jdk/src/share/classes/javax/swing/plaf/basic/BasicScrollBarUI.java
changeset 2 90ce3da70b43
child 2658 43e06bc950ec
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/swing/plaf/basic/BasicScrollBarUI.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1564 @@
+/*
+ * Copyright 1997-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+package javax.swing.plaf.basic;
+
+
+import sun.swing.DefaultLookup;
+import sun.swing.UIAction;
+
+import java.awt.*;
+import java.awt.event.*;
+
+import java.beans.*;
+
+import javax.swing.*;
+import javax.swing.event.*;
+import javax.swing.plaf.*;
+
+
+/**
+ * Implementation of ScrollBarUI for the Basic Look and Feel
+ *
+ * @author Rich Schiavi
+ * @author David Kloba
+ * @author Hans Muller
+ */
+public class BasicScrollBarUI
+    extends ScrollBarUI implements LayoutManager, SwingConstants
+{
+    private static final int POSITIVE_SCROLL = 1;
+    private static final int NEGATIVE_SCROLL = -1;
+
+    private static final int MIN_SCROLL = 2;
+    private static final int MAX_SCROLL = 3;
+
+    // NOTE: DO NOT use this field directly, SynthScrollBarUI assumes you'll
+    // call getMinimumThumbSize to access it.
+    protected Dimension minimumThumbSize;
+    protected Dimension maximumThumbSize;
+
+    protected Color thumbHighlightColor;
+    protected Color thumbLightShadowColor;
+    protected Color thumbDarkShadowColor;
+    protected Color thumbColor;
+    protected Color trackColor;
+    protected Color trackHighlightColor;
+
+    protected JScrollBar scrollbar;
+    protected JButton incrButton;
+    protected JButton decrButton;
+    protected boolean isDragging;
+    protected TrackListener trackListener;
+    protected ArrowButtonListener buttonListener;
+    protected ModelListener modelListener;
+
+    protected Rectangle thumbRect;
+    protected Rectangle trackRect;
+
+    protected int trackHighlight;
+
+    protected static final int NO_HIGHLIGHT = 0;
+    protected static final int DECREASE_HIGHLIGHT = 1;
+    protected static final int INCREASE_HIGHLIGHT = 2;
+
+    protected ScrollListener scrollListener;
+    protected PropertyChangeListener propertyChangeListener;
+    protected Timer scrollTimer;
+
+    private final static int scrollSpeedThrottle = 60; // delay in milli seconds
+
+    /** True indicates a middle click will absolutely position the
+     * scrollbar. */
+    private boolean supportsAbsolutePositioning;
+
+    /** Hint as to what width (when vertical) or height (when horizontal)
+     * should be.
+     */
+    private int scrollBarWidth;
+
+    private Handler handler;
+
+    private boolean thumbActive;
+
+    /**
+     * Determine whether scrollbar layout should use cached value or adjusted
+     * value returned by scrollbar's <code>getValue</code>.
+     */
+    private boolean useCachedValue = false;
+    /**
+     * The scrollbar value is cached to save real value if the view is adjusted.
+     */
+    private int scrollBarValue;
+
+    static void loadActionMap(LazyActionMap map) {
+        map.put(new Actions(Actions.POSITIVE_UNIT_INCREMENT));
+        map.put(new Actions(Actions.POSITIVE_BLOCK_INCREMENT));
+        map.put(new Actions(Actions.NEGATIVE_UNIT_INCREMENT));
+        map.put(new Actions(Actions.NEGATIVE_BLOCK_INCREMENT));
+        map.put(new Actions(Actions.MIN_SCROLL));
+        map.put(new Actions(Actions.MAX_SCROLL));
+    }
+
+
+    public static ComponentUI createUI(JComponent c)    {
+        return new BasicScrollBarUI();
+    }
+
+
+    protected void configureScrollBarColors()
+    {
+        LookAndFeel.installColors(scrollbar, "ScrollBar.background",
+                                  "ScrollBar.foreground");
+        thumbHighlightColor = UIManager.getColor("ScrollBar.thumbHighlight");
+        thumbLightShadowColor = UIManager.getColor("ScrollBar.thumbShadow");
+        thumbDarkShadowColor = UIManager.getColor("ScrollBar.thumbDarkShadow");
+        thumbColor = UIManager.getColor("ScrollBar.thumb");
+        trackColor = UIManager.getColor("ScrollBar.track");
+        trackHighlightColor = UIManager.getColor("ScrollBar.trackHighlight");
+    }
+
+
+    public void installUI(JComponent c)   {
+        scrollbar = (JScrollBar)c;
+        thumbRect = new Rectangle(0, 0, 0, 0);
+        trackRect = new Rectangle(0, 0, 0, 0);
+        installDefaults();
+        installComponents();
+        installListeners();
+        installKeyboardActions();
+    }
+
+    public void uninstallUI(JComponent c) {
+        scrollbar = (JScrollBar)c;
+        uninstallListeners();
+        uninstallDefaults();
+        uninstallComponents();
+        uninstallKeyboardActions();
+        thumbRect = null;
+        scrollbar = null;
+        incrButton = null;
+        decrButton = null;
+    }
+
+
+    protected void installDefaults()
+    {
+        scrollBarWidth = UIManager.getInt("ScrollBar.width");
+        if (scrollBarWidth <= 0) {
+            scrollBarWidth = 16;
+        }
+        minimumThumbSize = (Dimension)UIManager.get("ScrollBar.minimumThumbSize");
+        maximumThumbSize = (Dimension)UIManager.get("ScrollBar.maximumThumbSize");
+
+        Boolean absB = (Boolean)UIManager.get("ScrollBar.allowsAbsolutePositioning");
+        supportsAbsolutePositioning = (absB != null) ? absB.booleanValue() :
+                                      false;
+
+        trackHighlight = NO_HIGHLIGHT;
+        if (scrollbar.getLayout() == null ||
+                     (scrollbar.getLayout() instanceof UIResource)) {
+            scrollbar.setLayout(this);
+        }
+        configureScrollBarColors();
+        LookAndFeel.installBorder(scrollbar, "ScrollBar.border");
+        LookAndFeel.installProperty(scrollbar, "opaque", Boolean.TRUE);
+
+        scrollBarValue = scrollbar.getValue();
+    }
+
+
+    protected void installComponents(){
+        switch (scrollbar.getOrientation()) {
+        case JScrollBar.VERTICAL:
+            incrButton = createIncreaseButton(SOUTH);
+            decrButton = createDecreaseButton(NORTH);
+            break;
+
+        case JScrollBar.HORIZONTAL:
+            if (scrollbar.getComponentOrientation().isLeftToRight()) {
+                incrButton = createIncreaseButton(EAST);
+                decrButton = createDecreaseButton(WEST);
+            } else {
+                incrButton = createIncreaseButton(WEST);
+                decrButton = createDecreaseButton(EAST);
+            }
+            break;
+        }
+        scrollbar.add(incrButton);
+        scrollbar.add(decrButton);
+        // Force the children's enabled state to be updated.
