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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.util.*; | ||
| 28 | import java.awt.peer.ChoicePeer; | ||
| 29 | import java.awt.event.*; | ||
| 30 | import java.util.EventListener; | ||
| 31 | import java.io.ObjectOutputStream; | ||
| 32 | import java.io.ObjectInputStream; | ||
| 33 | import java.io.IOException; | ||
| 34 | |||
| 35 | import javax.accessibility.*; | ||
| 36 | |||
| 37 | /** | ||
| 38 | * The <code>Choice</code> class presents a pop-up menu of choices. | ||
| 39 | * The current choice is displayed as the title of the menu. | ||
| 40 | * <p> | ||
| 41 | * The following code example produces a pop-up menu: | ||
| 42 | * <p> | ||
| 43 | * <hr><blockquote><pre> | ||
| 44 | * Choice ColorChooser = new Choice(); | ||
| 45 | * ColorChooser.add("Green"); | ||
| 46 | * ColorChooser.add("Red"); | ||
| 47 | * ColorChooser.add("Blue"); | ||
| 48 | * </pre></blockquote><hr> | ||
| 49 | * <p> | ||
| 50 | * After this choice menu has been added to a panel, | ||
| 51 | * it appears as follows in its normal state: | ||
| 52 | * <p> | ||
| 53 | * <img src="doc-files/Choice-1.gif" alt="The following text describes the graphic" | ||
| 54 | * ALIGN=center HSPACE=10 VSPACE=7> | ||
| 55 | * <p> | ||
| 56 | * In the picture, <code>"Green"</code> is the current choice. | ||
| 57 | * Pushing the mouse button down on the object causes a menu to | ||
| 58 | * appear with the current choice highlighted. | ||
| 59 | * <p> | ||
| 60 | * Some native platforms do not support arbitrary resizing of | ||
| 61 | * <code>Choice</code> components and the behavior of | ||
| 62 | * <code>setSize()/getSize()</code> is bound by | ||
| 63 | * such limitations. | ||
| 64 | * Native GUI <code>Choice</code> components' size are often bound by such | ||
| 65 | * attributes as font size and length of items contained within | ||
| 66 | * the <code>Choice</code>. | ||
| 67 | * <p> | ||
| 68 | * @author Sami Shaio | ||
| 69 | * @author Arthur van Hoff | ||
| 70 | * @since JDK1.0 | ||
| 71 | */ | ||
| 72 | public class Choice extends Component implements ItemSelectable, Accessible { | ||
| 73 | /** | ||
| 74 | * The items for the <code>Choice</code>. | ||
| 75 | * This can be a <code>null</code> value. | ||
| 76 | * @serial | ||
| 77 | * @see #add(String) | ||
| 78 | * @see #addItem(String) | ||
| 79 | * @see #getItem(int) | ||
| 80 | * @see #getItemCount() | ||
| 81 | * @see #insert(String, int) | ||
| 82 | * @see #remove(String) | ||
| 83 | */ | ||
| 84 | Vector pItems; | ||
| 85 | |||
| 86 | /** | ||
| 87 | * The index of the current choice for this <code>Choice</code> | ||
| 88 | * or -1 if nothing is selected. | ||
| 89 | * @serial | ||
| 90 | * @see #getSelectedItem() | ||
| 91 | * @see #select(int) | ||
| 92 | */ | ||
| 93 | int selectedIndex = -1; | ||
| 94 | |||
| 95 | transient ItemListener itemListener; | ||
| 96 | |||
| 97 | private static final String base = "choice"; | ||
| 98 | private static int nameCounter = 0; | ||
| 99 | |||
| 100 | /* | ||
| 101 | * JDK 1.1 serialVersionUID | ||
| 102 | */ | ||
| 103 | private static final long serialVersionUID = -4075310674757313071L; | ||
| 104 | |||
| 105 | /** | ||
| 106 | * Creates a new choice menu. The menu initially has no items in it. | ||
| 107 | * <p> | ||
| 108 | * By default, the first item added to the choice menu becomes the | ||
| 109 | * selected item, until a different selection is made by the user | ||
| 110 | * by calling one of the <code>select</code> methods. | ||
| 111 | * @exception HeadlessException if GraphicsEnvironment.isHeadless() | ||
| 112 | * returns true | ||
| 113 | * @see java.awt.GraphicsEnvironment#isHeadless | ||
| 114 | * @see #select(int) | ||
| 115 | * @see #select(java.lang.String) | ||
| 116 | */ | ||
| 117 | public Choice() throws HeadlessException { | ||
| 118 | GraphicsEnvironment.checkHeadless(); | ||
| 119 | pItems = new Vector(); | ||
| 120 | } | ||
| 121 | |||
| 122 | /** | ||
