Source for javax.swing.JList

   1: /* JList.java --
   2:    Copyright (C) 2002, 2003, 2004, 2005, 2006,  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:    * This property indicates a <em>preference</em> for the number of rows
 949:    * displayed in the list, and will scale the
 950:    * {@link #getPreferredScrollableViewportSize} property accordingly. The actual
 951:    * number of displayed rows, when the list is placed in a real {@link
 952:    * JViewport} or other component, may be greater or less than this number.
 953:    */
 954:   int visibleRowCount;
 955: 
 956:   /**
 957:    * Fire a {@link ListSelectionEvent} to all the registered 
 958:    * ListSelectionListeners.
 959:    * 
 960:    * @param firstIndex  the lowest index covering the selection change.
 961:    * @param lastIndex  the highest index covering the selection change.
 962:    * @param isAdjusting  a flag indicating if this event is one in a series
 963:    *     of events updating the selection.
 964:    */
 965:   protected void fireSelectionValueChanged(int firstIndex, int lastIndex, 
 966:                                            boolean isAdjusting) 
 967:   {
 968:     ListSelectionEvent evt = new ListSelectionEvent(this, firstIndex, 
 969:                                                     lastIndex, isAdjusting);
 970:     ListSelectionListener listeners[] = getListSelectionListeners();
 971:     for (int i = 0; i < listeners.length; ++i)
 972:       {
 973:         listeners[i].valueChanged(evt);
 974:       }
 975:   }
 976: 
 977:   /**
 978:    * This private listener propagates {@link ListSelectionEvent} events
 979:    * from the list's "selectionModel" property to the list's {@link
 980:    * ListSelectionListener} listeners. It also listens to {@link
 981:    * ListDataEvent} events from the list's {@link #model} property. If this
 982:    * class receives either type of event, it triggers repainting of the
 983:    * list.
 984:    */
 985:   private class ListListener 
 986:     implements ListSelectionListener, ListDataListener
 987:   {
 988:     // ListDataListener events
 989:     public void contentsChanged(ListDataEvent event)
 990:     {
 991:       JList.this.revalidate();
 992:       JList.this.repaint();
 993:     }
 994:     public void intervalAdded(ListDataEvent event)
 995:     {
 996:       JList.this.revalidate();
 997:       JList.this.repaint();
 998:     }
 999:     public void intervalRemoved(ListDataEvent event)
1000:     {
1001:       JList.this.revalidate();
1002:       JList.this.repaint();
1003:     }
1004:     // ListSelectionListener events
1005:     public void valueChanged(ListSelectionEvent event)
1006:     {
1007:       JList.this.fireSelectionValueChanged(event.getFirstIndex(),
1008:                                            event.getLastIndex(),
1009:                                            event.getValueIsAdjusting());
1010:       JList.this.repaint();
1011:     }
1012:   }
1013: 
1014:   /** 
1015:    * Shared ListListener instance, subscribed to both the current {@link
1016:    * #model} and {@link #selectionModel} properties of the list.
1017:    */
1018:   ListListener listListener;
1019: 
1020: 
1021:   /**
1022:    * Creates a new <code>JList</code> object.
1023:    */
1024:   public JList()
1025:   {
1026:     init(new DefaultListModel());
1027:   }
1028: 
1029:   /**
1030:    * Creates a new <code>JList</code> object.
1031:    *
1032:    * @param items  the initial list items.
1033:    */
1034:   public JList(Object[] items)
1035:   {
1036:     init(createListModel(items));
1037:   }
1038: 
1039:   /**
1040:    * Creates a new <code>JList</code> object.
1041:    *
1042:    * @param items  the initial list items.
1043:    */
1044:   public JList(Vector items)
1045:   {
1046:     init(createListModel(items));
1047:   }
1048: 
1049:   /**
1050:    * Creates a new <code>JList</code> object.
1051:    *
1052:    * @param model  a model containing the list items (<code>null</code> not
1053:    *     permitted).
1054:    *     
1055:    * @throws IllegalArgumentException if <code>model</code> is 
1056:    *     <code>null</code>.
1057:    */
1058:   public JList(ListModel model)
1059:   {
1060:     init(model);
1061:   }
1062: 
1063:   /**
1064:    * Initializes the list.
1065:    *
1066:    * @param m  the list model (<code>null</code> not permitted).
1067:    */
1068:   private void init(ListModel m)
1069:   {
1070:     if (m == null)
1071:       throw new IllegalArgumentException("Null model not permitted.");
1072:     dragEnabled = false;
1073:     fixedCellHeight = -1;
1074:     fixedCellWidth = -1;
1075:     layoutOrientation = VERTICAL;
1076:     opaque = true;
1077:     visibleRowCount = 8;
1078: 
1079:     cellRenderer = new DefaultListCellRenderer();
1080:     listListener = new ListListener();
1081: 
1082:     model = m;
1083:     if (model != null)
1084:       model.addListDataListener(listListener);
1085: 
1086:     selectionModel = createSelectionModel();
1087:     if (selectionModel != null)
1088:       {
1089:         selectionModel.addListSelectionListener(listListener);
1090:         selectionModel.setSelectionMode
1091:                               (ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
1092:       }
1093:     setLayout(null);
1094:     
1095:     updateUI();
1096:   }
1097: 
1098:   /**
1099:    * Creates the default <code>ListSelectionModel</code>.
1100:    *
1101:    * @return the <code>ListSelectionModel</code>
1102:    */
1103:   protected ListSelectionModel createSelectionModel()
1104:   {
1105:     return new DefaultListSelectionModel();
1106:   }
1107:   
1108:   /**
1109:    * Gets the value of the {@link #fixedCellHeight} property. This property
1110:    * may be <code>-1</code> to indicate that no cell height has been
1111:    * set. This property is also set implicitly when the
1112:    * {@link #prototypeCellValue} property is set.
1113:    *
1114:    * @return The current value of the property 
1115:    * 
1116:    * @see #fixedCellHeight
1117:    * @see #setFixedCellHeight
1118:    * @see #setPrototypeCellValue
1119:    */
1120:   public int getFixedCellHeight()
1121:   {
1122:     return fixedCellHeight;
1123:   }
1124: 
1125:   /**
1126:    * Sets the value of the {@link #fixedCellHeight} property. This property
1127:    * may be <code>-1</code> to indicate that no cell height has been
1128:    * set. This property is also set implicitly when the {@link
1129:    * #prototypeCellValue} property is set, but setting it explicitly
1130:    * overrides the height computed from {@link #prototypeCellValue}.