+        scrollbar.setEnabled(scrollbar.isEnabled());
+    }
+
+    protected void uninstallComponents(){
+        scrollbar.remove(incrButton);
+        scrollbar.remove(decrButton);
+    }
+
+
+    protected void installListeners(){
+        trackListener = createTrackListener();
+        buttonListener = createArrowButtonListener();
+        modelListener = createModelListener();
+        propertyChangeListener = createPropertyChangeListener();
+
+        scrollbar.addMouseListener(trackListener);
+        scrollbar.addMouseMotionListener(trackListener);
+        scrollbar.getModel().addChangeListener(modelListener);
+        scrollbar.addPropertyChangeListener(propertyChangeListener);
+        scrollbar.addFocusListener(getHandler());
+
+        if (incrButton != null) {
+            incrButton.addMouseListener(buttonListener);
+        }
+        if (decrButton != null) {
+            decrButton.addMouseListener(buttonListener);
+        }
+
+        scrollListener = createScrollListener();
+        scrollTimer = new Timer(scrollSpeedThrottle, scrollListener);
+        scrollTimer.setInitialDelay(300);  // default InitialDelay?
+    }
+
+
+    protected void installKeyboardActions(){
+        LazyActionMap.installLazyActionMap(scrollbar, BasicScrollBarUI.class,
+                                           "ScrollBar.actionMap");
+
+        InputMap inputMap = getInputMap(JComponent.WHEN_FOCUSED);
+        SwingUtilities.replaceUIInputMap(scrollbar, JComponent.WHEN_FOCUSED,
+                                         inputMap);
+        inputMap = getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
+        SwingUtilities.replaceUIInputMap(scrollbar,
+                   JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, inputMap);
+    }
+
+    protected void uninstallKeyboardActions(){
+        SwingUtilities.replaceUIInputMap(scrollbar, JComponent.WHEN_FOCUSED,
+                                         null);
+        SwingUtilities.replaceUIActionMap(scrollbar, null);
+    }
+
+    private InputMap getInputMap(int condition) {
+        if (condition == JComponent.WHEN_FOCUSED) {
+            InputMap keyMap = (InputMap)DefaultLookup.get(
+                        scrollbar, this, "ScrollBar.focusInputMap");
+            InputMap rtlKeyMap;
+
+            if (scrollbar.getComponentOrientation().isLeftToRight() ||
+                ((rtlKeyMap = (InputMap)DefaultLookup.get(scrollbar, this, "ScrollBar.focusInputMap.RightToLeft")) == null)) {
+                return keyMap;
+            } else {
+                rtlKeyMap.setParent(keyMap);
+                return rtlKeyMap;
+            }
+        }
+        else if (condition == JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT) {
+            InputMap keyMap = (InputMap)DefaultLookup.get(
+                        scrollbar, this, "ScrollBar.ancestorInputMap");
+            InputMap rtlKeyMap;
+
+            if (scrollbar.getComponentOrientation().isLeftToRight() ||
+                ((rtlKeyMap = (InputMap)DefaultLookup.get(scrollbar, this, "ScrollBar.ancestorInputMap.RightToLeft")) == null)) {
+                return keyMap;
+            } else {
+                rtlKeyMap.setParent(keyMap);
+                return rtlKeyMap;
+            }
+        }
+        return null;
+    }
+
+
+    protected void uninstallListeners() {
+        scrollTimer.stop();
+        scrollTimer = null;
+
+        if (decrButton != null){
+            decrButton.removeMouseListener(buttonListener);
+        }
+        if (incrButton != null){
+            incrButton.removeMouseListener(buttonListener);
+        }
+
+        scrollbar.getModel().removeChangeListener(modelListener);
+        scrollbar.removeMouseListener(trackListener);
+        scrollbar.removeMouseMotionListener(trackListener);
+        scrollbar.removePropertyChangeListener(propertyChangeListener);
+        scrollbar.removeFocusListener(getHandler());
+        handler = null;
+    }
+
+
+    protected void uninstallDefaults(){
+        LookAndFeel.uninstallBorder(scrollbar);
+        if (scrollbar.getLayout() == this) {
+            scrollbar.setLayout(null);
+        }
+    }
+
+
+    private Handler getHandler() {
+        if (handler == null) {
+            handler = new Handler();
+        }
+        return handler;
+    }
+
+    protected TrackListener createTrackListener(){
+        return new TrackListener();
+    }
+
+    protected ArrowButtonListener createArrowButtonListener(){
+        return new ArrowButtonListener();
+    }
+
+    protected ModelListener createModelListener(){
+        return new ModelListener();
+    }
+
+    protected ScrollListener createScrollListener(){
+        return new ScrollListener();
+    }
+
+    protected PropertyChangeListener createPropertyChangeListener() {
+        return getHandler();
+    }
+
+    private void updateThumbState(int x, int y) {
+        Rectangle rect = getThumbBounds();
+
+        setThumbRollover(rect.contains(x, y));
+    }
+
+    /**
+     * Sets whether or not the mouse is currently over the thumb.
+     *
+     * @param active True indicates the thumb is currently active.
+     * @since 1.5
+     */
+    protected void setThumbRollover(boolean active) {
+        if (thumbActive != active) {
+            thumbActive = active;
+            scrollbar.repaint(getThumbBounds());
+        }
+    }
+
+    /**
+     * Returns true if the mouse is currently over the thumb.
+     *
+     * @return true if the thumb is currently active
+     * @since 1.5
+     */
+    public boolean isThumbRollover() {
+        return thumbActive;
+    }
+
+    public void paint(Graphics g, JComponent c) {
+        paintTrack(g, c, getTrackBounds());
+        Rectangle thumbBounds = getThumbBounds();
+        if (thumbBounds.intersects(g.getClipBounds())) {
+            paintThumb(g, c, thumbBounds);
+        }
+    }
+
+
+    /**
+     * A vertical scrollbar's preferred width is the maximum of
+     * preferred widths of the (non <code>null</code>)
+     * increment/decrement buttons,
+     * and the minimum width of the thumb. The preferred height is the
+     * sum of the preferred heights of the same parts.  The basis for
+     * the preferred size of a horizontal scrollbar is similar.
+     * <p>
+     * The <code>preferredSize</code> is only computed once, subsequent
+     * calls to this method just return a cached size.
+     *
+     * @param c the <code>JScrollBar</code> that's delegating this method to us
+     * @return the preferred size of a Basic JScrollBar
+     * @see #getMaximumSize
+     * @see #getMinimumSize
+     */
+    public Dimension getPreferredSize(JComponent c) {
+        return (scrollbar.getOrientation() == JScrollBar.VERTICAL)
+            ? new Dimension(scrollBarWidth, 48)
+            : new Dimension(48, scrollBarWidth);
+    }
+
+
+    /**
+     * @param c The JScrollBar that's delegating this method to us.
