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diff --git a/libjava/classpath/javax/swing/plaf/basic/BasicScrollPaneUI.java b/libjava/classpath/javax/swing/plaf/basic/BasicScrollPaneUI.java
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+/* BasicScrollPaneUI.java
+   Copyright (C) 2002, 2004, 2005, 2006, Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package javax.swing.plaf.basic;
+
+import java.awt.Dimension;
+import java.awt.Graphics;
+import java.awt.Point;
+import java.awt.Rectangle;
+import java.awt.event.ActionEvent;
+import java.awt.event.ContainerEvent;
+import java.awt.event.ContainerListener;
+import java.awt.event.MouseWheelEvent;
+import java.awt.event.MouseWheelListener;
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
+
+import javax.swing.AbstractAction;
+import javax.swing.ActionMap;
+import javax.swing.InputMap;
+import javax.swing.JComponent;
+import javax.swing.JScrollBar;
+import javax.swing.JScrollPane;
+import javax.swing.JSlider;
+import javax.swing.JViewport;
+import javax.swing.LookAndFeel;
+import javax.swing.ScrollPaneConstants;
+import javax.swing.ScrollPaneLayout;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+import javax.swing.border.Border;
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ChangeListener;
+import javax.swing.plaf.ActionMapUIResource;
+import javax.swing.plaf.ComponentUI;
+import javax.swing.plaf.ScrollPaneUI;
+import javax.swing.plaf.UIResource;
+
+/**
+ * A UI delegate for the {@link JScrollPane} component.
+ */
+public class BasicScrollPaneUI extends ScrollPaneUI
+  implements ScrollPaneConstants
+{
+
+  /**
+   * Listens for changes in the state of the horizontal scrollbar's model and
+   * updates the scrollpane accordingly.
+   *
+   * @author Roman Kennke (kennke@aicas.com)
+   */
+  public class HSBChangeListener implements ChangeListener
+  {
+
+    /**
+     * Receives notification when the state of the horizontal scrollbar
+     * model has changed.
+     *
+     * @param event the change event
+     */
+    public void stateChanged(ChangeEvent event)
+    {
+      JScrollBar hsb = scrollpane.getHorizontalScrollBar();
+      JViewport vp = scrollpane.getViewport();
+      Point viewPosition = vp.getViewPosition();
+      viewPosition.x = hsb.getValue();
+      vp.setViewPosition(viewPosition);
+    }
+
+  }
+
+  /**
+   * Listens for changes in the state of the vertical scrollbar's model and
+   * updates the scrollpane accordingly.
+   *
+   * @author Roman Kennke (kennke@aicas.com)
+   */
+  public class VSBChangeListener implements ChangeListener
+  {
+
+    /**
+     * Receives notification when the state of the vertical scrollbar
+     * model has changed.
+     *
+     * @param event the change event
+     */
+    public void stateChanged(ChangeEvent event)
+    {
+      JScrollBar vsb = scrollpane.getVerticalScrollBar();
+      JViewport vp = scrollpane.getViewport();
+      Point viewPosition = vp.getViewPosition();
+      viewPosition.y = vsb.getValue();
+      vp.setViewPosition(viewPosition);
+    }
+
+  }
+
+  /**
+   * Listens for changes of the viewport's extent size and updates the
+   * scrollpane accordingly.
+   *
+   * @author Roman Kennke (kennke@aicas.com)
+   */
+  public class ViewportChangeHandler implements ChangeListener
+  {
+
+    /**
+     * Receives notification when the view's size, position or extent size
+     * changes. When the extents size has changed, this method calls
+     * {@link BasicScrollPaneUI#syncScrollPaneWithViewport()} to adjust the
+     * scrollbars extents as well.
+     *
+     * @param event the change event
+     */
+    public void stateChanged(ChangeEvent event)
+    {
+      syncScrollPaneWithViewport();
+    }
+
+  }
+
+  /**
+   * Listens for property changes on the scrollpane and update the view
+   * accordingly.
+   *
+   * @author Roman Kennke (kennke@aicas.com)
+   */
+  public class PropertyChangeHandler implements PropertyChangeListener
+  {
+
+    /**
+     * Receives notification when any of the scrollpane's bound property
+     * changes. This method calls the appropriate update method on the
+     * <code>ScrollBarUI</code>.
