basicscrollbarui.java

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	scrollTimer.setRepeats(true);

	installComponents();
	installListeners();
	installDefaults();
	configureScrollBarColors();

	calculatePreferredSize();
	layoutContainer(scrollbar);
      }
  }

  /**
   * This method lays out the scrollbar.
   *
   * @param scrollbarContainer The Container to layout.
   */
  public void layoutContainer(Container scrollbarContainer)
  {
    if (scrollbarContainer instanceof JScrollBar)
      {
	if (scrollbar.getOrientation() == SwingConstants.HORIZONTAL)
	  layoutHScrollbar((JScrollBar) scrollbarContainer);
	else
	  layoutVScrollbar((JScrollBar) scrollbarContainer);
      }
  }

  /**
   * This method lays out the scrollbar horizontally.
   *
   * @param sb The JScrollBar to layout.
   */
  protected void layoutHScrollbar(JScrollBar sb)
  {
    // All we have to do is layout the 2 buttons?
    Rectangle vr = new Rectangle();
    SwingUtilities.calculateInnerArea(scrollbar, vr);

    // Update the rectangles.
    getTrackBounds();
    getThumbBounds();

    Dimension incrDims = incrButton.getPreferredSize();
    Dimension decrDims = decrButton.getPreferredSize();

    decrButton.setBounds(vr.x, vr.y, decrDims.width, trackRect.height);
    incrButton.setBounds(trackRect.x + trackRect.width, vr.y, incrDims.width,
                         trackRect.height);
  }

  /**
   * This method lays out the scrollbar vertically.
   *
   * @param sb The JScrollBar to layout.
   */
  protected void layoutVScrollbar(JScrollBar sb)
  {
    Rectangle vr = new Rectangle();
    SwingUtilities.calculateInnerArea(scrollbar, vr);

    // Update rectangles
    getTrackBounds();
    getThumbBounds();

    Dimension incrDims = incrButton.getPreferredSize();
    Dimension decrDims = decrButton.getPreferredSize();

    decrButton.setBounds(vr.x, vr.y, trackRect.width, decrDims.height);
    incrButton.setBounds(vr.x, trackRect.y + trackRect.height,
                         trackRect.width, incrDims.height);
  }

  /**
   * This method returns the minimum size required for the layout.
   *
   * @param scrollbarContainer The Container that is laid out.
   *
   * @return The minimum size.
   */
  public Dimension minimumLayoutSize(Container scrollbarContainer)
  {
    return preferredLayoutSize(scrollbarContainer);
  }

  /**
   * This method is called when the component is painted.
   *
   * @param g The Graphics object to paint with.
   * @param c The JComponent to paint.
   */
  public void paint(Graphics g, JComponent c)
  {
    layoutContainer(scrollbar);
    paintTrack(g, c, getTrackBounds());
    paintThumb(g, c, getThumbBounds());

    if (trackHighlight == INCREASE_HIGHLIGHT)
      paintIncreaseHighlight(g);
    else if (trackHighlight == DECREASE_HIGHLIGHT)
      paintDecreaseHighlight(g);
  }

  /**
   * This method is called when repainting and the mouse is  pressed in the
   * track. It paints the track below the thumb with the trackHighlight
   * color.
   *
   * @param g The Graphics object to paint with.
   */
  protected void paintDecreaseHighlight(Graphics g)
  {
    Color saved = g.getColor();

    g.setColor(trackHighlightColor);
    if (scrollbar.getOrientation() == HORIZONTAL)
      g.fillRect(trackRect.x, trackRect.y, thumbRect.x - trackRect.x,
                 trackRect.height);
    else
      g.fillRect(trackRect.x, trackRect.y, trackRect.width,
                 thumbRect.y - trackRect.y);
    g.setColor(saved);
  }