+     * @return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
+     * @see #getMinimumSize
+     * @see #getPreferredSize
+     */
+    public Dimension getMaximumSize(JComponent c) {
+        return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
+    }
+
+    protected JButton createDecreaseButton(int orientation)  {
+        return new BasicArrowButton(orientation,
+                                    UIManager.getColor("ScrollBar.thumb"),
+                                    UIManager.getColor("ScrollBar.thumbShadow"),
+                                    UIManager.getColor("ScrollBar.thumbDarkShadow"),
+                                    UIManager.getColor("ScrollBar.thumbHighlight"));
+    }
+
+    protected JButton createIncreaseButton(int orientation)  {
+        return new BasicArrowButton(orientation,
+                                    UIManager.getColor("ScrollBar.thumb"),
+                                    UIManager.getColor("ScrollBar.thumbShadow"),
+                                    UIManager.getColor("ScrollBar.thumbDarkShadow"),
+                                    UIManager.getColor("ScrollBar.thumbHighlight"));
+    }
+
+
+    protected void paintDecreaseHighlight(Graphics g)
+    {
+        Insets insets = scrollbar.getInsets();
+        Rectangle thumbR = getThumbBounds();
+        g.setColor(trackHighlightColor);
+
+        if (scrollbar.getOrientation() == JScrollBar.VERTICAL) {
+            int x = insets.left;
+            int y = decrButton.getY() + decrButton.getHeight();
+            int w = scrollbar.getWidth() - (insets.left + insets.right);
+            int h = thumbR.y - y;
+            g.fillRect(x, y, w, h);
+        }
+        else    {
+            int x, w;
+            if (scrollbar.getComponentOrientation().isLeftToRight()) {
+                x = decrButton.getX() + decrButton.getWidth();
+                w = thumbR.x - x;
+            } else {
+                x = thumbR.x + thumbR.width;
+                w = decrButton.getX() - x;
+            }
+            int y = insets.top;
+            int h = scrollbar.getHeight() - (insets.top + insets.bottom);
+            g.fillRect(x, y, w, h);
+        }
+    }
+
+
+    protected void paintIncreaseHighlight(Graphics g)
+    {
+        Insets insets = scrollbar.getInsets();
+        Rectangle thumbR = getThumbBounds();
+        g.setColor(trackHighlightColor);
+
+        if (scrollbar.getOrientation() == JScrollBar.VERTICAL) {
+            int x = insets.left;
+            int y = thumbR.y + thumbR.height;
+            int w = scrollbar.getWidth() - (insets.left + insets.right);
+            int h = incrButton.getY() - y;
+            g.fillRect(x, y, w, h);
+        }
+        else {
+            int x, w;
+            if (scrollbar.getComponentOrientation().isLeftToRight()) {
+                x = thumbR.x + thumbR.width;
+                w = incrButton.getX() - x;
+            } else {
+                x = incrButton.getX() + incrButton.getWidth();
+                w = thumbR.x - x;
+            }
+            int y = insets.top;
+            int h = scrollbar.getHeight() - (insets.top + insets.bottom);
+            g.fillRect(x, y, w, h);
+        }
+    }
+
+
+    protected void paintTrack(Graphics g, JComponent c, Rectangle trackBounds)
+    {
+        g.setColor(trackColor);
+        g.fillRect(trackBounds.x, trackBounds.y, trackBounds.width, trackBounds.height);
+
+        if(trackHighlight == DECREASE_HIGHLIGHT)        {
+            paintDecreaseHighlight(g);
+        }
+        else if(trackHighlight == INCREASE_HIGHLIGHT)           {
+            paintIncreaseHighlight(g);
+        }
+    }
+
+
+    protected void paintThumb(Graphics g, JComponent c, Rectangle thumbBounds)
+    {
+        if(thumbBounds.isEmpty() || !scrollbar.isEnabled())     {
+            return;
+        }
+
+        int w = thumbBounds.width;
+        int h = thumbBounds.height;
+
+        g.translate(thumbBounds.x, thumbBounds.y);
+
+        g.setColor(thumbDarkShadowColor);
+        g.drawRect(0, 0, w-1, h-1);
+        g.setColor(thumbColor);
+        g.fillRect(0, 0, w-1, h-1);
+
+        g.setColor(thumbHighlightColor);
+        g.drawLine(1, 1, 1, h-2);
+        g.drawLine(2, 1, w-3, 1);
+
+        g.setColor(thumbLightShadowColor);
+        g.drawLine(2, h-2, w-2, h-2);
+        g.drawLine(w-2, 1, w-2, h-3);
+
+        g.translate(-thumbBounds.x, -thumbBounds.y);
+    }
+
+
+    /**
+     * Return the smallest acceptable size for the thumb.  If the scrollbar
+     * becomes so small that this size isn't available, the thumb will be
+     * hidden.
+     * <p>
+     * <b>Warning </b>: the value returned by this method should not be
+     * be modified, it's a shared static constant.
+     *
+     * @return The smallest acceptable size for the thumb.
+     * @see #getMaximumThumbSize
+     */
+    protected Dimension getMinimumThumbSize() {
+        return minimumThumbSize;
+    }
+
+    /**
+     * Return the largest acceptable size for the thumb.  To create a fixed
+     * size thumb one make this method and <code>getMinimumThumbSize</code>
+     * return the same value.
+     * <p>
+     * <b>Warning </b>: the value returned by this method should not be
+     * be modified, it's a shared static constant.
+     *
+     * @return The largest acceptable size for the thumb.
+     * @see #getMinimumThumbSize
+     */
+    protected Dimension getMaximumThumbSize()   {
+        return maximumThumbSize;
+    }
+
+
+    /*
+     * LayoutManager Implementation
+     */
+
+    public void addLayoutComponent(String name, Component child) {}
+    public void removeLayoutComponent(Component child) {}
+
+    public Dimension preferredLayoutSize(Container scrollbarContainer)  {
+        return getPreferredSize((JComponent)scrollbarContainer);
+    }
+
+    public Dimension minimumLayoutSize(Container scrollbarContainer) {
+        return getMinimumSize((JComponent)scrollbarContainer);
+    }
+
+    private int getValue(JScrollBar sb) {
+        return (useCachedValue) ? scrollBarValue : sb.getValue();
+    }
+
+    protected void layoutVScrollbar(JScrollBar sb)
+    {
+        Dimension sbSize = sb.getSize();
+        Insets sbInsets = sb.getInsets();
+
+        /*
+         * Width and left edge of the buttons and thumb.
+         */
+        int itemW = sbSize.width - (sbInsets.left + sbInsets.right);
+        int itemX = sbInsets.left;
+
+        /* Nominal locations of the buttons, assuming their preferred
+         * size will fit.
+         */
+        boolean squareButtons = DefaultLookup.getBoolean(
+            scrollbar, this, "ScrollBar.squareButtons", false);
+        int decrButtonH = squareButtons ? itemW :
+                          decrButton.getPreferredSize().height;
+        int decrButtonY = sbInsets.top;
+
+        int incrButtonH = squareButtons ? itemW :
+                          incrButton.getPreferredSize().height;
+        int incrButtonY = sbSize.height - (sbInsets.bottom + incrButtonH);
+
+        /* The thumb must fit within the height left over after we
+         * subtract the preferredSize of the buttons and the insets.
