Source for javax.swing.JList

   1: /* JList.java --
   2:    Copyright (C) 2002, 2003, 2004, 2005  Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package javax.swing;
  40: 
  41: import java.awt.Color;
  42: import java.awt.Component;
  43: import java.awt.ComponentOrientation;
  44: import java.awt.Cursor;
  45: import java.awt.Dimension;
  46: import java.awt.Font;
  47: import java.awt.FontMetrics;
  48: import java.awt.Point;
  49: import java.awt.Rectangle;
  50: import java.awt.event.FocusListener;
  51: import java.beans.PropertyChangeEvent;
  52: import java.beans.PropertyChangeListener;
  53: import java.util.Locale;
  54: import java.util.Vector;
  55: 
  56: import javax.accessibility.Accessible;
  57: import javax.accessibility.AccessibleComponent;
  58: import javax.accessibility.AccessibleContext;
  59: import javax.accessibility.AccessibleRole;
  60: import javax.accessibility.AccessibleSelection;
  61: import javax.accessibility.AccessibleState;
  62: import javax.accessibility.AccessibleStateSet;
  63: import javax.swing.event.ListDataEvent;
  64: import javax.swing.event.ListDataListener;
  65: import javax.swing.event.ListSelectionEvent;
  66: import javax.swing.event.ListSelectionListener;
  67: import javax.swing.plaf.ListUI;
  68: import javax.swing.text.Position;
  69: 
  70: /**
  71:  * <p>This class is a facade over three separate objects: {@link
  72:  * javax.swing.ListModel}, {@link javax.swing.ListSelectionModel} and
  73:  * {@link javax.swing.plaf.ListUI}. The facade represents a unified "list"
  74:  * concept, with independently replacable (possibly client-provided) models
  75:  * for its contents and its current selection. In addition, each element in
  76:  * the list is rendered via a strategy class {@link
  77:  * javax.swing.ListCellRenderer}.</p>
  78:  *
  79:  * <p>Lists have many properties, some of which are stored in this class
  80:  * while others are delegated to the list's model or selection. The
  81:  * following properties are available:</p>
  82:  *
  83:  * <table>
  84:  * <tr><th>Property                       </th><th>Stored in</th><th>Bound?</th></tr>
  85:  * <tr><td>accessibleContext              </td><td>list     </td><td>no    </td></tr>
  86:  * <tr><td>anchorSelectionIndex           </td><td>selection</td><td>no    </td></tr>
  87:  * <tr><td>cellRenderer                   </td><td>list     </td><td>yes   </td></tr>
  88:  * <tr><td>dragEnabled                    </td><td>list     </td><td>no    </td></tr>
  89:  * <tr><td>firstVisibleIndex              </td><td>list     </td><td>no    </td></tr>
  90:  * <tr><td>fixedCellHeight                </td><td>list     </td><td>yes   </td></tr>
  91:  * <tr><td>fixedCellWidth                 </td><td>list     </td><td>yes   </td></tr>
  92:  * <tr><td>lastVisibleIndex               </td><td>list     </td><td>no    </td></tr>
  93:  * <tr><td>layoutOrientation              </td><td>list     </td><td>yes   </td></tr>
  94:  * <tr><td>leadSelectionIndex             </td><td>selection</td><td>no    </td></tr>
  95:  * <tr><td>maxSelectionIndex              </td><td>selection</td><td>no    </td></tr>
  96:  * <tr><td>minSelectionIndex              </td><td>selection</td><td>no    </td></tr>
  97:  * <tr><td>model                          </td><td>list     </td><td>yes   </td></tr>
  98:  * <tr><td>opaque                         </td><td>list     </td><td>no    </td></tr>
  99:  * <tr><td>preferredScrollableViewportSize</td><td>list     </td><td>no    </td></tr>
 100:  * <tr><td>prototypeCellValue             </td><td>list     </td><td>yes   </td></tr>
 101:  * <tr><td>scrollableTracksViewportHeight </td><td>list     </td><td>no    </td></tr>
 102:  * <tr><td>scrollableTracksViewportWidth  </td><td>list     </td><td>no    </td></tr>
 103:  * <tr><td>selectedIndex                  </td><td>selection</td><td>no    </td></tr>
 104:  * <tr><td>selectedIndices                </td><td>selection</td><td>no    </td></tr>
 105:  * <tr><td>selectedValue                  </td><td>model    </td><td>no    </td></tr>
 106:  * <tr><td>selectedValues                 </td><td>model    </td><td>no    </td></tr>
 107:  * <tr><td>selectionBackground            </td><td>list     </td><td>yes   </td></tr>
 108:  * <tr><td>selectionEmpty                 </td><td>selection</td><td>no    </td></tr>
 109:  * <tr><td>selectionForeground            </td><td>list     </td><td>yes   </td></tr>
 110:  * <tr><td>selectionMode                  </td><td>selection</td><td>no    </td></tr>
 111:  * <tr><td>selectionModel                 </td><td>list     </td><td>yes   </td></tr>
 112:  * <tr><td>UI                             </td><td>list     </td><td>yes   </td></tr>
 113:  * <tr><td>UIClassID                      </td><td>list     </td><td>no    </td></tr>
 114:  * <tr><td>valueIsAdjusting               </td><td>list     </td><td>no    </td></tr>
 115:  * <tr><td>visibleRowCount                </td><td>list     </td><td>no    </td></tr>
 116:  * </table> 
 117:  *
 118:  * @author Graydon Hoare (graydon@redhat.com)
 119:  */
 120: 
 121: public class JList extends JComponent implements Accessible, Scrollable
 122: {
 123: 
 124:   /**
 125:    * Provides accessibility support for <code>JList</code>.
 126:    */
 127:   protected class AccessibleJList extends AccessibleJComponent
 128:     implements AccessibleSelection, PropertyChangeListener,
 129:                ListSelectionListener, ListDataListener
 130:   {
 131: 
 132:     /**
 133:      * Provides accessibility support for list elements in <code>JList</code>s.
 134:      */
 135:     protected class AccessibleJListChild extends AccessibleContext
 136:       implements Accessible, AccessibleComponent
 137:     {
 138: 
 139:       /**
 140:        * The parent list.
 141:        */
 142:       JList parent;
 143: 
 144:       /**
 145:        * The index in the list for that child.
 146:        */
 147:       int listIndex;
 148: 
 149:       /**
 150:        * The cursor for this list child.
 151:        */
 152:       // TODO: Testcases show that this class somehow stores state about the
 153:       // cursor. I cannot make up though how that could affect
 154:       // the actual list.
 155:       Cursor cursor = Cursor.getDefaultCursor();
 156: 
 157:       /**
 158:        * Creates a new instance of <code>AccessibleJListChild</code>.
 159:        *
 160:        * @param list the list of which this is an accessible child
 161:        * @param index the list index for this child
 162:        */
 163:       public AccessibleJListChild(JList list, int index)
 164:       {
 165:         parent = list;
 166:         listIndex = index;
 167:       }
 168: 
 169:       /**
 170:        * Returns the accessible context of this object. Returns
 171:        * <code>this</code> since <code>AccessibleJListChild</code>s are their
 172:        * own accessible contexts.
 173:        *
 174:        * @return the accessible context of this object, <code>this</code>
 175:        */
 176:       public AccessibleContext getAccessibleContext()
 177:       {
 178:         return this;
 179:       }
 180: 
 181:       /**
 182:        * Returns the background color for this list child. This returns the
 183:        * background of the <code>JList</code> itself since the background
 184:        * cannot be set on list children individually
 185:        *
 186:        * @return the background color for this list child
 187:        */
 188:       public Color getBackground()
 189:       {
 190:         return parent.getBackground();
 191:       }
 192: 
 193:       /**
 194:        * Calling this method has no effect, since the background color cannot be
 195:        * set on list children individually.
 196:        *
 197:        * @param color not used here.
 198:        */
 199:       public void setBackground(Color color)
 200:       {
 201:         // Calling this method has no effect, since the background color cannot
 202:         // be set on list children individually.
 203:       }
 204: 
 205:       /**
 206:        * Returns the foreground color for this list child. This returns the
 207:        * background of the <code>JList</code> itself since the foreground
 208:        * cannot be set on list children individually.
 209:        *
 210:        * @return the background color for this list child
 211:        */
 212:       public Color getForeground()
 213:       {
 214:         return parent.getForeground();
 215:       }
 216: 
 217:       /**
 218:        * Calling this method has no effect, since the foreground color cannot be
 219:        * set on list children individually.
 220:        *
 221:        * @param color not used here.
 222:        */
 223:       public void setForeground(Color color)
 224:       {
 225:         // Calling this method has no effect, since the foreground color cannot
 226:         // be set on list children individually.
 227:       }
 228: 
 229:       /**
 230:        * Returns the cursor for this list child.
 231:        *
 232:        * @return the cursor for this list child
 233:        */
 234:       public Cursor getCursor()
 235:       {
 236:         // TODO: Testcases show that this method returns the cursor that has
 237:         // been set by setCursor. I cannot make up though how that could affect
 238:         // the actual list.
 239:         return cursor;
 240:       }
 241: 
 242:       /**
 243:        * Sets the cursor for this list child.
 244:        */
 245:       public void setCursor(Cursor cursor)
 246:       {
 247:         this.cursor = cursor;
 248:         // TODO: Testcases show that this method returns the cursor that has
 249:         // been set by setCursor. I cannot make up though how that could affect
 250:         // the actual list.
 251:       }
 252: 
 253:       /**
 254:        * Returns the font of the <code>JList</code> since it is not possible to
 255:        * set fonts for list children individually.