1131:    *
1132:    * @param h  the height.
1133:    * 
1134:    * @see #getFixedCellHeight
1135:    * @see #getPrototypeCellValue
1136:    */
1137:   public void setFixedCellHeight(int h)
1138:   {
1139:     if (fixedCellHeight == h)
1140:       return;
1141: 
1142:     int old = fixedCellHeight;
1143:     fixedCellHeight = h;
1144:     firePropertyChange("fixedCellHeight", old, h);
1145:   }
1146: 
1147: 
1148:   /**
1149:    * Gets 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.
1153:    *
1154:    * @return The current value of the property 
1155:    * 
1156:    * @see #setFixedCellWidth
1157:    * @see #setPrototypeCellValue
1158:    */
1159:   public int getFixedCellWidth()
1160:   {
1161:     return fixedCellWidth;
1162:   }
1163: 
1164:   /**
1165:    * Sets the value of the {@link #fixedCellWidth} property. This property
1166:    * may be <code>-1</code> to indicate that no cell width has been
1167:    * set. This property is also set implicitly when the {@link
1168:    * #prototypeCellValue} property is set, but setting it explicitly
1169:    * overrides the width computed from {@link #prototypeCellValue}.
1170:    *
1171:    * @param w  the width.
1172:    * 
1173:    * @see #getFixedCellHeight
1174:    * @see #getPrototypeCellValue
1175:    */
1176:   public void setFixedCellWidth(int w)
1177:   {
1178:     if (fixedCellWidth == w)
1179:       return;
1180:     
1181:     int old = fixedCellWidth;
1182:     fixedCellWidth = w;
1183:     firePropertyChange("fixedCellWidth", old, w);
1184:   }
1185: 
1186:   /** 
1187:    * Gets the value of the {@link #visibleRowCount} property.  The default 
1188:    * value is 8.
1189:    *
1190:    * @return the current value of the property.
1191:    * 
1192:    * @see #setVisibleRowCount(int)
1193:    */
1194:   public int getVisibleRowCount()
1195:   {
1196:     return visibleRowCount;
1197:   }
1198: 
1199:   /**
1200:    * Sets the value of the {@link #visibleRowCount} property. 
1201:    *
1202:    * @param vc The new property value
1203:    * 
1204:    * @see #getVisibleRowCount()
1205:    */
1206:   public void setVisibleRowCount(int vc)
1207:   {
1208:     if (visibleRowCount != vc)
1209:       {
1210:         int oldValue = visibleRowCount;
1211:         visibleRowCount = Math.max(vc, 0);
1212:         firePropertyChange("visibleRowCount", oldValue, vc);
1213:         revalidate();
1214:         repaint();
1215:       }
1216:   }
1217: 
1218:   /**
1219:    * Adds a {@link ListSelectionListener} to the listener list for this
1220:    * list. The listener will be called back with a {@link
1221:    * ListSelectionEvent} any time the list's {@link #selectionModel}
1222:    * property changes. The source of such events will be the JList,
1223:    * not the selection model.
1224:    *
1225:    * @param listener The new listener to add
1226:    */
1227:   public void addListSelectionListener(ListSelectionListener listener)
1228:   {
1229:     listenerList.add (ListSelectionListener.class, listener);
1230:   }
1231: 
1232:   /**
1233:    * Removes a {@link ListSelectionListener} from the listener list for
1234:    * this list. The listener will no longer be called when the list's
1235:    * {@link #selectionModel} changes.
1236:    *
1237:    * @param listener The listener to remove
1238:    */
1239:   public void removeListSelectionListener(ListSelectionListener listener)
1240:   {
1241:     listenerList.remove(ListSelectionListener.class, listener);
1242:   }
1243: 
1244:   /**
1245:    * Returns an array of all ListSelectionListeners subscribed to this
1246:    * list. 
1247:    *
1248:    * @return The current subscribed listeners
1249:    *
1250:    * @since 1.4
1251:    */
1252:   public ListSelectionListener[] getListSelectionListeners()
1253:   {
1254:     return (ListSelectionListener[]) getListeners(ListSelectionListener.class);
1255:   }
1256: 
1257:   /**
1258:    * Returns the selection mode for the list (one of: 
1259:    * {@link ListSelectionModel#SINGLE_SELECTION}, 
1260:    * {@link ListSelectionModel#SINGLE_INTERVAL_SELECTION} and 
1261:    * {@link ListSelectionModel#MULTIPLE_INTERVAL_SELECTION}).
1262:    * 
1263:    * @return The selection mode.
1264:    * 
1265:    * @see #setSelectionMode(int)
1266:    */
1267:   public int getSelectionMode()
1268:   {
1269:     return selectionModel.getSelectionMode();
1270:   }
1271:   
1272:   /**
1273:    * Sets the list's "selectionMode" property, which simply mirrors the
1274:    * same property on the list's {@link #selectionModel} property. This
1275:    * property should be one of the integer constants
1276:    * <code>SINGLE_SELECTION</code>, <code>SINGLE_INTERVAL_SELECTION</code>,
1277:    * or <code>MULTIPLE_INTERVAL_SELECTION</code> from the {@link
1278:    * ListSelectionModel} interface.
1279:    *
1280:    * @param a The new selection mode
1281:    */
1282:   public void setSelectionMode(int a)
1283:   {
1284:     selectionModel.setSelectionMode(a);
1285:   }
1286: 
1287:   /**
1288:    * Adds the interval <code>[a,a]</code> to the set of selections managed
1289:    * by this list's {@link #selectionModel} property. Depending on the
1290:    * selection mode, this may cause existing selections to become invalid,
1291:    * or may simply expand the set of selections. 
1292:    *
1293:    * @param a A number in the half-open range <code>[0, x)</code> where
1294:    * <code>x = getModel.getSize()</code>, indicating the index of an
1295:    * element in the list to select. When &lt; 0 the selection is cleared.
1296:    *
1297:    * @see #setSelectionMode
1298:    * @see #selectionModel
1299:    */
1300:   public void setSelectedIndex(int a)
1301:   {
1302:     if (a < 0)
1303:       selectionModel.clearSelection();
1304:     else
1305:       selectionModel.setSelectionInterval(a, a);
1306:   }
1307: 
1308:   /**
1309:    * For each element <code>a[i]</code> of the provided array
1310:    * <code>a</code>, calls {@link #setSelectedIndex} on <code>a[i]</code>.
