basicsliderui.java

gcc的组建

      {
	Object comp = list.nextElement();
	if (! (comp instanceof Component))
	  continue;
	label = (Component) comp;
	pref = label.getPreferredSize();
	if (pref != null && pref.height > tallest)
	  tallest = pref.height;
      }
    return tallest;
  }

  /**
   * This method returns the width of the label whose key has the highest
   * value.
   *
   * @return The width of the high value label or 0 if no label table exists.
   */
  protected int getWidthOfHighValueLabel()
  {
    Component highValueLabel = getHighestValueLabel();
    if (highValueLabel != null)
      return highValueLabel.getWidth();
    else
      return 0;
  }

  /**
   * This method returns the width of the label whose key has the lowest
   * value.
   *
   * @return The width of the low value label or 0 if no label table exists.
   */
  protected int getWidthOfLowValueLabel()
  {
    Component lowValueLabel = getLowestValueLabel();
    if (lowValueLabel != null)
      return lowValueLabel.getWidth();
    else
      return 0;
  }

  /**
   * This method returns the height of the label whose key has the highest
   * value.
   *
   * @return The height of the high value label or 0 if no label table exists.
   */
  protected int getHeightOfHighValueLabel()
  {
    Component highValueLabel = getHighestValueLabel();
    if (highValueLabel != null)
      return highValueLabel.getHeight();
    else
      return 0;
  }

  /**
   * This method returns the height of the label whose key has the lowest
   * value.
   *
   * @return The height of the low value label or 0 if no label table exists.
   */
  protected int getHeightOfLowValueLabel()
  {
    Component lowValueLabel = getLowestValueLabel();
    if (lowValueLabel != null)
      return lowValueLabel.getHeight();
    else
      return 0;
  }

  /**
   * This method returns whether the slider is to be drawn inverted.
   *
   * @return True is the slider is to be drawn inverted.
   */
  protected boolean drawInverted()
  {
    return ! (slider.getInverted() ^ leftToRightCache);
  }

  /**
   * This method returns the label whose key has the lowest value.
   *
   * @return The low value label or null if no label table exists.
   */
  protected Component getLowestValueLabel()
  {
    Integer key = new Integer(Integer.MAX_VALUE);
    Integer tmpKey;
    Dictionary labelTable = slider.getLabelTable();

    if (labelTable == null)
      return null;

    for (Enumeration list = labelTable.keys(); list.hasMoreElements();)
      {
	Object value = list.nextElement();
	if (! (value instanceof Integer))
	  continue;
	tmpKey = (Integer) value;
	if (tmpKey.intValue() < key.intValue())
	  key = tmpKey;
      }
    Object comp = labelTable.get(key);
    if (! (comp instanceof Component))
      return null;
    return (Component) comp;
  }

  /**
   * This method returns the label whose  key has the highest value.
   *
   * @return The high value label or null if no label table exists.
   */
  protected Component getHighestValueLabel()
  {
    Integer key = new Integer(Integer.MIN_VALUE);
    Integer tmpKey;
    Dictionary labelTable = slider.getLabelTable();

    if (labelTable == null)
      return null;

    for (Enumeration list = labelTable.keys(); list.hasMoreElements();)
      {
	Object value = list.nextElement();
	if (! (value instanceof Integer))
	  continue;
	tmpKey = (Integer) value;
	if (tmpKey.intValue() > key.intValue())
	  key = tmpKey;
      }
    Object comp = labelTable.get(key);
    if (! (comp instanceof Component))
      return null;
    return (Component) comp;
  }

  /**
   * This method is used to paint the {@link JSlider}. It delegates all its
   * duties to the various paint methods like paintTicks(),  paintTrack(),
   * paintThumb(), etc.
   *
   * @param g The {@link Graphics} object to paint with.
   * @param c The {@link JComponent} that is being painted.
   */
  public void paint(Graphics g, JComponent c)
  {
    // FIXME: Move this to propertyChangeEvent handler, when we get those.
    leftToRightCache = slider.getComponentOrientation() != ComponentOrientation.RIGHT_TO_LEFT;
    // FIXME: This next line is only here because the above line is here.
    calculateGeometry();

    if (slider.getPaintTrack())
      paintTrack(g);
    if (slider.getPaintTicks())
      paintTicks(g);
    if (slider.getPaintLabels())
      paintLabels(g);