 256:        *
 257:        * @return the font of the <code>JList</code>
 258:        */
 259:       public Font getFont()
 260:       {
 261:         return parent.getFont();
 262:       }
 263: 
 264:       /**
 265:        * Does nothing since it is not possible to set the font on list children
 266:        * individually.
 267:        *
 268:        * @param font not used here
 269:        */
 270:       public void setFont(Font font)
 271:       {
 272:         // Does nothing since it is not possible to set the font on list
 273:         // children individually.
 274:       }
 275: 
 276:       /**
 277:        * Returns the font metrics for the specified font. This method forwards
 278:        * to the parent <code>JList</code>. 
 279:        *
 280:        * @param font the font for which the font metrics is queried
 281:        *
 282:        * @return the font metrics for the specified font
 283:        */
 284:       public FontMetrics getFontMetrics(Font font)
 285:       {
 286:         return parent.getFontMetrics(font);
 287:       }
 288: 
 289:       /**
 290:        * Returns <code>true</code> if the parent <code>JList</code> is enabled,
 291:        * <code>false</code> otherwise. The list children cannot have an enabled
 292:        * flag set individually.
 293:        *
 294:        * @return <code>true</code> if the parent <code>JList</code> is enabled,
 295:        *         <code>false</code> otherwise
 296:        */
 297:       public boolean isEnabled()
 298:       {
 299:         return parent.isEnabled();
 300:       }
 301: 
 302:       /**
 303:        * Does nothing since the enabled flag cannot be set for list children
 304:        * individually.
 305:        *
 306:        * @param b not used here
 307:        */
 308:       public void setEnabled(boolean b)
 309:       {
 310:         // Does nothing since the enabled flag cannot be set for list children
 311:         // individually.
 312:       }
 313: 
 314:       /**
 315:        * Returns <code>true</code> if this list child is visible,
 316:        * <code>false</code> otherwise. The value of this property depends
 317:        * on {@link JList#getFirstVisibleIndex()} and
 318:        * {@link JList#getLastVisibleIndex()}.
 319:        *
 320:        * @return <code>true</code> if this list child is visible,
 321:        *         <code>false</code> otherwise
 322:        */
 323:       public boolean isVisible()
 324:       {
 325:         return listIndex >= parent.getFirstVisibleIndex()
 326:                && listIndex <= parent.getLastVisibleIndex();
 327:       }
 328: 
 329:       /**
 330:        * The value of the visible property cannot be modified, so this method
 331:        * does nothing.
 332:        *
 333:        * @param b not used here
 334:        */
 335:       public void setVisible(boolean b)
 336:       {
 337:         // The value of the visible property cannot be modified, so this method
 338:         // does nothing.
 339:       }
 340: 
 341:       /**
 342:        * Returns <code>true</code> if this list child is currently showing on
 343:        * screen and <code>false</code> otherwise. The list child is showing if
 344:        * it is visible and if it's parent JList is currently showing.
 345:        *
 346:        * @return <code>true</code> if this list child is currently showing on
 347:        *         screen and <code>false</code> otherwise
 348:        */
 349:       public boolean isShowing()
 350:       {
 351:         return isVisible() && parent.isShowing();
 352:       }
 353: 
 354:       /**
 355:        * Returns <code>true</code> if this list child covers the screen location
 356:        * <code>point</code> (relative to the <code>JList</code> coordinate
 357:        * system, <code>false</code> otherwise.
 358:        *
 359:        * @return <code>true</code> if this list child covers the screen location
 360:        *         <code>point</code> , <code>false</code> otherwise
 361:        */
 362:       public boolean contains(Point point)
 363:       {
 364:         return getBounds().contains(point);
 365:       }
 366: 
 367:       /**
 368:        * Returns the absolute screen location of this list child.
 369:        *
 370:        * @return the absolute screen location of this list child
 371:        */
 372:       public Point getLocationOnScreen()
 373:       {
 374:         Point loc = getLocation();
 375:         SwingUtilities.convertPointToScreen(loc, parent);
 376:         return loc;
 377:       }
 378: 
 379:       /**
 380:        * Returns the screen location of this list child relative to it's parent.
 381:        *
 382:        * @return the location of this list child relative to it's parent
 383:        *
 384:        * @see JList#indexToLocation(int)
 385:        */
 386:       public Point getLocation()
 387:       {
 388:         return parent.indexToLocation(listIndex);
 389:       }
 390: 
 391:       /**
 392:        * Does nothing since the screen location cannot be set on list children
 393:        * explictitly.
 394:        *
 395:        * @param point not used here
 396:        */
 397:       public void setLocation(Point point)
 398:       {
 399:         // Does nothing since the screen location cannot be set on list children
 400:         // explictitly.
 401:       }
 402: 
 403:       /**
 404:        * Returns the bounds of this list child.
 405:        *
 406:        * @return the bounds of this list child
 407:        *
 408:        * @see JList#getCellBounds(int, int)
 409:        */
 410:       public Rectangle getBounds()
 411:       {
 412:         return parent.getCellBounds(listIndex, listIndex);
 413:       }
 414: 
 415:       /**
 416:        * Does nothing since the bounds cannot be set on list children
 417:        * individually.
 418:        *
 419:        * @param rectangle not used here
 420:        */
 421:       public void setBounds(Rectangle rectangle)
 422:       {
 423:         // Does nothing since the bounds cannot be set on list children
 424:         // individually.
 425:       }
 426: 
 427:       /**
 428:        * Returns the size of this list child.
 429:        *
 430:        * @return the size of this list child
 431:        */
 432:       public Dimension getSize()
 433:       {
 434:         Rectangle b = getBounds();
 435:         return b.getSize();
 436:       }
 437: 
 438:       /**
 439:        * Does nothing since the size cannot be set on list children
 440:        * individually.
 441:        *
 442:        * @param dimension not used here
 443:        */
 444:       public void setSize(Dimension dimension)
 445:       {
 446:         // Does nothing since the size cannot be set on list children
 447:         // individually.
 448:       }
 449: 
 450:       /**
 451:        * Returns <code>null</code> because list children do not have children
 452:        * themselves
 453:        *
 454:        * @return <code>null</code>
 455:        */
 456:       public Accessible getAccessibleAt(Point point)
 457:       {
 458:         return null;
 459:       }
 460: 
 461:       /**
 462:        * Returns <code>true</code> since list children are focus traversable.
 463:        *
 464:        * @return true
 465:        */
 466:       public boolean isFocusTraversable()
 467:       {
 468:         // TODO: Is this 100% ok?
 469:         return true;
 470:       }
 471: 
 472:       /**
 473:        * Requests focus on the parent list. List children cannot request focus
 474:        * individually.
 475:        */
 476:       public void requestFocus()
 477:       {
 478:         // TODO: Is this 100% ok?
 479:         parent.requestFocus();
 480:       }
 481: 
 482:       /**
 483:        * Adds a focus listener to the parent list. List children do not have
 484:        * their own focus management.
 485:        *
 486:        * @param listener the focus listener to add
 487:        */
 488:       public void addFocusListener(FocusListener listener)
 489:       {
 490:         // TODO: Is this 100% ok?
 491:         parent.addFocusListener(listener);
 492:       }
 493: 
 494:       /**
 495:        * Removes a focus listener from the parent list. List children do not
 496:        * have their own focus management.
 497:        *
 498:        * @param listener the focus listener to remove
 499:        */
 500:       public void removeFocusListener(FocusListener listener)
 501:       {
 502:         // TODO: Is this 100%
 503:         parent.removeFocusListener(listener);
 504:       }
 505: 
 506:       /**
 507:        * Returns the accessible role of this list item, which is
 508:        * {@link AccessibleRole#LABEL}.
 509:        *
 510:        * @return {@link AccessibleRole#LABEL}
 511:        */
 512:       public AccessibleRole getAccessibleRole()
 513:       {
 514:         return AccessibleRole.LABEL;
 515:       }
 516: 
 517:       /**
 518:        * Returns the accessible state set of this list item.
 519:        *
 520:        * @return the accessible state set of this list item
 521:        */
 522:       public AccessibleStateSet getAccessibleStateSet()
 523:       {
 524:         AccessibleStateSet states = new AccessibleStateSet();
 525:         if (isVisible())
 526:           states.add(AccessibleState.VISIBLE);
 527:         if (isShowing())
 528:           states.add(AccessibleState.SHOWING);
 529:         if (isFocusTraversable())
 530:           states.add(AccessibleState.FOCUSABLE);
 531:         // TODO: How should the active state be handled? The API docs
 532:         // suggest that this state is set on the activated list child,
 533:         // that is the one that is drawn with a box. However, I don't know how
 534:         // to implement this.
 535: 
 536:         // TODO: We set the selectable state here because list children are
 537:         // selectable. Is there a way to disable single children?
 538:         if (parent.isEnabled())
 539:           states.add(AccessibleState.SELECTABLE);
 540:  
 541:         if (parent.isSelectedIndex(listIndex))
 542:           states.add(AccessibleState.SELECTED);
 543: 
 544:         // TODO: Handle more states here?
 545:         return states;
 546:       }
 547: 
 548:       /**
 549:        * Returns the index of this list child within it's parent list.
 550:        *
 551:        * @return the index of this list child within it's parent list
 552:        */
 553:       public int getAccessibleIndexInParent()
 554:       {
 555:         return listIndex;
 556:       }
 557: 
 558:       /**
 559:        * Returns <code>0</code> since list children don't have children
 560:        * themselves.
