Source for javax.swing.plaf.basic.BasicScrollPaneUI

   1: /* BasicScrollPaneUI.java
   2:    Copyright (C) 2002, 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.plaf.basic;
  40: 
  41: import java.awt.Dimension;
  42: import java.awt.Graphics;
  43: import java.awt.Point;
  44: import java.awt.Rectangle;
  45: import java.awt.event.ActionEvent;
  46: import java.awt.event.ContainerEvent;
  47: import java.awt.event.ContainerListener;
  48: import java.awt.event.MouseWheelEvent;
  49: import java.awt.event.MouseWheelListener;
  50: import java.beans.PropertyChangeEvent;
  51: import java.beans.PropertyChangeListener;
  52: 
  53: import javax.swing.AbstractAction;
  54: import javax.swing.ActionMap;
  55: import javax.swing.InputMap;
  56: import javax.swing.JComponent;
  57: import javax.swing.JScrollBar;
  58: import javax.swing.JScrollPane;
  59: import javax.swing.JSlider;
  60: import javax.swing.JViewport;
  61: import javax.swing.LookAndFeel;
  62: import javax.swing.ScrollPaneConstants;
  63: import javax.swing.ScrollPaneLayout;
  64: import javax.swing.SwingUtilities;
  65: import javax.swing.UIManager;
  66: import javax.swing.border.Border;
  67: import javax.swing.event.ChangeEvent;
  68: import javax.swing.event.ChangeListener;
  69: import javax.swing.plaf.ActionMapUIResource;
  70: import javax.swing.plaf.ComponentUI;
  71: import javax.swing.plaf.ScrollPaneUI;
  72: import javax.swing.plaf.UIResource;
  73: 
  74: /**
  75:  * A UI delegate for the {@link JScrollPane} component.
  76:  */
  77: public class BasicScrollPaneUI extends ScrollPaneUI
  78:   implements ScrollPaneConstants
  79: {
  80: 
  81:   /**
  82:    * Listens for changes in the state of the horizontal scrollbar's model and
  83:    * updates the scrollpane accordingly.
  84:    *
  85:    * @author Roman Kennke (kennke@aicas.com)
  86:    */
  87:   public class HSBChangeListener implements ChangeListener
  88:   {
  89: 
  90:     /**
  91:      * Receives notification when the state of the horizontal scrollbar
  92:      * model has changed.
  93:      *
  94:      * @param event the change event
  95:      */
  96:     public void stateChanged(ChangeEvent event)
  97:     {
  98:       JScrollBar hsb = scrollpane.getHorizontalScrollBar();
  99:       JViewport vp = scrollpane.getViewport();
 100:       Point viewPosition = vp.getViewPosition();
 101:       viewPosition.x = hsb.getValue();
 102:       vp.setViewPosition(viewPosition);
 103:     }
 104: 
 105:   }
 106: 
 107:   /**
 108:    * Listens for changes in the state of the vertical scrollbar's model and
 109:    * updates the scrollpane accordingly.
 110:    *
 111:    * @author Roman Kennke (kennke@aicas.com)
 112:    */
 113:   public class VSBChangeListener implements ChangeListener
 114:   {
 115: 
 116:     /**
 117:      * Receives notification when the state of the vertical scrollbar
 118:      * model has changed.
 119:      *
 120:      * @param event the change event
 121:      */
 122:     public void stateChanged(ChangeEvent event)
 123:     {
 124:       JScrollBar vsb = scrollpane.getVerticalScrollBar();
 125:       JViewport vp = scrollpane.getViewport();
 126:       Point viewPosition = vp.getViewPosition();
 127:       viewPosition.y = vsb.getValue();
 128:       vp.setViewPosition(viewPosition);
 129:     }
 130: 
 131:   }
 132: 
 133:   /**
 134:    * Listens for changes of the viewport's extent size and updates the
 135:    * scrollpane accordingly.
 136:    *
 137:    * @author Roman Kennke (kennke@aicas.com)
 138:    */
 139:   public class ViewportChangeHandler implements ChangeListener
 140:   {
 141: 
 142:     /**
 143:      * Receives notification when the view's size, position or extent size
 144:      * changes. When the extents size has changed, this method calls
 145:      * {@link BasicScrollPaneUI#syncScrollPaneWithViewport()} to adjust the
 146:      * scrollbars extents as well.
