTEventMulticaster.getListeners(l, listenerType); | ||
| 347 | } | ||
| 348 | |||
| 349 | // REMIND: remove when filtering is done at lower level | ||
| 350 | boolean eventEnabled(AWTEvent e) { | ||
| 351 | if (e.id == ActionEvent.ACTION_PERFORMED) { | ||
| 352 | if ((eventMask & AWTEvent.ACTION_EVENT_MASK) != 0 || | ||
| 353 | actionListener != null) { | ||
| 354 | return true; | ||
| 355 | } | ||
| 356 | return false; | ||
| 357 | } | ||
| 358 | return super.eventEnabled(e); | ||
| 359 | } | ||
| 360 | |||
| 361 | /** | ||
| 362 | * Processes events on this button. If an event is | ||
| 363 | * an instance of <code>ActionEvent</code>, this method invokes | ||
| 364 | * the <code>processActionEvent</code> method. Otherwise, | ||
| 365 | * it invokes <code>processEvent</code> on the superclass. | ||
| 366 | * <p>Note that if the event parameter is <code>null</code> | ||
| 367 | * the behavior is unspecified and may result in an | ||
| 368 | * exception. | ||
| 369 | * | ||
| 370 | * @param e the event | ||
| 371 | * @see java.awt.event.ActionEvent | ||
| 372 | * @see java.awt.Button#processActionEvent | ||
| 373 | * @since JDK1.1 | ||
| 374 | */ | ||
| 375 | protected void processEvent(AWTEvent e) { | ||
| 376 | if (e instanceof ActionEvent) { | ||
| 377 | processActionEvent((ActionEvent)e); | ||
| 378 | return; | ||
| 379 | } | ||
| 380 | super.processEvent(e); | ||
| 381 | } | ||
| 382 | |||
| 383 | /** | ||
| 384 | * Processes action events occurring on this button | ||
| 385 | * by dispatching them to any registered | ||
| 386 | * <code>ActionListener</code> objects. | ||
| 387 | * <p> | ||
| 388 | * This method is not called unless action events are | ||
| 389 | * enabled for this button. Action events are enabled | ||
| 390 | * when one of the following occurs: | ||
| 391 | * <p><ul> | ||
| 392 | * <li>An <code>ActionListener</code> object is registered | ||
| 393 | * via <code>addActionListener</code>. | ||
| 394 | * <li>Action events are enabled via <code>enableEvents</code>. | ||
| 395 | * </ul> | ||
| 396 | * <p>Note that if the event parameter is <code>null</code> | ||
| 397 | * the behavior is unspecified and may result in an | ||
| 398 | * exception. | ||
| 399 | * | ||
| 400 | * @param e the action event | ||
| 401 | * @see java.awt.event.ActionListener | ||
| 402 | * @see java.awt.Button#addActionListener | ||
| 403 | * @see java.awt.Component#enableEvents | ||
| 404 | * @since JDK1.1 | ||
| 405 | */ | ||
| 406 | protected void processActionEvent(ActionEvent e) { | ||
| 407 | ActionListener listener = actionListener; | ||
| 408 | if (listener != null) { | ||
| 409 | listener.actionPerformed(e); | ||
| 410 | } | ||
| 411 | } | ||
| 412 | |||
| 413 | /** | ||
| 414 | * Returns a string representing the state of this <code>Button</code>. | ||
| 415 | * This method is intended to be used only for debugging purposes, and the | ||
| 416 | * content and format of the returned string may vary between | ||
| 417 | * implementations. The returned string may be empty but may not be | ||
| 418 | * <code>null</code>. | ||
| 419 | * | ||
| 420 | * @return the parameter string of this button | ||
| 421 | */ | ||
| 422 | protected String paramString() { | ||
| 423 | return super.paramString() + ",label=" + label; | ||
| 424 | } | ||
| 425 | |||
| 426 | |||
| 427 | /* Serialization support. | ||
| 428 | */ | ||
| 429 | |||
| 430 | /* | ||
| 431 | * Button Serial Data Version. | ||
| 432 | * @serial | ||
| 433 | */ | ||
| 434 | private int buttonSerializedDataVersion = 1; | ||
| 435 | |||
| 436 | /** | ||
| 437 | * Writes default serializable fields to stream. Writes | ||
| 438 | * a list of serializable <code>ActionListeners</code> | ||
| 439 | * as optional data. The non-serializable | ||
| 440 | * <code>ActionListeners</code> are detected and | ||
| 441 | * no attempt is made to serialize them. | ||
| 442 | * | ||
| 443 | * @serialData <code>null</code> terminated sequence of 0 or | ||
| 444 | * more pairs: the pair consists of a <code>String</code> | ||
| 445 | * and an <code>Object</code>; the <code>String</code> | ||
| 446 | * indicates the type of object and is one of the following: | ||
| 447 | * <code>actionListenerK</code> indicating an | ||
