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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 | +package java.awt; | |
| 26 | + | |
| 27 | +import java.awt.peer.CheckboxPeer; | |
| 28 | +import java.awt.event.*; | |
| 29 | +import java.util.EventListener; | |
| 30 | +import java.io.ObjectOutputStream; | |
| 31 | +import java.io.ObjectInputStream; | |
| 32 | +import java.io.IOException; | |
| 33 | +import javax.accessibility.*; | |
| 34 | + | |
| 35 | + | |
| 36 | +/** | |
| 37 | + * A check box is a graphical component that can be in either an | |
| 38 | + * "on" (<code>true</code>) or "off" (<code>false</code>) state. | |
| 39 | + * Clicking on a check box changes its state from | |
| 40 | + * "on" to "off," or from "off" to "on." | |
| 41 | + * <p> | |
| 42 | + * The following code example creates a set of check boxes in | |
| 43 | + * a grid layout: | |
| 44 | + * <p> | |
| 45 | + * <hr><blockquote><pre> | |
| 46 | + * setLayout(new GridLayout(3, 1)); | |
| 47 | + * add(new Checkbox("one", null, true)); | |
| 48 | + * add(new Checkbox("two")); | |
| 49 | + * add(new Checkbox("three")); | |
| 50 | + * </pre></blockquote><hr> | |
| 51 | + * <p> | |
| 52 | + * This image depicts the check boxes and grid layout | |
| 53 | + * created by this code example: | |
| 54 | + * <p> | |
| 55 | + * <img src="doc-files/Checkbox-1.gif" alt="The following context describes the graphic." | |
| 56 | + * ALIGN=center HSPACE=10 VSPACE=7> | |
| 57 | + * <p> | |
| 58 | + * The button labeled <code>one</code> is in the "on" state, and the | |
| 59 | + * other two are in the "off" state. In this example, which uses the | |
| 60 | + * <code>GridLayout</code> class, the states of the three check | |
| 61 | + * boxes are set independently. | |
| 62 | + * <p> | |
| 63 | + * Alternatively, several check boxes can be grouped together under | |
| 64 | + * the control of a single object, using the | |
| 65 | + * <code>CheckboxGroup</code> class. | |
| 66 | + * In a check box group, at most one button can be in the "on" | |
| 67 | + * state at any given time. Clicking on a check box to turn it on | |
| 68 | + * forces any other check box in the same group that is on | |
| 69 | + * into the "off" state. | |
| 70 | + * | |
| 71 | + * @author Sami Shaio | |
| 72 | + * @see java.awt.GridLayout | |
| 73 | + * @see java.awt.CheckboxGroup | |
| 74 | + * @since JDK1.0 | |
| 75 | + */ | |
| 76 | +public class Checkbox extends Component implements ItemSelectable, Accessible { | |
| 77 | + | |
| 78 | + static { | |
| 79 | + /* ensure that the necessary native libraries are loaded */ | |
| 80 | + Toolkit.loadLibraries(); | |
| 81 | + if (!GraphicsEnvironment.isHeadless()) { | |
| 82 | + initIDs(); | |
| 83 | + } | |
| 84 | + } | |
| 85 | + | |
| 86 | + /** | |
| 87 | + * The label of the Checkbox. | |
| 88 | + * This field can be null. | |
| 89 | + * @serial | |
| 90 | + * @see #getLabel() | |
| 91 | + * @see #setLabel(String) | |
| 92 | + */ | |
| 93 | + String label; | |
| 94 | + | |
| 95 | + /** | |
| 96 | + * The state of the <code>Checkbox</code>. | |
| 97 | + * @serial | |
| 98 | + * @see #getState() | |
| 99 | + * @see #setState(boolean) | |
| 100 | + */ | |
| 101 | + boolean state; | |
| 102 | + | |
| 103 | + /** | |
| 104 | + * The check box group. | |
| 105 | + * This field can be null indicating that the checkbox | |
| 106 | + * is not a group checkbox. | |
| 107 | + * @serial | |
| 108 | + * @see #getCheckboxGroup() | |
| 109 | + * @see #setCheckboxGroup(CheckboxGroup) | |
| 110 | + */ | |
| 111 | + CheckboxGroup group; | |
| 112 | + | |
| 113 | + transient ItemListener itemListener; | |
| 114 | + | |
| 115 | + private static final String base = "checkbox"; | |
| 116 | + private static int nameCounter = 0; | |
| 117 | + | |
| 118 | + /* | |
| 119 | + * JDK 1.1 serialVersionUID | |
| 120 | + */ | |
| 121 | + private static final long serialVersionUID = 7270714317450821763L; | |
| 122 | + | |
| 123 | + /** | |
| 124 | + * Helper function for setState and CheckboxGroup.setSelectedCheckbox | |
| 125 | + * Should remain package-private. | |
| 126 | + */ | |
| 127 | + void setStateInternal(boolean state) { | |
| 128 | + this.state = state; | |
| 129 | + CheckboxPeer peer = (CheckboxPeer)this.peer; | |
| 130 | + if (peer != null) { | |