+     *
+     * @param e the property change event
+     *
+     * @see BasicScrollPaneUI#updateColumnHeader(PropertyChangeEvent)
+     * @see BasicScrollPaneUI#updateRowHeader(PropertyChangeEvent)
+     * @see BasicScrollPaneUI#updateScrollBarDisplayPolicy(PropertyChangeEvent)
+     * @see BasicScrollPaneUI#updateViewport(PropertyChangeEvent)
+     */
+    public void propertyChange(PropertyChangeEvent e)
+    {
+      String propName = e.getPropertyName();
+      if (propName.equals("viewport"))
+        updateViewport(e);
+      else if (propName.equals("rowHeader"))
+        updateRowHeader(e);
+      else if (propName.equals("columnHeader"))
+        updateColumnHeader(e);
+      else if (propName.equals("horizontalScrollBarPolicy")
+          || e.getPropertyName().equals("verticalScrollBarPolicy"))
+        updateScrollBarDisplayPolicy(e);
+      else if (propName.equals("verticalScrollBar"))
+        {
+          JScrollBar oldSb = (JScrollBar) e.getOldValue();
+          oldSb.getModel().removeChangeListener(vsbChangeListener);
+          JScrollBar newSb = (JScrollBar) e.getNewValue();
+          newSb.getModel().addChangeListener(vsbChangeListener);
+        }
+      else if (propName.equals("horizontalScrollBar"))
+        {
+          JScrollBar oldSb = (JScrollBar) e.getOldValue();
+          oldSb.getModel().removeChangeListener(hsbChangeListener);
+          JScrollBar newSb = (JScrollBar) e.getNewValue();
+          newSb.getModel().addChangeListener(hsbChangeListener);
+        }
+    }
+
+  }
+
+  /**
+   * Listens for mouse wheel events and update the scrollpane accordingly.
+   *
+   * @author Roman Kennke (kennke@aicas.com)
+   *
+   * @since 1.4
+   */
+  protected class MouseWheelHandler implements MouseWheelListener
+  {
+    /**
+     * Use to compute the visible rectangle.
+     */
+    final Rectangle rect = new Rectangle();
+
+    /**
+     * Scroll with the mouse wheel.
+     *
+     * @author Audrius Meskauskas (audriusa@Bioinformatics.org)
+     */
+    public void mouseWheelMoved(MouseWheelEvent e)
+    {
+      if (scrollpane.isWheelScrollingEnabled() && e.getScrollAmount() != 0)
+        {
+          // Try to scroll vertically first.
+          JScrollBar scrollBar = scrollpane.getVerticalScrollBar();
+          if (scrollBar == null || ! scrollBar.isVisible())
+            scrollBar = scrollpane.getHorizontalScrollBar();
+          if (scrollBar != null && scrollBar.isVisible())
+            {
+              int direction = e.getWheelRotation() < 0 ? -1 : 1;
+              int scrollType = e.getScrollType();
+              if (scrollType == MouseWheelEvent.WHEEL_UNIT_SCROLL)
+                BasicScrollBarUI.scrollByUnits(scrollBar, direction,
+                                               e.getScrollAmount());
+              else if (scrollType == MouseWheelEvent.WHEEL_BLOCK_SCROLL)
+                BasicScrollBarUI.scrollByBlock(scrollBar, direction);
+            }
+        }
+    }
+  }
+
+  /**
+   * Adds/removes the mouse wheel listener when the component is added/removed
+   * to/from the scroll pane view port.
+   *
+   * @author Audrius Meskauskas (audriusa@bioinformatics.org)
+   */
+  class ViewportContainerListener implements ContainerListener
+  {
+    /**
+     * Add the mouse wheel listener, allowing to scroll with the mouse.
+     */
+    public void componentAdded(ContainerEvent e)
+    {
+      e.getChild().addMouseWheelListener(mouseWheelListener);
+    }
+
+    /**
+     * Remove the mouse wheel listener.
+     */
+    public void componentRemoved(ContainerEvent e)
+    {
+      e.getChild().removeMouseWheelListener(mouseWheelListener);
+    }
+  }
+
+  /**
+   * The number of pixels by that we should scroll the content that does
+   * not implement Scrollable.
+   */
+  static int SCROLL_NON_SCROLLABLES = 10;
+
+  /**
+   * The number of rows to scroll per mouse wheel click. From impression,
+   * Sun seems using the value 3.