 561:        *
 562:        * @return <code>0</code>
 563:        */
 564:       public int getAccessibleChildrenCount()
 565:       {
 566:         return 0;
 567:       }
 568: 
 569:       /**
 570:        * Returns <code>null</code> since list children don't have children
 571:        * themselves.
 572:        *
 573:        * @return <code>null</code>
 574:        */
 575:       public Accessible getAccessibleChild(int i)
 576:       {
 577:         return null;
 578:       }
 579: 
 580:       /**
 581:        * Returns the locale of this component. This call is forwarded to the
 582:        * parent list since list children don't have a separate locale setting.
 583:        *
 584:        * @return the locale of this component
 585:        */
 586:       public Locale getLocale()
 587:       {
 588:         return parent.getLocale();
 589:       }
 590: 
 591:       /**
 592:        * This method does
 593:        * nothing, list children are transient accessible objects which means
 594:        * that they don't fire property change events.
 595:        *
 596:        * @param l not used here
 597:        */
 598:       public void addPropertyChangeListener(PropertyChangeListener l)
 599:       {
 600:         // Do nothing here.
 601:       }
 602: 
 603:       /**
 604:        * This method does
 605:        * nothing, list children are transient accessible objects which means
 606:        * that they don't fire property change events.
 607:        *
 608:        * @param l not used here
 609:        */
 610:       public void removePropertyChangeListener(PropertyChangeListener l)
 611:       {
 612:         // Do nothing here.
 613:       }
 614:       
 615:       // TODO: Implement the remaining methods of this class.
 616:     }
 617:     
 618:     /**
 619:      * Create a new AccessibleJList.
 620:      */
 621:     public AccessibleJList()
 622:     {
 623:       // Nothing to do here.
 624:     }
 625: 
 626:     /**
 627:      * Returns the number of selected accessible children.
 628:      *
 629:      * @return the number of selected accessible children
 630:      */
 631:     public int getAccessibleSelectionCount()
 632:     {
 633:       return getSelectedIndices().length;
 634:     }
 635: 
 636:     /**
 637:      * Returns the n-th selected accessible child.
 638:      *
 639:      * @param n the index of the selected child to return
 640:      *
 641:      * @return the n-th selected accessible child
 642:      */
 643:     public Accessible getAccessibleSelection(int n)
 644:     {
 645:       return new AccessibleJListChild(JList.this, getSelectedIndices()[n]);
 646:     }
 647: 
 648:     /**
 649:      * Returns <code>true</code> if the n-th child is selected,
 650:      * <code>false</code> otherwise.
 651:      *
 652:      * @param n the index of the child of which the selected state is queried
 653:      *
 654:      * @return <code>true</code> if the n-th child is selected,
 655:      *         <code>false</code> otherwise
 656:      */
 657:     public boolean isAccessibleChildSelected(int n)
 658:     {
 659:       return isSelectedIndex(n);
 660:     }
 661: 
 662:     /**
 663:      * Adds the accessible item with the specified index to the selected items.
 664:      * If multiple selections are supported, the item is added to the selection,
 665:      * otherwise the item replaces the current selection.
 666:      *
 667:      * @param i the index of the item to add to the selection
 668:      */
 669:     public void addAccessibleSelection(int i)
 670:     {
 671:       addSelectionInterval(i, i);
 672:     }
 673: 
 674:     /**
 675:      * Removes the accessible item with the specified index to the selection.
 676:      *
 677:      * @param i the index of the item to be removed from the selection
 678:      */
 679:     public void removeAccessibleSelection(int i)
 680:     {
 681:       removeSelectionInterval(i, i);
 682:     }
 683: 
 684:     /**
 685:      * Remove all selection items from the selection.
 686:      */
 687:     public void clearAccessibleSelection()
 688:     {
 689:       clearSelection();
 690:     }
 691: 
 692:     /**
 693:      * Selects all items if multiple selections are supported.
 694:      * Otherwise do nothing.
 695:      */
 696:     public void selectAllAccessibleSelection()
 697:     {
 698:       addSelectionInterval(0, getModel().getSize());
 699:     }
 700: 
 701:     /**
 702:      * Receices notification when the list selection is changed. This method
 703:      * fires two property change events, the first with
 704:      * {@link AccessibleContext#ACCESSIBLE_VISIBLE_DATA_PROPERTY} and the second
 705:      * with {@link AccessibleContext#ACCESSIBLE_SELECTION_PROPERTY}.
 706:      *
 707:      * @param event the list selection event
 708:      */
 709:     public void valueChanged(ListSelectionEvent event)
 710:     {
 711:       firePropertyChange(ACCESSIBLE_VISIBLE_DATA_PROPERTY, Boolean.FALSE,
 712:                          Boolean.TRUE);
 713:       firePropertyChange(ACCESSIBLE_SELECTION_PROPERTY, Boolean.FALSE,
 714:                          Boolean.TRUE);
 715:     }
 716: 
 717:     /**
 718:      * Receives notification when items have changed in the
 719:      * <code>JList</code>. This method fires a property change event with
 720:      * {@link AccessibleContext#ACCESSIBLE_VISIBLE_DATA_PROPERTY}.
 721:      *
 722:      * @param event the list data event
 723:      */
 724:     public void contentsChanged(ListDataEvent event)
 725:     {
 726:       firePropertyChange(ACCESSIBLE_VISIBLE_DATA_PROPERTY, Boolean.FALSE,
 727:                          Boolean.TRUE);
 728:     }
 729: 
 730:     /**
 731:      * Receives notification when items are inserted into the
 732:      * <code>JList</code>. This method fires a property change event with
 733:      * {@link AccessibleContext#ACCESSIBLE_VISIBLE_DATA_PROPERTY}.
 734:      *
 735:      * @param event the list data event
 736:      */
 737:     public void intervalAdded(ListDataEvent event)
 738:     {
 739:       firePropertyChange(ACCESSIBLE_VISIBLE_DATA_PROPERTY, Boolean.FALSE,
 740:                          Boolean.TRUE);
 741:     }
 742: 
 743:     /**
 744:      * Receives notification when items are removed from the
 745:      * <code>JList</code>. This method fires a property change event with
 746:      * {@link AccessibleContext#ACCESSIBLE_VISIBLE_DATA_PROPERTY}.
 747:      *
 748:      * @param event the list data event
 749:      */
 750:     public void intervalRemoved(ListDataEvent event)
 751:     {
 752:       firePropertyChange(ACCESSIBLE_VISIBLE_DATA_PROPERTY, Boolean.FALSE,
 753:                          Boolean.TRUE);
 754:     }
 755: 
 756: 
 757:     /**
 758:      * Receives notification about changes of the <code>JList</code>'s
 759:      * properties. This is used to re-register this object as listener to
 760:      * the data model and selection model when the data model or selection model
 761:      * changes.
 762:      *
 763:      * @param e the property change event
 764:      */
 765:     public void propertyChange(PropertyChangeEvent e)
 766:     {
 767:       String propertyName = e.getPropertyName();
 768:       if (propertyName.equals("model"))
 769:         {
 770:           ListModel oldModel = (ListModel) e.getOldValue();
 771:           oldModel.removeListDataListener(this);
 772:           ListModel newModel = (ListModel) e.getNewValue();
 773:           newModel.addListDataListener(this);
 774:         }
 775:       else if (propertyName.equals("selectionModel"))
 776:         {
 777:           ListSelectionModel oldModel = (ListSelectionModel) e.getOldValue();
 778:           oldModel.removeListSelectionListener(this);
 779:           ListSelectionModel newModel = (ListSelectionModel) e.getNewValue();
 780:           oldModel.addListSelectionListener(this);
 781:         }
 782:     }
 783: 
 784:     /**
 785:      * Return the state set of the <code>JList</code>.
 786:      *
 787:      * @return the state set of the <code>JList</code>
 788:      */
 789:     public AccessibleStateSet getAccessibleStateSet()
 790:     {
 791:       // TODO: Figure out if there is possibly more state that must be
 792:       // handled here.
 793:       AccessibleStateSet s = super.getAccessibleStateSet();
 794:       if (getSelectionMode() != ListSelectionModel.SINGLE_SELECTION)
 795:         s.add(AccessibleState.MULTISELECTABLE);
 796:       return s;
 797:     }
 798: 
 799:     /**
 800:      * Returns the accessible role for <code>JList</code>,
 801:      * {@link AccessibleRole#LIST}.
 802:      *
 803:      * @return the accessible role for <code>JList</code>
 804:      */
 805:     public AccessibleRole getAccessibleRole()
 806:     {
 807:       return AccessibleRole.LIST;
 808:     }
 809: 
 810:     /**
 811:      * Returns the accessible child at the visual location <code>p</code>
 812:      * (relative to the upper left corner of the <code>JList</code>). If there
 813:      * is no child at that location, this returns <code>null</code>.
 814:      *
 815:      * @param p the screen location for which to return the accessible child
 816:      *
 817:      * @return the accessible child at the specified location, or
 818:      *         <code>null</code> if there is no child at that location
 819:      */
 820:     public Accessible getAccessibleAt(Point p)
 821:     {
 822:       int childIndex = locationToIndex(p);
 823:       return getAccessibleChild(childIndex);
 824:     }
 825: 
 826:     /**
 827:      * Returns the number of accessible children in the <code>JList</code>.
 828:      *
 829:      * @return the number of accessible children in the <code>JList</code>
 830:      */
 831:     public int getAccessibleChildrenCount()
 832:     {
 833:       return getModel().getSize();
 834:     }
 835: 
 836:     /**
 837:      * Returns the n-th accessible child of this <code>JList</code>. This will
 838:      * be an instance of {@link AccessibleJListChild}. If there is no child
 839:      * at that index, <code>null</code> is returned.