  /**
   * This method is called when repainting and the mouse is  pressed in the
   * track. It paints the track above the thumb with the trackHighlight
   * color.
   *
   * @param g The Graphics objet to paint with.
   */
  protected void paintIncreaseHighlight(Graphics g)
  {
    Color saved = g.getColor();

    g.setColor(trackHighlightColor);
    if (scrollbar.getOrientation() == HORIZONTAL)
      g.fillRect(thumbRect.x + thumbRect.width, trackRect.y,
                 trackRect.x + trackRect.width - thumbRect.x - thumbRect.width,
                 trackRect.height);
    else
      g.fillRect(trackRect.x, thumbRect.y + thumbRect.height, trackRect.width,
                 trackRect.y + trackRect.height - thumbRect.y
                 - thumbRect.height);
    g.setColor(saved);
  }

  /**
   * This method paints the thumb.
   *
   * @param g The Graphics object to paint with.
   * @param c The Component that is being painted.
   * @param thumbBounds The thumb bounds.
   */
  protected void paintThumb(Graphics g, JComponent c, Rectangle thumbBounds)
  {
    Color saved = g.getColor();
    Point x;
    Point y;
    Point z;
    Polygon lines;

    g.setColor(thumbHighlightColor);
    x = new Point(thumbBounds.x + 1, thumbBounds.y + 1);
    y = new Point(x);
    y.translate(thumbBounds.width - 2, 0);
    z = new Point(x);
    z.translate(0, thumbBounds.height - 2);

    lines = new Polygon(new int[] { x.x, y.x, z.x },
                        new int[] { x.y, y.y, z.y }, 3);

    g.drawPolygon(lines);

    g.setColor(thumbLightShadowColor);
    x = new Point(thumbBounds.x + thumbBounds.width - 1,
                  thumbBounds.y + thumbBounds.height - 1);
    y = new Point(x);
    y.translate(-(thumbBounds.width - 2), 0);
    z = new Point(x);
    z.translate(0, -(thumbBounds.height - 2));

    lines = new Polygon(new int[] { x.x, y.x, z.x },
                        new int[] { x.y, y.y, z.y }, 3);
    g.drawPolygon(lines);

    g.setColor(thumbDarkShadowColor);
    x = new Point(thumbBounds.x + thumbBounds.width,
                  thumbBounds.y + thumbBounds.height);
    y = new Point(x);
    y.translate(-thumbBounds.width, 0);
    z = new Point(x);
    z.translate(0, -thumbBounds.height);

    lines = new Polygon(new int[] { x.x, y.x, z.x },
                        new int[] { x.y, y.y, z.y }, 3);
    g.drawPolygon(lines);

    g.setColor(thumbColor);
    g.fillRect(thumbBounds.x, thumbBounds.y, thumbBounds.width,
               thumbBounds.height);

    g.setColor(saved);
  }

  /**
   * This method paints the track.
   *
   * @param g The Graphics object to paint with.
   * @param c The JComponent being painted.
   * @param trackBounds The track's bounds.
   */
  protected void paintTrack(Graphics g, JComponent c, Rectangle trackBounds)
  {
    Color saved = g.getColor();
    g.setColor(trackColor);
    g.fill3DRect(trackBounds.x, trackBounds.y, trackBounds.width,
                 trackBounds.height, false);
    g.setColor(saved);
  }

  /**
   * This method returns the preferred size for the layout.
   *
   * @param scrollbarContainer The Container to find a size for.
   *
   * @return The preferred size for the layout.
   */
  public Dimension preferredLayoutSize(Container scrollbarContainer)
  {
    if (scrollbarContainer instanceof JComponent)
      return getPreferredSize((JComponent) scrollbarContainer);
    else
      return null;
  }

  /**
   * This method removes a child component from the layout.
   *
   * @param child The child to remove.
   */
  public void removeLayoutComponent(Component child)
  {
    // You should not be removing stuff from this component.
  }

  /**
   * The method scrolls the thumb by a block in the  direction specified.
   *
   * @param direction The direction to scroll.
   */
  protected void scrollByBlock(int direction)
  {
    scrollbar.setValue(scrollbar.getValue()
                       + scrollbar.getBlockIncrement(direction));
  }

  /**
   * The method scrolls the thumb by a unit in the direction specified.
   *
   * @param direction The direction to scroll.
   */
  protected void scrollByUnit(int direction)
  {
    scrollbar.setValue(scrollbar.getValue()
                       + scrollbar.getUnitIncrement(direction));
  }