| 123 | * Constructs a name for this component. Called by | ||
| 124 | * <code>getName</code> when the name is <code>null</code>. | ||
| 125 | */ | ||
| 126 | String constructComponentName() { | ||
| 127 | synchronized (Choice.class) { | ||
| 128 | return base + nameCounter++; | ||
| 129 | } | ||
| 130 | } | ||
| 131 | |||
| 132 | /** | ||
| 133 | * Creates the <code>Choice</code>'s peer. This peer allows us | ||
| 134 | * to change the look | ||
| 135 | * of the <code>Choice</code> without changing its functionality. | ||
| 136 | * @see java.awt.Toolkit#createChoice(java.awt.Choice) | ||
| 137 | * @see java.awt.Component#getToolkit() | ||
| 138 | */ | ||
| 139 | public void addNotify() { | ||
| 140 | synchronized (getTreeLock()) { | ||
| 141 | if (peer == null) | ||
| 142 | peer = getToolkit().createChoice(this); | ||
| 143 | super.addNotify(); | ||
| 144 | } | ||
| 145 | } | ||
| 146 | |||
| 147 | /** | ||
| 148 | * Returns the number of items in this <code>Choice</code> menu. | ||
| 149 | * @return the number of items in this <code>Choice</code> menu | ||
| 150 | * @see #getItem | ||
| 151 | * @since JDK1.1 | ||
| 152 | */ | ||
| 153 | public int getItemCount() { | ||
| 154 | return countItems(); | ||
| 155 | } | ||
| 156 | |||
| 157 | /** | ||
| 158 | * @deprecated As of JDK version 1.1, | ||
| 159 | * replaced by <code>getItemCount()</code>. | ||
| 160 | */ | ||
| 161 | @Deprecated | ||
| 162 | public int countItems() { | ||
| 163 | return pItems.size(); | ||
| 164 | } | ||
| 165 | |||
| 166 | /** | ||
| 167 | * Gets the string at the specified index in this | ||
| 168 | * <code>Choice</code> menu. | ||
| 169 | * @param index the index at which to begin | ||
| 170 | * @see #getItemCount | ||
| 171 | */ | ||
| 172 | public String getItem(int index) { | ||
| 173 | return getItemImpl(index); | ||
| 174 | } | ||
| 175 | |||
| 176 | /* | ||
| 177 | * This is called by the native code, so client code can't | ||
| 178 | * be called on the toolkit thread. | ||
| 179 | */ | ||
| 180 | final String getItemImpl(int index) { | ||
| 181 | return (String)pItems.elementAt(index); | ||
| 182 | } | ||
| 183 | |||
| 184 | /** | ||
| 185 | * Adds an item to this <code>Choice</code> menu. | ||
| 186 | * @param item the item to be added | ||
| 187 | * @exception NullPointerException if the item's value is | ||
| 188 | * <code>null</code> | ||
| 189 | * @since JDK1.1 | ||
| 190 | */ | ||
| 191 | public void add(String item) { | ||
| 192 | addItem(item); | ||
| 193 | } | ||
| 194 | |||
| 195 | /** | ||
| 196 | * Obsolete as of Java 2 platform v1.1. Please use the | ||
| 197 | * <code>add</code> method instead. | ||
| 198 | * <p> | ||
| 199 | * Adds an item to this <code>Choice</code> menu. | ||
| 200 | * @param item the item to be added | ||
| 201 | * @exception NullPointerException if the item's value is equal to | ||
| 202 | * <code>null</code> | ||
| 203 | */ | ||
| 204 | public void addItem(String item) { | ||
| 205 | synchronized (this) { | ||
| 206 | insertNoInvalidate(item, pItems.size()); | ||
| 207 | } | ||
| 208 | |||
| 209 | // This could change the preferred size of the Component. | ||
| 210 | invalidateIfValid(); | ||
| 211 | } | ||
| 212 | |||
| 213 | /** | ||
| 214 | * Inserts an item to this <code>Choice</code>, | ||
| 215 | * but does not invalidate the <code>Choice</code>. | ||
| 216 | * Client methods must provide their own synchronization before | ||
| 217 | * invoking this method. | ||
| 218 | * @param item the item to be added | ||
| 219 | * @param index the new item position | ||
| 220 | * @exception NullPointerException if the item's value is equal to | ||
| 221 | * <code>null</code> | ||
| 222 | */ | ||
| 223 | private void insertNoInvalidate(String item, int index) { | ||
| 224 | if (item == null) { | ||
| 225 | throw new | ||
| 226 | NullPointerException("cannot add null item to Choice"); | ||
| 227 | } | ||
| 228 | pItems.insertElementAt(item, index); | ||
| 229 | ChoicePeer peer = (ChoicePeer)this.peer; | ||