 840:      *
 841:      * @param n the index of the child to return
 842:      *
 843:      * @return the n-th accessible child of this <code>JList</code>
 844:      */
 845:     public Accessible getAccessibleChild(int n)
 846:     {
 847:       if (getModel().getSize() <= n)
 848:         return null;
 849:       return new AccessibleJListChild(JList.this, n);
 850:     }
 851:   }
 852: 
 853:   private static final long serialVersionUID = 4406629526391098046L;
 854: 
 855:   /** 
 856:    * Constant value used in "layoutOrientation" property. This value means
 857:    * that cells are laid out in a single vertical column. This is the default. 
 858:    */
 859:   public static final int VERTICAL = 0;
 860: 
 861:   /** 
 862:    * Constant value used in "layoutOrientation" property. This value means
 863:    * that cells are laid out in multiple columns "newspaper style", filling
 864:    * vertically first, then horizontally. 
 865:    */
 866:   public static final int VERTICAL_WRAP = 1;
 867:   
 868:   /** 
 869:    * Constant value used in "layoutOrientation" property. This value means
 870:    * that cells are laid out in multiple columns "newspaper style",
 871:    * filling horizontally first, then vertically. 
 872:    */
 873:   public static final int HORIZONTAL_WRAP = 2;
 874: 
 875:   /**
 876:    * This property indicates whether "drag and drop" functions are enabled
 877:    * on the list.
 878:    */
 879:   boolean dragEnabled;
 880: 
 881:   /** This property provides a strategy for rendering cells in the list. */
 882:   ListCellRenderer cellRenderer;
 883: 
 884:   /**
 885:    * This property indicates an fixed width to assign to all cells in the
 886:    * list. If its value is <code>-1</code>, no width has been
 887:    * assigned. This value can be set explicitly, or implicitly by setting
 888:    * the {@link #prototypeCellValue} property.
 889:    */
 890:   int fixedCellWidth;
 891:   
 892:   /**
 893:    * This property indicates an fixed height to assign to all cells in the
 894:    * list. If its value is <code>-1</code>, no height has been
 895:    * assigned. This value can be set explicitly, or implicitly by setting
 896:    * the {@link #prototypeCellValue} property.
 897:    */
 898:   int fixedCellHeight;
 899: 
 900:   /** 
 901:    * This property holds the current layout orientation of the list, which
 902:    * is one of the integer constants {@link #VERTICAL}, {@link
 903:    * #VERTICAL_WRAP}, or {@link #HORIZONTAL_WRAP}. 
 904:    */
 905:   int layoutOrientation;
 906:   
 907:   /** This property holds the data elements displayed by the list. */
 908:   ListModel model;
 909: 
 910:   /**
 911:    * <p>This property holds a reference to a "prototype" data value --
 912:    * typically a String -- which is used to calculate the {@link
 913:    * #fixedCellWidth} and {@link #fixedCellHeight} properties, using the
 914:    * {@link #cellRenderer} property to acquire a component to render the
 915:    * prototype.</p>
 916:    *
 917:    * <p>It is important that you <em>not</em> set this value to a
 918:    * component. It has to be a <em>data value</em> such as the objects you
 919:    * would find in the list's model. Setting it to a component will have
 920:    * undefined (and undesirable) affects. </p>
 921:    */
 922:   Object prototypeCellValue;
 923: 
 924:   /** 
 925:    * This property specifies a foreground color for the selected cells in
 926:    * the list. When {@link ListCellRenderer#getListCellRendererComponent}
 927:    * is called with a selected cell object, the component returned will
 928:    * have its "foreground" set to this color.
 929:    */
 930:   Color selectionBackground;
 931: 
 932:   /** 
 933:    * This property specifies a background color for the selected cells in
 934:    * the list. When {@link ListCellRenderer#getListCellRendererComponent}
 935:    * is called with a selected cell object, the component returned will
 936:    * have its "background" property set to this color.
 937:    */
 938:   Color selectionForeground;
 939: 
 940:   /** 
 941:    * This property holds a description of which data elements in the {@link
 942:    * #model} property should be considered "selected", when displaying and
 943:    * interacting with the list.
 944:    */
 945:   ListSelectionModel selectionModel;
 946: 
 947: 
 948:   /**
 949:    * This property indicates that the list's selection is currently
 950:    * "adjusting" -- perhaps due to a user actively dragging the mouse over
 951:    * multiple list elements -- and is therefore likely to change again in
 952:    * the near future. A {@link ListSelectionListener} might choose to delay
 953:    * updating its view of the list's selection until this property is
 954:    * false, meaning that the adjustment has completed.
 955:    */
 956:   boolean valueIsAdjusting;
 957: 
 958:   /** 
 959:    * This property indicates a <em>preference</em> for the number of rows
 960:    * displayed in the list, and will scale the
 961:    * {@link #getPreferredScrollableViewportSize} property accordingly. The actual
 962:    * number of displayed rows, when the list is placed in a real {@link
 963:    * JViewport} or other component, may be greater or less than this number.
 964:    */
 965:   int visibleRowCount;
 966: 
 967:   /**
 968:    * Fire a {@link ListSelectionEvent} to all the registered ListSelectionListeners.
 969:    */
 970:   protected void fireSelectionValueChanged(int firstIndex, int lastIndex, boolean isAdjusting) 
 971:   {
 972:     ListSelectionEvent evt = new ListSelectionEvent(this, firstIndex, lastIndex, isAdjusting);
 973:     ListSelectionListener listeners[] = getListSelectionListeners();
 974:     for (int i = 0; i < listeners.length; ++i)
 975:       {
 976:         listeners[i].valueChanged(evt);
 977:       }
 978:   }
 979: 
 980:   /**
 981:    * This private listener propagates {@link ListSelectionEvent} events
 982:    * from the list's "selectionModel" property to the list's {@link
 983:    * ListSelectionListener} listeners. It also listens to {@link
 984:    * ListDataEvent} events from the list's {@link #model} property. If this
 985:    * class receives either type of event, it triggers repainting of the
 986:    * list.
 987:    */
 988:   private class ListListener 
 989:     implements ListSelectionListener, ListDataListener
 990:   {
 991:     // ListDataListener events
 992:     public void contentsChanged(ListDataEvent event)
 993:     {
 994:       JList.this.revalidate();
 995:       JList.this.repaint();
 996:     }
 997:     public void intervalAdded(ListDataEvent event)
 998:     {
 999:       JList.this.revalidate();
1000:       JList.this.repaint();
1001:     }
1002:     public void intervalRemoved(ListDataEvent event)
1003:     {
1004:       JList.this.revalidate();
1005:       JList.this.repaint();
1006:     }
1007:     // ListSelectionListener events
1008:     public void valueChanged(ListSelectionEvent event)
1009:     {
1010:       JList.this.fireSelectionValueChanged(event.getFirstIndex(),
1011:                                            event.getLastIndex(),
1012:                                            event.getValueIsAdjusting());
1013:       JList.this.repaint();
1014:     }
1015:   }
1016: 
1017:   /** 
1018:    * Shared ListListener instance, subscribed to both the current {@link
1019:    * #model} and {@link #selectionModel} properties of the list.
1020:    */
1021:   ListListener listListener;
1022: 
1023: 
1024:   /**
1025:    * Creates a new JList object.
1026:    */
1027:   public JList()
1028:   {
1029:     init();
1030:   }
1031: 
1032:   /**
1033:    * Creates a new JList object.
1034:    *
1035:    * @param listData Initial data to populate the list with
1036:    */
1037:   public JList(Object[] listData)
1038:   {
1039:     init();
1040:     setListData(listData);
1041:   }
1042: 
1043:   /**
1044:    * Creates a new JList object.
1045:    *
1046:    * @param listData Initial data to populate the list with
1047:    */
1048:   public JList(Vector listData)
1049:   {
1050:     init();
1051:     setListData(listData);
1052:   }
1053: 
1054:   /**
1055:    * Creates a new JList object.
1056:    *
1057:    * @param listData Initial data to populate the list with
1058:    */
1059:   public JList(ListModel listData)
1060:   {
1061:     init();
1062:     setModel(listData);
1063:   }
1064: 
1065:   void init()
1066:   {
1067:     dragEnabled = false;
1068:     fixedCellHeight = -1;
1069:     fixedCellWidth = -1;
1070:     layoutOrientation = VERTICAL;
1071:     opaque = true;
1072:     valueIsAdjusting = false;
1073:     visibleRowCount = 8;
1074: 
1075:     cellRenderer = new DefaultListCellRenderer();
1076:     listListener = new ListListener();
1077: 
1078:     setModel(new DefaultListModel());
1079:     setSelectionModel(createSelectionModel());
1080: 
1081:     updateUI();
1082:   }
1083: 
1084:   /**
1085:    * Creates the default <code>ListSelectionModel</code>.
1086:    *
1087:    * @return the <code>ListSelectionModel</code>
1088:    */
1089:   protected ListSelectionModel createSelectionModel()
1090:   {
1091:     return new DefaultListSelectionModel();
1092:   }
1093:   
1094:   /**
1095:    * Gets the value of the {@link #fixedCellHeight} property. This property
1096:    * may be <code>-1</code> to indicate that no cell height has been
1097:    * set. This property is also set implicitly when the
1098:    * {@link #prototypeCellValue} property is set.