+         */
+        int sbInsetsH = sbInsets.top + sbInsets.bottom;
+        int sbButtonsH = decrButtonH + incrButtonH;
+        float trackH = sbSize.height - (sbInsetsH + sbButtonsH);
+
+        /* Compute the height and origin of the thumb.   The case
+         * where the thumb is at the bottom edge is handled specially
+         * to avoid numerical problems in computing thumbY.  Enforce
+         * the thumbs min/max dimensions.  If the thumb doesn't
+         * fit in the track (trackH) we'll hide it later.
+         */
+        float min = sb.getMinimum();
+        float extent = sb.getVisibleAmount();
+        float range = sb.getMaximum() - min;
+        float value = getValue(sb);
+
+        int thumbH = (range <= 0)
+            ? getMaximumThumbSize().height : (int)(trackH * (extent / range));
+        thumbH = Math.max(thumbH, getMinimumThumbSize().height);
+        thumbH = Math.min(thumbH, getMaximumThumbSize().height);
+
+        int thumbY = incrButtonY - thumbH;
+        if (value < (sb.getMaximum() - sb.getVisibleAmount())) {
+            float thumbRange = trackH - thumbH;
+            thumbY = (int)(0.5f + (thumbRange * ((value - min) / (range - extent))));
+            thumbY +=  decrButtonY + decrButtonH;
+        }
+
+        /* If the buttons don't fit, allocate half of the available
+         * space to each and move the lower one (incrButton) down.
+         */
+        int sbAvailButtonH = (sbSize.height - sbInsetsH);
+        if (sbAvailButtonH < sbButtonsH) {
+            incrButtonH = decrButtonH = sbAvailButtonH / 2;
+            incrButtonY = sbSize.height - (sbInsets.bottom + incrButtonH);
+        }
+        decrButton.setBounds(itemX, decrButtonY, itemW, decrButtonH);
+        incrButton.setBounds(itemX, incrButtonY, itemW, incrButtonH);
+
+        /* Update the trackRect field.
+         */
+        int itrackY = decrButtonY + decrButtonH;
+        int itrackH = incrButtonY - itrackY;
+        trackRect.setBounds(itemX, itrackY, itemW, itrackH);
+
+        /* If the thumb isn't going to fit, zero it's bounds.  Otherwise
+         * make sure it fits between the buttons.  Note that setting the
+         * thumbs bounds will cause a repaint.
+         */
+        if(thumbH >= (int)trackH)       {
+            if (UIManager.getBoolean("ScrollBar.alwaysShowThumb")) {
+                // This is used primarily for GTK L&F, which expands the
+                // thumb to fit the track when it would otherwise be hidden.
+                setThumbBounds(itemX, itrackY, itemW, itrackH);
+            } else {
+                // Other L&F's simply hide the thumb in this case.
+                setThumbBounds(0, 0, 0, 0);
+            }
+        }
+        else {
+            if ((thumbY + thumbH) > incrButtonY) {
+                thumbY = incrButtonY - thumbH;
+            }
+            if (thumbY  < (decrButtonY + decrButtonH)) {
+                thumbY = decrButtonY + decrButtonH + 1;
+            }
+            setThumbBounds(itemX, thumbY, itemW, thumbH);
+        }
+    }
+
+
+    protected void layoutHScrollbar(JScrollBar sb)
+    {
+        Dimension sbSize = sb.getSize();
+        Insets sbInsets = sb.getInsets();
+
+        /* Height and top edge of the buttons and thumb.
+         */
+        int itemH = sbSize.height - (sbInsets.top + sbInsets.bottom);
+        int itemY = sbInsets.top;
+
+        boolean ltr = sb.getComponentOrientation().isLeftToRight();
+
+        /* Nominal locations of the buttons, assuming their preferred
+         * size will fit.
+         */
+        boolean squareButtons = DefaultLookup.getBoolean(
+            scrollbar, this, "ScrollBar.squareButtons", false);
+        int leftButtonW = squareButtons ? itemH :
+                          decrButton.getPreferredSize().width;
+        int rightButtonW = squareButtons ? itemH :
+                          incrButton.getPreferredSize().width;
+        if (!ltr) {
+            int temp = leftButtonW;
+            leftButtonW = rightButtonW;
+            rightButtonW = temp;
+        }
+        int leftButtonX = sbInsets.left;
+        int rightButtonX = sbSize.width - (sbInsets.right + rightButtonW);
+
+        /* The thumb must fit within the width left over after we
+         * subtract the preferredSize of the buttons and the insets.
+         */
+        int sbInsetsW = sbInsets.left + sbInsets.right;
+        int sbButtonsW = leftButtonW + rightButtonW;
+        float trackW = sbSize.width - (sbInsetsW + sbButtonsW);
+
+        /* Compute the width and origin of the thumb.  Enforce
+         * the thumbs min/max dimensions.  The case where the thumb
+         * is at the right edge is handled specially to avoid numerical
+         * problems in computing thumbX.  If the thumb doesn't
+         * fit in the track (trackH) we'll hide it later.
+         */
+        float min = sb.getMinimum();
+        float max = sb.getMaximum();
+        float extent = sb.getVisibleAmount();
+        float range = max - min;
+        float value = getValue(sb);
+
+        int thumbW = (range <= 0)
+            ? getMaximumThumbSize().width : (int)(trackW * (extent / range));
+        thumbW = Math.max(thumbW, getMinimumThumbSize().width);
+        thumbW = Math.min(thumbW, getMaximumThumbSize().width);
+
+        int thumbX = ltr ? rightButtonX - thumbW : leftButtonX + leftButtonW;
+        if (value < (max - sb.getVisibleAmount())) {
+            float thumbRange = trackW - thumbW;
+            if( ltr ) {
+                thumbX = (int)(0.5f + (thumbRange * ((value - min) / (range - extent))));
+            } else {
+                thumbX = (int)(0.5f + (thumbRange * ((max - extent - value) / (range - extent))));
+            }
+            thumbX +=  leftButtonX + leftButtonW;
+        }
+
+        /* If the buttons don't fit, allocate half of the available
+         * space to each and move the right one over.
+         */
+        int sbAvailButtonW = (sbSize.width - sbInsetsW);
+        if (sbAvailButtonW < sbButtonsW) {
+            rightButtonW = leftButtonW = sbAvailButtonW / 2;
+            rightButtonX = sbSize.width - (sbInsets.right + rightButtonW);
+        }
+
+        (ltr ? decrButton : incrButton).setBounds(leftButtonX, itemY, leftButtonW, itemH);
+        (ltr ? incrButton : decrButton).setBounds(rightButtonX, itemY, rightButtonW, itemH);
+
+        /* Update the trackRect field.
+         */
+        int itrackX = leftButtonX + leftButtonW;
+        int itrackW = rightButtonX - itrackX;
+        trackRect.setBounds(itrackX, itemY, itrackW, itemH);
+
+        /* Make sure the thumb fits between the buttons.  Note
+         * that setting the thumbs bounds causes a repaint.