| 448 | * <code>ActionListener</code> object | ||
| 449 | * | ||
| 450 | * @param s the <code>ObjectOutputStream</code> to write | ||
| 451 | * @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener) | ||
| 452 | * @see java.awt.Component#actionListenerK | ||
| 453 | * @see #readObject(ObjectInputStream) | ||
| 454 | */ | ||
| 455 | private void writeObject(ObjectOutputStream s) | ||
| 456 | throws IOException | ||
| 457 | { | ||
| 458 | s.defaultWriteObject(); | ||
| 459 | |||
| 460 | AWTEventMulticaster.save(s, actionListenerK, actionListener); | ||
| 461 | s.writeObject(null); | ||
| 462 | } | ||
| 463 | |||
| 464 | /** | ||
| 465 | * Reads the <code>ObjectInputStream</code> and if | ||
| 466 | * it isn't <code>null</code> adds a listener to | ||
| 467 | * receive action events fired by the button. | ||
| 468 | * Unrecognized keys or values will be ignored. | ||
| 469 | * | ||
| 470 | * @param s the <code>ObjectInputStream</code> to read | ||
| 471 | * @exception HeadlessException if | ||
| 472 | * <code>GraphicsEnvironment.isHeadless</code> returns | ||
| 473 | * <code>true</code> | ||
| 474 | * @serial | ||
| 475 | * @see #removeActionListener(ActionListener) | ||
| 476 | * @see #addActionListener(ActionListener) | ||
| 477 | * @see java.awt.GraphicsEnvironment#isHeadless | ||
| 478 | * @see #writeObject(ObjectOutputStream) | ||
| 479 | */ | ||
| 480 | private void readObject(ObjectInputStream s) | ||
| 481 | throws ClassNotFoundException, IOException, HeadlessException | ||
| 482 | { | ||
| 483 | GraphicsEnvironment.checkHeadless(); | ||
| 484 | s.defaultReadObject(); | ||
| 485 | |||
| 486 | Object keyOrNull; | ||
| 487 | while(null != (keyOrNull = s.readObject())) { | ||
| 488 | String key = ((String)keyOrNull).intern(); | ||
| 489 | |||
| 490 | if (actionListenerK == key) | ||
| 491 | addActionListener((ActionListener)(s.readObject())); | ||
| 492 | |||
| 493 | else // skip value for unrecognized key | ||
| 494 | s.readObject(); | ||
| 495 | } | ||
| 496 | } | ||
| 497 | |||
| 498 | |||
| 499 | ///////////////// | ||
| 500 | // Accessibility support | ||
| 501 | //////////////// | ||
| 502 | |||
| 503 | /** | ||
| 504 | * Gets the <code>AccessibleContext</code> associated with | ||
| 505 | * this <code>Button</code>. For buttons, the | ||
| 506 | * <code>AccessibleContext</code> takes the form of an | ||
| 507 | * <code>AccessibleAWTButton</code>. | ||
| 508 | * A new <code>AccessibleAWTButton</code> instance is | ||
| 509 | * created if necessary. | ||
| 510 | * | ||
| 511 | * @return an <code>AccessibleAWTButton</code> that serves as the | ||
| 512 | * <code>AccessibleContext</code> of this <code>Button</code> | ||
| 513 | * @beaninfo | ||
| 514 | * expert: true | ||
| 515 | * description: The AccessibleContext associated with this Button. | ||
| 516 | * @since 1.3 | ||
| 517 | */ | ||
| 518 | public AccessibleContext getAccessibleContext() { | ||
| 519 | if (accessibleContext == null) { | ||
| 520 | accessibleContext = new AccessibleAWTButton(); | ||
| 521 | } | ||
| 522 | return accessibleContext; | ||
| 523 | } | ||
| 524 | |||
| 525 | /** | ||
| 526 | * This class implements accessibility support for the | ||
| 527 | * <code>Button</code> class. It provides an implementation of the | ||
| 528 | * Java Accessibility API appropriate to button user-interface elements. | ||
| 529 | * @since 1.3 | ||
| 530 | */ | ||
| 531 | protected class AccessibleAWTButton extends AccessibleAWTComponent | ||
| 532 | implements AccessibleAction, AccessibleValue | ||
| 533 | { | ||
| 534 | /* | ||
| 535 | * JDK 1.3 serialVersionUID | ||
| 536 | */ | ||
| 537 | private static final long serialVersionUID = -5932203980244017102L; | ||
| 538 | |||
| 539 | /** | ||
| 540 | * Get the accessible name of this object. | ||
| 541 | * | ||
| 542 | * @return the localized name of the object -- can be null if this | ||
| 543 | * object does not have a name | ||
| 544 | */ | ||
| 545 | public String getAccessibleName() { | ||
| 546 | if (accessibleName != null) { | ||
| 547 | return accessibleName; | ||
| 548 | } else { | ||
| 549 | if (getLabel() == null) { | ||
| 550 | return super.getAccessibleName(); | ||
| 551 | } else { | ||