1099:    *
1100:    * @return The current value of the property 
1101:    * 
1102:    * @see #fixedCellHeight
1103:    * @see #setFixedCellHeight
1104:    * @see #setPrototypeCellValue
1105:    */
1106:   public int getFixedCellHeight()
1107:   {
1108:     return fixedCellHeight;
1109:   }
1110: 
1111:   /**
1112:    * Sets the value of the {@link #fixedCellHeight} property. This property
1113:    * may be <code>-1</code> to indicate that no cell height has been
1114:    * set. This property is also set implicitly when the {@link
1115:    * #prototypeCellValue} property is set, but setting it explicitly
1116:    * overrides the height computed from {@link #prototypeCellValue}.
1117:    *
1118:    * @see #getFixedCellHeight
1119:    * @see #getPrototypeCellValue
1120:    */
1121:   public void setFixedCellHeight(int h)
1122:   {
1123:     if (fixedCellHeight == h)
1124:       return;
1125: 
1126:     int old = fixedCellHeight;
1127:     fixedCellHeight = h;
1128:     firePropertyChange("fixedCellWidth", old, h);
1129:   }
1130: 
1131: 
1132:   /**
1133:    * Gets the value of the {@link #fixedCellWidth} property. This property
1134:    * may be <code>-1</code> to indicate that no cell width has been
1135:    * set. This property is also set implicitly when the {@link
1136:    * #prototypeCellValue} property is set.
1137:    *
1138:    * @return The current value of the property 
1139:    * 
1140:    * @see #setFixedCellWidth
1141:    * @see #setPrototypeCellValue
1142:    */
1143:   public int getFixedCellWidth()
1144:   {
1145:     return fixedCellWidth;
1146:   }
1147: 
1148:   /**
1149:    * Sets the value of the {@link #fixedCellWidth} property. This property
1150:    * may be <code>-1</code> to indicate that no cell width has been
1151:    * set. This property is also set implicitly when the {@link
1152:    * #prototypeCellValue} property is set, but setting it explicitly
1153:    * overrides the width computed from {@link #prototypeCellValue}.
1154:    *
1155:    * @see #getFixedCellHeight
1156:    * @see #getPrototypeCellValue
1157:    */
1158:   public void setFixedCellWidth(int w)
1159:   {
1160:     if (fixedCellWidth == w)
1161:       return;
1162:     
1163:     int old = fixedCellWidth;
1164:     fixedCellWidth = w;
1165:     firePropertyChange("fixedCellWidth", old, w);
1166:   }
1167: 
1168:   /** 
1169:    * Gets the value of the {@link #visibleRowCount} property. 
1170:    *
1171:    * @return the current value of the property.
1172:    */
1173: 
1174:   public int getVisibleRowCount()
1175:   {
1176:     return visibleRowCount;
1177:   }
1178: 
1179:   /**
1180:    * Sets the value of the {@link #visibleRowCount} property. 
1181:    *
1182:    * @param vc The new property value
1183:    */
1184:   public void setVisibleRowCount(int vc)
1185:   {
1186:     visibleRowCount = vc;
1187:     revalidate();
1188:     repaint();
1189:   }
1190: 
1191:   /**
1192:    * Adds a {@link ListSelectionListener} to the listener list for this
1193:    * list. The listener will be called back with a {@link
1194:    * ListSelectionEvent} any time the list's {@link #selectionModel}
1195:    * property changes. The source of such events will be the JList,
1196:    * not the selection model.
1197:    *
1198:    * @param listener The new listener to add
1199:    */
1200:   public void addListSelectionListener(ListSelectionListener listener)
1201:   {
1202:     listenerList.add (ListSelectionListener.class, listener);
1203:   }
1204: 
1205:   /**
1206:    * Removes a {@link ListSelectionListener} from the listener list for
1207:    * this list. The listener will no longer be called when the list's
1208:    * {@link #selectionModel} changes.
1209:    *
1210:    * @param listener The listener to remove
1211:    */
1212:   public void removeListSelectionListener(ListSelectionListener listener)
1213:   {
1214:     listenerList.remove(ListSelectionListener.class, listener);
1215:   }
1216: 
1217:   /**
1218:    * Returns an array of all ListSelectionListeners subscribed to this
1219:    * list. 
1220:    *
1221:    * @return The current subscribed listeners
1222:    *
1223:    * @since 1.4
1224:    */
1225:   public ListSelectionListener[] getListSelectionListeners()
1226:   {
1227:     return (ListSelectionListener[]) getListeners(ListSelectionListener.class);
1228:   }
1229: 
1230:   public int getSelectionMode()
1231:   {
1232:     return selectionModel.getSelectionMode();
1233:   }
1234:   
1235:   /**
1236:    * Sets the list's "selectionMode" property, which simply mirrors the
1237:    * same property on the list's {@link #selectionModel} property. This
1238:    * property should be one of the integer constants
1239:    * <code>SINGLE_SELECTION</code>, <code>SINGLE_INTERVAL_SELECTION</code>,
1240:    * or <code>MULTIPLE_INTERVAL_SELECTION</code> from the {@link
1241:    * ListSelectionModel} interface.
1242:    *
1243:    * @param a The new selection mode
1244:    */
1245:   public void setSelectionMode(int a)
1246:   {
1247:     selectionModel.setSelectionMode(a);
1248:   }
1249: 
1250:   /**
1251:    * Adds the interval <code>[a,a]</code> to the set of selections managed
1252:    * by this list's {@link #selectionModel} property. Depending on the
1253:    * selection mode, this may cause existing selections to become invalid,
1254:    * or may simply expand the set of selections. 
1255:    *
1256:    * @param a A number in the half-open range <code>[0, x)</code> where
1257:    * <code>x = getModel.getSize()</code>, indicating the index of an
1258:    * element in the list to select.
1259:    *
1260:    * @see #setSelectionMode
1261:    * @see #selectionModel
1262:    */
1263:   public void setSelectedIndex(int a)
1264:   {
1265:     selectionModel.setSelectionInterval(a, a);
1266:   }
1267: 
1268:   /**
1269:    * For each element <code>a[i]</code> of the provided array
1270:    * <code>a</code>, calls {@link #setSelectedIndex} on <code>a[i]</code>.
1271:    *
1272:    * @see #setSelectionMode
1273:    * @see #selectionModel
1274:    */
1275:   public void setSelectedIndices(int [] a)
1276:   {
1277:     for (int i = 0; i < a.length; ++i)
1278:       setSelectedIndex(a[i]);
1279:   }
1280: 
1281:   /**
1282:    * Returns the minimum index of an element in the list which is currently
1283:    * selected.
1284:    *
1285:    * @return A number in the half-open range <code>[0, x)</code> where
1286:    * <code>x = getModel.getSize()</code>, indicating the minimum index of
1287:    * an element in the list for which the element is selected, or
1288:    * <code>-1</code> if no elements are selected
1289:    */
1290:   public int getSelectedIndex()
1291:   {
1292:     return selectionModel.getMinSelectionIndex();
1293:   }
1294: 
1295:   /**
1296:    * Returns <code>true</code> if the model's selection is empty, otherwise
1297:    * <code>false</code>. 
1298:    *
1299:    * @return The return value of {@link ListSelectionModel#isSelectionEmpty}
1300:    */
1301:   public boolean isSelectionEmpty()
1302:   {
1303:     return selectionModel.isSelectionEmpty();
1304:   }
1305: 
1306:   /**
1307:    * Returns the list index of the upper left or upper right corner of the
1308:    * visible rectangle of this list, depending on the {@link
1309:    * Component#getComponentOrientation} property.
1310:    *
1311:    * @return The index of the first visible list cell, or <code>-1</code>
1312:    * if none is visible.
1313:    */
1314:   public int getFirstVisibleIndex()
1315:   {
1316:     ComponentOrientation or = getComponentOrientation();
1317:     Rectangle r = getVisibleRect();
1318:     if (or == ComponentOrientation.RIGHT_TO_LEFT)
1319:       r.translate((int) r.getWidth() - 1, 0);
1320:     return getUI().locationToIndex(this, r.getLocation());      
1321:   }
1322: 
1323: 
1324:   /**
1325:    * Returns index of the cell to which specified location is closest to
1326:    * @param location for which to look for in the list
1327:    * 
1328:    * @return index of the cell to which specified location is closest to.
1329:    */
1330:    public int locationToIndex(Point location)
1331:    {
1332:      return getUI().locationToIndex(this, location);      
1333:    }
1334: 
1335:   /**
1336:    * Returns location of the cell located at the specified index in the list.
1337:    * @param index of the cell for which location will be determined
1338:    * 
1339:    * @return location of the cell located at the specified index in the list.
1340:    */
1341:    public Point indexToLocation(int index)
1342:    {
1343:      return getUI().indexToLocation(this, index);
1344:    }
1345: 
1346:   /**
1347:    * Returns the list index of the lower right or lower left corner of the
1348:    * visible rectangle of this list, depending on the {@link
1349:    * Component#getComponentOrientation} property.
1350:    *
1351:    * @return The index of the last visible list cell, or <code>-1</code>
1352:    * if none is visible.
1353:    */
1354:   public int getLastVisibleIndex()
1355:   {
1356:     ComponentOrientation or = getComponentOrientation();
1357:     Rectangle r = getVisibleRect();
1358:     r.translate(0, (int) r.getHeight() - 1);
1359:     if (or == ComponentOrientation.LEFT_TO_RIGHT)
1360:       r.translate((int) r.getWidth() - 1, 0);
1361:     if (getUI().locationToIndex(this, r.getLocation()) == -1
1362:         && indexToLocation(getModel().getSize() - 1).y < r.y)
1363:       return getModel().getSize() - 1;
1364:     return getUI().locationToIndex(this, r.getLocation());
1365:   }
1366: 
1367:   /**
1368:    * Returns the indices of values in the {@link #model} property which are
1369:    * selected.