| 131 | + peer.setState(state); | |
| 132 | + } | |
| 133 | + } | |
| 134 | + | |
| 135 | + /** | |
| 136 | + * Creates a check box with an empty string for its label. | |
| 137 | + * The state of this check box is set to "off," and it is not | |
| 138 | + * part of any check box group. | |
| 139 | + * @exception HeadlessException if GraphicsEnvironment.isHeadless() | |
| 140 | + * returns true | |
| 141 | + * @see java.awt.GraphicsEnvironment#isHeadless | |
| 142 | + */ | |
| 143 | + public Checkbox() throws HeadlessException { | |
| 144 | + this("", false, null); | |
| 145 | + } | |
| 146 | + | |
| 147 | + /** | |
| 148 | + * Creates a check box with the specified label. The state | |
| 149 | + * of this check box is set to "off," and it is not part of | |
| 150 | + * any check box group. | |
| 151 | + * | |
| 152 | + * @param label a string label for this check box, | |
| 153 | + * or <code>null</code> for no label. | |
| 154 | + * @exception HeadlessException if | |
| 155 | + * <code>GraphicsEnvironment.isHeadless</code> | |
| 156 | + * returns <code>true</code> | |
| 157 | + * @see java.awt.GraphicsEnvironment#isHeadless | |
| 158 | + */ | |
| 159 | + public Checkbox(String label) throws HeadlessException { | |
| 160 | + this(label, false, null); | |
| 161 | + } | |
| 162 | + | |
| 163 | + /** | |
| 164 | + * Creates a check box with the specified label | |
| 165 | + * and sets the specified state. | |
| 166 | + * This check box is not part of any check box group. | |
| 167 | + * | |
| 168 | + * @param label a string label for this check box, | |
| 169 | + * or <code>null</code> for no label | |
| 170 | + * @param state the initial state of this check box | |
| 171 | + * @exception HeadlessException if | |
| 172 | + * <code>GraphicsEnvironment.isHeadless</code> | |
| 173 | + * returns <code>true</code> | |
| 174 | + * @see java.awt.GraphicsEnvironment#isHeadless | |
| 175 | + */ | |
| 176 | + public Checkbox(String label, boolean state) throws HeadlessException { | |
| 177 | + this(label, state, null); | |
| 178 | + } | |
| 179 | + | |
| 180 | + /** | |
| 181 | + * Constructs a Checkbox with the specified label, set to the | |
| 182 | + * specified state, and in the specified check box group. | |
| 183 | + * | |
| 184 | + * @param label a string label for this check box, | |
| 185 | + * or <code>null</code> for no label. | |
| 186 | + * @param state the initial state of this check box. | |
| 187 | + * @param group a check box group for this check box, | |
| 188 | + * or <code>null</code> for no group. | |
| 189 | + * @exception HeadlessException if | |
| 190 | + * <code>GraphicsEnvironment.isHeadless</code> | |
| 191 | + * returns <code>true</code> | |
| 192 | + * @see java.awt.GraphicsEnvironment#isHeadless | |
| 193 | + * @since JDK1.1 | |
| 194 | + */ | |
| 195 | + public Checkbox(String label, boolean state, CheckboxGroup group) | |
| 196 | + throws HeadlessException { | |
| 197 | + GraphicsEnvironment.checkHeadless(); | |
| 198 | + this.label = label; | |
| 199 | + this.state = state; | |
| 200 | + this.group = group; | |
| 201 | + if (state && (group != null)) { | |
| 202 | + group.setSelectedCheckbox(this); | |
| 203 | + } | |
| 204 | + } | |
| 205 | + | |
| 206 | + /** | |
| 207 | + * Creates a check box with the specified label, in the specified | |
| 208 | + * check box group, and set to the specified state. | |
| 209 | + * | |
| 210 | + * @param label a string label for this check box, | |
| 211 | + * or <code>null</code> for no label. | |
| 212 | + * @param group a check box group for this check box, | |
| 213 | + * or <code>null</code> for no group. | |
| 214 | + * @param state the initial state of this check box. | |
| 215 | + * @exception HeadlessException if | |
| 216 | + * <code>GraphicsEnvironment.isHeadless</code> | |
| 217 | + * returns <code>true</code> | |
| 218 | + * @see java.awt.GraphicsEnvironment#isHeadless | |
| 219 | + * @since JDK1.1 | |
| 220 | + */ | |
| 221 | + public Checkbox(String label, CheckboxGroup group, boolean state) | |
| 222 | + throws HeadlessException { | |
| 223 | + this(label, state, group); | |
| 224 | + } | |
| 225 | + | |
| 226 | + /** | |
| 227 | + * Constructs a name for this component. Called by | |
| 228 | + * <code>getName</code> when the name is <code>null</code>. | |
| 229 | + * | |