+         */
+        if (thumbW >= (int)trackW) {
+            if (UIManager.getBoolean("ScrollBar.alwaysShowThumb")) {
+                // This is used primarily for GTK L&F, which expands the
+                // thumb to fit the track when it would otherwise be hidden.
+                setThumbBounds(itrackX, itemY, itrackW, itemH);
+            } else {
+                // Other L&F's simply hide the thumb in this case.
+                setThumbBounds(0, 0, 0, 0);
+            }
+        }
+        else {
+            if (thumbX + thumbW > rightButtonX) {
+                thumbX = rightButtonX - thumbW;
+            }
+            if (thumbX  < leftButtonX + leftButtonW) {
+                thumbX = leftButtonX + leftButtonW + 1;
+            }
+            setThumbBounds(thumbX, itemY, thumbW, itemH);
+        }
+    }
+
+    public void layoutContainer(Container scrollbarContainer)
+    {
+        /* If the user is dragging the value, we'll assume that the
+         * scrollbars layout is OK modulo the thumb which is being
+         * handled by the dragging code.
+         */
+        if (isDragging) {
+            return;
+        }
+
+        JScrollBar scrollbar = (JScrollBar)scrollbarContainer;
+        switch (scrollbar.getOrientation()) {
+        case JScrollBar.VERTICAL:
+            layoutVScrollbar(scrollbar);
+            break;
+
+        case JScrollBar.HORIZONTAL:
+            layoutHScrollbar(scrollbar);
+            break;
+        }
+    }
+
+
+    /**
+     * Set the bounds of the thumb and force a repaint that includes
+     * the old thumbBounds and the new one.
+     *
+     * @see #getThumbBounds
+     */
+    protected void setThumbBounds(int x, int y, int width, int height)
+    {
+        /* If the thumbs bounds haven't changed, we're done.
+         */
+        if ((thumbRect.x == x) &&
+            (thumbRect.y == y) &&
+            (thumbRect.width == width) &&
+            (thumbRect.height == height)) {
+            return;
+        }
+
+        /* Update thumbRect, and repaint the union of x,y,w,h and
+         * the old thumbRect.
+         */
+        int minX = Math.min(x, thumbRect.x);
+        int minY = Math.min(y, thumbRect.y);
+        int maxX = Math.max(x + width, thumbRect.x + thumbRect.width);
+        int maxY = Math.max(y + height, thumbRect.y + thumbRect.height);
+
+        thumbRect.setBounds(x, y, width, height);
+        scrollbar.repaint(minX, minY, maxX - minX, maxY - minY);
+
+        // Once there is API to determine the mouse location this will need
+        // to be changed.
+        setThumbRollover(false);
+    }
+
+
+    /**
+     * Return the current size/location of the thumb.
+     * <p>
+     * <b>Warning </b>: the value returned by this method should not be
+     * be modified, it's a reference to the actual rectangle, not a copy.
+     *
+     * @return The current size/location of the thumb.
+     * @see #setThumbBounds
+     */
+    protected Rectangle getThumbBounds() {
+        return thumbRect;
+    }
+
+
+    /**
+     * Returns the current bounds of the track, i.e. the space in between
+     * the increment and decrement buttons, less the insets.  The value
+     * returned by this method is updated each time the scrollbar is
+     * laid out (validated).
+     * <p>
+     * <b>Warning </b>: the value returned by this method should not be
+     * be modified, it's a reference to the actual rectangle, not a copy.
+     *
+     * @return the current bounds of the scrollbar track
+     * @see #layoutContainer
+     */
+    protected Rectangle getTrackBounds() {
+        return trackRect;
+    }
+
+    /*
+     * Method for scrolling by a block increment.
+     * Added for mouse wheel scrolling support, RFE 4202656.
+     */
+    static void scrollByBlock(JScrollBar scrollbar, int direction) {
+        // This method is called from BasicScrollPaneUI to implement wheel
+        // scrolling, and also from scrollByBlock().
+            int oldValue = scrollbar.getValue();
+            int blockIncrement = scrollbar.getBlockIncrement(direction);
+            int delta = blockIncrement * ((direction > 0) ? +1 : -1);
+            int newValue = oldValue + delta;
+
+            // Check for overflow.
+            if (delta > 0 && newValue < oldValue) {
+                newValue = scrollbar.getMaximum();
+            }
+            else if (delta < 0 && newValue > oldValue) {
+                newValue = scrollbar.getMinimum();
+            }
+
+            scrollbar.setValue(newValue);
+    }
+
+    protected void scrollByBlock(int direction)
+    {
+        scrollByBlock(scrollbar, direction);
+            trackHighlight = direction > 0 ? INCREASE_HIGHLIGHT : DECREASE_HIGHLIGHT;
+            Rectangle dirtyRect = getTrackBounds();
+            scrollbar.repaint(dirtyRect.x, dirtyRect.y, dirtyRect.width, dirtyRect.height);
+    }
+
+    /*
+     * Method for scrolling by a unit increment.
+     * Added for mouse wheel scrolling support, RFE 4202656.
+     *
+     * If limitByBlock is set to true, the scrollbar will scroll at least 1
+     * unit increment, but will not scroll farther than the block increment.
+     * See BasicScrollPaneUI.Handler.mouseWheelMoved().
+     */
+    static void scrollByUnits(JScrollBar scrollbar, int direction,
+                              int units, boolean limitToBlock) {
+        // This method is called from BasicScrollPaneUI to implement wheel
+        // scrolling, as well as from scrollByUnit().
+        int delta;
+        int limit = -1;
+
+        if (limitToBlock) {
+            if (direction < 0) {
+                limit = scrollbar.getValue() -
+                                         scrollbar.getBlockIncrement(direction);
+            }
+            else {
+                limit = scrollbar.getValue() +
+                                         scrollbar.getBlockIncrement(direction);
+            }
+        }
+
+        for (int i=0; i<units; i++) {
+            if (direction > 0) {
+                delta = scrollbar.getUnitIncrement(direction);
+            }
+            else {
+                delta = -scrollbar.getUnitIncrement(direction);
+            }
+
+            int oldValue = scrollbar.getValue();
+            int newValue = oldValue + delta;
+
+            // Check for overflow.
+            if (delta > 0 && newValue < oldValue) {
+                newValue = scrollbar.getMaximum();
+            }
+            else if (delta < 0 && newValue > oldValue) {
+                newValue = scrollbar.getMinimum();
+            }
+            if (oldValue == newValue) {
+                break;
+            }
+
+            if (limitToBlock && i > 0) {
+                assert limit != -1;
+                if ((direction < 0 && newValue < limit) ||
+                    (direction > 0 && newValue > limit)) {
+                    break;
+                }
+            }
+            scrollbar.setValue(newValue);
+        }
+    }
+
+    protected void scrollByUnit(int direction)  {
+        scrollByUnits(scrollbar, direction, 1, false);
+    }
+
+    /**
+     * Indicates whether the user can absolutely position the thumb with
+     * a mouse gesture (usually the middle mouse button).