1311:    *
1312:    * @param a  an array of selected indices (<code>null</code> not permitted).
1313:    * 
1314:    * @throws NullPointerException if <code>a</code> is <code>null</code>.
1315:    * @see #setSelectionMode
1316:    * @see #selectionModel
1317:    */
1318:   public void setSelectedIndices(int [] a)
1319:   {
1320:     for (int i = 0; i < a.length; ++i)
1321:       setSelectedIndex(a[i]);
1322:   }
1323: 
1324:   /**
1325:    * Returns the minimum index of an element in the list which is currently
1326:    * selected.
1327:    *
1328:    * @return A number in the half-open range <code>[0, x)</code> where
1329:    * <code>x = getModel.getSize()</code>, indicating the minimum index of
1330:    * an element in the list for which the element is selected, or
1331:    * <code>-1</code> if no elements are selected
1332:    */
1333:   public int getSelectedIndex()
1334:   {
1335:     return selectionModel.getMinSelectionIndex();
1336:   }
1337: 
1338:   /**
1339:    * Returns <code>true</code> if the model's selection is empty, otherwise
1340:    * <code>false</code>. 
1341:    *
1342:    * @return The return value of {@link ListSelectionModel#isSelectionEmpty}
1343:    */
1344:   public boolean isSelectionEmpty()
1345:   {
1346:     return selectionModel.isSelectionEmpty();
1347:   }
1348: 
1349:   /**
1350:    * Returns the list index of the upper left or upper right corner of the
1351:    * visible rectangle of this list, depending on the {@link
1352:    * Component#getComponentOrientation} property.
1353:    *
1354:    * @return The index of the first visible list cell, or <code>-1</code>
1355:    * if none is visible.
1356:    */
1357:   public int getFirstVisibleIndex()
1358:   {
1359:     ComponentOrientation or = getComponentOrientation();
1360:     Rectangle r = getVisibleRect();
1361:     if (or == ComponentOrientation.RIGHT_TO_LEFT)
1362:       r.translate((int) r.getWidth() - 1, 0);
1363:     return getUI().locationToIndex(this, r.getLocation());      
1364:   }
1365: 
1366: 
1367:   /**
1368:    * Returns index of the cell to which specified location is closest to. If
1369:    * the location is outside the bounds of the list, then the greatest index
1370:    * in the list model is returned. If the list model is empty, then
1371:    * <code>-1</code> is returned.
1372:    *
1373:    * @param location for which to look for in the list
1374:    * 
1375:    * @return index of the cell to which specified location is closest to.
1376:    */
1377:    public int locationToIndex(Point location)
1378:    {
1379:      return getUI().locationToIndex(this, location);      
1380:    }
1381: 
1382:   /**
1383:    * Returns location of the cell located at the specified index in the list.
1384:    * @param index of the cell for which location will be determined
1385:    * 
1386:    * @return location of the cell located at the specified index in the list.
1387:    */
1388:    public Point indexToLocation(int index)
1389:    {
1390:      return getUI().indexToLocation(this, index);
1391:    }
1392: 
1393:   /**
1394:    * Returns the list index of the lower right or lower left corner of the
1395:    * visible rectangle of this list, depending on the {@link
1396:    * Component#getComponentOrientation} property.
1397:    *
1398:    * @return The index of the last visible list cell, or <code>-1</code>
1399:    * if none is visible.
1400:    */
1401:   public int getLastVisibleIndex()
1402:   {
1403:     ComponentOrientation or = getComponentOrientation();
1404:     Rectangle r = getVisibleRect();
1405:     r.translate(0, (int) r.getHeight() - 1);
1406:     if (or == ComponentOrientation.LEFT_TO_RIGHT)
1407:       r.translate((int) r.getWidth() - 1, 0);
1408:     if (getUI().locationToIndex(this, r.getLocation()) == -1
1409:         && indexToLocation(getModel().getSize() - 1).y < r.y)
1410:       return getModel().getSize() - 1;
1411:     return getUI().locationToIndex(this, r.getLocation());
1412:   }
1413: 
1414:   /**
1415:    * Returns the indices of values in the {@link #model} property which are
1416:    * selected.
1417:    *
1418:    * @return An array of model indices, each of which is selected according
1419:    *         to the {@link #getSelectedValues} property
1420:    */
1421:   public int[] getSelectedIndices()
1422:   {
1423:     int lo, hi, n, i, j;
1424:     if (selectionModel.isSelectionEmpty())
1425:       return new int[0];
1426:     lo = selectionModel.getMinSelectionIndex();
1427:     hi = selectionModel.getMaxSelectionIndex();
1428:     n = 0;
1429:     for (i = lo; i <= hi; ++i)
1430:       if (selectionModel.isSelectedIndex(i))
1431:         n++;
1432:     int [] v = new int[n];
1433:     j = 0;
1434:     for (i = lo; i <= hi; ++i)
1435:       if (selectionModel.isSelectedIndex(i))
1436:         v[j++] = i;
1437:     return v;
1438:   }
1439: 
1440:   /**
1441:    * Indicates whether the list element at a given index value is
1442:    * currently selected.
1443:    *
1444:    * @param a The index to check 
1445:    * @return <code>true</code> if <code>a</code> is the index of a selected
1446:    * list element
1447:    */
1448:   public boolean isSelectedIndex(int a)
1449:   {
1450:     return selectionModel.isSelectedIndex(a);
1451:   }
1452: 
1453:   /**
1454:    * Returns the first value in the list's {@link #model} property which is
1455:    * selected, according to the list's {@link #selectionModel} property.
1456:    * This is equivalent to calling
1457:    * <code>getModel()getElementAt(getSelectedIndex())</code>, with a check
1458:    * for the special index value of <code>-1</code> which returns null
1459:    * <code>null</code>.
1460:    *
1461:    * @return The first selected element, or <code>null</code> if no element
1462:    * is selected.
1463:    *
1464:    * @see #getSelectedValues
1465:    */
1466:   public Object getSelectedValue()
1467:   {
1468:     int index = getSelectedIndex();
1469:     if (index == -1)
1470:       return null;
1471:     return getModel().getElementAt(index);
1472:   }
1473: 
1474:   /**
1475:    * Returns all the values in the list's {@link #model} property which are
1476:    * selected, according to the list's {@link #selectionModel} property.