| 230 | + * @return a name for this component | |
| 231 | + */ | |
| 232 | + String constructComponentName() { | |
| 233 | + synchronized (Checkbox.class) { | |
| 234 | + return base + nameCounter++; | |
| 235 | + } | |
| 236 | + } | |
| 237 | + | |
| 238 | + /** | |
| 239 | + * Creates the peer of the Checkbox. The peer allows you to change the | |
| 240 | + * look of the Checkbox without changing its functionality. | |
| 241 | + * | |
| 242 | + * @see java.awt.Toolkit#createCheckbox(java.awt.Checkbox) | |
| 243 | + * @see java.awt.Component#getToolkit() | |
| 244 | + */ | |
| 245 | + public void addNotify() { | |
| 246 | + synchronized (getTreeLock()) { | |
| 247 | + if (peer == null) | |
| 248 | + peer = getToolkit().createCheckbox(this); | |
| 249 | + super.addNotify(); | |
| 250 | + } | |
| 251 | + } | |
| 252 | + | |
| 253 | + /** | |
| 254 | + * Gets the label of this check box. | |
| 255 | + * | |
| 256 | + * @return the label of this check box, or <code>null</code> | |
| 257 | + * if this check box has no label. | |
| 258 | + * @see #setLabel(String) | |
| 259 | + */ | |
| 260 | + public String getLabel() { | |
| 261 | + return label; | |
| 262 | + } | |
| 263 | + | |
| 264 | + /** | |
| 265 | + * Sets this check box's label to be the string argument. | |
| 266 | + * | |
| 267 | + * @param label a string to set as the new label, or | |
| 268 | + * <code>null</code> for no label. | |
| 269 | + * @see #getLabel | |
| 270 | + */ | |
| 271 | + public void setLabel(String label) { | |
| 272 | + boolean testvalid = false; | |
| 273 | + | |
| 274 | + synchronized (this) { | |
| 275 | + if (label != this.label && (this.label == null || | |
| 276 | + !this.label.equals(label))) { | |
| 277 | + this.label = label; | |
| 278 | + CheckboxPeer peer = (CheckboxPeer)this.peer; | |
| 279 | + if (peer != null) { | |
| 280 | + peer.setLabel(label); | |
| 281 | + } | |
| 282 | + testvalid = true; | |
| 283 | + } | |
| 284 | + } | |
| 285 | + | |
| 286 | + // This could change the preferred size of the Component. | |
| 287 | + if (testvalid) { | |
| 288 | + invalidateIfValid(); | |
| 289 | + } | |
| 290 | + } | |
| 291 | + | |
| 292 | + /** | |
| 293 | + * Determines whether this check box is in the "on" or "off" state. | |
| 294 | + * The boolean value <code>true</code> indicates the "on" state, | |
| 295 | + * and <code>false</code> indicates the "off" state. | |
| 296 | + * | |
| 297 | + * @return the state of this check box, as a boolean value | |
| 298 | + * @see #setState | |
| 299 | + */ | |
| 300 | + public boolean getState() { | |
| 301 | + return state; | |
| 302 | + } | |
| 303 | + | |
| 304 | + /** | |
| 305 | + * Sets the state of this check box to the specified state. | |
| 306 | + * The boolean value <code>true</code> indicates the "on" state, | |
| 307 | + * and <code>false</code> indicates the "off" state. | |
| 308 | + * | |
| 309 | + * <p>Note that this method should be primarily used to | |
| 310 | + * initialize the state of the checkbox. Programmatically | |
| 311 | + * setting the state of the checkbox will <i>not</i> trigger | |
| 312 | + * an <code>ItemEvent</code>. The only way to trigger an | |
| 313 | + * <code>ItemEvent</code> is by user interaction. | |
| 314 | + * | |
| 315 | + * @param state the boolean state of the check box | |
| 316 | + * @see #getState | |
| 317 | + */ | |
| 318 | + public void setState(boolean state) { | |
| 319 | + /* Cannot hold check box lock when calling group.setSelectedCheckbox. */ | |
| 320 | + CheckboxGroup group = this.group; | |
| 321 | + if (group != null) { | |
| 322 | + if (state) { | |
| 323 | + group.setSelectedCheckbox(this); | |
| 324 | + } else if (group.getSelectedCheckbox() == this) { | |
| 325 | + state = true; | |
| 326 | + } | |
| 327 | + } | |
| 328 | + setStateInternal(state); | |
| 329 | + } | |
| 330 | + | |
| 331 | + /** | |
| 332 | + * Returns an array (length 1) containing the checkbox | |
| 333 | + * label or null if the checkbox is not selected. | |
| 334 | + * @see ItemSelectable | |
| 335 | + */ | |
| 336 | + public Object[] getSelectedObjects() { | |
| 337 | + if (state) { | |
| 338 | + Object[] items = new Object[1]; | |
| 339 | + items[0] = label; | |
| 340 | + return items; | |
| 341 | + } | |
| 342 | + return null; | |
| 343 | + } | |
| 344 | + | |