+     *
+     * @return true if a mouse gesture can absolutely position the thumb
+     * @since 1.5
+     */
+    public boolean getSupportsAbsolutePositioning() {
+        return supportsAbsolutePositioning;
+    }
+
+    /**
+     * A listener to listen for model changes.
+     *
+     */
+    protected class ModelListener implements ChangeListener {
+        public void stateChanged(ChangeEvent e) {
+            if (!useCachedValue) {
+                scrollBarValue = scrollbar.getValue();
+            }
+            layoutContainer(scrollbar);
+            useCachedValue = false;
+        }
+    }
+
+
+    /**
+     * Track mouse drags.
+     */
+    protected class TrackListener
+        extends MouseAdapter implements MouseMotionListener
+    {
+        protected transient int offset;
+        protected transient int currentMouseX, currentMouseY;
+        private transient int direction = +1;
+
+        public void mouseReleased(MouseEvent e)
+        {
+            if (isDragging) {
+                updateThumbState(e.getX(), e.getY());
+            }
+            if (SwingUtilities.isRightMouseButton(e) ||
+                (!getSupportsAbsolutePositioning() &&
+                 SwingUtilities.isMiddleMouseButton(e)))
+                return;
+            if(!scrollbar.isEnabled())
+                return;
+
+            Rectangle r = getTrackBounds();
+            scrollbar.repaint(r.x, r.y, r.width, r.height);
+
+            trackHighlight = NO_HIGHLIGHT;
+            isDragging = false;
+            offset = 0;
+            scrollTimer.stop();
+            useCachedValue = true;
+            scrollbar.setValueIsAdjusting(false);
+        }
+
+
+        /**
+         * If the mouse is pressed above the "thumb" component
+         * then reduce the scrollbars value by one page ("page up"),
+         * otherwise increase it by one page.  If there is no
+         * thumb then page up if the mouse is in the upper half
+         * of the track.
+         */
+        public void mousePressed(MouseEvent e)
+        {
+            if (SwingUtilities.isRightMouseButton(e) ||
+                (!getSupportsAbsolutePositioning() &&
+                 SwingUtilities.isMiddleMouseButton(e)))
+                return;
+            if(!scrollbar.isEnabled())
+                return;
+
+            if (!scrollbar.hasFocus() && scrollbar.isRequestFocusEnabled()) {
+                scrollbar.requestFocus();
+            }
+
+            useCachedValue = true;
+            scrollbar.setValueIsAdjusting(true);
+
+            currentMouseX = e.getX();
+            currentMouseY = e.getY();
+
+            // Clicked in the Thumb area?
+            if(getThumbBounds().contains(currentMouseX, currentMouseY)) {
+                switch (scrollbar.getOrientation()) {
+                case JScrollBar.VERTICAL:
+                    offset = currentMouseY - getThumbBounds().y;
+                    break;
+                case JScrollBar.HORIZONTAL:
+                    offset = currentMouseX - getThumbBounds().x;
+                    break;
+                }
+                isDragging = true;
+                return;
+            }
+            else if (getSupportsAbsolutePositioning() &&
+                     SwingUtilities.isMiddleMouseButton(e)) {
+                switch (scrollbar.getOrientation()) {
+                case JScrollBar.VERTICAL:
+                    offset = getThumbBounds().height / 2;
+                    break;
+                case JScrollBar.HORIZONTAL:
+                    offset = getThumbBounds().width / 2;
+                    break;
+                }
+                isDragging = true;
+                setValueFrom(e);
+                return;
+            }
+            isDragging = false;
+
+            Dimension sbSize = scrollbar.getSize();
+            direction = +1;
+
+            switch (scrollbar.getOrientation()) {
+            case JScrollBar.VERTICAL:
+                if (getThumbBounds().isEmpty()) {
+                    int scrollbarCenter = sbSize.height / 2;
+                    direction = (currentMouseY < scrollbarCenter) ? -1 : +1;
+                } else {
+                    int thumbY = getThumbBounds().y;
+                    direction = (currentMouseY < thumbY) ? -1 : +1;
+                }
+                break;
+            case JScrollBar.HORIZONTAL:
+                if (getThumbBounds().isEmpty()) {
+                    int scrollbarCenter = sbSize.width / 2;
+                    direction = (currentMouseX < scrollbarCenter) ? -1 : +1;
+                } else {
+                    int thumbX = getThumbBounds().x;
+                    direction = (currentMouseX < thumbX) ? -1 : +1;
+                }
+                if (!scrollbar.getComponentOrientation().isLeftToRight()) {
+                    direction = -direction;
+                }
+                break;
+            }
+            scrollByBlock(direction);
+
+            scrollTimer.stop();
+            scrollListener.setDirection(direction);
+            scrollListener.setScrollByBlock(true);
+            startScrollTimerIfNecessary();
+        }
+
+
+        /**
+         * Set the models value to the position of the thumb's top of Vertical
+         * scrollbar, or the left/right of Horizontal scrollbar in
+         * left-to-right/right-to-left scrollbar relative to the origin of the
+         * track.
+         */
+        public void mouseDragged(MouseEvent e) {
+            if (SwingUtilities.isRightMouseButton(e) ||
+                (!getSupportsAbsolutePositioning() &&
+                 SwingUtilities.isMiddleMouseButton(e)))
+                return;
+            if(!scrollbar.isEnabled() || getThumbBounds().isEmpty()) {
+                return;
+            }
+            if (isDragging) {
+                setValueFrom(e);
+            } else {
+                currentMouseX = e.getX();
+                currentMouseY = e.getY();
+                updateThumbState(currentMouseX, currentMouseY);
+                startScrollTimerIfNecessary();
+            }
+        }
+
+        private void setValueFrom(MouseEvent e) {
+            boolean active = isThumbRollover();
+            BoundedRangeModel model = scrollbar.getModel();
+            Rectangle thumbR = getThumbBounds();
+            float trackLength;
+            int thumbMin, thumbMax, thumbPos;
+
+            if (scrollbar.getOrientation() == JScrollBar.VERTICAL) {
+                thumbMin = decrButton.getY() + decrButton.getHeight();
+                thumbMax = incrButton.getY() - thumbR.height;
+                thumbPos = Math.min(thumbMax, Math.max(thumbMin, (e.getY() - offset)));
+                setThumbBounds(thumbR.x, thumbPos, thumbR.width, thumbR.height);
+                trackLength = getTrackBounds().height;
+            }
+            else {
+                if (scrollbar.getComponentOrientation().isLeftToRight()) {
+                    thumbMin = decrButton.getX() + decrButton.getWidth();
+                    thumbMax = incrButton.getX() - thumbR.width;
+                } else {
+                    thumbMin = incrButton.getX() + incrButton.getWidth();
+                    thumbMax = decrButton.getX() - thumbR.width;
+                }
+                thumbPos = Math.min(thumbMax, Math.max(thumbMin, (e.getX() - offset)));
+                setThumbBounds(thumbPos, thumbR.y, thumbR.width, thumbR.height);
+                trackLength = getTrackBounds().width;
+            }
+
+            /* Set the scrollbars value.  If the thumb has reached the end of
+             * the scrollbar, then just set the value to its maximum.  Otherwise
+             * compute the value as accurately as possible.