1477:    * 
1478:    * @return An array containing all the selected values
1479:    * @see #setSelectedValue
1480:    */
1481:   public Object[] getSelectedValues()
1482:   {
1483:     int[] idx = getSelectedIndices();
1484:     Object[] v = new Object[idx.length];
1485:     for (int i = 0; i < idx.length; ++i)
1486:       v[i] = getModel().getElementAt(idx[i]);
1487:     return v;
1488:   }
1489: 
1490:   /**
1491:    * Gets the value of the {@link #selectionBackground} property.
1492:    *
1493:    * @return The current value of the property
1494:    */
1495:   public Color getSelectionBackground()
1496:   {
1497:     return selectionBackground;
1498:   }
1499: 
1500:   /**
1501:    * Sets the value of the {@link #selectionBackground} property.
1502:    *
1503:    * @param c The new value of the property
1504:    */
1505:   public void setSelectionBackground(Color c)
1506:   {
1507:     if (selectionBackground == c)
1508:       return;
1509: 
1510:     Color old = selectionBackground;
1511:     selectionBackground = c;
1512:     firePropertyChange("selectionBackground", old, c);
1513:     repaint();
1514:   }
1515: 
1516:   /**
1517:    * Gets the value of the {@link #selectionForeground} property.
1518:    *
1519:    * @return The current value of the property
1520:    */
1521:   public Color getSelectionForeground()
1522:   {
1523:     return selectionForeground;
1524:   }
1525:   
1526:   /**
1527:    * Sets the value of the {@link #selectionForeground} property.
1528:    *
1529:    * @param c The new value of the property
1530:    */
1531:   public void setSelectionForeground(Color c)
1532:   {
1533:     if (selectionForeground == c)
1534:       return;
1535: 
1536:     Color old = selectionForeground;
1537:     selectionForeground = c;
1538:     firePropertyChange("selectionForeground", old, c);
1539:   }
1540: 
1541:   /**
1542:    * Sets the selection to cover only the specified value, if it
1543:    * exists in the model. 
1544:    *
1545:    * @param obj The object to select
1546:    * @param scroll Whether to scroll the list to make the newly selected
1547:    * value visible
1548:    *
1549:    * @see #ensureIndexIsVisible
1550:    */
1551: 
1552:   public void setSelectedValue(Object obj, boolean scroll)
1553:   {
1554:     for (int i = 0; i < model.getSize(); ++i)
1555:       {
1556:         if (model.getElementAt(i).equals(obj))
1557:           {
1558:             setSelectedIndex(i);
1559:             if (scroll)
1560:               ensureIndexIsVisible(i);
1561:             break;
1562:           }
1563:       }
1564:   }
1565: 
1566:   /**
1567:    * Scrolls this list to make the specified cell visible. This
1568:    * only works if the list is contained within a viewport.
1569:    *
1570:    * @param i The list index to make visible
1571:    *
1572:    * @see JComponent#scrollRectToVisible
1573:    */
1574:   public void ensureIndexIsVisible(int i)
1575:   {
1576:     Rectangle r = getUI().getCellBounds(this, i, i);
1577:     if (r != null)
1578:       scrollRectToVisible(r);
1579:   }
1580: 
1581:   /**
1582:    * Sets the {@link #model} property of the list to a new anonymous
1583:    * {@link AbstractListModel} subclass which accesses the provided Object
1584:    * array directly.
1585:    *
1586:    * @param listData The object array to build a new list model on
1587:    * @see #setModel
1588:    */
1589:   public void setListData(Object[] listData)
1590:   {
1591:     setModel(createListModel(listData));
1592:   }
1593: 
1594:   /**
1595:    * Returns a {@link ListModel} backed by the specified array.
1596:    * 
1597:    * @param items  the list items (don't use <code>null</code>).
1598:    * 
1599:    * @return A list model containing the specified items.
1600:    */
1601:   private ListModel createListModel(final Object[] items)
1602:   {
1603:     return new AbstractListModel()
1604:       {
1605:         public int getSize()
1606:         {
1607:           return items.length;
1608:         }
1609:         public Object getElementAt(int i)
1610:         {
1611:           return items[i];
1612:         }
1613:       };
1614:   }
1615:   
1616:   /**
1617:    * Returns a {@link ListModel} backed by the specified vector.
1618:    * 
1619:    * @param items  the list items (don't use <code>null</code>).
1620:    * 
1621:    * @return A list model containing the specified items.
1622:    */
1623:   private ListModel createListModel(final Vector items)
1624:   {
1625:     return new AbstractListModel()
1626:       {
1627:         public int getSize()
1628:         {
1629:           return items.size();
1630:         }
1631:         public Object getElementAt(int i)
1632:         {
1633:           return items.get(i);
1634:         }
1635:       };
1636:   }
1637: 
1638:   /**
1639:    * Sets the {@link #model} property of the list to a new anonymous {@link
1640:    * AbstractListModel} subclass which accesses the provided vector
1641:    * directly.
1642:    *
1643:    * @param listData The object array to build a new list model on
1644:    * @see #setModel
1645:    */
1646:   public void setListData(Vector listData)
1647:   {
1648:     setModel(createListModel(listData));
1649:   }
1650: 
1651:   /**
1652:    * Gets the value of the {@link #cellRenderer} property. 
1653:    *
1654:    * @return The current value of the property
1655:    */
1656:   public ListCellRenderer getCellRenderer()
1657:   {
1658:     return cellRenderer;
1659:   }
1660: 
1661:   /**
1662:    * Sets the value of the {@link #getCellRenderer} property.
1663:    *
1664:    * @param renderer The new property value
1665:    */
1666:   public void setCellRenderer(ListCellRenderer renderer)
1667:   {
1668:     if (cellRenderer == renderer)
1669:       return;
1670:     
1671:     ListCellRenderer old = cellRenderer;
1672:     cellRenderer = renderer;
1673:     firePropertyChange("cellRenderer", old, renderer);
1674:     revalidate();
1675:     repaint();
1676:   }
1677: 
1678:   /**
1679:    * Gets the value of the {@link #model} property. 
1680:    *
1681:    * @return The current value of the property
1682:    */
1683:   public ListModel getModel()
1684:   {
1685:     return model;
1686:   }
1687: 
1688:   /**
1689:    * Sets the value of the {@link #model} property. The list's {@link
1690:    * #listListener} is unsubscribed from the existing model, if it exists,
1691:    * and re-subscribed to the new model.
1692:    *
1693:    * @param model  the new model (<code>null</code> not permitted).