1370:    *
1371:    * @return An array of model indices, each of which is selected according
1372:    *         to the {@link #getSelectedValues} property
1373:    */
1374:   public int[] getSelectedIndices()
1375:   {
1376:     int lo, hi, n, i, j;
1377:     if (selectionModel.isSelectionEmpty())
1378:       return new int[0];
1379:     lo = selectionModel.getMinSelectionIndex();
1380:     hi = selectionModel.getMaxSelectionIndex();
1381:     n = 0;
1382:     for (i = lo; i <= hi; ++i)
1383:       if (selectionModel.isSelectedIndex(i))
1384:         n++;
1385:     int [] v = new int[n];
1386:     j = 0;
1387:     for (i = lo; i <= hi; ++i)
1388:       if (selectionModel.isSelectedIndex(i))
1389:         v[j++] = i;
1390:     return v;
1391:   }
1392: 
1393:   /**
1394:    * Indicates whether the list element at a given index value is
1395:    * currently selected.
1396:    *
1397:    * @param a The index to check 
1398:    * @return <code>true</code> if <code>a</code> is the index of a selected
1399:    * list element
1400:    */
1401:   public boolean isSelectedIndex(int a)
1402:   {
1403:     return selectionModel.isSelectedIndex(a);
1404:   }
1405: 
1406:   /**
1407:    * Returns the first value in the list's {@link #model} property which is
1408:    * selected, according to the list's {@link #selectionModel} property.
1409:    * This is equivalent to calling
1410:    * <code>getModel()getElementAt(getSelectedIndex())</code>, with a check
1411:    * for the special index value of <code>-1</code> which returns null
1412:    * <code>null</code>.
1413:    *
1414:    * @return The first selected element, or <code>null</code> if no element
1415:    * is selected.
1416:    *
1417:    * @see #getSelectedValues
1418:    */
1419:   public Object getSelectedValue()
1420:   {
1421:     int index = getSelectedIndex();
1422:     if (index == -1)
1423:       return null;
1424:     return getModel().getElementAt(index);
1425:   }
1426: 
1427:   /**
1428:    * Returns all the values in the list's {@link #model} property which
1429:    * are selected, according to the list's {@link #selectionModel} property.
1430:    *
1431:    * @return An array containing all the selected values
1432:    *
1433:    * @see #setSelectedValue
1434:    */
1435:   public Object[] getSelectedValues()
1436:   {
1437:     int [] idx = getSelectedIndices();
1438:     Object [] v = new Object[idx.length];
1439:     for (int i = 0; i < idx.length; ++i)
1440:       v[i] = getModel().getElementAt(i);
1441:     return v;
1442:   }
1443: 
1444:   /**
1445:    * Gets the value of the {@link #selectionBackground} property.
1446:    *
1447:    * @return The current value of the property
1448:    */
1449:   public Color getSelectionBackground()
1450:   {
1451:     return selectionBackground;
1452:   }
1453: 
1454:   /**
1455:    * Sets the value of the {@link #selectionBackground} property.
1456:    *
1457:    * @param c The new value of the property
1458:    */
1459:   public void setSelectionBackground(Color c)
1460:   {
1461:     if (selectionBackground == c)
1462:       return;
1463: 
1464:     Color old = selectionBackground;
1465:     selectionBackground = c;
1466:     firePropertyChange("selectionBackground", old, c);
1467:     repaint();
1468:   }
1469: 
1470:   /**
1471:    * Gets the value of the {@link #selectionForeground} property.
1472:    *
1473:    * @return The current value of the property
1474:    */
1475:   public Color getSelectionForeground()
1476:   {
1477:     return selectionForeground;
1478:   }
1479:   
1480:   /**
1481:    * Sets the value of the {@link #selectionForeground} property.
1482:    *
1483:    * @param c The new value of the property
1484:    */
1485:   public void setSelectionForeground(Color c)
1486:   {
1487:     if (selectionForeground == c)
1488:       return;
1489: 
1490:     Color old = selectionForeground;
1491:     selectionForeground = c;
1492:     firePropertyChange("selectionForeground", old, c);
1493:   }
1494: 
1495:   /**
1496:    * Sets the selection to cover only the specified value, if it
1497:    * exists in the model. 
1498:    *
1499:    * @param obj The object to select
1500:    * @param scroll Whether to scroll the list to make the newly selected
1501:    * value visible
1502:    *
1503:    * @see #ensureIndexIsVisible
1504:    */
1505: 
1506:   public void setSelectedValue(Object obj, boolean scroll)
1507:   {
1508:     for (int i = 0; i < model.getSize(); ++i)
1509:       {
1510:         if (model.getElementAt(i).equals(obj))
1511:           {
1512:             setSelectedIndex(i);
1513:             if (scroll)
1514:               ensureIndexIsVisible(i);
1515:             break;
1516:           }
1517:       }
1518:   }
1519: 
1520:   /**
1521:    * Scrolls this list to make the specified cell visible. This
1522:    * only works if the list is contained within a viewport.
1523:    *
1524:    * @param i The list index to make visible
1525:    *
1526:    * @see JComponent#scrollRectToVisible
1527:    */
1528:   public void ensureIndexIsVisible(int i)
1529:   {
1530:     scrollRectToVisible(getUI().getCellBounds(this, i, i));
1531:   }
1532: 
1533:   /**
1534:    * Sets the {@link #model} property of the list to a new anonymous
1535:    * {@link AbstractListModel} subclass which accesses the provided Object
1536:    * array directly.
1537:    *
1538:    * @param listData The object array to build a new list model on
1539:    * @see #setModel
1540:    */
1541:   public void setListData(final Object[] listData)
1542:   {
1543:     setModel(new AbstractListModel()
1544:         {
1545:           public int getSize()
1546:           {
1547:             return listData.length;
1548:           }
1549: 
1550:           public Object getElementAt(int i)
1551:           {
1552:             return listData[i];
1553:           }
1554:         });
1555:   }
1556: 
1557:   /**
1558:    * Sets the {@link #model} property of the list to a new anonymous {@link
1559:    * AbstractListModel} subclass which accesses the provided vector
1560:    * directly.
1561:    *
1562:    * @param listData The object array to build a new list model on
1563:    * @see #setModel
1564:    */
1565:   public void setListData(final Vector listData)
1566:   {
1567:     setModel(new AbstractListModel()
1568:         {
1569:           public int getSize()
1570:           {
1571:             return listData.size();
1572:           }
1573: 
1574:           public Object getElementAt(int i)
1575:           {
1576:             return listData.elementAt(i);
1577:           }
1578:         });
1579:   }
1580: 
1581:   /**
1582:    * Gets the value of the {@link #cellRenderer} property. 
1583:    *
1584:    * @return The current value of the property
1585:    */
1586:   public ListCellRenderer getCellRenderer()
1587:   {
1588:     return cellRenderer;
1589:   }
1590: 
1591:   /**
1592:    * Sets the value of the {@link #getCellRenderer} property.
1593:    *
1594:    * @param renderer The new property value
1595:    */
1596:   public void setCellRenderer(ListCellRenderer renderer)
1597:   {
1598:     if (cellRenderer == renderer)
1599:       return;
1600:     
1601:     ListCellRenderer old = cellRenderer;
1602:     cellRenderer = renderer;
1603:     firePropertyChange("cellRenderer", old, renderer);
1604:     revalidate();
1605:     repaint();
1606:   }
1607: 
1608:   /**
1609:    * Gets the value of the {@link #model} property. 
1610:    *
1611:    * @return The current value of the property
1612:    */
1613:   public ListModel getModel()
1614:   {
1615:     return model;
1616:   }
1617: 
1618:   /**
1619:    * Sets the value of the {@link #model} property. The list's {@link
1620:    * #listListener} is unsubscribed from the existing model, if it exists,
1621:    * and re-subscribed to the new model.
1622:    *
1623:    * @param model The new property value
1624:    */
1625:   public void setModel(ListModel model)
1626:   {
1627:     if (this.model == model)
1628:       return;
1629:     
1630:     if (this.model != null)
1631:       this.model.removeListDataListener(listListener);
1632:     
1633:     ListModel old = this.model;
1634:     this.model = model;
1635:     
1636:     if (this.model != null)
1637:       this.model.addListDataListener(listListener);
1638:     
1639:     firePropertyChange("model", old, model);
1640:     revalidate();
1641:     repaint();
1642:   }
1643: 
1644: 
1645:   public ListSelectionModel getSelectionModel()
1646:   {
1647:     return selectionModel;
1648:   }
1649: 
1650:   /**
1651:    * Sets the value of the {@link #selectionModel} property. The list's
1652:    * {@link #listListener} is unsubscribed from the existing selection
1653:    * model, if it exists, and re-subscribed to the new selection model.
1654:    *
1655:    * @param model The new property value
1656:    */
1657:   public void setSelectionModel(ListSelectionModel model)
1658:   {
1659:     if (selectionModel == model)
1660:       return;
1661:     
1662:     if (selectionModel != null)
1663:       selectionModel.removeListSelectionListener(listListener);
1664:     
1665:     ListSelectionModel old = selectionModel;
1666:     selectionModel = model;
1667:     
1668:     if (selectionModel != null)
1669:       selectionModel.addListSelectionListener(listListener);
1670:     
1671:     firePropertyChange("selectionModel", old, model);
1672:     revalidate();
1673:     repaint();
1674:   }
1675: 
1676:   /**
1677:    * Gets the value of the UI property.