 147:      *
 148:      * @param event the change event
 149:      */
 150:     public void stateChanged(ChangeEvent event)
 151:     {
 152:       syncScrollPaneWithViewport();
 153:     }
 154: 
 155:   }
 156: 
 157:   /**
 158:    * Listens for property changes on the scrollpane and update the view
 159:    * accordingly.
 160:    *
 161:    * @author Roman Kennke (kennke@aicas.com)
 162:    */
 163:   public class PropertyChangeHandler implements PropertyChangeListener
 164:   {
 165: 
 166:     /**
 167:      * Receives notification when any of the scrollpane's bound property
 168:      * changes. This method calls the appropriate update method on the
 169:      * <code>ScrollBarUI</code>.
 170:      *
 171:      * @param e the property change event
 172:      *
 173:      * @see BasicScrollPaneUI#updateColumnHeader(PropertyChangeEvent)
 174:      * @see BasicScrollPaneUI#updateRowHeader(PropertyChangeEvent)
 175:      * @see BasicScrollPaneUI#updateScrollBarDisplayPolicy(PropertyChangeEvent)
 176:      * @see BasicScrollPaneUI#updateViewport(PropertyChangeEvent)
 177:      */
 178:     public void propertyChange(PropertyChangeEvent e)
 179:     {
 180:       String propName = e.getPropertyName();
 181:       if (propName.equals("viewport"))
 182:         updateViewport(e);
 183:       else if (propName.equals("rowHeader"))
 184:         updateRowHeader(e);
 185:       else if (propName.equals("columnHeader"))
 186:         updateColumnHeader(e);
 187:       else if (propName.equals("horizontalScrollBarPolicy")
 188:           || e.getPropertyName().equals("verticalScrollBarPolicy"))
 189:         updateScrollBarDisplayPolicy(e);
 190:       else if (propName.equals("verticalScrollBar"))
 191:         {
 192:           JScrollBar oldSb = (JScrollBar) e.getOldValue();
 193:           oldSb.getModel().removeChangeListener(vsbChangeListener);
 194:           JScrollBar newSb = (JScrollBar) e.getNewValue();
 195:           newSb.getModel().addChangeListener(vsbChangeListener);
 196:         }
 197:       else if (propName.equals("horizontalScrollBar"))
 198:         {
 199:           JScrollBar oldSb = (JScrollBar) e.getOldValue();
 200:           oldSb.getModel().removeChangeListener(hsbChangeListener);
 201:           JScrollBar newSb = (JScrollBar) e.getNewValue();
 202:           newSb.getModel().addChangeListener(hsbChangeListener);
 203:         }
 204:     }
 205: 
 206:   }
 207: 
 208:   /**
 209:    * Listens for mouse wheel events and update the scrollpane accordingly.
 210:    *
 211:    * @author Roman Kennke (kennke@aicas.com)
 212:    *
 213:    * @since 1.4
 214:    */
 215:   protected class MouseWheelHandler implements MouseWheelListener
 216:   {
 217:     /**
 218:      * Use to compute the visible rectangle.
 219:      */
 220:     final Rectangle rect = new Rectangle();
 221: 
 222:     /**
 223:      * Scroll with the mouse wheel.
 224:      *
 225:      * @author Audrius Meskauskas (audriusa@Bioinformatics.org)
 226:      */
 227:     public void mouseWheelMoved(MouseWheelEvent e)
 228:     {
 229:       if (scrollpane.isWheelScrollingEnabled() && e.getScrollAmount() != 0)
 230:         {
 231:           // Try to scroll vertically first.
 232:           JScrollBar scrollBar = scrollpane.getVerticalScrollBar();
 233:           if (scrollBar == null || ! scrollBar.isVisible())
 234:             scrollBar = scrollpane.getHorizontalScrollBar();
 235:           if (scrollBar != null && scrollBar.isVisible())
 236:             {
 237:               int direction = e.getWheelRotation() < 0 ? -1 : 1;
 238:               int scrollType = e.getScrollType();
 239:               if (scrollType == MouseWheelEvent.WHEEL_UNIT_SCROLL)
 240:                 BasicScrollBarUI.scrollByUnits(scrollBar, direction,
 241:                                                e.getScrollAmount());
 242:               else if (scrollType == MouseWheelEvent.WHEEL_BLOCK_SCROLL)
 243:                 BasicScrollBarUI.scrollByBlock(scrollBar, direction);
 244:             }
 245:         }
 246:     }
 247:   }
 248: 
 249:   /**
 250:    * Adds/removes the mouse wheel listener when the component is added/removed
 251:    * to/from the scroll pane view port.