1694:    * 
1695:    * @throws IllegalArgumentException if <code>model</code> is 
1696:    *         <code>null</code>.
1697:    */
1698:   public void setModel(ListModel model)
1699:   {
1700:     if (model == null) 
1701:       throw new IllegalArgumentException("Null 'model' argument.");
1702:     if (this.model == model)
1703:       return;
1704:     
1705:     if (this.model != null)
1706:       this.model.removeListDataListener(listListener);
1707:     
1708:     ListModel old = this.model;
1709:     this.model = model;
1710:     
1711:     if (this.model != null)
1712:       this.model.addListDataListener(listListener);
1713:     
1714:     firePropertyChange("model", old, model);
1715:     revalidate();
1716:     repaint();
1717:   }
1718: 
1719:   /**
1720:    * Returns the selection model for the {@link JList} component.  Note that
1721:    * this class contains a range of convenience methods for configuring the
1722:    * selection model:<br>
1723:    * <ul>
1724:    *   <li>{@link #clearSelection()};</li>
1725:    *   <li>{@link #setSelectionMode(int)};</li>
1726:    *   <li>{@link #addSelectionInterval(int, int)};</li>
1727:    *   <li>{@link #setSelectedIndex(int)};</li>
1728:    *   <li>{@link #setSelectedIndices(int[])};</li>
1729:    *   <li>{@link #setSelectionInterval(int, int)}.</li>
1730:    * </ul>
1731:    * 
1732:    * @return The selection model.
1733:    */
1734:   public ListSelectionModel getSelectionModel()
1735:   {
1736:     return selectionModel;
1737:   }
1738: 
1739:   /**
1740:    * Sets the value of the {@link #selectionModel} property. The list's
1741:    * {@link #listListener} is unsubscribed from the existing selection
1742:    * model, if it exists, and re-subscribed to the new selection model.
1743:    *
1744:    * @param model The new property value
1745:    */
1746:   public void setSelectionModel(ListSelectionModel model)
1747:   {
1748:     if (selectionModel == model)
1749:       return;
1750:     
1751:     if (selectionModel != null)
1752:       selectionModel.removeListSelectionListener(listListener);
1753:     
1754:     ListSelectionModel old = selectionModel;
1755:     selectionModel = model;
1756:     
1757:     if (selectionModel != null)
1758:       selectionModel.addListSelectionListener(listListener);
1759:     
1760:     firePropertyChange("selectionModel", old, model);
1761:     revalidate();
1762:     repaint();
1763:   }
1764: 
1765:   /**
1766:    * Gets the value of the UI property.
1767:    *
1768:    * @return The current property value
1769:    */
1770:   public ListUI getUI()
1771:   {
1772:     return (ListUI) ui;
1773:   }
1774: 
1775:   /**
1776:    * Sets the value of the UI property.
1777:    *
1778:    * @param ui The new property value
1779:    */
1780:   public void setUI(ListUI ui)
1781:   {
1782:     super.setUI(ui);
1783:   }
1784: 
1785:   /**
1786:    * Calls {@link #setUI} with the {@link ListUI} subclass
1787:    * returned from calling {@link UIManager#getUI}.
1788:    */
1789:   public void updateUI()
1790:   {
1791:     setUI((ListUI) UIManager.getUI(this));
1792:   }
1793: 
1794:   /**
1795:    * Return the class identifier for the list's UI property.  This should
1796:    * be the constant string <code>"ListUI"</code>, and map to an
1797:    * appropriate UI class in the {@link UIManager}.
1798:    *
1799:    * @return The class identifier
1800:    */
1801:   public String getUIClassID()
1802:   {
1803:     return "ListUI";
1804:   }
1805: 
1806: 
1807:   /**
1808:    * Returns the current value of the {@link #prototypeCellValue}
1809:    * property. This property holds a reference to a "prototype" data value
1810:    * -- typically a String -- which is used to calculate the {@link
1811:    * #fixedCellWidth} and {@link #fixedCellHeight} properties, using the
1812:    * {@link #cellRenderer} property to acquire a component to render the
1813:    * prototype.
1814:    *
1815:    * @return The current prototype cell value
1816:    * @see #setPrototypeCellValue
1817:    */
1818:   public Object getPrototypeCellValue()
1819:   {
1820:     return prototypeCellValue;
1821:   }
1822: 
1823:   /**
1824:    * <p>Set the {@link #prototypeCellValue} property. This property holds a
1825:    * reference to a "prototype" data value -- typically a String -- which
1826:    * is used to calculate the {@link #fixedCellWidth} and {@link
1827:    * #fixedCellHeight} properties, using the {@link #cellRenderer} property
1828:    * to acquire a component to render the prototype.</p>
1829:    *
1830:    * <p>It is important that you <em>not</em> set this value to a
1831:    * component. It has to be a <em>data value</em> such as the objects you
1832:    * would find in the list's model. Setting it to a component will have
1833:    * undefined (and undesirable) affects. </p>
1834:    *
1835:    * @param obj The new prototype cell value
1836:    * @see #getPrototypeCellValue
1837:    */
1838:   public void setPrototypeCellValue(Object obj)
1839:   {
1840:     if (prototypeCellValue == obj)
1841:       return;
1842: 
1843:     Object old = prototypeCellValue;
1844:     Component comp = getCellRenderer()
1845:       .getListCellRendererComponent(this, obj, 0, false, false); 
1846:     Dimension d = comp.getPreferredSize();
1847:     fixedCellWidth = d.width;
1848:     fixedCellHeight = d.height;
1849:     prototypeCellValue = obj;
1850:     firePropertyChange("prototypeCellValue", old, obj);
1851:   }
1852: 
1853:   public AccessibleContext getAccessibleContext()
1854:   {
1855:     return new AccessibleJList();
1856:   }
1857: 
1858:   /**
1859:    * Returns a size indicating how much space this list would like to
1860:    * consume, when contained in a scrollable viewport. This is part of the
1861:    * {@link Scrollable} interface, which interacts with {@link
1862:    * ScrollPaneLayout} and {@link JViewport} to define scrollable objects.
1863:    *
1864:    * @return The preferred size
1865:    */
1866:   public Dimension getPreferredScrollableViewportSize()
1867:   {
1868:     //If the layout orientation is not VERTICAL, then this will 
1869:     //return the value from getPreferredSize. The current ListUI is 
1870:     //expected to override getPreferredSize to return an appropriate value.