| 345 | + /** | |
| 346 | + * Determines this check box's group. | |
| 347 | + * @return this check box's group, or <code>null</code> | |
| 348 | + * if the check box is not part of a check box group. | |
| 349 | + * @see #setCheckboxGroup(CheckboxGroup) | |
| 350 | + */ | |
| 351 | + public CheckboxGroup getCheckboxGroup() { | |
| 352 | + return group; | |
| 353 | + } | |
| 354 | + | |
| 355 | + /** | |
| 356 | + * Sets this check box's group to the specified check box group. | |
| 357 | + * If this check box is already in a different check box group, | |
| 358 | + * it is first taken out of that group. | |
| 359 | + * <p> | |
| 360 | + * If the state of this check box is <code>true</code> and the new | |
| 361 | + * group already has a check box selected, this check box's state | |
| 362 | + * is changed to <code>false</code>. If the state of this check | |
| 363 | + * box is <code>true</code> and the new group has no check box | |
| 364 | + * selected, this check box becomes the selected checkbox for | |
| 365 | + * the new group and its state is <code>true</code>. | |
| 366 | + * | |
| 367 | + * @param g the new check box group, or <code>null</code> | |
| 368 | + * to remove this check box from any check box group | |
| 369 | + * @see #getCheckboxGroup | |
| 370 | + */ | |
| 371 | + public void setCheckboxGroup(CheckboxGroup g) { | |
| 372 | + CheckboxGroup oldGroup; | |
| 373 | + boolean oldState; | |
| 374 | + | |
| 375 | + /* Do nothing if this check box has already belonged | |
| 376 | + * to the check box group g. | |
| 377 | + */ | |
| 378 | + if (this.group == g) { | |
| 379 | + return; | |
| 380 | + } | |
| 381 | + | |
| 382 | + synchronized (this) { | |
| 383 | + oldGroup = this.group; | |
| 384 | + oldState = getState(); | |
| 385 | + | |
| 386 | + this.group = g; | |
| 387 | + CheckboxPeer peer = (CheckboxPeer)this.peer; | |
| 388 | + if (peer != null) { | |
| 389 | + peer.setCheckboxGroup(g); | |
| 390 | + } | |
| 391 | + if (this.group != null && getState()) { | |
| 392 | + if (this.group.getSelectedCheckbox() != null) { | |
| 393 | + setState(false); | |
| 394 | + } else { | |
| 395 | + this.group.setSelectedCheckbox(this); | |
| 396 | + } | |
| 397 | + } | |
| 398 | + } | |
| 399 | + | |
| 400 | + /* Locking check box below could cause deadlock with | |
| 401 | + * CheckboxGroup's setSelectedCheckbox method. | |
| 402 | + * | |
| 403 | + * Fix for 4726853 by kdm@sparc.spb.su | |
| 404 | + * Here we should check if this check box was selected | |
| 405 | + * in the previous group and set selected check box to | |
| 406 | + * null for that group if so. | |
| 407 | + */ | |
| 408 | + if (oldGroup != null && oldState) { | |
| 409 | + oldGroup.setSelectedCheckbox(null); | |
| 410 | + } | |
| 411 | + } | |
| 412 | + | |
| 413 | + /** | |
| 414 | + * Adds the specified item listener to receive item events from | |
| 415 | + * this check box. Item events are sent to listeners in response | |
| 416 | + * to user input, but not in response to calls to setState(). | |
| 417 | + * If l is null, no exception is thrown and no action is performed. | |
| 418 | + * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" | |
| 419 | + * >AWT Threading Issues</a> for details on AWT's threading model. | |
| 420 | + * | |
| 421 | + * @param l the item listener | |
| 422 | + * @see #removeItemListener | |
| 423 | + * @see #getItemListeners | |
| 424 | + * @see #setState | |
| 425 | + * @see java.awt.event.ItemEvent | |
| 426 | + * @see java.awt.event.ItemListener | |
| 427 | + * @since JDK1.1 | |
| 428 | + */ | |
| 429 | + public synchronized void addItemListener(ItemListener l) { | |
| 430 | + if (l == null) { | |
| 431 | + return; | |
| 432 | + } | |
| 433 | + itemListener = AWTEventMulticaster.add(itemListener, l); | |
| 434 | + newEventsOnly = true; | |
| 435 | + } | |
| 436 | + | |
| 437 | + /** | |
| 438 | + * Removes the specified item listener so that the item listener | |
| 439 | + * no longer receives item events from this check box. | |
| 440 | + * If l is null, no exception is thrown and no action is performed. | |
| 441 | + * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" | |
| 442 | + * >AWT Threading Issues</a> for details on AWT's threading model. | |
| 443 | + * | |
| 444 | + * @param l the item listener | |