| 230 | if (peer != null) { | ||
| 231 | peer.add(item, index); | ||
| 232 | } | ||
| 233 | // no selection or selection shifted up | ||
| 234 | if (selectedIndex < 0 || selectedIndex >= index) { | ||
| 235 | select(0); | ||
| 236 | } | ||
| 237 | } | ||
| 238 | |||
| 239 | |||
| 240 | /** | ||
| 241 | * Inserts the item into this choice at the specified position. | ||
| 242 | * Existing items at an index greater than or equal to | ||
| 243 | * <code>index</code> are shifted up by one to accommodate | ||
| 244 | * the new item. If <code>index</code> is greater than or | ||
| 245 | * equal to the number of items in this choice, | ||
| 246 | * <code>item</code> is added to the end of this choice. | ||
| 247 | * <p> | ||
| 248 | * If the item is the first one being added to the choice, | ||
| 249 | * then the item becomes selected. Otherwise, if the | ||
| 250 | * selected item was one of the items shifted, the first | ||
| 251 | * item in the choice becomes the selected item. If the | ||
| 252 | * selected item was no among those shifted, it remains | ||
| 253 | * the selected item. | ||
| 254 | * @param item the non-<code>null</code> item to be inserted | ||
| 255 | * @param index the position at which the item should be inserted | ||
| 256 | * @exception IllegalArgumentException if index is less than 0 | ||
| 257 | */ | ||
| 258 | public void insert(String item, int index) { | ||
| 259 | synchronized (this) { | ||
| 260 | if (index < 0) { | ||
| 261 | throw new IllegalArgumentException("index less than zero."); | ||
| 262 | } | ||
| 263 | /* if the index greater than item count, add item to the end */ | ||
| 264 | index = Math.min(index, pItems.size()); | ||
| 265 | |||
| 266 | insertNoInvalidate(item, index); | ||
| 267 | } | ||
| 268 | |||
| 269 | // This could change the preferred size of the Component. | ||
| 270 | invalidateIfValid(); | ||
| 271 | } | ||
| 272 | |||
| 273 | /** | ||
| 274 | * Removes the first occurrence of <code>item</code> | ||
| 275 | * from the <code>Choice</code> menu. If the item | ||
| 276 | * being removed is the currently selected item, | ||
| 277 | * then the first item in the choice becomes the | ||
| 278 | * selected item. Otherwise, the currently selected | ||
| 279 | * item remains selected (and the selected index is | ||
| 280 | * updated accordingly). | ||
| 281 | * @param item the item to remove from this <code>Choice</code> menu | ||
| 282 | * @exception IllegalArgumentException if the item doesn't | ||
| 283 | * exist in the choice menu | ||
| 284 | * @since JDK1.1 | ||
| 285 | */ | ||
| 286 | public void remove(String item) { | ||
| 287 | synchronized (this) { | ||
| 288 | int index = pItems.indexOf(item); | ||
| 289 | if (index < 0) { | ||
| 290 | throw new IllegalArgumentException("item " + item + | ||
| 291 | " not found in choice"); | ||
| 292 | } else { | ||
| 293 | removeNoInvalidate(index); | ||
| 294 | } | ||
| 295 | } | ||
| 296 | |||
| 297 | // This could change the preferred size of the Component. | ||
| 298 | invalidateIfValid(); | ||
| 299 | } | ||
| 300 | |||
| 301 | /** | ||
| 302 | * Removes an item from the choice menu | ||
| 303 | * at the specified position. If the item | ||
| 304 | * being removed is the currently selected item, | ||
| 305 | * then the first item in the choice becomes the | ||
| 306 | * selected item. Otherwise, the currently selected | ||
| 307 | * item remains selected (and the selected index is | ||
| 308 | * updated accordingly). | ||
| 309 | * @param position the position of the item | ||
| 310 | * @throws IndexOutOfBoundsException if the specified | ||
| 311 | * position is out of bounds | ||
| 312 | * @since JDK1.1 | ||
| 313 | */ | ||
| 314 | public void remove(int position) { | ||
| 315 | synchronized (this) { | ||
| 316 | removeNoInvalidate(position); | ||
| 317 | } | ||
| 318 | |||
| 319 | // This could change the preferred size of the Component. | ||
| 320 | invalidateIfValid(); | ||
| 321 | } | ||