1871:     if (getLayoutOrientation() != VERTICAL)
1872:       return getPreferredSize();        
1873: 
1874:     int size = getModel().getSize();
1875:     
1876:     // Trivial case: if fixedCellWidth and fixedCellHeight were set 
1877:     // just use them
1878:     if (fixedCellHeight != -1 && fixedCellWidth != -1)
1879:       return new Dimension(fixedCellWidth, size * fixedCellHeight);
1880:         
1881:     // If the model is empty we use 16 * the number of visible rows
1882:     // for the height and either fixedCellWidth (if set) or 256
1883:     // for the width
1884:     if (size == 0)
1885:       {
1886:         if (fixedCellWidth == -1)
1887:           return new Dimension(256, 16 * getVisibleRowCount());
1888:         else
1889:           return new Dimension(fixedCellWidth, 16 * getVisibleRowCount());
1890:       }
1891: 
1892:     // Calculate the width: if fixedCellWidth was set use that, otherwise
1893:     // use the preferredWidth
1894:     int prefWidth;
1895:     if (fixedCellWidth != -1)
1896:       prefWidth = fixedCellWidth;
1897:     else
1898:       prefWidth = getPreferredSize().width;
1899: 
1900:     // Calculate the height: if fixedCellHeight was set use that, otherwise
1901:     // use the height of the first row multiplied by the number of visible
1902:     // rows
1903:     int prefHeight;
1904:     if (fixedCellHeight != -1)
1905:       prefHeight = fixedCellHeight;
1906:     else
1907:       prefHeight = getVisibleRowCount() * getCellBounds(0, 0).height;
1908: 
1909:     return new Dimension (prefWidth, prefHeight);
1910:   }
1911: 
1912:   /**
1913:    * <p>Return the number of pixels the list must scroll in order to move a
1914:    * "unit" of the list into the provided visible rectangle. When the
1915:    * provided direction is positive, the call describes a "downwards"
1916:    * scroll, which will be exposing a cell at a <em>greater</em> index in
1917:    * the list than those elements currently showing. Then the provided
1918:    * direction is negative, the call describes an "upwards" scroll, which
1919:    * will be exposing a cell at a <em>lesser</em> index in the list than
1920:    * those elements currently showing.</p>
1921:    *
1922:    * <p>If the provided orientation is <code>HORIZONTAL</code>, the above
1923:    * comments refer to "rightwards" for positive direction, and "leftwards"
1924:    * for negative.</p>
1925:    * 
1926:    *
1927:    * @param visibleRect The rectangle to scroll an element into
1928:    * @param orientation One of the numeric consants <code>VERTICAL</code>
1929:    * or <code>HORIZONTAL</code>
1930:    * @param direction An integer indicating the scroll direction: positive means
1931:    * forwards (down, right), negative means backwards (up, left)
1932:    *
1933:    * @return The scrollable unit increment, in pixels
1934:    */
1935:   public int getScrollableUnitIncrement(Rectangle visibleRect,
1936:                                         int orientation, int direction)
1937:   {
1938:     ListUI lui = this.getUI();
1939:     if (orientation == SwingConstants.VERTICAL)
1940:       {
1941:         if (direction > 0)
1942:           {
1943:             // Scrolling down
1944:             Point bottomLeft = new Point(visibleRect.x,
1945:                                          visibleRect.y + visibleRect.height);
1946:             int curIdx = lui.locationToIndex(this, bottomLeft);
1947:             Rectangle curBounds = lui.getCellBounds(this, curIdx, curIdx);
1948:             if (curBounds.y + curBounds.height == bottomLeft.y)
1949:               {
1950:                 // we are at the exact bottom of the current cell, so we 
1951:                 // are being asked to scroll to the end of the next one
1952:                 if (curIdx + 1 < model.getSize())
1953:                   {
1954:                     // there *is* a next item in the list
1955:                     Rectangle nxtBounds = lui.getCellBounds(this, curIdx + 1, curIdx + 1);
1956:                     return nxtBounds.height;
1957:                   }
1958:                 else
1959:                   {
1960:                     // no next item, no advance possible
1961:                     return 0;
1962:                   }
1963:               }
1964:             else
1965:               {
1966:                 // we are part way through an existing cell, so we are being
1967:                 // asked to scroll to the bottom of it
1968:                 return (curBounds.y + curBounds.height) - bottomLeft.y;
1969:               }              
1970:           }
1971:         else
1972:           {
1973:             // scrolling up
1974:             Point topLeft = new Point(visibleRect.x, visibleRect.y);
1975:             int curIdx = lui.locationToIndex(this, topLeft);
1976:             Rectangle curBounds = lui.getCellBounds(this, curIdx, curIdx);
1977:             if (curBounds.y == topLeft.y)
1978:               {
1979:                 // we are at the exact top of the current cell, so we 
1980:                 // are being asked to scroll to the top of the previous one
1981:                 if (curIdx > 0)
1982:                   {
1983:                     // there *is* a previous item in the list
1984:                     Rectangle nxtBounds = lui.getCellBounds(this, curIdx - 1, curIdx - 1);
1985:                     return -nxtBounds.height;
1986:                   }
1987:                 else
1988:                   {
1989:                     // no previous item, no advance possible
1990:                     return 0;
1991:                   }
1992:               }
1993:             else
1994:               {
1995:                 // we are part way through an existing cell, so we are being
1996:                 // asked to scroll to the top of it
1997:                 return curBounds.y - topLeft.y;
1998:               }              
1999:           }
2000:       }
2001: 
2002:     // FIXME: handle horizontal scrolling (also wrapping?)
2003:     return 1;
2004:   }
2005: 
2006:   /**
2007:    * <p>Return the number of pixels the list must scroll in order to move a
2008:    * "block" of the list into the provided visible rectangle. When the
2009:    * provided direction is positive, the call describes a "downwards"
2010:    * scroll, which will be exposing a cell at a <em>greater</em> index in
2011:    * the list than those elements currently showing. Then the provided
2012:    * direction is negative, the call describes an "upwards" scroll, which
2013:    * will be exposing a cell at a <em>lesser</em> index in the list than
2014:    * those elements currently showing.</p>
2015:    *
2016:    * <p>If the provided orientation is <code>HORIZONTAL</code>, the above
2017:    * comments refer to "rightwards" for positive direction, and "leftwards"
2018:    * for negative.</p>
2019:    * 
2020:    *
2021:    * @param visibleRect The rectangle to scroll an element into
2022:    * @param orientation One of the numeric consants <code>VERTICAL</code>
2023:    * or <code>HORIZONTAL</code>
2024:    * @param direction An integer indicating the scroll direction: positive means
2025:    * forwards (down, right), negative means backwards (up, left)
2026:    *
2027:    * @return The scrollable unit increment, in pixels
2028:    */
2029:   public int getScrollableBlockIncrement(Rectangle visibleRect,
2030:                                          int orientation, int direction)
2031:   {
2032:       if (orientation == VERTICAL)
2033:       return visibleRect.height * direction;
2034:       else
2035:       return visibleRect.width * direction;
2036:   }
2037: 
2038:   /**
2039:    * Gets the value of the <code>scrollableTracksViewportWidth</code> property.