| 445 | + * @see #addItemListener | |
| 446 | + * @see #getItemListeners | |
| 447 | + * @see java.awt.event.ItemEvent | |
| 448 | + * @see java.awt.event.ItemListener | |
| 449 | + * @since JDK1.1 | |
| 450 | + */ | |
| 451 | + public synchronized void removeItemListener(ItemListener l) { | |
| 452 | + if (l == null) { | |
| 453 | + return; | |
| 454 | + } | |
| 455 | + itemListener = AWTEventMulticaster.remove(itemListener, l); | |
| 456 | + } | |
| 457 | + | |
| 458 | + /** | |
| 459 | + * Returns an array of all the item listeners | |
| 460 | + * registered on this checkbox. | |
| 461 | + * | |
| 462 | + * @return all of this checkbox's <code>ItemListener</code>s | |
| 463 | + * or an empty array if no item | |
| 464 | + * listeners are currently registered | |
| 465 | + * | |
| 466 | + * @see #addItemListener | |
| 467 | + * @see #removeItemListener | |
| 468 | + * @see java.awt.event.ItemEvent | |
| 469 | + * @see java.awt.event.ItemListener | |
| 470 | + * @since 1.4 | |
| 471 | + */ | |
| 472 | + public synchronized ItemListener[] getItemListeners() { | |
| 473 | + return (ItemListener[]) (getListeners(ItemListener.class)); | |
| 474 | + } | |
| 475 | + | |
| 476 | + /** | |
| 477 | + * Returns an array of all the objects currently registered | |
| 478 | + * as <code><em>Foo</em>Listener</code>s | |
| 479 | + * upon this <code>Checkbox</code>. | |
| 480 | + * <code><em>Foo</em>Listener</code>s are registered using the | |
| 481 | + * <code>add<em>Foo</em>Listener</code> method. | |
| 482 | + * | |
| 483 | + * <p> | |
| 484 | + * You can specify the <code>listenerType</code> argument | |
| 485 | + * with a class literal, such as | |
| 486 | + * <code><em>Foo</em>Listener.class</code>. | |
| 487 | + * For example, you can query a | |
| 488 | + * <code>Checkbox</code> <code>c</code> | |
| 489 | + * for its item listeners with the following code: | |
| 490 | + * | |
| 491 | + * <pre>ItemListener[] ils = (ItemListener[])(c.getListeners(ItemListener.class));</pre> | |
| 492 | + * | |
| 493 | + * If no such listeners exist, this method returns an empty array. | |
| 494 | + * | |
| 495 | + * @param listenerType the type of listeners requested; this parameter | |
| 496 | + * should specify an interface that descends from | |
| 497 | + * <code>java.util.EventListener</code> | |
| 498 | + * @return an array of all objects registered as | |
| 499 | + * <code><em>Foo</em>Listener</code>s on this checkbox, | |
| 500 | + * or an empty array if no such | |
| 501 | + * listeners have been added | |
| 502 | + * @exception ClassCastException if <code>listenerType</code> | |
| 503 | + * doesn't specify a class or interface that implements | |
| 504 | + * <code>java.util.EventListener</code> | |
| 505 | + * | |
| 506 | + * @see #getItemListeners | |
| 507 | + * @since 1.3 | |
| 508 | + */ | |
| 509 | + public <T extends EventListener> T[] getListeners(Class<T> listenerType) { | |
| 510 | + EventListener l = null; | |
| 511 | + if (listenerType == ItemListener.class) { | |
| 512 | + l = itemListener; | |
| 513 | + } else { | |
| 514 | + return super.getListeners(listenerType); | |
| 515 | + } | |
| 516 | + return AWTEventMulticaster.getListeners(l, listenerType); | |
| 517 | + } | |
| 518 | + | |
| 519 | + // REMIND: remove when filtering is done at lower level | |
| 520 | + boolean eventEnabled(AWTEvent e) { | |
| 521 | + if (e.id == ItemEvent.ITEM_STATE_CHANGED) { | |
| 522 | + if ((eventMask & AWTEvent.ITEM_EVENT_MASK) != 0 || | |
| 523 | + itemListener != null) { | |
| 524 | + return true; | |
| 525 | + } | |
| 526 | + return false; | |
| 527 | + } | |
| 528 | + return super.eventEnabled(e); | |
| 529 | + } | |
| 530 | + | |
| 531 | + /** | |
| 532 | + * Processes events on this check box. | |
| 533 | + * If the event is an instance of <code>ItemEvent</code>, | |
| 534 | + * this method invokes the <code>processItemEvent</code> method. | |
| 535 | + * Otherwise, it calls its superclass's <code>processEvent</code> method. | |
| 536 | + * <p>Note that if the event parameter is <code>null</code> | |
| 537 | + * the behavior is unspecified and may result in an | |
| 538 | + * exception. | |
| 539 | + * | |
| 540 | + * @param e the event | |
| 541 | + * @see java.awt.event.ItemEvent | |
| 542 | + * @see #processItemEvent | |
| 543 | + * @since JDK1.1 | |