| 552 | return getLabel(); | ||
| 553 | } | ||
| 554 | } | ||
| 555 | } | ||
| 556 | |||
| 557 | /** | ||
| 558 | * Get the AccessibleAction associated with this object. In the | ||
| 559 | * implementation of the Java Accessibility API for this class, | ||
| 560 | * return this object, which is responsible for implementing the | ||
| 561 | * AccessibleAction interface on behalf of itself. | ||
| 562 | * | ||
| 563 | * @return this object | ||
| 564 | */ | ||
| 565 | public AccessibleAction getAccessibleAction() { | ||
| 566 | return this; | ||
| 567 | } | ||
| 568 | |||
| 569 | /** | ||
| 570 | * Get the AccessibleValue associated with this object. In the | ||
| 571 | * implementation of the Java Accessibility API for this class, | ||
| 572 | * return this object, which is responsible for implementing the | ||
| 573 | * AccessibleValue interface on behalf of itself. | ||
| 574 | * | ||
| 575 | * @return this object | ||
| 576 | */ | ||
| 577 | public AccessibleValue getAccessibleValue() { | ||
| 578 | return this; | ||
| 579 | } | ||
| 580 | |||
| 581 | /** | ||
| 582 | * Returns the number of Actions available in this object. The | ||
| 583 | * default behavior of a button is to have one action - toggle | ||
| 584 | * the button. | ||
| 585 | * | ||
| 586 | * @return 1, the number of Actions in this object | ||
| 587 | */ | ||
| 588 | public int getAccessibleActionCount() { | ||
| 589 | return 1; | ||
| 590 | } | ||
| 591 | |||
| 592 | /** | ||
| 593 | * Return a description of the specified action of the object. | ||
| 594 | * | ||
| 595 | * @param i zero-based index of the actions | ||
| 596 | */ | ||
| 597 | public String getAccessibleActionDescription(int i) { | ||
| 598 | if (i == 0) { | ||
| 599 | // [[[PENDING: WDW -- need to provide a localized string]]] | ||
| 600 | return "click"; | ||
| 601 | } else { | ||
| 602 | return null; | ||
| 603 | } | ||
| 604 | } | ||
| 605 | |||
| 606 | /** | ||
| 607 | * Perform the specified Action on the object | ||
| 608 | * | ||
| 609 | * @param i zero-based index of actions | ||
| 610 | * @return true if the the action was performed; else false. | ||
| 611 | */ | ||
| 612 | public boolean doAccessibleAction(int i) { | ||
| 613 | if (i == 0) { | ||
| 614 | // Simulate a button click | ||
| 615 | Toolkit.getEventQueue().postEvent( | ||
| 616 | new ActionEvent(Button.this, | ||
| 617 | ActionEvent.ACTION_PERFORMED, | ||
| 618 | Button.this.getActionCommand())); | ||
| 619 | return true; | ||
| 620 | } else { | ||
| 621 | return false; | ||
| 622 | } | ||
| 623 | } | ||
| 624 | |||
| 625 | /** | ||
| 626 | * Get the value of this object as a Number. | ||
| 627 | * | ||
| 628 | * @return An Integer of 0 if this isn't selected or an Integer of 1 if | ||
| 629 | * this is selected. | ||
| 630 | * @see javax.swing.AbstractButton#isSelected() | ||
| 631 | */ | ||
| 632 | public Number getCurrentAccessibleValue() { | ||
| 633 | return Integer.valueOf(0); | ||
| 634 | } | ||
| 635 | |||
| 636 | /** | ||
| 637 | * Set the value of this object as a Number. | ||
| 638 | * | ||
| 639 | * @return True if the value was set. | ||
| 640 | */ | ||
| 641 | public boolean setCurrentAccessibleValue(Number n) { | ||
| 642 | return false; | ||
| 643 | } | ||
| 644 | |||
| 645 | /** | ||
| 646 | * Get the minimum value of this object as a Number. | ||
| 647 | * | ||
| 648 | * @return An Integer of 0. | ||
| 649 | */ | ||
| 650 | public Number getMinimumAccessibleValue() { | ||
| 651 | return Integer.valueOf(0); | ||
| 652 | } | ||
| 653 | |||
| 654 | /** | ||
| 655 | * Get the maximum value of this object as a Number. | ||
| 656 | * | ||
| 657 | * @return An Integer of 0. | ||
| 658 | */ | ||
| 659 | public Number getMaximumAccessibleValue() { | ||
| 660 | return Integer.valueOf(0); | ||
| 661 | } | ||
| 662 | |||
| 663 | /** | ||
| 664 | * Get the role of this object. | ||
| 665 | * | ||
| 666 | * @return an instance of AccessibleRole describing the role of the | ||
| 667 | * object | ||
| 668 | * @see AccessibleRole | ||
| 669 | */ | ||
| 670 | public AccessibleRole getAccessibleRole() { | ||
| 671 | return AccessibleRole.PUSH_BUTTON; | ||
| 672 | } | ||
| 673 | } // inner class AccessibleAWTButton | ||
| 674 | |||
| 675 | } | ||