| 322 | |||
| 323 | /** | ||
| 324 | * Removes an item from the <code>Choice</code> at the | ||
| 325 | * specified position, but does not invalidate the <code>Choice</code>. | ||
| 326 | * Client methods must provide their | ||
| 327 | * own synchronization before invoking this method. | ||
| 328 | * @param position the position of the item | ||
| 329 | */ | ||
| 330 | private void removeNoInvalidate(int position) { | ||
| 331 | pItems.removeElementAt(position); | ||
| 332 | ChoicePeer peer = (ChoicePeer)this.peer; | ||
| 333 | if (peer != null) { | ||
| 334 | peer.remove(position); | ||
| 335 | } | ||
| 336 | /* Adjust selectedIndex if selected item was removed. */ | ||
| 337 | if (pItems.size() == 0) { | ||
| 338 | selectedIndex = -1; | ||
| 339 | } else if (selectedIndex == position) { | ||
| 340 | select(0); | ||
| 341 | } else if (selectedIndex > position) { | ||
| 342 | select(selectedIndex-1); | ||
| 343 | } | ||
| 344 | } | ||
| 345 | |||
| 346 | |||
| 347 | /** | ||
| 348 | * Removes all items from the choice menu. | ||
| 349 | * @see #remove | ||
| 350 | * @since JDK1.1 | ||
| 351 | */ | ||
| 352 | public void removeAll() { | ||
| 353 | synchronized (this) { | ||
| 354 | if (peer != null) { | ||
| 355 | ((ChoicePeer)peer).removeAll(); | ||
| 356 | } | ||
| 357 | pItems.removeAllElements(); | ||
| 358 | selectedIndex = -1; | ||
| 359 | } | ||
| 360 | |||
| 361 | // This could change the preferred size of the Component. | ||
| 362 | invalidateIfValid(); | ||
| 363 | } | ||
| 364 | |||
| 365 | /** | ||
| 366 | * Gets a representation of the current choice as a string. | ||
| 367 | * @return a string representation of the currently | ||
| 368 | * selected item in this choice menu | ||
| 369 | * @see #getSelectedIndex | ||
| 370 | */ | ||
| 371 | public synchronized String getSelectedItem() { | ||
| 372 | return (selectedIndex >= 0) ? getItem(selectedIndex) : null; | ||
| 373 | } | ||
| 374 | |||
| 375 | /** | ||
| 376 | * Returns an array (length 1) containing the currently selected | ||
| 377 | * item. If this choice has no items, returns <code>null</code>. | ||
| 378 | * @see ItemSelectable | ||
| 379 | */ | ||
| 380 | public synchronized Object[] getSelectedObjects() { | ||
| 381 | if (selectedIndex >= 0) { | ||
| 382 | Object[] items = new Object[1]; | ||
| 383 | items[0] = getItem(selectedIndex); | ||
| 384 | return items; | ||
| 385 | } | ||
| 386 | return null; | ||
| 387 | } | ||
| 388 | |||
| 389 | /** | ||
| 390 | * Returns the index of the currently selected item. | ||
| 391 | * If nothing is selected, returns -1. | ||
| 392 | * | ||
| 393 | * @return the index of the currently selected item, or -1 if nothing | ||
| 394 | * is currently selected | ||
| 395 | * @see #getSelectedItem | ||
| 396 | */ | ||
| 397 | public int getSelectedIndex() { | ||
| 398 | return selectedIndex; | ||
| 399 | } | ||
| 400 | |||
| 401 | /** | ||
| 402 | * Sets the selected item in this <code>Choice</code> menu to be the | ||
| 403 | * item at the specified position. | ||
| 404 | * | ||
| 405 | * <p>Note that this method should be primarily used to | ||
| 406 | * initially select an item in this component. | ||
| 407 | * Programmatically calling this method will <i>not</i> trigger | ||
| 408 | * an <code>ItemEvent</code>. The only way to trigger an | ||
| 409 | * <code>ItemEvent</code> is by user interaction. | ||
| 410 | * | ||
| 411 | * @param pos the positon of the selected item | ||
| 412 | * @exception IllegalArgumentException if the specified | ||
| 413 | * position is greater than the | ||
| 414 | * number of items or less than zero | ||
| 415 | * @see #getSelectedItem | ||
| 416 | * @see #getSelectedIndex | ||
| 417 | */ | ||
| 418 | public synchronized void select(int pos) { | ||
| 419 | if ((pos >= pItems.size()) || (pos < 0)) { | ||
| 420 | throw new IllegalArgumentException("illegal Choice item position: " + pos); | ||
| 421 | } | ||
| 422 | if (pItems.size() > 0) { | ||
| 423 | selectedIndex = pos; | ||