| 544 | + */ | |
| 545 | + protected void processEvent(AWTEvent e) { | |
| 546 | + if (e instanceof ItemEvent) { | |
| 547 | + processItemEvent((ItemEvent)e); | |
| 548 | + return; | |
| 549 | + } | |
| 550 | + super.processEvent(e); | |
| 551 | + } | |
| 552 | + | |
| 553 | + /** | |
| 554 | + * Processes item events occurring on this check box by | |
| 555 | + * dispatching them to any registered | |
| 556 | + * <code>ItemListener</code> objects. | |
| 557 | + * <p> | |
| 558 | + * This method is not called unless item events are | |
| 559 | + * enabled for this component. Item events are enabled | |
| 560 | + * when one of the following occurs: | |
| 561 | + * <p><ul> | |
| 562 | + * <li>An <code>ItemListener</code> object is registered | |
| 563 | + * via <code>addItemListener</code>. | |
| 564 | + * <li>Item events are enabled via <code>enableEvents</code>. | |
| 565 | + * </ul> | |
| 566 | + * <p>Note that if the event parameter is <code>null</code> | |
| 567 | + * the behavior is unspecified and may result in an | |
| 568 | + * exception. | |
| 569 | + * | |
| 570 | + * @param e the item event | |
| 571 | + * @see java.awt.event.ItemEvent | |
| 572 | + * @see java.awt.event.ItemListener | |
| 573 | + * @see #addItemListener | |
| 574 | + * @see java.awt.Component#enableEvents | |
| 575 | + * @since JDK1.1 | |
| 576 | + */ | |
| 577 | + protected void processItemEvent(ItemEvent e) { | |
| 578 | + ItemListener listener = itemListener; | |
| 579 | + if (listener != null) { | |
| 580 | + listener.itemStateChanged(e); | |
| 581 | + } | |
| 582 | + } | |
| 583 | + | |
| 584 | + /** | |
| 585 | + * Returns a string representing the state of this <code>Checkbox</code>. | |
| 586 | + * This method is intended to be used only for debugging purposes, and the | |
| 587 | + * content and format of the returned string may vary between | |
| 588 | + * implementations. The returned string may be empty but may not be | |
| 589 | + * <code>null</code>. | |
| 590 | + * | |
| 591 | + * @return the parameter string of this check box | |
| 592 | + */ | |
| 593 | + protected String paramString() { | |
| 594 | + String str = super.paramString(); | |
| 595 | + String label = this.label; | |
| 596 | + if (label != null) { | |
| 597 | + str += ",label=" + label; | |
| 598 | + } | |
| 599 | + return str + ",state=" + state; | |
| 600 | + } | |
| 601 | + | |
| 602 | + | |
| 603 | + /* Serialization support. | |
| 604 | + */ | |
| 605 | + | |
| 606 | + /* | |
| 607 | + * Serialized data version | |
| 608 | + * @serial | |
| 609 | + */ | |
| 610 | + private int checkboxSerializedDataVersion = 1; | |
| 611 | + | |
| 612 | + /** | |
| 613 | + * Writes default serializable fields to stream. Writes | |
| 614 | + * a list of serializable <code>ItemListeners</code> | |
| 615 | + * as optional data. The non-serializable | |
| 616 | + * <code>ItemListeners</code> are detected and | |
| 617 | + * no attempt is made to serialize them. | |
| 618 | + * | |
| 619 | + * @param s the <code>ObjectOutputStream</code> to write | |
| 620 | + * @serialData <code>null</code> terminated sequence of 0 | |
| 621 | + * or more pairs; the pair consists of a <code>String</code> | |
| 622 | + * and an <code>Object</code>; the <code>String</code> indicates | |
| 623 | + * the type of object and is one of the following: | |
| 624 | + * <code>itemListenerK</code> indicating an | |
| 625 | + * <code>ItemListener</code> object | |
| 626 | + * | |
| 627 | + * @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener) | |
| 628 | + * @see java.awt.Component#itemListenerK | |
| 629 | + * @see #readObject(ObjectInputStream) | |
| 630 | + */ | |
| 631 | + private void writeObject(ObjectOutputStream s) | |
| 632 | + throws java.io.IOException | |
| 633 | + { | |
| 634 | + s.defaultWriteObject(); | |
| 635 | + | |
| 636 | + AWTEventMulticaster.save(s, itemListenerK, itemListener); | |
| 637 | + s.writeObject(null); | |
| 638 | + } | |
| 639 | + | |
| 640 | + /** | |
| 641 | + * Reads the <code>ObjectInputStream</code> and if it | |
| 642 | + * isn't <code>null</code> adds a listener to receive | |
| 643 | + * item events fired by the <code>Checkbox</code>. | |
| 644 | + * Unrecognized keys or values will be ignored. | |
| 645 | + * | |
| 646 | + * @param s the <code>ObjectInputStream</code> to read | |