    //FIXME: Paint focus.
    paintThumb(g);
  }

  /**
   * This method recalculates any rectangles that need to be recalculated
   * after the insets of the component have changed.
   */
  protected void recalculateIfInsetsChanged()
  {
    // Examining a test program shows that either Sun calls private
    // methods that we don't know about, or these don't do anything.
    calculateFocusRect();

    calculateContentRect();
    calculateThumbSize();
    calculateTrackBuffer();
    calculateTrackRect();
    calculateThumbLocation();

    calculateTickRect();
    calculateLabelRect();
  }

  /**
   * This method recalculates any rectangles that need to be recalculated
   * after the orientation of the slider changes.
   */
  protected void recalculateIfOrientationChanged()
  {
    // Examining a test program shows that either Sun calls private
    // methods that we don't know about, or these don't do anything.  
    calculateThumbSize();
    calculateTrackBuffer();
    calculateTrackRect();
    calculateThumbLocation();

    calculateTickRect();
    calculateLabelRect();
  }

  /**
   * This method is called during a repaint if the slider has focus. It draws
   * an outline of the  focusRect using the color returned by
   * getFocusColor().
   *
   * @param g The {@link Graphics} object to draw with.
   */
  public void paintFocus(Graphics g)
  {
    Color saved_color = g.getColor();

    g.setColor(getFocusColor());

    g.drawRect(focusRect.x, focusRect.y, focusRect.width, focusRect.height);

    g.setColor(saved_color);
  }

  /**
   * <p>
   * This method is called during a repaint if the  track is to be drawn. It
   * draws a 3D rectangle to  represent the track. The track is not the size
   * of the trackRect. The top and left edges of the track should be outlined
   * with the shadow color. The bottom and right edges should be outlined
   * with the highlight color.
   * </p>
   * <pre>
   *    a---d   
   *    |   |   
   *    |   |   a------------------------d
   *    |   |   |                        |
   *    |   |   b------------------------c
   *    |   |
   *    |   |   
   *    b---c
   * </pre>
   * 
   * <p>
   * The b-a-d path needs to be drawn with the shadow color and the b-c-d path
   * needs to be drawn with the highlight color.
   * </p>
   *
   * @param g The {@link Graphics} object to draw with.
   */
  public void paintTrack(Graphics g)
  {
    Color saved_color = g.getColor();
    int width;
    int height;

    Point a = new Point(trackRect.x, trackRect.y);
    Point b = new Point(a);
    Point c = new Point(a);
    Point d = new Point(a);

    if (slider.getOrientation() == JSlider.HORIZONTAL)
      {
	width = trackRect.width;
	height = (thumbRect.height / 4 == 0) ? 1 : thumbRect.height / 4;

	a.translate(0, (trackRect.height / 2) - (height / 2));
	b.translate(0, (trackRect.height / 2) + (height / 2));
	c.translate(trackRect.width, (trackRect.height / 2) + (height / 2));
	d.translate(trackRect.width, (trackRect.height / 2) - (height / 2));
      }
    else
      {
	width = (thumbRect.width / 4 == 0) ? 1 : thumbRect.width / 4;
	height = trackRect.height;

	a.translate((trackRect.width / 2) - (width / 2), 0);
	b.translate((trackRect.width / 2) - (width / 2), trackRect.height);
	c.translate((trackRect.width / 2) + (width / 2), trackRect.height);
	d.translate((trackRect.width / 2) + (width / 2), 0);
      }
    g.setColor(Color.GRAY);
    g.fillRect(a.x, a.y, width, height);

    g.setColor(getHighlightColor());
    g.drawLine(b.x, b.y, c.x, c.y);
    g.drawLine(c.x, c.y, d.x, d.y);

    g.setColor(getShadowColor());
    g.drawLine(b.x, b.y, a.x, a.y);
    g.drawLine(a.x, a.y, d.x, d.y);

    g.setColor(saved_color);
  }

  /**
   * This method is called during a repaint if the ticks are to be drawn. This
   * method must still verify that the majorTickSpacing and minorTickSpacing
   * are greater than zero before drawing the ticks.
   *
   * @param g The {@link Graphics} object to draw with.
   */
  public void paintTicks(Graphics g)
  {
    int max = slider.getMaximum();
    int min = slider.getMinimum();
    int majorSpace = slider.getMajorTickSpacing();
    int minorSpace = slider.getMinorTickSpacing();