  /**
   * This method sets the thumb's bounds.
   *
   * @param x The X position of the thumb.
   * @param y The Y position of the thumb.
   * @param width The width of the thumb.
   * @param height The height of the thumb.
   */
  protected void setThumbBounds(int x, int y, int width, int height)
  {
    thumbRect.x = x;
    thumbRect.y = y;
    thumbRect.width = width;
    thumbRect.height = height;
  }

  /**
   * This method uninstalls any components that  are a part of or related to
   * this scrollbar.
   */
  protected void uninstallComponents()
  {
    scrollbar.remove(incrButton);
    scrollbar.remove(decrButton);
    incrButton = null;
    decrButton = null;
  }

  /**
   * This method uninstalls any defaults that this scrollbar acquired from the
   * Basic Look and Feel defaults.
   */
  protected void uninstallDefaults()
  {
    scrollbar.setForeground(null);
    scrollbar.setBackground(null);
    scrollbar.setBorder(null);
  }

  /**
   * This method uninstalls any keyboard actions this scrollbar acquired
   * during install.
   */
  protected void uninstallKeyboardActions()
  {
    // FIXME: implement.
  }

  /**
   * This method uninstalls any listeners that were registered during install.
   */
  protected void uninstallListeners()
  {
    scrollTimer.removeActionListener(scrollListener);

    scrollbar.getModel().removeChangeListener(modelListener);
    scrollbar.removePropertyChangeListener(propertyChangeListener);

    decrButton.removeMouseListener(buttonListener);
    incrButton.removeMouseListener(buttonListener);

    scrollbar.removeMouseListener(trackListener);
    scrollbar.removeMouseMotionListener(trackListener);

    propertyChangeListener = null;
    modelListener = null;
    buttonListener = null;
    trackListener = null;
    scrollListener = null;
  }

  /**
   * This method uninstalls the UI. This includes removing any defaults,
   * listeners, and components that this UI may have initialized. It also
   * nulls any instance data.
   *
   * @param c The Component to uninstall for.
   */
  public void uninstallUI(JComponent c)
  {
    uninstallDefaults();
    uninstallListeners();
    uninstallComponents();

    scrollTimer = null;

    thumbRect = null;
    trackRect = null;

    trackColor = null;
    trackHighlightColor = null;
    thumbColor = null;
    thumbHighlightColor = null;
    thumbDarkShadowColor = null;
    thumbLightShadowColor = null;

    scrollbar = null;
  }

  /**
   * This method returns the value in the scrollbar's range given the y
   * coordinate. If the value is out of range, it will return the closest
   * legal value.
   *
   * @param yPos The y coordinate to calculate a value for.
   *
   * @return The value for the y coordinate.
   */
  private int valueForYPosition(int yPos)
  {
    int min = scrollbar.getMinimum();
    int max = scrollbar.getMaximum();
    int len = trackRect.height;

    int value;

    // If the length is 0, you shouldn't be able to even see where the thumb is.
    // This really shouldn't ever happen, but just in case, we'll return the middle.
    if (len == 0)
      return ((max - min) / 2);

    value = ((yPos - trackRect.y) * (max - min) / len + min);

    // If this isn't a legal value, then we'll have to move to one now.
    if (value > max)
      value = max;
    else if (value < min)
      value = min;
    return value;
  }

  /**
   * This method returns the value in the scrollbar's range given the x
   * coordinate. If the value is out of range, it will return the closest
   * legal value.
   *
   * @param xPos The x coordinate to calculate a value for.
   *
   * @return The value for the x coordinate.
   */
  private int valueForXPosition(int xPos)
  {
    int min = scrollbar.getMinimum();
    int max = scrollbar.getMaximum();
    int len = trackRect.width;

    int value;

    // If the length is 0, you shouldn't be able to even see where the slider is.
    // This really shouldn't ever happen, but just in case, we'll return the middle.
    if (len == 0)
      return ((max - min) / 2);

    value = ((xPos - trackRect.x) * (max - min) / len + min);

    // If this isn't a legal value, then we'll have to move to one now.
    if (value > max)
      value = max;
    else if (value < min)
      value = min;
    return value;
  }
}