| 647 | + * @exception HeadlessException if | |
| 648 | + * <code>GraphicsEnvironment.isHeadless</code> returns | |
| 649 | + * <code>true</code> | |
| 650 | + * @serial | |
| 651 | + * @see #removeItemListener(ItemListener) | |
| 652 | + * @see #addItemListener(ItemListener) | |
| 653 | + * @see java.awt.GraphicsEnvironment#isHeadless | |
| 654 | + * @see #writeObject(ObjectOutputStream) | |
| 655 | + */ | |
| 656 | + private void readObject(ObjectInputStream s) | |
| 657 | + throws ClassNotFoundException, IOException, HeadlessException | |
| 658 | + { | |
| 659 | + GraphicsEnvironment.checkHeadless(); | |
| 660 | + s.defaultReadObject(); | |
| 661 | + | |
| 662 | + Object keyOrNull; | |
| 663 | + while(null != (keyOrNull = s.readObject())) { | |
| 664 | + String key = ((String)keyOrNull).intern(); | |
| 665 | + | |
| 666 | + if (itemListenerK == key) | |
| 667 | + addItemListener((ItemListener)(s.readObject())); | |
| 668 | + | |
| 669 | + else // skip value for unrecognized key | |
| 670 | + s.readObject(); | |
| 671 | + } | |
| 672 | + } | |
| 673 | + | |
| 674 | + /** | |
| 675 | + * Initialize JNI field and method ids | |
| 676 | + */ | |
| 677 | + private static native void initIDs(); | |
| 678 | + | |
| 679 | + | |
| 680 | +///////////////// | |
| 681 | +// Accessibility support | |
| 682 | +//////////////// | |
| 683 | + | |
| 684 | + | |
| 685 | + /** | |
| 686 | + * Gets the AccessibleContext associated with this Checkbox. | |
| 687 | + * For checkboxes, the AccessibleContext takes the form of an | |
| 688 | + * AccessibleAWTCheckbox. | |
| 689 | + * A new AccessibleAWTCheckbox is created if necessary. | |
| 690 | + * | |
| 691 | + * @return an AccessibleAWTCheckbox that serves as the | |
| 692 | + * AccessibleContext of this Checkbox | |
| 693 | + * @since 1.3 | |
| 694 | + */ | |
| 695 | + public AccessibleContext getAccessibleContext() { | |
| 696 | + if (accessibleContext == null) { | |
| 697 | + accessibleContext = new AccessibleAWTCheckbox(); | |
| 698 | + } | |
| 699 | + return accessibleContext; | |
| 700 | + } | |
| 701 | + | |
| 702 | + /** | |
| 703 | + * This class implements accessibility support for the | |
| 704 | + * <code>Checkbox</code> class. It provides an implementation of the | |
| 705 | + * Java Accessibility API appropriate to checkbox user-interface elements. | |
| 706 | + * @since 1.3 | |
| 707 | + */ | |
| 708 | + protected class AccessibleAWTCheckbox extends AccessibleAWTComponent | |
| 709 | + implements ItemListener, AccessibleAction, AccessibleValue | |
| 710 | + { | |
| 711 | + /* | |
| 712 | + * JDK 1.3 serialVersionUID | |
| 713 | + */ | |
| 714 | + private static final long serialVersionUID = 7881579233144754107L; | |
| 715 | + | |
| 716 | + public AccessibleAWTCheckbox() { | |
| 717 | + super(); | |
| 718 | + Checkbox.this.addItemListener(this); | |
| 719 | + } | |
| 720 | + | |
| 721 | + /** | |
| 722 | + * Fire accessible property change events when the state of the | |
| 723 | + * toggle button changes. | |
| 724 | + */ | |
| 725 | + public void itemStateChanged(ItemEvent e) { | |
| 726 | + Checkbox cb = (Checkbox) e.getSource(); | |
| 727 | + if (Checkbox.this.accessibleContext != null) { | |
| 728 | + if (cb.getState()) { | |
| 729 | + Checkbox.this.accessibleContext.firePropertyChange( | |
| 730 | + AccessibleContext.ACCESSIBLE_STATE_PROPERTY, | |
| 731 | + null, AccessibleState.CHECKED); | |
| 732 | + } else { | |
| 733 | + Checkbox.this.accessibleContext.firePropertyChange( | |
| 734 | + AccessibleContext.ACCESSIBLE_STATE_PROPERTY, | |
| 735 | + AccessibleState.CHECKED, null); | |
| 736 | + } | |
| 737 | + } | |
| 738 | + } | |
| 739 | + | |
| 740 | + /** | |
| 741 | + * Get the AccessibleAction associated with this object. In the | |
| 742 | + * implementation of the Java Accessibility API for this class, | |
| 743 | + * return this object, which is responsible for implementing the | |
| 744 | + * AccessibleAction interface on behalf of itself. | |
| 745 | + * | |
| 746 | + * @return this object | |
| 747 | + */ | |
| 748 | + public AccessibleAction getAccessibleAction() { | |
| 749 | + return this; | |
| 750 | + } | |
| 751 | + | |
| 752 | + /** | |
| 753 | + * Get the AccessibleValue associated with this object. In the | |