+             */
+            if (thumbPos == thumbMax) {
+                if (scrollbar.getOrientation() == JScrollBar.VERTICAL ||
+                    scrollbar.getComponentOrientation().isLeftToRight()) {
+                    scrollbar.setValue(model.getMaximum() - model.getExtent());
+                } else {
+                    scrollbar.setValue(model.getMinimum());
+                }
+            }
+            else {
+                float valueMax = model.getMaximum() - model.getExtent();
+                float valueRange = valueMax - model.getMinimum();
+                float thumbValue = thumbPos - thumbMin;
+                float thumbRange = thumbMax - thumbMin;
+                int value;
+                if (scrollbar.getOrientation() == JScrollBar.VERTICAL ||
+                    scrollbar.getComponentOrientation().isLeftToRight()) {
+                    value = (int)(0.5 + ((thumbValue / thumbRange) * valueRange));
+                } else {
+                    value = (int)(0.5 + (((thumbMax - thumbPos) / thumbRange) * valueRange));
+                }
+
+                useCachedValue = true;
+                scrollBarValue = value + model.getMinimum();
+                scrollbar.setValue(adjustValueIfNecessary(scrollBarValue));
+            }
+            setThumbRollover(active);
+        }
+
+        private int adjustValueIfNecessary(int value) {
+            if (scrollbar.getParent() instanceof JScrollPane) {
+                JScrollPane scrollpane = (JScrollPane)scrollbar.getParent();
+                JViewport viewport = scrollpane.getViewport();
+                Component view = viewport.getView();
+                if (view instanceof JList) {
+                    JList list = (JList)view;
+                    if (DefaultLookup.getBoolean(list, list.getUI(),
+                                                 "List.lockToPositionOnScroll", false)) {
+                        int adjustedValue = value;
+                        int mode = list.getLayoutOrientation();
+                        int orientation = scrollbar.getOrientation();
+                        if (orientation == JScrollBar.VERTICAL && mode == JList.VERTICAL) {
+                            int index = list.locationToIndex(new Point(0, value));
+                            Rectangle rect = list.getCellBounds(index, index);
+                            if (rect != null) {
+                                adjustedValue = rect.y;
+                            }
+                        }
+                        if (orientation == JScrollBar.HORIZONTAL &&
+                            (mode == JList.VERTICAL_WRAP || mode == JList.HORIZONTAL_WRAP)) {
+                            if (scrollpane.getComponentOrientation().isLeftToRight()) {
+                                int index = list.locationToIndex(new Point(value, 0));
+                                Rectangle rect = list.getCellBounds(index, index);
+                                if (rect != null) {
+                                    adjustedValue = rect.x;
+                                }
+                            }
+                            else {
+                                Point loc = new Point(value, 0);
+                                int extent = viewport.getExtentSize().width;
+                                loc.x += extent - 1;
+                                int index = list.locationToIndex(loc);
+                                Rectangle rect = list.getCellBounds(index, index);
+                                if (rect != null) {
+                                    adjustedValue = rect.x + rect.width - extent;
+                                }
+                            }
+                        }
+                        value = adjustedValue;
+
+                    }
+                }
+            }
+            return value;
+        }
+
+        private void startScrollTimerIfNecessary() {
+            if (scrollTimer.isRunning()) {
+                return;
+            }
+
+            Rectangle tb = getThumbBounds();
+
+            switch (scrollbar.getOrientation()) {
+            case JScrollBar.VERTICAL:
+                if (direction > 0) {
+                    if (tb.y + tb.height < trackListener.currentMouseY) {
+                        scrollTimer.start();
+                    }
+                } else if (tb.y > trackListener.currentMouseY) {
+                    scrollTimer.start();
+                }
+                break;
+            case JScrollBar.HORIZONTAL:
+                if ((direction > 0 && isMouseAfterThumb())
+                        || (direction < 0 && isMouseBeforeThumb())) {
+
+                    scrollTimer.start();
+                }
+                break;
+            }
+        }
+
+        public void mouseMoved(MouseEvent e) {
+            if (!isDragging) {
+                updateThumbState(e.getX(), e.getY());
+            }
+        }
+
+        /**
+         * Invoked when the mouse exits the scrollbar.
+         *
+         * @param e MouseEvent further describing the event
+         * @since 1.5
+         */
+        public void mouseExited(MouseEvent e) {
+            if (!isDragging) {
+                setThumbRollover(false);
+            }
+        }
+    }
+
+
+    /**
+     * Listener for cursor keys.
+     */
+    protected class ArrowButtonListener extends MouseAdapter
+    {
+        // Because we are handling both mousePressed and Actions
+        // we need to make sure we don't fire under both conditions.
+        // (keyfocus on scrollbars causes action without mousePress
+        boolean handledEvent;
+
+        public void mousePressed(MouseEvent e)          {
+            if(!scrollbar.isEnabled()) { return; }
+            // not an unmodified left mouse button
+            //if(e.getModifiers() != InputEvent.BUTTON1_MASK) {return; }
+            if( ! SwingUtilities.isLeftMouseButton(e)) { return; }
+
+            int direction = (e.getSource() == incrButton) ? 1 : -1;
+
+            scrollByUnit(direction);
+            scrollTimer.stop();
+            scrollListener.setDirection(direction);
+            scrollListener.setScrollByBlock(false);
+            scrollTimer.start();
+
+            handledEvent = true;
+            if (!scrollbar.hasFocus() && scrollbar.isRequestFocusEnabled()) {
+                scrollbar.requestFocus();
+            }
+        }
+
+        public void mouseReleased(MouseEvent e)         {
+            scrollTimer.stop();
+            handledEvent = false;
+            scrollbar.setValueIsAdjusting(false);
+        }
+    }
+
+
+    /**
+     * Listener for scrolling events initiated in the
+     * <code>ScrollPane</code>.