 252:    *
 253:    * @author Audrius Meskauskas (audriusa@bioinformatics.org)
 254:    */
 255:   class ViewportContainerListener implements ContainerListener
 256:   {
 257:     /**
 258:      * Add the mouse wheel listener, allowing to scroll with the mouse.
 259:      */
 260:     public void componentAdded(ContainerEvent e)
 261:     {
 262:       e.getChild().addMouseWheelListener(mouseWheelListener);
 263:     }
 264: 
 265:     /**
 266:      * Remove the mouse wheel listener.
 267:      */
 268:     public void componentRemoved(ContainerEvent e)
 269:     {
 270:       e.getChild().removeMouseWheelListener(mouseWheelListener);
 271:     }
 272:   }
 273: 
 274:   /**
 275:    * The number of pixels by that we should scroll the content that does
 276:    * not implement Scrollable.
 277:    */
 278:   static int SCROLL_NON_SCROLLABLES = 10;
 279: 
 280:   /**
 281:    * The number of rows to scroll per mouse wheel click. From impression,
 282:    * Sun seems using the value 3.
 283:    */
 284:   static int ROWS_PER_WHEEL_CLICK = 3;
 285: 
 286:   /** The Scrollpane for which the UI is provided by this class. */
 287:   protected JScrollPane scrollpane;
 288: 
 289:   /**
 290:    * The horizontal scrollbar listener.
 291:    */
 292:   protected ChangeListener hsbChangeListener;
 293: 
 294:   /**
 295:    * The vertical scrollbar listener.
 296:    */
 297:   protected ChangeListener vsbChangeListener;
 298: 
 299:   /**
 300:    * The viewport listener.
 301:    */
 302:   protected ChangeListener viewportChangeListener;
 303: 
 304:   /**
 305:    * The scrollpane property change listener.
 306:    */
 307:   protected PropertyChangeListener spPropertyChangeListener;
 308: 
 309:   /**
 310:    * The mousewheel listener for the scrollpane.
 311:    */
 312:   MouseWheelListener mouseWheelListener;
 313: 
 314:   /**
 315:    * The listener to add and remove the mouse wheel listener to/from
 316:    * the component container.
 317:    */
 318:   ContainerListener containerListener;
 319: 
 320:   public static ComponentUI createUI(final JComponent c)
 321:   {
 322:     return new BasicScrollPaneUI();
 323:   }
 324: 
 325:   protected void installDefaults(JScrollPane p)
 326:   {
 327:     scrollpane = p;
 328:     LookAndFeel.installColorsAndFont(p, "ScrollPane.background",
 329:                                      "ScrollPane.foreground",
 330:                                      "ScrollPane.font");
 331:     LookAndFeel.installBorder(p, "ScrollPane.border");
 332: 
 333:     // Install Viewport border.
 334:     Border vpBorder = p.getViewportBorder();
 335:     if (vpBorder == null || vpBorder instanceof UIResource)
 336:       {
 337:         vpBorder = UIManager.getBorder("ScrollPane.viewportBorder");
 338:         p.setViewportBorder(vpBorder);
 339:       }
 340: 
 341:     p.setOpaque(true);
 342:   }
 343: 
 344:   protected void uninstallDefaults(JScrollPane p)
 345:   {
 346:     LookAndFeel.uninstallBorder(p);
 347:     Border vpBorder = p.getViewportBorder();
 348:     if (vpBorder != null && vpBorder instanceof UIResource)
 349:       p.setViewportBorder(null);
 350:   }
 351: 
 352:   public void installUI(final JComponent c)
 353:   {
 354:     super.installUI(c);
 355:     installDefaults((JScrollPane) c);
 356:     installListeners((JScrollPane) c);
 357:     installKeyboardActions((JScrollPane) c);
 358:   }
 359: 
 360:   /**
 361:    * Installs the listeners on the scrollbars, the viewport and the scrollpane.