2040:    *
2041:    * @return <code>true</code> if the viewport is larger (horizontally)
2042:    * than the list and the list should be expanded to fit the viewport;
2043:    * <code>false</code> if the viewport is smaller than the list and the
2044:    * list should scroll (horizontally) within the viewport
2045:    */
2046:   public boolean getScrollableTracksViewportWidth()
2047:   {
2048:     Component parent = getParent();
2049:     boolean retVal = false;
2050:     if (parent instanceof JViewport)
2051:       {
2052:         JViewport viewport = (JViewport) parent;
2053:         Dimension pref = getPreferredSize();
2054:         if (viewport.getSize().width > pref.width)
2055:           retVal = true;
2056:         if ((getLayoutOrientation() == HORIZONTAL_WRAP)
2057:             && (getVisibleRowCount() <= 0))
2058:           retVal = true;
2059:       }
2060:     return retVal;
2061:   }
2062: 
2063:   /**
2064:    * Gets the value of the </code>scrollableTracksViewportWidth</code> property.
2065:    *
2066:    * @return <code>true</code> if the viewport is larger (vertically)
2067:    * than the list and the list should be expanded to fit the viewport;
2068:    * <code>false</code> if the viewport is smaller than the list and the
2069:    * list should scroll (vertically) within the viewport
2070:    */
2071:   public boolean getScrollableTracksViewportHeight()
2072:   {
2073:     Component parent = getParent();
2074:     boolean retVal = false;
2075:     if (parent instanceof JViewport)
2076:       {
2077:         JViewport viewport = (JViewport) parent;
2078:         Dimension pref = getPreferredSize();
2079:         if (viewport.getSize().height > pref.height)
2080:           retVal = true;
2081:         if ((getLayoutOrientation() == VERTICAL_WRAP)
2082:             && (getVisibleRowCount() <= 0))
2083:           retVal = true;
2084:       }
2085:     return retVal;
2086:   }
2087: 
2088:   /**
2089:    * Returns the index of the anchor item in the current selection, or
2090:    * <code>-1</code> if there is no anchor item.
2091:    * 
2092:    * @return The item index.
2093:    */
2094:   public int getAnchorSelectionIndex()
2095:   {
2096:     return selectionModel.getAnchorSelectionIndex();
2097:   }
2098: 
2099:   /**
2100:    * Returns the index of the lead item in the current selection, or
2101:    * <code>-1</code> if there is no lead item.
2102:    * 
2103:    * @return The item index.
2104:    */
2105:   public int getLeadSelectionIndex()
2106:   {
2107:     return selectionModel.getLeadSelectionIndex();
2108:   }
2109: 
2110:   /**
2111:    * Returns the lowest item index in the current selection, or <code>-1</code>
2112:    * if there is no selection.
2113:    * 
2114:    * @return The index.
2115:    * 
2116:    * @see #getMaxSelectionIndex()
2117:    */
2118:   public int getMinSelectionIndex()
2119:   {
2120:     return selectionModel.getMinSelectionIndex();
2121:   }
2122: 
2123:   /**
2124:    * Returns the highest item index in the current selection, or 
2125:    * <code>-1</code> if there is no selection.
2126:    * 
2127:    * @return The index.
2128:    * 
2129:    * @see #getMinSelectionIndex()
2130:    */
2131:   public int getMaxSelectionIndex()
2132:   {
2133:     return selectionModel.getMaxSelectionIndex();
2134:   }
2135: 
2136:   /**
2137:    * Clears the current selection.
2138:    */
2139:   public void clearSelection()
2140:   {
2141:     selectionModel.clearSelection();
2142:   }
2143: 
2144:   /**
2145:    * Sets the current selection to the items in the specified range (inclusive).
2146:    * Note that <code>anchor</code> can be less than, equal to, or greater than 
2147:    * <code>lead</code>.
2148:    * 
2149:    * @param anchor  the index of the anchor item.
2150:    * @param lead  the index of the anchor item.
2151:    */
2152:   public void setSelectionInterval(int anchor, int lead)
2153:   {
2154:     selectionModel.setSelectionInterval(anchor, lead);
2155:   }
2156: 
2157:   /**
2158:    * Adds the specified interval to the current selection.  Note that 
2159:    * <code>anchor</code> can be less than, equal to, or greater than 
2160:    * <code>lead</code>.
2161:    * 
2162:    * @param anchor  the index of the anchor item.
2163:    * @param lead  the index of the lead item.
2164:    */
2165:   public void addSelectionInterval(int anchor, int lead)
2166:   {
2167:     selectionModel.addSelectionInterval(anchor, lead);
2168:   }
2169: 
2170:   /**
2171:    * Removes the specified interval from the current selection.  Note that 
2172:    * <code>index0</code> can be less than, equal to, or greater than 
2173:    * <code>index1</code>.
2174:    * 
2175:    * @param index0  an index for one end of the range.
2176:    * @param index1  an index for the other end of the range.
2177:    */
2178:   public void removeSelectionInterval(int index0, int index1)
2179:   {
2180:     selectionModel.removeSelectionInterval(index0, index1);
2181:   }
2182: 
2183:   /**
2184:    * Returns the <code>valueIsAdjusting</code> flag from the list's selection
2185:    * model.
2186:    *
2187:    * @return the value
2188:    */
2189:   public boolean getValueIsAdjusting()
2190:   {
2191:     return selectionModel.getValueIsAdjusting();
2192:   }
2193: 
2194:   /**
2195:    * Sets the <code>valueIsAdjusting</code> flag in the list's selection 
2196:    * model.
2197:    *
2198:    * @param isAdjusting the new value
2199:    */
2200:   public void setValueIsAdjusting(boolean isAdjusting)
2201:   {
2202:     selectionModel.setValueIsAdjusting(isAdjusting);
2203:   }
2204: 
2205:   /**
2206:    * Return the value of the <code>dragEnabled</code> property.