+   */
+  static int ROWS_PER_WHEEL_CLICK = 3;
+
+  /** The Scrollpane for which the UI is provided by this class. */
+  protected JScrollPane scrollpane;
+
+  /**
+   * The horizontal scrollbar listener.
+   */
+  protected ChangeListener hsbChangeListener;
+
+  /**
+   * The vertical scrollbar listener.
+   */
+  protected ChangeListener vsbChangeListener;
+
+  /**
+   * The viewport listener.
+   */
+  protected ChangeListener viewportChangeListener;
+
+  /**
+   * The scrollpane property change listener.
+   */
+  protected PropertyChangeListener spPropertyChangeListener;
+
+  /**
+   * The mousewheel listener for the scrollpane.
+   */
+  MouseWheelListener mouseWheelListener;
+
+  /**
+   * The listener to add and remove the mouse wheel listener to/from
+   * the component container.
+   */
+  ContainerListener containerListener;
+
+  public static ComponentUI createUI(final JComponent c)
+  {
+    return new BasicScrollPaneUI();
+  }
+
+  protected void installDefaults(JScrollPane p)
+  {
+    scrollpane = p;
+    LookAndFeel.installColorsAndFont(p, "ScrollPane.background",
+                                     "ScrollPane.foreground",
+                                     "ScrollPane.font");
+    LookAndFeel.installBorder(p, "ScrollPane.border");
+
+    // Install Viewport border.
+    Border vpBorder = p.getViewportBorder();
+    if (vpBorder == null || vpBorder instanceof UIResource)
+      {
+        vpBorder = UIManager.getBorder("ScrollPane.viewportBorder");
+        p.setViewportBorder(vpBorder);
+      }
+
+    p.setOpaque(true);
+  }
+
+  protected void uninstallDefaults(JScrollPane p)
+  {
+    LookAndFeel.uninstallBorder(p);
+    Border vpBorder = p.getViewportBorder();
+    if (vpBorder != null && vpBorder instanceof UIResource)
+      p.setViewportBorder(null);
+  }
+
+  public void installUI(final JComponent c)
+  {
+    super.installUI(c);
+    installDefaults((JScrollPane) c);
+    installListeners((JScrollPane) c);
+    installKeyboardActions((JScrollPane) c);
+  }
+
+  /**
+   * Installs the listeners on the scrollbars, the viewport and the scrollpane.
+   *
+   * @param sp the scrollpane on which to install the listeners
+   */
+  protected void installListeners(JScrollPane sp)
+  {
+    if (spPropertyChangeListener == null)
+      spPropertyChangeListener = createPropertyChangeListener();
+    sp.addPropertyChangeListener(spPropertyChangeListener);
+
+    if (hsbChangeListener == null)
+      hsbChangeListener = createHSBChangeListener();
+    sp.getHorizontalScrollBar().getModel().addChangeListener(hsbChangeListener);
+
+    if (vsbChangeListener == null)
+      vsbChangeListener = createVSBChangeListener();
+    sp.getVerticalScrollBar().getModel().addChangeListener(vsbChangeListener);
+
+    if (viewportChangeListener == null)
+      viewportChangeListener = createViewportChangeListener();
+
+    if (mouseWheelListener == null)
+      mouseWheelListener = createMouseWheelListener();
+
+    if (containerListener == null)
+      containerListener = new ViewportContainerListener();
+
+    JViewport v = sp.getViewport();
+    v.addChangeListener(viewportChangeListener);
+    v.addContainerListener(containerListener);
+
+    // Add mouse wheel listeners to the componets that are probably already
+    // in the view port.
+    for (int i = 0; i < v.getComponentCount(); i++)
+      v.getComponent(i).addMouseWheelListener(mouseWheelListener);
+  }
+
+  InputMap getInputMap(int condition)
+  {
+    if (condition == JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT)
+      return (InputMap) UIManager.get("ScrollPane.ancestorInputMap");
+    return null;
+  }
+
+  /**
+   * Returns the action map for the {@link JScrollPane}.  All scroll panes
+   * share a single action map which is created the first time this method is
+   * called, then stored in the UIDefaults table for subsequent access.
+   *
+   * @return The shared action map.
+   */
+  ActionMap getActionMap()
+  {
+    ActionMap map = (ActionMap) UIManager.get("ScrollPane.actionMap");
+
+    if (map == null) // first time here
+      {
+        map = createActionMap();
+        if (map != null)
+          UIManager.put("ScrollPane.actionMap", map);
+      }
+    return map;
+  }
+
+  /**
+   * Creates the action map shared by all {@link JSlider} instances.