| 754 | + * implementation of the Java Accessibility API for this class, | |
| 755 | + * return this object, which is responsible for implementing the | |
| 756 | + * AccessibleValue interface on behalf of itself. | |
| 757 | + * | |
| 758 | + * @return this object | |
| 759 | + */ | |
| 760 | + public AccessibleValue getAccessibleValue() { | |
| 761 | + return this; | |
| 762 | + } | |
| 763 | + | |
| 764 | + /** | |
| 765 | + * Returns the number of Actions available in this object. | |
| 766 | + * If there is more than one, the first one is the "default" | |
| 767 | + * action. | |
| 768 | + * | |
| 769 | + * @return the number of Actions in this object | |
| 770 | + */ | |
| 771 | + public int getAccessibleActionCount() { | |
| 772 | + return 0; // To be fully implemented in a future release | |
| 773 | + } | |
| 774 | + | |
| 775 | + /** | |
| 776 | + * Return a description of the specified action of the object. | |
| 777 | + * | |
| 778 | + * @param i zero-based index of the actions | |
| 779 | + */ | |
| 780 | + public String getAccessibleActionDescription(int i) { | |
| 781 | + return null; // To be fully implemented in a future release | |
| 782 | + } | |
| 783 | + | |
| 784 | + /** | |
| 785 | + * Perform the specified Action on the object | |
| 786 | + * | |
| 787 | + * @param i zero-based index of actions | |
| 788 | + * @return true if the the action was performed; else false. | |
| 789 | + */ | |
| 790 | + public boolean doAccessibleAction(int i) { | |
| 791 | + return false; // To be fully implemented in a future release | |
| 792 | + } | |
| 793 | + | |
| 794 | + /** | |
| 795 | + * Get the value of this object as a Number. If the value has not been | |
| 796 | + * set, the return value will be null. | |
| 797 | + * | |
| 798 | + * @return value of the object | |
| 799 | + * @see #setCurrentAccessibleValue | |
| 800 | + */ | |
| 801 | + public Number getCurrentAccessibleValue() { | |
| 802 | + return null; // To be fully implemented in a future release | |
| 803 | + } | |
| 804 | + | |
| 805 | + /** | |
| 806 | + * Set the value of this object as a Number. | |
| 807 | + * | |
| 808 | + * @return True if the value was set; else False | |
| 809 | + * @see #getCurrentAccessibleValue | |
| 810 | + */ | |
| 811 | + public boolean setCurrentAccessibleValue(Number n) { | |
| 812 | + return false; // To be fully implemented in a future release | |
| 813 | + } | |
| 814 | + | |
| 815 | + /** | |
| 816 | + * Get the minimum value of this object as a Number. | |
| 817 | + * | |
| 818 | + * @return Minimum value of the object; null if this object does not | |
| 819 | + * have a minimum value | |
| 820 | + * @see #getMaximumAccessibleValue | |
| 821 | + */ | |
| 822 | + public Number getMinimumAccessibleValue() { | |
| 823 | + return null; // To be fully implemented in a future release | |
| 824 | + } | |
| 825 | + | |
| 826 | + /** | |
| 827 | + * Get the maximum value of this object as a Number. | |
| 828 | + * | |
| 829 | + * @return Maximum value of the object; null if this object does not | |
| 830 | + * have a maximum value | |
| 831 | + * @see #getMinimumAccessibleValue | |
| 832 | + */ | |
| 833 | + public Number getMaximumAccessibleValue() { | |
| 834 | + return null; // To be fully implemented in a future release | |
| 835 | + } | |
| 836 | + | |
| 837 | + /** | |
| 838 | + * Get the role of this object. | |
| 839 | + * | |
| 840 | + * @return an instance of AccessibleRole describing the role of | |
| 841 | + * the object | |
| 842 | + * @see AccessibleRole | |
| 843 | + */ | |
| 844 | + public AccessibleRole getAccessibleRole() { | |
| 845 | + return AccessibleRole.CHECK_BOX; | |
| 846 | + } | |
| 847 | + | |
| 848 | + /** | |
| 849 | + * Get the state set of this object. | |
| 850 | + * | |
| 851 | + * @return an instance of AccessibleState containing the current state | |
| 852 | + * of the object | |
| 853 | + * @see AccessibleState | |
| 854 | + */ | |
| 855 | + public AccessibleStateSet getAccessibleStateSet() { | |
| 856 | + AccessibleStateSet states = super.getAccessibleStateSet(); | |
| 857 | + if (getState()) { | |
| 858 | + states.add(AccessibleState.CHECKED); | |
| 859 | + } | |
| 860 | + return states; | |
| 861 | + } | |
| 862 | + | |
| 863 | + | |
| 864 | + } // inner class AccessibleAWTCheckbox | |
| 865 | + | |
| 866 | +} | |