 362:    *
 363:    * @param sp the scrollpane on which to install the listeners
 364:    */
 365:   protected void installListeners(JScrollPane sp)
 366:   {
 367:     if (spPropertyChangeListener == null)
 368:       spPropertyChangeListener = createPropertyChangeListener();
 369:     sp.addPropertyChangeListener(spPropertyChangeListener);
 370: 
 371:     if (hsbChangeListener == null)
 372:       hsbChangeListener = createHSBChangeListener();
 373:     sp.getHorizontalScrollBar().getModel().addChangeListener(hsbChangeListener);
 374: 
 375:     if (vsbChangeListener == null)
 376:       vsbChangeListener = createVSBChangeListener();
 377:     sp.getVerticalScrollBar().getModel().addChangeListener(vsbChangeListener);
 378: 
 379:     if (viewportChangeListener == null)
 380:       viewportChangeListener = createViewportChangeListener();
 381: 
 382:     if (mouseWheelListener == null)
 383:       mouseWheelListener = createMouseWheelListener();
 384: 
 385:     if (containerListener == null)
 386:       containerListener = new ViewportContainerListener();
 387: 
 388:     JViewport v = sp.getViewport();
 389:     v.addChangeListener(viewportChangeListener);
 390:     v.addContainerListener(containerListener);
 391: 
 392:     // Add mouse wheel listeners to the componets that are probably already
 393:     // in the view port.
 394:     for (int i = 0; i < v.getComponentCount(); i++)
 395:       v.getComponent(i).addMouseWheelListener(mouseWheelListener);
 396:   }
 397: 
 398:   InputMap getInputMap(int condition)
 399:   {
 400:     if (condition == JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT)
 401:       return (InputMap) UIManager.get("ScrollPane.ancestorInputMap");
 402:     return null;
 403:   }
 404: 
 405:   /**
 406:    * Returns the action map for the {@link JScrollPane}.  All scroll panes
 407:    * share a single action map which is created the first time this method is
 408:    * called, then stored in the UIDefaults table for subsequent access.
 409:    *
 410:    * @return The shared action map.
 411:    */
 412:   ActionMap getActionMap()
 413:   {
 414:     ActionMap map = (ActionMap) UIManager.get("ScrollPane.actionMap");
 415: 
 416:     if (map == null) // first time here
 417:       {
 418:         map = createActionMap();
 419:         if (map != null)
 420:           UIManager.put("ScrollPane.actionMap", map);
 421:       }
 422:     return map;
 423:   }
 424: 
 425:   /**
 426:    * Creates the action map shared by all {@link JSlider} instances.
 427:    * This method is called once by {@link #getActionMap()} when it
 428:    * finds no action map in the UIDefaults table...after the map is
 429:    * created, it gets added to the defaults table so that subsequent
 430:    * calls to {@link #getActionMap()} will return the same shared
 431:    * instance.
 432:    *
 433:    * @return The action map.
 434:    */
 435:   ActionMap createActionMap()
 436:   {
 437:     ActionMap map = new ActionMapUIResource();
 438:     map.put("scrollLeft",
 439:             new AbstractAction("scrollLeft") {
 440:               public void actionPerformed(ActionEvent event)
 441:               {
 442:                 JScrollPane sp = (JScrollPane) event.getSource();
 443:                 JScrollBar sb = sp.getHorizontalScrollBar();
 444:                 if (sb.isVisible())
 445:                   {
 446:                     int delta = sb.getBlockIncrement(-1);
 447:                     sb.setValue(sb.getValue() + delta);
 448:                   }
 449:               }
 450:             }
 451:     );
 452:     map.put("scrollEnd",
 453:             new AbstractAction("scrollEnd") {
 454:               public void actionPerformed(ActionEvent event)
 455:               {
 456:                 JScrollPane sp = (JScrollPane) event.getSource();
 457:                 JScrollBar sb1 = sp.getHorizontalScrollBar();
 458:                 if (sb1.isVisible())
 459:                   {
 460:                     sb1.setValue(sb1.getMaximum());
 461:                   }
 462:                 JScrollBar sb2 = sp.getVerticalScrollBar();
 463:                 if (sb2.isVisible())
 464:                   {
 465:                     sb2.setValue(sb2.getMaximum());
 466:                   }
 467:               }
 468:             }
 469:     );
 470:     map.put("unitScrollUp",
 471:             new AbstractAction("unitScrollUp") {
 472:               public void actionPerformed(ActionEvent event)
 473:               {
 474:                 JScrollPane sp = (JScrollPane) event.getSource();
 475:                 JScrollBar sb = sp.getVerticalScrollBar();
 476:                 if (sb.isVisible())
 477:                   {