+   * This method is called once by {@link #getActionMap()} when it
+   * finds no action map in the UIDefaults table...after the map is
+   * created, it gets added to the defaults table so that subsequent
+   * calls to {@link #getActionMap()} will return the same shared
+   * instance.
+   *
+   * @return The action map.
+   */
+  ActionMap createActionMap()
+  {
+    ActionMap map = new ActionMapUIResource();
+    map.put("scrollLeft",
+            new AbstractAction("scrollLeft") {
+              public void actionPerformed(ActionEvent event)
+              {
+                JScrollPane sp = (JScrollPane) event.getSource();
+                JScrollBar sb = sp.getHorizontalScrollBar();
+                if (sb.isVisible())
+                  {
+                    int delta = sb.getBlockIncrement(-1);
+                    sb.setValue(sb.getValue() + delta);
+                  }
+              }
+            }
+    );
+    map.put("scrollEnd",
+            new AbstractAction("scrollEnd") {
+              public void actionPerformed(ActionEvent event)
+              {
+                JScrollPane sp = (JScrollPane) event.getSource();
+                JScrollBar sb1 = sp.getHorizontalScrollBar();
+                if (sb1.isVisible())
+                  {
+                    sb1.setValue(sb1.getMaximum());
+                  }
+                JScrollBar sb2 = sp.getVerticalScrollBar();
+                if (sb2.isVisible())
+                  {
+                    sb2.setValue(sb2.getMaximum());
+                  }
+              }
+            }
+    );
+    map.put("unitScrollUp",
+            new AbstractAction("unitScrollUp") {
+              public void actionPerformed(ActionEvent event)
+              {
+                JScrollPane sp = (JScrollPane) event.getSource();
+                JScrollBar sb = sp.getVerticalScrollBar();
+                if (sb.isVisible())
+                  {
+                    int delta = sb.getUnitIncrement(-1);
+                    sb.setValue(sb.getValue() + delta);
+                  }
+              }
+            }
+    );
+    map.put("unitScrollLeft",
+            new AbstractAction("unitScrollLeft") {
+              public void actionPerformed(ActionEvent event)
+              {
+                JScrollPane sp = (JScrollPane) event.getSource();
+                JScrollBar sb = sp.getHorizontalScrollBar();
+                if (sb.isVisible())
+                  {
+                    int delta = sb.getUnitIncrement(-1);
+                    sb.setValue(sb.getValue() + delta);
+                  }
+              }
+            }
+    );
+    map.put("scrollUp",
+            new AbstractAction("scrollUp") {
+              public void actionPerformed(ActionEvent event)
+              {
+                JScrollPane sp = (JScrollPane) event.getSource();
+                JScrollBar sb = sp.getVerticalScrollBar();
+                if (sb.isVisible())
+                  {
+                    int delta = sb.getBlockIncrement(-1);
+                    sb.setValue(sb.getValue() + delta);
+                  }
+              }
+            }
+    );
+    map.put("scrollRight",
+            new AbstractAction("scrollRight") {
+              public void actionPerformed(ActionEvent event)
+              {
+                JScrollPane sp = (JScrollPane) event.getSource();
+                JScrollBar sb = sp.getHorizontalScrollBar();
+                if (sb.isVisible())
+                  {
+                    int delta = sb.getBlockIncrement(1);
+                    sb.setValue(sb.getValue() + delta);
+                  }
+              }
+            }
+    );
+    map.put("scrollHome",
+            new AbstractAction("scrollHome") {
+              public void actionPerformed(ActionEvent event)
+              {
+                JScrollPane sp = (JScrollPane) event.getSource();
+                JScrollBar sb1 = sp.getHorizontalScrollBar();
+                if (sb1.isVisible())
+                  {
+                    sb1.setValue(sb1.getMinimum());
+                  }
+                JScrollBar sb2 = sp.getVerticalScrollBar();
+                if (sb2.isVisible())
+                  {
+                    sb2.setValue(sb2.getMinimum());
+                  }
+              }
+            }
+    );
+    map.put("scrollDown",