| 424 | ChoicePeer peer = (ChoicePeer)this.peer; | ||
| 425 | if (peer != null) { | ||
| 426 | peer.select(pos); | ||
| 427 | } | ||
| 428 | } | ||
| 429 | } | ||
| 430 | |||
| 431 | /** | ||
| 432 | * Sets the selected item in this <code>Choice</code> menu | ||
| 433 | * to be the item whose name is equal to the specified string. | ||
| 434 | * If more than one item matches (is equal to) the specified string, | ||
| 435 | * the one with the smallest index is selected. | ||
| 436 | * | ||
| 437 | * <p>Note that this method should be primarily used to | ||
| 438 | * initially select an item in this component. | ||
| 439 | * Programmatically calling this method will <i>not</i> trigger | ||
| 440 | * an <code>ItemEvent</code>. The only way to trigger an | ||
| 441 | * <code>ItemEvent</code> is by user interaction. | ||
| 442 | * | ||
| 443 | * @param str the specified string | ||
| 444 | * @see #getSelectedItem | ||
| 445 | * @see #getSelectedIndex | ||
| 446 | */ | ||
| 447 | public synchronized void select(String str) { | ||
| 448 | int index = pItems.indexOf(str); | ||
| 449 | if (index >= 0) { | ||
| 450 | select(index); | ||
| 451 | } | ||
| 452 | } | ||
| 453 | |||
| 454 | /** | ||
| 455 | * Adds the specified item listener to receive item events from | ||
| 456 | * this <code>Choice</code> menu. Item events are sent in response | ||
| 457 | * to user input, but not in response to calls to <code>select</code>. | ||
| 458 | * If l is <code>null</code>, no exception is thrown and no action | ||
| 459 | * is performed. | ||
| 460 | * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" | ||
| 461 | * >AWT Threading Issues</a> for details on AWT's threading model. | ||
| 462 | * @param l the item listener | ||
| 463 | * @see #removeItemListener | ||
| 464 | * @see #getItemListeners | ||
| 465 | * @see #select | ||
| 466 | * @see java.awt.event.ItemEvent | ||
| 467 | * @see java.awt.event.ItemListener | ||
| 468 | * @since JDK1.1 | ||
| 469 | */ | ||
| 470 | public synchronized void addItemListener(ItemListener l) { | ||
| 471 | if (l == null) { | ||
| 472 | return; | ||
| 473 | } | ||
| 474 | itemListener = AWTEventMulticaster.add(itemListener, l); | ||
| 475 | newEventsOnly = true; | ||
| 476 | } | ||
| 477 | |||
| 478 | /** | ||
| 479 | * Removes the specified item listener so that it no longer receives | ||
| 480 | * item events from this <code>Choice</code> menu. | ||
| 481 | * If l is <code>null</code>, no exception is thrown and no | ||
| 482 | * action is performed. | ||
| 483 | * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads" | ||
| 484 | * >AWT Threading Issues</a> for details on AWT's threading model. | ||
| 485 | * @param l the item listener | ||
| 486 | * @see #addItemListener | ||
| 487 | * @see #getItemListeners | ||
| 488 | * @see java.awt.event.ItemEvent | ||
| 489 | * @see java.awt.event.ItemListener | ||
| 490 | * @since JDK1.1 | ||
| 491 | */ | ||
| 492 | public synchronized void removeItemListener(ItemListener l) { | ||
| 493 | if (l == null) { | ||
| 494 | return; | ||
| 495 | } | ||
| 496 | itemListener = AWTEventMulticaster.remove(itemListener, l); | ||
| 497 | } | ||
| 498 | |||
| 499 | /** | ||
| 500 | * Returns an array of all the item listeners | ||
| 501 | * registered on this choice. | ||
| 502 | * | ||
| 503 | * @return all of this choice's <code>ItemListener</code>s | ||
| 504 | * or an empty array if no item | ||
| 505 | * listeners are currently registered | ||
| 506 | * | ||
| 507 | * @see #addItemListener | ||
| 508 | * @see #removeItemListener | ||
| 509 | * @see java.awt.event.ItemEvent | ||
| 510 | * @see java.awt.event.ItemListener | ||
| 511 | * @since 1.4 | ||
| 512 | */ | ||
| 513 | public synchronized ItemListener[] getItemListeners() { | ||
| 514 | return (ItemListener[])(getListeners(ItemListener.class)); | ||
| 515 | } | ||
| 516 | |||
| 517 | /** | ||
| 518 | * Returns an array of all the objects currently registered | ||