 478:                     int delta = sb.getUnitIncrement(-1);
 479:                     sb.setValue(sb.getValue() + delta);
 480:                   }
 481:               }
 482:             }
 483:     );
 484:     map.put("unitScrollLeft",
 485:             new AbstractAction("unitScrollLeft") {
 486:               public void actionPerformed(ActionEvent event)
 487:               {
 488:                 JScrollPane sp = (JScrollPane) event.getSource();
 489:                 JScrollBar sb = sp.getHorizontalScrollBar();
 490:                 if (sb.isVisible())
 491:                   {
 492:                     int delta = sb.getUnitIncrement(-1);
 493:                     sb.setValue(sb.getValue() + delta);
 494:                   }
 495:               }
 496:             }
 497:     );
 498:     map.put("scrollUp",
 499:             new AbstractAction("scrollUp") {
 500:               public void actionPerformed(ActionEvent event)
 501:               {
 502:                 JScrollPane sp = (JScrollPane) event.getSource();
 503:                 JScrollBar sb = sp.getVerticalScrollBar();
 504:                 if (sb.isVisible())
 505:                   {
 506:                     int delta = sb.getBlockIncrement(-1);
 507:                     sb.setValue(sb.getValue() + delta);
 508:                   }
 509:               }
 510:             }
 511:     );
 512:     map.put("scrollRight",
 513:             new AbstractAction("scrollRight") {
 514:               public void actionPerformed(ActionEvent event)
 515:               {
 516:                 JScrollPane sp = (JScrollPane) event.getSource();
 517:                 JScrollBar sb = sp.getHorizontalScrollBar();
 518:                 if (sb.isVisible())
 519:                   {
 520:                     int delta = sb.getBlockIncrement(1);
 521:                     sb.setValue(sb.getValue() + delta);
 522:                   }
 523:               }
 524:             }
 525:     );
 526:     map.put("scrollHome",
 527:             new AbstractAction("scrollHome") {
 528:               public void actionPerformed(ActionEvent event)
 529:               {
 530:                 JScrollPane sp = (JScrollPane) event.getSource();
 531:                 JScrollBar sb1 = sp.getHorizontalScrollBar();
 532:                 if (sb1.isVisible())
 533:                   {
 534:                     sb1.setValue(sb1.getMinimum());
 535:                   }
 536:                 JScrollBar sb2 = sp.getVerticalScrollBar();
 537:                 if (sb2.isVisible())
 538:                   {
 539:                     sb2.setValue(sb2.getMinimum());
 540:                   }
 541:               }
 542:             }
 543:     );
 544:     map.put("scrollDown",
 545:             new AbstractAction("scrollDown") {
 546:               public void actionPerformed(ActionEvent event)
 547:               {
 548:                 JScrollPane sp = (JScrollPane) event.getSource();
 549:                 JScrollBar sb = sp.getVerticalScrollBar();
 550:                 if (sb.isVisible())
 551:                   {
 552:                     int delta = sb.getBlockIncrement(1);
 553:                     sb.setValue(sb.getValue() + delta);
 554:                   }
 555:               }
 556:             }
 557:     );
 558:     map.put("unitScrollDown",
 559:             new AbstractAction("unitScrollDown") {
 560:               public void actionPerformed(ActionEvent event)
 561:               {
 562:                 JScrollPane sp = (JScrollPane) event.getSource();
 563:                 JScrollBar sb = sp.getVerticalScrollBar();
 564:                 if (sb.isVisible())
 565:                   {
 566:                     int delta = sb.getUnitIncrement(1);
 567:                     sb.setValue(sb.getValue() + delta);
 568:                   }
 569:               }
 570:             }
 571:     );
 572:     map.put("unitScrollRight",
 573:             new AbstractAction("unitScrollRight") {
 574:               public void actionPerformed(ActionEvent event)
 575:               {
 576:                 JScrollPane sp = (JScrollPane) event.getSource();
 577:                 JScrollBar sb = sp.getHorizontalScrollBar();
 578:                 if (sb.isVisible())
 579:                   {
 580:                     int delta = sb.getUnitIncrement(1);
 581:                     sb.setValue(sb.getValue() + delta);
 582:                   }
 583:               }
 584:             }
 585:     );
 586:     return map;
 587:   }
 588: 
 589:   /**
 590:    * Installs additional keyboard actions on the scrollpane. This is a hook
 591:    * method provided to subclasses in order to install their own keyboard
 592:    * actions.