+            new AbstractAction("scrollDown") {
+              public void actionPerformed(ActionEvent event)
+              {
+                JScrollPane sp = (JScrollPane) event.getSource();
+                JScrollBar sb = sp.getVerticalScrollBar();
+                if (sb.isVisible())
+                  {
+                    int delta = sb.getBlockIncrement(1);
+                    sb.setValue(sb.getValue() + delta);
+                  }
+              }
+            }
+    );
+    map.put("unitScrollDown",
+            new AbstractAction("unitScrollDown") {
+              public void actionPerformed(ActionEvent event)
+              {
+                JScrollPane sp = (JScrollPane) event.getSource();
+                JScrollBar sb = sp.getVerticalScrollBar();
+                if (sb.isVisible())
+                  {
+                    int delta = sb.getUnitIncrement(1);
+                    sb.setValue(sb.getValue() + delta);
+                  }
+              }
+            }
+    );
+    map.put("unitScrollRight",
+            new AbstractAction("unitScrollRight") {
+              public void actionPerformed(ActionEvent event)
+              {
+                JScrollPane sp = (JScrollPane) event.getSource();
+                JScrollBar sb = sp.getHorizontalScrollBar();
+                if (sb.isVisible())
+                  {
+                    int delta = sb.getUnitIncrement(1);
+                    sb.setValue(sb.getValue() + delta);
+                  }
+              }
+            }
+    );
+    return map;
+  }
+
+  /**
+   * Installs additional keyboard actions on the scrollpane. This is a hook
+   * method provided to subclasses in order to install their own keyboard
+   * actions.
+   *
+   * @param sp the scrollpane to install keyboard actions on
+   */
+  protected void installKeyboardActions(JScrollPane sp)
+  {
+    InputMap keyMap = getInputMap(
+        JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
+    SwingUtilities.replaceUIInputMap(sp,
+        JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, keyMap);
+    ActionMap map = getActionMap();
+    SwingUtilities.replaceUIActionMap(sp, map);
+  }
+
+  /**
+   * Uninstalls all keyboard actions from the JScrollPane that have been
+   * installed by {@link #installKeyboardActions}. This is a hook method
+   * provided to subclasses to add their own keyboard actions.
+   *
+   * @param sp the scrollpane to uninstall keyboard actions from
+   */
+  protected void uninstallKeyboardActions(JScrollPane sp)
+  {
+    SwingUtilities.replaceUIActionMap(sp, null);
+    SwingUtilities.replaceUIInputMap(sp,
+        JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, null);
+  }
+
+  /**
+   * Creates and returns the change listener for the horizontal scrollbar.
+   *
+   * @return the change listener for the horizontal scrollbar
+   */
+  protected ChangeListener createHSBChangeListener()
+  {
+    return new HSBChangeListener();
+  }
+
+  /**
+   * Creates and returns the change listener for the vertical scrollbar.
+   *
+   * @return the change listener for the vertical scrollbar
+   */
+  protected ChangeListener createVSBChangeListener()
+  {
+    return new VSBChangeListener();
+  }
+
+  /**
+   * Creates and returns the change listener for the viewport.
+   *
+   * @return the change listener for the viewport
+   */
+  protected ChangeListener createViewportChangeListener()
+  {
+    return new ViewportChangeHandler();
+  }
+
+  /**
+   * Creates and returns the property change listener for the scrollpane.
+   *
+   * @return the property change listener for the scrollpane
+   */
+  protected PropertyChangeListener createPropertyChangeListener()
+  {
+    return new PropertyChangeHandler();
+  }
+
+  /**
+   * Creates and returns the mouse wheel listener for the scrollpane.
+   *
+   * @return the mouse wheel listener for the scrollpane
+   *
+   * @since 1.4
+   */
+  protected MouseWheelListener createMouseWheelListener()
+  {
+    return new MouseWheelHandler();
+  }
+
+  public void uninstallUI(final JComponent c)
+  {
+    uninstallDefaults((JScrollPane) c);
+    uninstallListeners(c);
+    installKeyboardActions((JScrollPane) c);
+  }
+
+  /**
+   * Uninstalls all the listeners that have been installed in
+   * {@link #installListeners(JScrollPane)}.