| 519 | * as <code><em>Foo</em>Listener</code>s | ||
| 520 | * upon this <code>Choice</code>. | ||
| 521 | * <code><em>Foo</em>Listener</code>s are registered using the | ||
| 522 | * <code>add<em>Foo</em>Listener</code> method. | ||
| 523 | * | ||
| 524 | * <p> | ||
| 525 | * You can specify the <code>listenerType</code> argument | ||
| 526 | * with a class literal, such as | ||
| 527 | * <code><em>Foo</em>Listener.class</code>. | ||
| 528 | * For example, you can query a | ||
| 529 | * <code>Choice</code> <code>c</code> | ||
| 530 | * for its item listeners with the following code: | ||
| 531 | * | ||
| 532 | * <pre>ItemListener[] ils = (ItemListener[])(c.getListeners(ItemListener.class));</pre> | ||
| 533 | * | ||
| 534 | * If no such listeners exist, this method returns an empty array. | ||
| 535 | * | ||
| 536 | * @param listenerType the type of listeners requested; this parameter | ||
| 537 | * should specify an interface that descends from | ||
| 538 | * <code>java.util.EventListener</code> | ||
| 539 | * @return an array of all objects registered as | ||
| 540 | * <code><em>Foo</em>Listener</code>s on this choice, | ||
| 541 | * or an empty array if no such | ||
| 542 | * listeners have been added | ||
| 543 | * @exception ClassCastException if <code>listenerType</code> | ||
| 544 | * doesn't specify a class or interface that implements | ||
| 545 | * <code>java.util.EventListener</code> | ||
| 546 | * | ||
| 547 | * @see #getItemListeners | ||
| 548 | * @since 1.3 | ||
| 549 | */ | ||
| 550 | public <T extends EventListener> T[] getListeners(Class<T> listenerType) { | ||
| 551 | EventListener l = null; | ||
| 552 | if (listenerType == ItemListener.class) { | ||
| 553 | l = itemListener; | ||
| 554 | } else { | ||
| 555 | return super.getListeners(listenerType); | ||
| 556 | } | ||
| 557 | return AWTEventMulticaster.getListeners(l, listenerType); | ||
| 558 | } | ||
| 559 | |||
| 560 | // REMIND: remove when filtering is done at lower level | ||
| 561 | boolean eventEnabled(AWTEvent e) { | ||
| 562 | if (e.id == ItemEvent.ITEM_STATE_CHANGED) { | ||
| 563 | if ((eventMask & AWTEvent.ITEM_EVENT_MASK) != 0 || | ||
| 564 | itemListener != null) { | ||
| 565 | return true; | ||
| 566 | } | ||
| 567 | return false; | ||
| 568 | } | ||
| 569 | return super.eventEnabled(e); | ||
| 570 | } | ||
| 571 | |||
| 572 | /** | ||
| 573 | * Processes events on this choice. If the event is an | ||
| 574 | * instance of <code>ItemEvent</code>, it invokes the | ||
| 575 | * <code>processItemEvent</code> method. Otherwise, it calls its | ||
| 576 | * superclass's <code>processEvent</code> method. | ||
| 577 | * <p>Note that if the event parameter is <code>null</code> | ||
| 578 | * the behavior is unspecified and may result in an | ||
| 579 | * exception. | ||
| 580 | * | ||
| 581 | * @param e the event | ||
| 582 | * @see java.awt.event.ItemEvent | ||
| 583 | * @see #processItemEvent | ||
| 584 | * @since JDK1.1 | ||
| 585 | */ | ||
| 586 | protected void processEvent(AWTEvent e) { | ||
| 587 | if (e instanceof ItemEvent) { | ||
| 588 | processItemEvent((ItemEvent)e); | ||
| 589 | return; | ||
| 590 | } | ||
| 591 | super.processEvent(e); | ||
| 592 | } | ||
| 593 | |||
| 594 | /** | ||
| 595 | * Processes item events occurring on this <code>Choice</code> | ||
| 596 | * menu by dispatching them to any registered | ||
| 597 | * <code>ItemListener</code> objects. | ||
| 598 | * <p> | ||
| 599 | * This method is not called unless item events are | ||
| 600 | * enabled for this component. Item events are enabled | ||
| 601 | * when one of the following occurs: | ||
| 602 | * <p><ul> | ||
| 603 | * <li>An <code>ItemListener</code> object is registered | ||
| 604 | * via <code>addItemListener</code>. | ||
| 605 | * <li>Item events are enabled via <code>enableEvents</code>. | ||
| 606 | * </ul> | ||
| 607 | * <p>Note that if the event parameter is <code>null</code> | ||
| 608 | * the behavior is unspecified and may result in an | ||
| 609 | * exception. | ||