+     */
+    protected class ScrollListener implements ActionListener
+    {
+        int direction = +1;
+        boolean useBlockIncrement;
+
+        public ScrollListener() {
+            direction = +1;
+            useBlockIncrement = false;
+        }
+
+        public ScrollListener(int dir, boolean block)   {
+            direction = dir;
+            useBlockIncrement = block;
+        }
+
+        public void setDirection(int direction) { this.direction = direction; }
+        public void setScrollByBlock(boolean block) { this.useBlockIncrement = block; }
+
+        public void actionPerformed(ActionEvent e) {
+            if(useBlockIncrement)       {
+                scrollByBlock(direction);
+                // Stop scrolling if the thumb catches up with the mouse
+                if(scrollbar.getOrientation() == JScrollBar.VERTICAL)   {
+                    if(direction > 0)   {
+                        if(getThumbBounds().y + getThumbBounds().height
+                                >= trackListener.currentMouseY)
+                                    ((Timer)e.getSource()).stop();
+                    } else if(getThumbBounds().y <= trackListener.currentMouseY)        {
+                        ((Timer)e.getSource()).stop();
+                    }
+                } else {
+                    if ((direction > 0 && !isMouseAfterThumb())
+                           || (direction < 0 && !isMouseBeforeThumb())) {
+
+                       ((Timer)e.getSource()).stop();
+                    }
+                }
+            } else {
+                scrollByUnit(direction);
+            }
+
+            if(direction > 0
+                && scrollbar.getValue()+scrollbar.getVisibleAmount()
+                        >= scrollbar.getMaximum())
+                ((Timer)e.getSource()).stop();
+            else if(direction < 0
+                && scrollbar.getValue() <= scrollbar.getMinimum())
+                ((Timer)e.getSource()).stop();
+        }
+    }
+
+    private boolean isMouseLeftOfThumb() {
+        return trackListener.currentMouseX < getThumbBounds().x;
+    }
+
+    private boolean isMouseRightOfThumb() {
+        Rectangle tb = getThumbBounds();
+        return trackListener.currentMouseX > tb.x + tb.width;
+    }
+
+    private boolean isMouseBeforeThumb() {
+        return scrollbar.getComponentOrientation().isLeftToRight()
+            ? isMouseLeftOfThumb()
+            : isMouseRightOfThumb();
+    }
+
+    private boolean isMouseAfterThumb() {
+        return scrollbar.getComponentOrientation().isLeftToRight()
+            ? isMouseRightOfThumb()
+            : isMouseLeftOfThumb();
+    }
+
+    private void updateButtonDirections() {
+        int orient = scrollbar.getOrientation();
+        if (scrollbar.getComponentOrientation().isLeftToRight()) {
+            if (incrButton instanceof BasicArrowButton) {
+                ((BasicArrowButton)incrButton).setDirection(
+                        orient == HORIZONTAL? EAST : SOUTH);
+            }
+            if (decrButton instanceof BasicArrowButton) {
+                ((BasicArrowButton)decrButton).setDirection(
+                        orient == HORIZONTAL? WEST : NORTH);
+            }
+        }
+        else {
+            if (incrButton instanceof BasicArrowButton) {
+                ((BasicArrowButton)incrButton).setDirection(
+                        orient == HORIZONTAL? WEST : SOUTH);
+            }
+            if (decrButton instanceof BasicArrowButton) {
+                ((BasicArrowButton)decrButton).setDirection(
+                        orient == HORIZONTAL ? EAST : NORTH);
+            }
+        }
+    }
+
+    public class PropertyChangeHandler implements PropertyChangeListener
+    {
+        // NOTE: This class exists only for backward compatability. All
+        // its functionality has been moved into Handler. If you need to add
+        // new functionality add it to the Handler, but make sure this
+        // class calls into the Handler.
+
+        public void propertyChange(PropertyChangeEvent e) {
+            getHandler().propertyChange(e);
+        }
+    }
+
+
+    /**
+     * Used for scrolling the scrollbar.
+     */
+    private static class Actions extends UIAction {
+        private static final String POSITIVE_UNIT_INCREMENT =
+                                    "positiveUnitIncrement";
+        private static final String POSITIVE_BLOCK_INCREMENT =
+                                    "positiveBlockIncrement";
+        private static final String NEGATIVE_UNIT_INCREMENT =
+                                    "negativeUnitIncrement";
+        private static final String NEGATIVE_BLOCK_INCREMENT =
+                                    "negativeBlockIncrement";
+        private static final String MIN_SCROLL = "minScroll";
+        private static final String MAX_SCROLL = "maxScroll";
+
+        Actions(String name) {
+            super(name);
+        }
+
+        public void actionPerformed(ActionEvent e) {
+            JScrollBar scrollBar = (JScrollBar)e.getSource();
+            String key = getName();
+            if (key == POSITIVE_UNIT_INCREMENT) {
+                scroll(scrollBar, POSITIVE_SCROLL, false);
+            }
+            else if (key == POSITIVE_BLOCK_INCREMENT) {
+                scroll(scrollBar, POSITIVE_SCROLL, true);
+            }
+            else if (key == NEGATIVE_UNIT_INCREMENT) {
+                scroll(scrollBar, NEGATIVE_SCROLL, false);
+            }
+            else if (key == NEGATIVE_BLOCK_INCREMENT) {
+                scroll(scrollBar, NEGATIVE_SCROLL, true);
+            }
+            else if (key == MIN_SCROLL) {
+                scroll(scrollBar, BasicScrollBarUI.MIN_SCROLL, true);
+            }
+            else if (key == MAX_SCROLL) {
+                scroll(scrollBar, BasicScrollBarUI.MAX_SCROLL, true);
+            }
+        }
+        private void scroll(JScrollBar scrollBar, int dir, boolean block) {
+
+            if (dir == NEGATIVE_SCROLL || dir == POSITIVE_SCROLL) {
+                int amount;
+                // Don't use the BasicScrollBarUI.scrollByXXX methods as we
+                // don't want to use an invokeLater to reset the trackHighlight
+                // via an invokeLater
+                if (block) {
+                    if (dir == NEGATIVE_SCROLL) {
+                        amount = -1 * scrollBar.getBlockIncrement(-1);
+                    }
+                    else {
+                        amount = scrollBar.getBlockIncrement(1);
+                    }
+                }
+                else {
+                    if (dir == NEGATIVE_SCROLL) {
+                        amount = -1 * scrollBar.getUnitIncrement(-1);
+                    }
+                    else {
+                        amount = scrollBar.getUnitIncrement(1);
+                    }
+                }
+                scrollBar.setValue(scrollBar.getValue() + amount);
+            }
+            else if (dir == BasicScrollBarUI.MIN_SCROLL) {
+                scrollBar.setValue(scrollBar.getMinimum());
+            }
+            else if (dir == BasicScrollBarUI.MAX_SCROLL) {
+                scrollBar.setValue(scrollBar.getMaximum());
+            }
+        }
+    }
+
+
+    //
+    // EventHandler
+    //
+    private class Handler implements FocusListener, PropertyChangeListener {
+        //
+        // FocusListener
+        //
+        public void focusGained(FocusEvent e) {
+            scrollbar.repaint();
+        }
+
+        public void focusLost(FocusEvent e) {
+            scrollbar.repaint();
+        }
+
+
+        //
+        // PropertyChangeListener
+        //
+        public void propertyChange(PropertyChangeEvent e) {
+            String propertyName = e.getPropertyName();
+
+            if ("model" == propertyName) {
+                BoundedRangeModel oldModel = (BoundedRangeModel)e.getOldValue();
+                BoundedRangeModel newModel = (BoundedRangeModel)e.getNewValue();
+                oldModel.removeChangeListener(modelListener);
+                newModel.addChangeListener(modelListener);
+                scrollbar.repaint();
+                scrollbar.revalidate();
+            } else if ("orientation" == propertyName) {
+                updateButtonDirections();
+            } else if ("componentOrientation" == propertyName) {
+                updateButtonDirections();
+                InputMap inputMap = getInputMap(JComponent.WHEN_FOCUSED);
+                SwingUtilities.replaceUIInputMap(scrollbar, JComponent.WHEN_FOCUSED, inputMap);
+            }
+        }
+    }
+}