    if (majorSpace > 0)
      {
	if (slider.getOrientation() == JSlider.HORIZONTAL)
	  {
	    double loc = tickRect.x + 0.5;
	    double increment = (max == min) ? 0
	        : majorSpace * (double) (tickRect.width - 1) / (max - min);
            if (drawInverted())
	      {
		loc += tickRect.width;
		increment *= -1;
	      }
            g.translate(0, tickRect.y);
	    for (int i = min; i <= max; i += majorSpace)
	      {
		paintMajorTickForHorizSlider(g, tickRect, (int) loc);
		loc += increment;
	      }
            g.translate(0, -tickRect.y);
	  }
	else
	  {
	    double loc = tickRect.height + tickRect.y + 0.5;
	    double increment = (max == min) ? 0
	        : -majorSpace * (double) (tickRect.height - 1) / (max - min);
	    if (drawInverted())
	      {
		loc = tickRect.y + 0.5;
		increment *= -1;
	      }
            g.translate(tickRect.x, 0);
	    for (int i = min; i <= max; i += majorSpace)
	      {
		paintMajorTickForVertSlider(g, tickRect, (int) loc);
		loc += increment;
	      }
            g.translate(-tickRect.x, 0);
	  }
      }
    if (minorSpace > 0)
      {
	if (slider.getOrientation() == JSlider.HORIZONTAL)
	  {
	    double loc = tickRect.x + 0.5;
	    double increment = (max == min) ? 0
	        : minorSpace * (double) (tickRect.width - 1) / (max - min);
	    if (drawInverted())
	      {
		loc += tickRect.width;
		increment *= -1;
	      }
            g.translate(0, tickRect.y);
	    for (int i = min; i <= max; i += minorSpace)
	      {
		paintMinorTickForHorizSlider(g, tickRect, (int) loc);
		loc += increment;
	      }
            g.translate(0, -tickRect.y);
	  }
	else
	  {
	    double loc = tickRect.height + tickRect.y + 0.5;
	    double increment = (max == min) ? 0
	        : -minorSpace * (double) (tickRect.height - 1) / (max - min);
	    if (drawInverted())
	      {
		loc = tickRect.y + 0.5;
		increment *= -1;
	      }
            g.translate(tickRect.x, 0);
	    for (int i = min; i <= max; i += minorSpace)
	      {
		paintMinorTickForVertSlider(g, tickRect, (int) loc);
		loc += increment;
	      }
            g.translate(-tickRect.x, 0);
	  }
      }
  }

  /* Minor ticks start at 1/4 of the height (or width) of the tickRect and extend
     to 1/2 of the tickRect.

     Major ticks start at 1/4 of the height and extend to 3/4.
   */

  /**
   * This method paints a minor tick for a horizontal slider at the given x
   * value. x represents the x coordinate to paint at.
   *
   * @param g The {@link Graphics} object to draw with.
   * @param tickBounds The tickRect rectangle.
   * @param x The x coordinate to draw the tick at.
   */
  protected void paintMinorTickForHorizSlider(Graphics g,
                                              Rectangle tickBounds, int x)
  {
    int y = tickRect.height / 4;
    Color saved = g.getColor();
    g.setColor(Color.BLACK);

    g.drawLine(x, y, x, y + tickRect.height / 4);
    g.setColor(saved);
  }

  /**
   * This method paints a major tick for a horizontal slider at the given x
   * value. x represents the x coordinate to paint at.
   *
   * @param g The {@link Graphics} object to draw with.
   * @param tickBounds The tickRect rectangle.
   * @param x The x coordinate to draw the tick at.
   */
  protected void paintMajorTickForHorizSlider(Graphics g,
                                              Rectangle tickBounds, int x)
  {
    int y = tickRect.height / 4;
    Color saved = g.getColor();
    g.setColor(Color.BLACK);

    g.drawLine(x, y, x, y + tickRect.height / 2);
    g.setColor(saved);
  }

  /**
   * This method paints a minor tick for a vertical slider at the given y
   * value. y represents the y coordinate to paint at.
   *
   * @param g The {@link Graphics} object to draw with.
   * @param tickBounds The tickRect rectangle.
   * @param y The y coordinate to draw the tick at.
   */
  protected void paintMinorTickForVertSlider(Graphics g, Rectangle tickBounds,
                                             int y)
  {
    int x = tickRect.width / 4;
    Color saved = g.getColor();
    g.setColor(Color.BLACK);

    g.drawLine(x, y, x + tickRect.width / 4, y);
    g.setColor(saved);