 593:    *
 594:    * @param sp the scrollpane to install keyboard actions on
 595:    */
 596:   protected void installKeyboardActions(JScrollPane sp)
 597:   {
 598:     InputMap keyMap = getInputMap(
 599:         JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
 600:     SwingUtilities.replaceUIInputMap(sp,
 601:         JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, keyMap);
 602:     ActionMap map = getActionMap();
 603:     SwingUtilities.replaceUIActionMap(sp, map);
 604:   }
 605: 
 606:   /**
 607:    * Uninstalls all keyboard actions from the JScrollPane that have been
 608:    * installed by {@link #installKeyboardActions}. This is a hook method
 609:    * provided to subclasses to add their own keyboard actions.
 610:    *
 611:    * @param sp the scrollpane to uninstall keyboard actions from
 612:    */
 613:   protected void uninstallKeyboardActions(JScrollPane sp)
 614:   {
 615:     SwingUtilities.replaceUIActionMap(sp, null);
 616:     SwingUtilities.replaceUIInputMap(sp,
 617:         JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, null);
 618:   }
 619: 
 620:   /**
 621:    * Creates and returns the change listener for the horizontal scrollbar.
 622:    *
 623:    * @return the change listener for the horizontal scrollbar
 624:    */
 625:   protected ChangeListener createHSBChangeListener()
 626:   {
 627:     return new HSBChangeListener();
 628:   }
 629: 
 630:   /**
 631:    * Creates and returns the change listener for the vertical scrollbar.
 632:    *
 633:    * @return the change listener for the vertical scrollbar
 634:    */
 635:   protected ChangeListener createVSBChangeListener()
 636:   {
 637:     return new VSBChangeListener();
 638:   }
 639: 
 640:   /**
 641:    * Creates and returns the change listener for the viewport.
 642:    *
 643:    * @return the change listener for the viewport
 644:    */
 645:   protected ChangeListener createViewportChangeListener()
 646:   {
 647:     return new ViewportChangeHandler();
 648:   }
 649: 
 650:   /**
 651:    * Creates and returns the property change listener for the scrollpane.
 652:    *
 653:    * @return the property change listener for the scrollpane
 654:    */
 655:   protected PropertyChangeListener createPropertyChangeListener()
 656:   {
 657:     return new PropertyChangeHandler();
 658:   }
 659: 
 660:   /**
 661:    * Creates and returns the mouse wheel listener for the scrollpane.
 662:    *
 663:    * @return the mouse wheel listener for the scrollpane
 664:    *
 665:    * @since 1.4
 666:    */
 667:   protected MouseWheelListener createMouseWheelListener()
 668:   {
 669:     return new MouseWheelHandler();
 670:   }
 671: 
 672:   public void uninstallUI(final JComponent c)
 673:   {
 674:     uninstallDefaults((JScrollPane) c);
 675:     uninstallListeners(c);
 676:     installKeyboardActions((JScrollPane) c);
 677:   }
 678: 
 679:   /**
 680:    * Uninstalls all the listeners that have been installed in
 681:    * {@link #installListeners(JScrollPane)}.
 682:    *
 683:    * @param c the scrollpane from which to uninstall the listeners
 684:    */
 685:   protected void uninstallListeners(JComponent c)
 686:   {
 687:     JScrollPane sp = (JScrollPane) c;
 688:     sp.removePropertyChangeListener(spPropertyChangeListener);
 689:     sp.getHorizontalScrollBar().getModel()
 690:                                .removeChangeListener(hsbChangeListener);
 691:     sp.getVerticalScrollBar().getModel()
 692:                              .removeChangeListener(vsbChangeListener);
 693: 
 694:     JViewport v = sp.getViewport();
 695:     v.removeChangeListener(viewportChangeListener);
 696:     v.removeContainerListener(containerListener);
 697: 
 698:     for (int i = 0; i < v.getComponentCount(); i++)
 699:       v.getComponent(i).removeMouseWheelListener(mouseWheelListener);
 700: 
 701:   }
 702: 
 703:   public Dimension getMinimumSize(JComponent c)
 704:   {
 705:     JScrollPane p = (JScrollPane) c;
 706:     ScrollPaneLayout sl = (ScrollPaneLayout) p.getLayout();
 707:     return sl.minimumLayoutSize(c);
 708:   }
 709: 
 710:   public void paint(Graphics g, JComponent c)
 711:   {
 712:     Border vpBorder = scrollpane.getViewportBorder();
 713:     if (vpBorder != null)
 714:       {
 715:         Rectangle r = scrollpane.getViewportBorderBounds();
 716:         vpBorder.paintBorder(scrollpane, g, r.x, r.y, r.width, r.height);
 717:       }
 718:   }
 719: 
 720:   /**
 721:    * Synchronizes the scrollbar and header settings positions and extent
 722:    * with the viewport's view position and extent.