+   *
+   * @param c the scrollpane from which to uninstall the listeners
+   */
+  protected void uninstallListeners(JComponent c)
+  {
+    JScrollPane sp = (JScrollPane) c;
+    sp.removePropertyChangeListener(spPropertyChangeListener);
+    sp.getHorizontalScrollBar().getModel()
+                               .removeChangeListener(hsbChangeListener);
+    sp.getVerticalScrollBar().getModel()
+                             .removeChangeListener(vsbChangeListener);
+
+    JViewport v = sp.getViewport();
+    v.removeChangeListener(viewportChangeListener);
+    v.removeContainerListener(containerListener);
+
+    for (int i = 0; i < v.getComponentCount(); i++)
+      v.getComponent(i).removeMouseWheelListener(mouseWheelListener);
+
+  }
+
+  public Dimension getMinimumSize(JComponent c)
+  {
+    JScrollPane p = (JScrollPane) c;
+    ScrollPaneLayout sl = (ScrollPaneLayout) p.getLayout();
+    return sl.minimumLayoutSize(c);
+  }
+
+  public void paint(Graphics g, JComponent c)
+  {
+    Border vpBorder = scrollpane.getViewportBorder();
+    if (vpBorder != null)
+      {
+        Rectangle r = scrollpane.getViewportBorderBounds();
+        vpBorder.paintBorder(scrollpane, g, r.x, r.y, r.width, r.height);
+      }
+  }
+
+  /**
+   * Synchronizes the scrollbar and header settings positions and extent
+   * with the viewport's view position and extent.
+   */
+  protected void syncScrollPaneWithViewport()
+  {
+    JViewport vp = scrollpane.getViewport();
+
+    if (vp != null)
+      {
+        Dimension extentSize = vp.getExtentSize();
+        Point viewPos = vp.getViewPosition();
+        Dimension viewSize = vp.getViewSize();
+
+        // Update the vertical scrollbar.
+        JScrollBar vsb = scrollpane.getVerticalScrollBar();
+        if (vsb != null)
+          {
+            int extent = extentSize.height;
+            int max = viewSize.height;
+            int val = Math.max(0, Math.min(viewPos.y, max - extent));
+            vsb.setValues(val, extent, 0, max);
+          }
+
+        // Update the horizontal scrollbar.
+        JScrollBar hsb = scrollpane.getHorizontalScrollBar();
+        if (hsb != null)
+          {
+            int extent = extentSize.width;
+            int max = viewSize.width;
+            int val = Math.max(0, Math.min(viewPos.x, max - extent));
+            hsb.setValues(val, extent, 0, max);
+          }
+
+        // Update the row header.
+        JViewport rowHeader = scrollpane.getRowHeader();
+        if (rowHeader != null)
+          {
+            Point p = new Point(0, viewPos.y);
+            rowHeader.setViewPosition(p);
+          }
+
+        // Update the column header.
+        JViewport colHeader = scrollpane.getColumnHeader();
+        if (colHeader != null)
+          {
+            Point p = new Point(viewPos.x, 0);
+            colHeader.setViewPosition(p);
+          }
+      }
+  }
+
+  /**
+   * Receives notification when the <code>columnHeader</code> property has
+   * changed on the scrollpane.
+   *
+   * @param ev the property change event
+   */
+  protected void updateColumnHeader(PropertyChangeEvent ev)
+  {
+    // TODO: Find out what should be done here. Or is this only a hook?
+  }
+
+  /**
+   * Receives notification when the <code>rowHeader</code> property has changed
+   * on the scrollpane.
+   *
+   * @param ev the property change event
+   */
+  protected void updateRowHeader(PropertyChangeEvent ev)
+  {
+    // TODO: Find out what should be done here. Or is this only a hook?
+  }
+
+  /**
+   * Receives notification when the <code>scrollBarDisplayPolicy</code>
+   * property has changed on the scrollpane.
+   *
+   * @param ev the property change event
+   */
+  protected void updateScrollBarDisplayPolicy(PropertyChangeEvent ev)
+  {
+    scrollpane.revalidate();
+    scrollpane.repaint();
+  }
+
+  /**
+   * Receives notification when the <code>viewport</code> property has changed
+   * on the scrollpane.
+   *
+   * This method sets removes the viewportChangeListener from the old viewport
+   * and adds it to the new viewport.
+   *
+   * @param ev the property change event
+   */
+  protected void updateViewport(PropertyChangeEvent ev)
+  {
+    JViewport oldViewport = (JViewport) ev.getOldValue();
+    oldViewport.removeChangeListener(viewportChangeListener);
+    JViewport newViewport = (JViewport) ev.getNewValue();
+    newViewport.addChangeListener(viewportChangeListener);
+    syncScrollPaneWithViewport();
+  }
+}