1678:    *
1679:    * @return The current property value
1680:    */
1681:   public ListUI getUI()
1682:   {
1683:     return (ListUI) ui;
1684:   }
1685: 
1686:   /**
1687:    * Sets the value of the UI property.
1688:    *
1689:    * @param ui The new property value
1690:    */
1691:   public void setUI(ListUI ui)
1692:   {
1693:     super.setUI(ui);
1694:   }
1695: 
1696:   /**
1697:    * Calls {@link #setUI} with the {@link ListUI} subclass
1698:    * returned from calling {@link UIManager#getUI}.
1699:    */
1700:   public void updateUI()
1701:   {
1702:     setUI((ListUI) UIManager.getUI(this));
1703:   }
1704: 
1705:   /**
1706:    * Return the class identifier for the list's UI property.  This should
1707:    * be the constant string <code>"ListUI"</code>, and map to an
1708:    * appropriate UI class in the {@link UIManager}.
1709:    *
1710:    * @return The class identifier
1711:    */
1712:   public String getUIClassID()
1713:   {
1714:     return "ListUI";
1715:   }
1716: 
1717: 
1718:   /**
1719:    * Returns the current value of the {@link #prototypeCellValue}
1720:    * property. This property holds a reference to a "prototype" data value
1721:    * -- typically a String -- which is used to calculate the {@link
1722:    * #fixedCellWidth} and {@link #fixedCellHeight} properties, using the
1723:    * {@link #cellRenderer} property to acquire a component to render the
1724:    * prototype.
1725:    *
1726:    * @return The current prototype cell value
1727:    * @see #setPrototypeCellValue
1728:    */
1729:   public Object getPrototypeCellValue()
1730:   {
1731:     return prototypeCellValue;
1732:   }
1733: 
1734:   /**
1735:    * <p>Set the {@link #prototypeCellValue} property. This property holds a
1736:    * reference to a "prototype" data value -- typically a String -- which
1737:    * is used to calculate the {@link #fixedCellWidth} and {@link
1738:    * #fixedCellHeight} properties, using the {@link #cellRenderer} property
1739:    * to acquire a component to render the prototype.</p>
1740:    *
1741:    * <p>It is important that you <em>not</em> set this value to a
1742:    * component. It has to be a <em>data value</em> such as the objects you
1743:    * would find in the list's model. Setting it to a component will have
1744:    * undefined (and undesirable) affects. </p>
1745:    *
1746:    * @param obj The new prototype cell value
1747:    * @see #getPrototypeCellValue
1748:    */
1749:   public void setPrototypeCellValue(Object obj)
1750:   {
1751:     if (prototypeCellValue == obj)
1752:       return;
1753: 
1754:     Object old = prototypeCellValue;
1755:     Component comp = getCellRenderer()
1756:       .getListCellRendererComponent(this, obj, 0, false, false); 
1757:     Dimension d = comp.getPreferredSize();
1758:     fixedCellWidth = d.width;
1759:     fixedCellHeight = d.height;
1760:     prototypeCellValue = obj;
1761:     firePropertyChange("prototypeCellValue", old, obj);
1762:   }
1763: 
1764:   public AccessibleContext getAccessibleContext()
1765:   {
1766:     return new AccessibleJList();
1767:   }
1768: 
1769:   /**
1770:    * Returns a size indicating how much space this list would like to
1771:    * consume, when contained in a scrollable viewport. This is part of the
1772:    * {@link Scrollable} interface, which interacts with {@link
1773:    * ScrollPaneLayout} and {@link JViewport} to define scrollable objects.
1774:    *
1775:    * @return The preferred size
1776:    */
1777:   public Dimension getPreferredScrollableViewportSize()
1778:   {
1779:     //If the layout orientation is not VERTICAL, then this will 
1780:     //return the value from getPreferredSize. The current ListUI is 
1781:     //expected to override getPreferredSize to return an appropriate value.
1782:     if (getLayoutOrientation() != VERTICAL)
1783:       return getPreferredSize();        
1784: 
1785:     int size = getModel().getSize();
1786:     
1787:     // Trivial case: if fixedCellWidth and fixedCellHeight were set 
1788:     // just use them
1789:     if (fixedCellHeight != -1 && fixedCellWidth != -1)
1790:       return new Dimension(fixedCellWidth, size * fixedCellHeight);
1791:         
1792:     // If the model is empty we use 16 * the number of visible rows
1793:     // for the height and either fixedCellWidth (if set) or 256
1794:     // for the width
1795:     if (size == 0)
1796:       {
1797:         if (fixedCellWidth == -1)
1798:           return new Dimension(256, 16 * getVisibleRowCount());
1799:         else
1800:           return new Dimension(fixedCellWidth, 16 * getVisibleRowCount());
1801:       }
1802: 
1803:     // Calculate the width: if fixedCellWidth was set use that, otherwise
1804:     // use the preferredWidth
1805:     int prefWidth;
1806:     if (fixedCellWidth != -1)
1807:       prefWidth = fixedCellWidth;
1808:     else
1809:       prefWidth = getPreferredSize().width;
1810: 
1811:     // Calculate the height: if fixedCellHeight was set use that, otherwise
1812:     // use the height of the first row multiplied by the number of visible
1813:     // rows
1814:     int prefHeight;
1815:     if (fixedCellHeight != -1)
1816:       prefHeight = fixedCellHeight;
1817:     else
1818:       prefHeight = getVisibleRowCount() * getCellBounds(0, 0).height;
1819: 
1820:     return new Dimension (prefWidth, prefHeight);
1821:   }
1822: 
1823:   /**
1824:    * <p>Return the number of pixels the list must scroll in order to move a
1825:    * "unit" of the list into the provided visible rectangle. When the
1826:    * provided direction is positive, the call describes a "downwards"
1827:    * scroll, which will be exposing a cell at a <em>greater</em> index in
1828:    * the list than those elements currently showing. Then the provided
1829:    * direction is negative, the call describes an "upwards" scroll, which
1830:    * will be exposing a cell at a <em>lesser</em> index in the list than
1831:    * those elements currently showing.</p>
1832:    *
1833:    * <p>If the provided orientation is <code>HORIZONTAL</code>, the above
1834:    * comments refer to "rightwards" for positive direction, and "leftwards"
1835:    * for negative.</p>
1836:    * 
1837:    *
1838:    * @param visibleRect The rectangle to scroll an element into
1839:    * @param orientation One of the numeric consants <code>VERTICAL</code>
1840:    * or <code>HORIZONTAL</code>
1841:    * @param direction An integer indicating the scroll direction: positive means
1842:    * forwards (down, right), negative means backwards (up, left)
1843:    *
1844:    * @return The scrollable unit increment, in pixels
1845:    */
1846:   public int getScrollableUnitIncrement(Rectangle visibleRect,
1847:                                         int orientation, int direction)
1848:   {
1849:     ListUI lui = this.getUI();
1850:     if (orientation == SwingConstants.VERTICAL)
1851:       {
1852:         if (direction > 0)
1853:           {
1854:             // Scrolling down
1855:             Point bottomLeft = new Point(visibleRect.x,
1856:                                          visibleRect.y + visibleRect.height);
1857:             int curIdx = lui.locationToIndex(this, bottomLeft);
1858:             Rectangle curBounds = lui.getCellBounds(this, curIdx, curIdx);
1859:             if (curBounds.y + curBounds.height == bottomLeft.y)
1860:               {
1861:                 // we are at the exact bottom of the current cell, so we 
1862:                 // are being asked to scroll to the end of the next one
1863:                 if (curIdx + 1 < model.getSize())
1864:                   {
1865:                     // there *is* a next item in the list
1866:                     Rectangle nxtBounds = lui.getCellBounds(this, curIdx + 1, curIdx + 1);
1867:                     return nxtBounds.height;
1868:                   }
1869:                 else
1870:                   {
1871:                     // no next item, no advance possible
1872:                     return 0;
1873:                   }
1874:               }
1875:             else
1876:               {
1877:                 // we are part way through an existing cell, so we are being
1878:                 // asked to scroll to the bottom of it
1879:                 return (curBounds.y + curBounds.height) - bottomLeft.y;
1880:               }              
1881:           }
1882:         else
1883:           {
1884:             // scrolling up
1885:             Point topLeft = new Point(visibleRect.x, visibleRect.y);
1886:             int curIdx = lui.locationToIndex(this, topLeft);
1887:             Rectangle curBounds = lui.getCellBounds(this, curIdx, curIdx);
1888:             if (curBounds.y == topLeft.y)
1889:               {
1890:                 // we are at the exact top of the current cell, so we 
1891:                 // are being asked to scroll to the top of the previous one
1892:                 if (curIdx > 0)
1893:                   {
1894:                     // there *is* a previous item in the list
1895:                     Rectangle nxtBounds = lui.getCellBounds(this, curIdx - 1, curIdx - 1);
1896:                     return -nxtBounds.height;
1897:                   }
1898:                 else
1899:                   {
1900:                     // no previous item, no advance possible
1901:                     return 0;
1902:                   }
1903:               }
1904:             else
1905:               {
1906:                 // we are part way through an existing cell, so we are being
1907:                 // asked to scroll to the top of it
1908:                 return curBounds.y - topLeft.y;
1909:               }              
1910:           }
1911:       }
1912: 
1913:     // FIXME: handle horizontal scrolling (also wrapping?)