| 610 | * | ||
| 611 | * @param e the item event | ||
| 612 | * @see java.awt.event.ItemEvent | ||
| 613 | * @see java.awt.event.ItemListener | ||
| 614 | * @see #addItemListener(ItemListener) | ||
| 615 | * @see java.awt.Component#enableEvents | ||
| 616 | * @since JDK1.1 | ||
| 617 | */ | ||
| 618 | protected void processItemEvent(ItemEvent e) { | ||
| 619 | ItemListener listener = itemListener; | ||
| 620 | if (listener != null) { | ||
| 621 | listener.itemStateChanged(e); | ||
| 622 | } | ||
| 623 | } | ||
| 624 | |||
| 625 | /** | ||
| 626 | * Returns a string representing the state of this <code>Choice</code> | ||
| 627 | * menu. This method is intended to be used only for debugging purposes, | ||
| 628 | * and the content and format of the returned string may vary between | ||
| 629 | * implementations. The returned string may be empty but may not be | ||
| 630 | * <code>null</code>. | ||
| 631 | * | ||
| 632 | * @return the parameter string of this <code>Choice</code> menu | ||
| 633 | */ | ||
| 634 | protected String paramString() { | ||
| 635 | return super.paramString() + ",current=" + getSelectedItem(); | ||
| 636 | } | ||
| 637 | |||
| 638 | |||
| 639 | /* Serialization support. | ||
| 640 | */ | ||
| 641 | |||
| 642 | /* | ||
| 643 | * Choice Serial Data Version. | ||
| 644 | * @serial | ||
| 645 | */ | ||
| 646 | private int choiceSerializedDataVersion = 1; | ||
| 647 | |||
| 648 | /** | ||
| 649 | * Writes default serializable fields to stream. Writes | ||
| 650 | * a list of serializable <code>ItemListeners</code> | ||
| 651 | * as optional data. The non-serializable | ||
| 652 | * <code>ItemListeners</code> are detected and | ||
| 653 | * no attempt is made to serialize them. | ||
| 654 | * | ||
| 655 | * @param s the <code>ObjectOutputStream</code> to write | ||
| 656 | * @serialData <code>null</code> terminated sequence of 0 | ||
| 657 | * or more pairs; the pair consists of a <code>String</code> | ||
| 658 | * and an <code>Object</code>; the <code>String</code> indicates | ||
| 659 | * the type of object and is one of the following: | ||
| 660 | * <code>itemListenerK</code> indicating an | ||
| 661 | * <code>ItemListener</code> object | ||
| 662 | * | ||
| 663 | * @see AWTEventMulticaster#save(ObjectOutputStream, String, EventListener) | ||
| 664 | * @see java.awt.Component#itemListenerK | ||
| 665 | * @see #readObject(ObjectInputStream) | ||
| 666 | */ | ||
| 667 | private void writeObject(ObjectOutputStream s) | ||
| 668 | throws java.io.IOException | ||
| 669 | { | ||
| 670 | s.defaultWriteObject(); | ||
| 671 | |||
| 672 | AWTEventMulticaster.save(s, itemListenerK, itemListener); | ||
| 673 | s.writeObject(null); | ||
| 674 | } | ||
| 675 | |||
| 676 | /** | ||
| 677 | * Reads the <code>ObjectInputStream</code> and if it | ||
| 678 | * isn't <code>null</code> adds a listener to receive | ||
| 679 | * item events fired by the <code>Choice</code> item. | ||
| 680 | * Unrecognized keys or values will be ignored. | ||
| 681 | * | ||
| 682 | * @param s the <code>ObjectInputStream</code> to read | ||
| 683 | * @exception HeadlessException if | ||
| 684 | * <code>GraphicsEnvironment.isHeadless</code> returns | ||
| 685 | * <code>true</code> | ||
| 686 | * @serial | ||
| 687 | * @see #removeItemListener(ItemListener) | ||
| 688 | * @see #addItemListener(ItemListener) | ||
| 689 | * @see java.awt.GraphicsEnvironment#isHeadless | ||
| 690 | * @see #writeObject(ObjectOutputStream) | ||
| 691 | */ | ||
| 692 | private void readObject(ObjectInputStream s) | ||
| 693 | throws ClassNotFoundException, IOException, HeadlessException | ||
| 694 | { | ||
| 695 | GraphicsEnvironment.checkHeadless(); | ||
| 696 | s.defaultReadObject(); | ||
| 697 | |||
| 698 | Object keyOrNull; | ||
| 699 | while(null != (keyOrNull = s.readObject())) { | ||
| 700 | String key = ((String)keyOrNull).intern(); | ||
| 701 | |||
| 702 | if (itemListenerK == key) | ||
| 703 | addItemListener((ItemListener)(s.readObject())); | ||