 723:    */
 724:   protected void syncScrollPaneWithViewport()
 725:   {
 726:     JViewport vp = scrollpane.getViewport();
 727: 
 728:     if (vp != null)
 729:       {
 730:         Dimension extentSize = vp.getExtentSize();
 731:         Point viewPos = vp.getViewPosition();
 732:         Dimension viewSize = vp.getViewSize();
 733: 
 734:         // Update the vertical scrollbar.
 735:         JScrollBar vsb = scrollpane.getVerticalScrollBar();
 736:         if (vsb != null)
 737:           {
 738:             int extent = extentSize.height;
 739:             int max = viewSize.height;
 740:             int val = Math.max(0, Math.min(viewPos.y, max - extent));
 741:             vsb.setValues(val, extent, 0, max);
 742:           }
 743: 
 744:         // Update the horizontal scrollbar.
 745:         JScrollBar hsb = scrollpane.getHorizontalScrollBar();
 746:         if (hsb != null)
 747:           {
 748:             int extent = extentSize.width;
 749:             int max = viewSize.width;
 750:             int val = Math.max(0, Math.min(viewPos.x, max - extent));
 751:             hsb.setValues(val, extent, 0, max);
 752:           }
 753: 
 754:         // Update the row header.
 755:         JViewport rowHeader = scrollpane.getRowHeader();
 756:         if (rowHeader != null)
 757:           {
 758:             Point p = new Point(0, viewPos.y);
 759:             rowHeader.setViewPosition(p);
 760:           }
 761: 
 762:         // Update the column header.
 763:         JViewport colHeader = scrollpane.getColumnHeader();
 764:         if (colHeader != null)
 765:           {
 766:             Point p = new Point(viewPos.x, 0);
 767:             colHeader.setViewPosition(p);
 768:           }
 769:       }
 770:   }
 771: 
 772:   /**
 773:    * Receives notification when the <code>columnHeader</code> property has
 774:    * changed on the scrollpane.
 775:    *
 776:    * @param ev the property change event
 777:    */
 778:   protected void updateColumnHeader(PropertyChangeEvent ev)
 779:   {
 780:     // TODO: Find out what should be done here. Or is this only a hook?
 781:   }
 782: 
 783:   /**
 784:    * Receives notification when the <code>rowHeader</code> property has changed
 785:    * on the scrollpane.
 786:    *
 787:    * @param ev the property change event
 788:    */
 789:   protected void updateRowHeader(PropertyChangeEvent ev)
 790:   {
 791:     // TODO: Find out what should be done here. Or is this only a hook?
 792:   }
 793: 
 794:   /**
 795:    * Receives notification when the <code>scrollBarDisplayPolicy</code>
 796:    * property has changed on the scrollpane.
 797:    *
 798:    * @param ev the property change event
 799:    */
 800:   protected void updateScrollBarDisplayPolicy(PropertyChangeEvent ev)
 801:   {
 802:     scrollpane.revalidate();
 803:     scrollpane.repaint();
 804:   }
 805: 
 806:   /**
 807:    * Receives notification when the <code>viewport</code> property has changed
 808:    * on the scrollpane.
 809:    *
 810:    * This method sets removes the viewportChangeListener from the old viewport
 811:    * and adds it to the new viewport.
 812:    *
 813:    * @param ev the property change event
 814:    */
 815:   protected void updateViewport(PropertyChangeEvent ev)
 816:   {
 817:     JViewport oldViewport = (JViewport) ev.getOldValue();
 818:     oldViewport.removeChangeListener(viewportChangeListener);
 819:     JViewport newViewport = (JViewport) ev.getNewValue();
 820:     newViewport.addChangeListener(viewportChangeListener);
 821:     syncScrollPaneWithViewport();
 822:   }
 823: }