2207:    *
2208:    * @return the value
2209:    * 
2210:    * @since 1.4
2211:    */
2212:   public boolean getDragEnabled()
2213:   {
2214:     return dragEnabled;
2215:   }
2216: 
2217:   /**
2218:    * Set the <code>dragEnabled</code> property.
2219:    *
2220:    * @param enabled new value
2221:    * 
2222:    * @since 1.4
2223:    */
2224:   public void setDragEnabled(boolean enabled)
2225:   {
2226:     dragEnabled = enabled;
2227:   }
2228: 
2229:   /**
2230:    * Returns the layout orientation, which will be one of {@link #VERTICAL}, 
2231:    * {@link #VERTICAL_WRAP} and {@link #HORIZONTAL_WRAP}.  The default value
2232:    * is {@link #VERTICAL}.
2233:    *
2234:    * @return the orientation.
2235:    *
2236:    * @see #setLayoutOrientation(int)
2237:    * @since 1.4
2238:    */
2239:   public int getLayoutOrientation()
2240:   {
2241:     return layoutOrientation;
2242:   }
2243: 
2244:   /**
2245:    * Sets the layout orientation (this is a bound property with the name
2246:    * 'layoutOrientation').  Valid orientations are {@link #VERTICAL}, 
2247:    * {@link #VERTICAL_WRAP} and {@link #HORIZONTAL_WRAP}.
2248:    *
2249:    * @param orientation the orientation.
2250:    *
2251:    * @throws IllegalArgumentException if <code>orientation</code> is not one
2252:    *     of the specified values.
2253:    * @since 1.4
2254:    * @see #getLayoutOrientation()
2255:    */
2256:   public void setLayoutOrientation(int orientation)
2257:   {
2258:     if (orientation < JList.VERTICAL || orientation > JList.HORIZONTAL_WRAP)
2259:       throw new IllegalArgumentException();
2260:     if (layoutOrientation == orientation)
2261:       return;
2262: 
2263:     int old = layoutOrientation;
2264:     layoutOrientation = orientation;
2265:     firePropertyChange("layoutOrientation", old, orientation);
2266:   }
2267: 
2268:   /**
2269:    * Returns the bounds of the rectangle that encloses both list cells
2270:    * with index0 and index1.
2271:    *
2272:    * @param index0 the index of the first cell
2273:    * @param index1 the index of the second cell
2274:    *
2275:    * @return  the bounds of the rectangle that encloses both list cells
2276:    *     with index0 and index1, <code>null</code> if one of the indices is
2277:    *     not valid
2278:    */
2279:   public Rectangle getCellBounds(int index0, int index1)
2280:   {
2281:     ListUI ui = getUI();
2282:     Rectangle bounds = null;
2283:     if (ui != null)
2284:       {
2285:         bounds = ui.getCellBounds(this, index0, index1);
2286:       }
2287:     // When the UI is null, this method also returns null in the RI.
2288:     return bounds;
2289:   }
2290: 
2291:   /**
2292:    * Returns the index of the next list element (beginning at 
2293:    * <code>startIndex</code> and moving in the specified direction through the
2294:    * list, looping around if necessary) that starts with <code>prefix</code>
2295:    * (ignoring case).
2296:    *
2297:    * @param prefix the prefix to search for in the cell values
2298:    * @param startIndex the index where to start searching from
2299:    * @param direction the search direction, either {@link Position.Bias#Forward}
2300:    *     or {@link Position.Bias#Backward} (<code>null</code> is interpreted
2301:    *     as {@link Position.Bias#Backward}.
2302:    *
2303:    * @return the index of the found element or -1 if no such element has
2304:    *     been found
2305:    *
2306:    * @throws IllegalArgumentException if prefix is <code>null</code> or
2307:    *     startIndex is not valid
2308:    *
2309:    * @since 1.4
2310:    */
2311:   public int getNextMatch(String prefix, int startIndex, 
2312:                           Position.Bias direction)
2313:   {
2314:     if (prefix == null)
2315:       throw new IllegalArgumentException("The argument 'prefix' must not be"
2316:                                          + " null.");
2317:     if (startIndex < 0)
2318:       throw new IllegalArgumentException("The argument 'startIndex' must not"
2319:                                          + " be less than zero.");
2320: 
2321:     int size = model.getSize();
2322:     if (startIndex >= model.getSize())
2323:       throw new IllegalArgumentException("The argument 'startIndex' must not"
2324:                                          + " be greater than the number of"
2325:                                          + " elements in the ListModel.");
2326: 
2327:     int result = -1;
2328:     int current = startIndex;
2329:     int delta = -1;
2330:     int itemCount = model.getSize();
2331:     boolean finished = false;
2332:     prefix = prefix.toUpperCase();
2333:     
2334:     if (direction == Position.Bias.Forward)
2335:       delta = 1;
2336:     while (!finished)
2337:       {
2338:         String itemStr = model.getElementAt(current).toString().toUpperCase();
2339:         if (itemStr.startsWith(prefix))
2340:           return current;
2341:         current = (current + delta);
2342:         if (current == -1)
2343:           current += itemCount;
2344:         else
2345:           current = current % itemCount; 
2346:         finished = current == startIndex;
2347:       }
2348:     return result;
2349:   }
2350:   
2351:   /**
2352:    * Returns a string describing the attributes for the <code>JList</code>
2353:    * component, for use in debugging.  The return value is guaranteed to be 
2354:    * non-<code>null</code>, but the format of the string may vary between
2355:    * implementations.
2356:    *
2357:    * @return A string describing the attributes of the <code>JList</code>.
2358:    */
2359:   protected String paramString()
2360:   {
2361:     StringBuffer sb = new StringBuffer(super.paramString());
2362:     sb.append(",fixedCellHeight=").append(getFixedCellHeight());
2363:     sb.append(",fixedCellWidth=").append(getFixedCellWidth());
2364:     sb.append(",selectionBackground=");
2365:     if (getSelectionBackground() != null)
2366:       sb.append(getSelectionBackground());
2367:     sb.append(",selectionForeground=");
2368:     if (getSelectionForeground() != null)
2369:       sb.append(getSelectionForeground());
2370:     sb.append(",visibleRowCount=").append(getVisibleRowCount());
2371:     sb.append(",layoutOrientation=").append(getLayoutOrientation());
2372:     return sb.toString();
2373:   }
2374: }