| 704 | |||
| 705 | else // skip value for unrecognized key | ||
| 706 | s.readObject(); | ||
| 707 | } | ||
| 708 | } | ||
| 709 | |||
| 710 | |||
| 711 | ///////////////// | ||
| 712 | // Accessibility support | ||
| 713 | //////////////// | ||
| 714 | |||
| 715 | |||
| 716 | /** | ||
| 717 | * Gets the <code>AccessibleContext</code> associated with this | ||
| 718 | * <code>Choice</code>. For <code>Choice</code> components, | ||
| 719 | * the <code>AccessibleContext</code> takes the form of an | ||
| 720 | * <code>AccessibleAWTChoice</code>. A new <code>AccessibleAWTChoice</code> | ||
| 721 | * instance is created if necessary. | ||
| 722 | * | ||
| 723 | * @return an <code>AccessibleAWTChoice</code> that serves as the | ||
| 724 | * <code>AccessibleContext</code> of this <code>Choice</code> | ||
| 725 | * @since 1.3 | ||
| 726 | */ | ||
| 727 | public AccessibleContext getAccessibleContext() { | ||
| 728 | if (accessibleContext == null) { | ||
| 729 | accessibleContext = new AccessibleAWTChoice(); | ||
| 730 | } | ||
| 731 | return accessibleContext; | ||
| 732 | } | ||
| 733 | |||
| 734 | /** | ||
| 735 | * This class implements accessibility support for the | ||
| 736 | * <code>Choice</code> class. It provides an implementation of the | ||
| 737 | * Java Accessibility API appropriate to choice user-interface elements. | ||
| 738 | * @since 1.3 | ||
| 739 | */ | ||
| 740 | protected class AccessibleAWTChoice extends AccessibleAWTComponent | ||
| 741 | implements AccessibleAction | ||
| 742 | { | ||
| 743 | /* | ||
| 744 | * JDK 1.3 serialVersionUID | ||
| 745 | */ | ||
| 746 | private static final long serialVersionUID = 7175603582428509322L; | ||
| 747 | |||
| 748 | public AccessibleAWTChoice() { | ||
| 749 | super(); | ||
| 750 | } | ||
| 751 | |||
| 752 | /** | ||
| 753 | * Get the AccessibleAction 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 | * AccessibleAction interface on behalf of itself. | ||
| 757 | * | ||
| 758 | * @return this object | ||
| 759 | * @see AccessibleAction | ||
| 760 | */ | ||
| 761 | public AccessibleAction getAccessibleAction() { | ||
| 762 | return this; | ||
| 763 | } | ||
| 764 | |||
| 765 | /** | ||
| 766 | * Get the role of this object. | ||
| 767 | * | ||
| 768 | * @return an instance of AccessibleRole describing the role of the | ||
| 769 | * object | ||
| 770 | * @see AccessibleRole | ||
| 771 | */ | ||
| 772 | public AccessibleRole getAccessibleRole() { | ||
| 773 | return AccessibleRole.COMBO_BOX; | ||
| 774 | } | ||
| 775 | |||
| 776 | /** | ||
| 777 | * Returns the number of accessible actions available in this object | ||
| 778 | * If there are more than one, the first one is considered the "default" | ||
| 779 | * action of the object. | ||
| 780 | * | ||
| 781 | * @return the zero-based number of Actions in this object | ||
| 782 | */ | ||
| 783 | public int getAccessibleActionCount() { | ||
| 784 | return 0; // To be fully implemented in a future release | ||
| 785 | } | ||
| 786 | |||
| 787 | /** | ||
| 788 | * Returns a description of the specified action of the object. | ||
| 789 | * | ||
| 790 | * @param i zero-based index of the actions | ||
| 791 | * @return a String description of the action | ||
| 792 | * @see #getAccessibleActionCount | ||
| 793 | */ | ||
| 794 | public String getAccessibleActionDescription(int i) { | ||
| 795 | return null; // To be fully implemented in a future release | ||
| 796 | } | ||
| 797 | |||
| 798 | /** | ||
| 799 | * Perform the specified Action on the object | ||
| 800 | * | ||
| 801 | * @param i zero-based index of actions | ||
| 802 | * @return true if the action was performed; otherwise false. | ||
| 803 | * @see #getAccessibleActionCount | ||
| 804 | */ | ||
| 805 | public boolean doAccessibleAction(int i) { | ||
| 806 | return false; // To be fully implemented in a future release | ||
| 807 | } | ||
| 808 | |||
| 809 | } // inner class AccessibleAWTChoice | ||
| 810 | |||
| 811 | } | ||