1914:     return 1;
1915:   }
1916: 
1917:   /**
1918:    * <p>Return the number of pixels the list must scroll in order to move a
1919:    * "block" of the list into the provided visible rectangle. When the
1920:    * provided direction is positive, the call describes a "downwards"
1921:    * scroll, which will be exposing a cell at a <em>greater</em> index in
1922:    * the list than those elements currently showing. Then the provided
1923:    * direction is negative, the call describes an "upwards" scroll, which
1924:    * will be exposing a cell at a <em>lesser</em> index in the list than
1925:    * those elements currently showing.</p>
1926:    *
1927:    * <p>If the provided orientation is <code>HORIZONTAL</code>, the above
1928:    * comments refer to "rightwards" for positive direction, and "leftwards"
1929:    * for negative.</p>
1930:    * 
1931:    *
1932:    * @param visibleRect The rectangle to scroll an element into
1933:    * @param orientation One of the numeric consants <code>VERTICAL</code>
1934:    * or <code>HORIZONTAL</code>
1935:    * @param direction An integer indicating the scroll direction: positive means
1936:    * forwards (down, right), negative means backwards (up, left)
1937:    *
1938:    * @return The scrollable unit increment, in pixels
1939:    */
1940:   public int getScrollableBlockIncrement(Rectangle visibleRect,
1941:                                          int orientation, int direction)
1942:   {
1943:       if (orientation == VERTICAL)
1944:       return visibleRect.height * direction;
1945:       else
1946:       return visibleRect.width * direction;
1947:   }
1948: 
1949:   /**
1950:    * Gets the value of the <code>scrollableTracksViewportWidth</code> property.
1951:    *
1952:    * @return <code>true</code> if the viewport is larger (horizontally)
1953:    * than the list and the list should be expanded to fit the viewport;
1954:    * <code>false</code> if the viewport is smaller than the list and the
1955:    * list should scroll (horizontally) within the viewport
1956:    */
1957:   public boolean getScrollableTracksViewportWidth()
1958:   {
1959:     Component parent = getParent();
1960:     boolean retVal = false;
1961:     if (parent instanceof JViewport)
1962:       {
1963:         JViewport viewport = (JViewport) parent;
1964:         Dimension pref = getPreferredSize();
1965:         if (viewport.getSize().width > pref.width)
1966:           retVal = true;
1967:         if ((getLayoutOrientation() == HORIZONTAL_WRAP)
1968:             && (getVisibleRowCount() <= 0))
1969:           retVal = true;
1970:       }
1971:     return retVal;
1972:   }
1973: 
1974:   /**
1975:    * Gets the value of the </code>scrollableTracksViewportWidth</code> property.
1976:    *
1977:    * @return <code>true</code> if the viewport is larger (vertically)
1978:    * than the list and the list should be expanded to fit the viewport;
1979:    * <code>false</code> if the viewport is smaller than the list and the
1980:    * list should scroll (vertically) within the viewport
1981:    */
1982:   public boolean getScrollableTracksViewportHeight()
1983:   {
1984:     Component parent = getParent();
1985:     boolean retVal = false;
1986:     if (parent instanceof JViewport)
1987:       {
1988:         JViewport viewport = (JViewport) parent;
1989:         Dimension pref = getPreferredSize();
1990:         if (viewport.getSize().height > pref.height)
1991:           retVal = true;
1992:         if ((getLayoutOrientation() == VERTICAL_WRAP)
1993:             && (getVisibleRowCount() <= 0))
1994:           retVal = true;
1995:       }
1996:     return retVal;
1997:   }
1998: 
1999:   public int getAnchorSelectionIndex()
2000:   {
2001:     return selectionModel.getAnchorSelectionIndex();
2002:   }
2003: 
2004:   public int getLeadSelectionIndex()
2005:   {
2006:     return selectionModel.getLeadSelectionIndex();
2007:   }
2008: 
2009:   public int getMinSelectionIndex()
2010:   {
2011:     return selectionModel.getMaxSelectionIndex();
2012:   }
2013: 
2014:   public int getMaxSelectionIndex()
2015:   {
2016:     return selectionModel.getMaxSelectionIndex();
2017:   }
2018: 
2019:   public void clearSelection()
2020:   {
2021:     selectionModel.clearSelection();
2022:   }
2023: 
2024:   public void setSelectionInterval(int anchor, int lead)
2025:   {
2026:     selectionModel.setSelectionInterval(anchor, lead);
2027:   }
2028: 
2029:   public void addSelectionInterval(int anchor, int lead)
2030:   {
2031:     selectionModel.addSelectionInterval(anchor, lead);
2032:   }
2033: 
2034:   public void removeSelectionInterval(int index0, int index1)
2035:   {
2036:     selectionModel.removeSelectionInterval(index0, index1);
2037:   }
2038: 
2039:   /**
2040:    * Returns the value of the <code>valueIsAdjusting</code> property.
2041:    *
2042:    * @return the value
2043:    */
2044:   public boolean getValueIsAdjusting()
2045:   {
2046:     return valueIsAdjusting;
2047:   }
2048: 
2049:   /**
2050:    * Sets the <code>valueIsAdjusting</code> property.
2051:    *
2052:    * @param isAdjusting the new value
2053:    */
2054:   public void setValueIsAdjusting(boolean isAdjusting)
2055:   {
2056:     valueIsAdjusting = isAdjusting;
2057:   }
2058: 
2059:   /**
2060:    * Return the value of the <code>dragEnabled</code> property.
2061:    *
2062:    * @return the value
2063:    * 
2064:    * @since 1.4
2065:    */
2066:   public boolean getDragEnabled()
2067:   {
2068:     return dragEnabled;
2069:   }
2070: 
2071:   /**
2072:    * Set the <code>dragEnabled</code> property.
2073:    *
2074:    * @param enabled new value
2075:    * 
2076:    * @since 1.4
2077:    */
2078:   public void setDragEnabled(boolean enabled)
2079:   {
2080:     dragEnabled = enabled;
2081:   }
2082: 
2083:   /**
2084:    * Returns the layout orientation.
2085:    *
2086:    * @return the orientation, one of <code>JList.VERTICAL</code>,
2087:    * <code>JList.VERTICAL_WRAP</code> and <code>JList.HORIZONTAL_WRAP</code>
2088:    *
2089:    * @since 1.4
2090:    */
2091:   public int getLayoutOrientation()
2092:   {
2093:     return layoutOrientation;
2094:   }
2095: 
2096:   /**
2097:    * Sets the layout orientation.
2098:    *
2099:    * @param orientation the orientation to set, one of <code>JList.VERTICAL</code>,
2100:    * <code>JList.VERTICAL_WRAP</code> and <code>JList.HORIZONTAL_WRAP</code>
2101:    *
2102:    * @since 1.4
2103:    */
2104:   public void setLayoutOrientation(int orientation)
2105:   {
2106:     if (layoutOrientation == orientation)
2107:       return;
2108: 
2109:     int old = layoutOrientation;
2110:     layoutOrientation = orientation;
2111:     firePropertyChange("layoutOrientation", old, orientation);
2112:   }
2113: 
2114:   /**
2115:    * Returns the bounds of the rectangle that encloses both list cells
2116:    * with index0 and index1.
2117:    *
2118:    * @param index0 the index of the first cell
2119:    * @param index1 the index of the second cell
2120:    *
2121:    * @return  the bounds of the rectangle that encloses both list cells
2122:    *     with index0 and index1, <code>null</code> if one of the indices is
2123:    *     not valid
2124:    */
2125:   public Rectangle getCellBounds(int index0, int index1)
2126:   {
2127:     return getUI().getCellBounds(this, index0, index1);
2128:   }
2129: 
2130:   /**
2131:    * Returns the next list element (beginning from <code>startIndex</code>
2132:    * that starts with <code>prefix</code>. Searching is done in the direction
2133:    * specified by <code>bias</code>.
2134:    *
2135:    * @param prefix the prefix to search for in the cell values
2136:    * @param startIndex the index where to start searching from
2137:    * @param bias the search direction, either {@link Position.Bias#Forward}
2138:    *     or {@link Position.Bias#Backward}
2139:    *
2140:    * @return the index of the found element or -1 if no such element has
2141:    *     been found
2142:    *
2143:    * @throws IllegalArgumentException if prefix is <code>null</code> or
2144:    *     startIndex is not valid
2145:    *
2146:    * @since 1.4
2147:    */
2148:   public int getNextMatch(String prefix, int startIndex, Position.Bias bias)
2149:   {
2150:     if (prefix == null)
2151:       throw new IllegalArgumentException("The argument 'prefix' must not be"
2152:                                          + " null.");
2153:     if (startIndex < 0)
2154:       throw new IllegalArgumentException("The argument 'startIndex' must not"
2155:                                          + " be less than zero.");
2156: 
2157:     int size = model.getSize();
2158:     if (startIndex > model.getSize())
2159:       throw new IllegalArgumentException("The argument 'startIndex' must not"
2160:                                          + " be greater than the number of"
2161:                                          + " elements in the ListModel.");
2162: 
2163:     int index = -1;
2164:     if (bias == Position.Bias.Forward)
2165:       {
2166:         for (int i = startIndex; i < size; i++)
2167:           {
2168:             String item = model.getElementAt(i).toString();
2169:             if (item.startsWith(prefix))
2170:               {
2171:                 index = i;
2172:                 break;
2173:               }
2174:           }
2175:       }
2176:     else
2177:       {
2178:         for (int i = startIndex; i >= 0; i--)
2179:           {
2180:             String item = model.getElementAt(i).toString();
2181:             if (item.startsWith(prefix))
2182:               {
2183:                 index = i;
2184:                 break;
2185:               }
2186:           }
2187:       }
2188:     return index;
2189:   }
2190: }