basicsliderui.java

来自「Mac OS X 10.4.9 for x86 Source Code gcc」· Java 代码 · 共 2,219 行 · 第 1/5 页

	      }
	  }
      }
  }

  /**
   * This method paints the label on the horizontal slider at the value
   * specified. The value is not a coordinate. It is a value within the range
   * of the  slider. If the value is not within the range of the slider, this
   * method will do nothing. This method should not paint outside the
   * boundaries of the labelRect.
   *
   * @param g The {@link Graphics} object to draw with.
   * @param value The value to paint at.
   * @param label The label to paint.
   */
  protected void paintHorizontalLabel(Graphics g, int value, Component label)
  {
    // This relies on clipping working properly or we'll end up
    // painting all over the place. If our preferred size is ignored, then
    // the labels may not fit inside the slider's bounds. Rather than mucking 
    // with font sizes and possible icon sizes, we'll set the bounds for
    // the label and let it get clipped.
    Dimension dim = label.getPreferredSize();
    int w = (int) dim.getWidth();
    int h = (int) dim.getHeight();

    int max = slider.getMaximum();
    int min = slider.getMinimum();

    if (value > max || value < min)
      return;

    //           value
    //             |
    //        ------------
    //        |          |
    //        |          |
    //        |          |
    //  The label must move w/2 to the right to fit directly under the value.
    int xpos = xPositionForValue(value) - w / 2;
    int ypos = labelRect.y;

    // We want to center the label around the xPositionForValue
    // So we use xpos - w / 2. However, if value is min and the label 
    // is large, we run the risk of going out of bounds. So we bring it back
    // to 0 if it becomes negative.
    if (xpos < 0)
      xpos = 0;

    // If the label + starting x position is greater than
    // the x space in the label rectangle, we reset it to the largest
    // amount possible in the rectangle. This means ugliness.
    if (xpos + w > labelRect.x + labelRect.width)
      w = labelRect.x + labelRect.width - xpos;

    // If the label is too tall. We reset it to the height of the label
    // rectangle.
    if (h > labelRect.height)
      h = labelRect.height;

    label.setBounds(xpos, ypos, w, h);
    javax.swing.SwingUtilities.paintComponent(g, label, null, label.getBounds());
  }

  /**
   * This method paints the label on the vertical slider at the value
   * specified. The value is not a coordinate. It is a value within the range
   * of the  slider. If the value is not within the range of the slider, this
   * method will do nothing. This method should not paint outside the
   * boundaries of the labelRect.
   *
   * @param g The {@link Graphics} object to draw with.
   * @param value The value to paint at.
   * @param label The label to paint.
   */
  protected void paintVerticalLabel(Graphics g, int value, Component label)
  {
    Dimension dim = label.getPreferredSize();
    int w = (int) dim.getWidth();
    int h = (int) dim.getHeight();

    int max = slider.getMaximum();
    int min = slider.getMinimum();

    if (value > max || value < min)
      return;

    int xpos = labelRect.x;
    int ypos = yPositionForValue(value) - h / 2;

    if (ypos < 0)
      ypos = 0;

    if (ypos + h > labelRect.y + labelRect.height)
      h = labelRect.y + labelRect.height - ypos;

    if (w > labelRect.width)
      w = labelRect.width;

    label.setBounds(xpos, ypos, w, h);
    javax.swing.SwingUtilities.paintComponent(g, label, null, label.getBounds());
  }

  /**
   * <p>
   * This method paints a thumb. There are two types of thumb:
   * </p>
   * <pre>
   *   Vertical         Horizontal
   *    a---b            a-----b
   *    |   |            |      \
   *    e   c            |       c
   *     \ /             |      /
   *      d              e-----d
   *  </pre>
   * 
   * <p>
   * In the case of vertical thumbs, we highlight the path b-a-e-d and shadow
   * the path b-c-d. In the case of horizontal thumbs, we highlight the path
   * c-b-a-e and shadow the path c-d-e. In both cases we fill the path
   * a-b-c-d-e before shadows and highlights are drawn.
   * </p>
   *
   * @param g The graphics object to paint with
   */
  public void paintThumb(Graphics g)
  {
    Color saved_color = g.getColor();

    Polygon thumb = new Polygon();

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

    Polygon bright;
    Polygon dark;
    Polygon all;

    // This will be in X-dimension if the slider is inverted and y if it isn't.	  	  
    int turnPoint;

    if (slider.getOrientation() == JSlider.HORIZONTAL)
      {
	turnPoint = thumbRect.height * 3 / 4;

	b.translate(thumbRect.width, 0);
	c.translate(thumbRect.width, turnPoint);
	d.translate(thumbRect.width / 2, thumbRect.height);
	e.translate(0, turnPoint);

	bright = new Polygon(new int[] { b.x, a.x, e.x, d.x },
	                     new int[] { b.y, a.y, e.y, d.y }, 4);

	dark = new Polygon(new int[] { b.x, c.x, d.x },
	                   new int[] { b.y, c.y, d.y }, 3);
	all = new Polygon(new int[] { a.x + 1, b.x, c.x, d.x, e.x + 1 },
	                  new int[] { a.y + 1, b.y + 1, c.y, d.y + 1, e.y }, 5);
      }
    else
      {
	turnPoint = thumbRect.width * 3 / 4;

	b.translate(turnPoint, 0);
	c.translate(thumbRect.width, thumbRect.height / 2);
	d.translate(turnPoint, thumbRect.height);
	e.translate(0, thumbRect.height);

	bright = new Polygon(new int[] { c.x, b.x, a.x, e.x },
	                     new int[] { c.y, b.y, a.y, e.y }, 4);

	dark = new Polygon(new int[] { c.x, d.x, e.x + 1 },
	                   new int[] { c.y, d.y, e.y }, 3);

	all = new Polygon(new int[] { a.x + 1, b.x, c.x - 1, d.x, e.x + 1 },
	                  new int[] { a.y + 1, b.y + 1, c.y, d.y, e.y }, 5);
      }

    g.setColor(Color.WHITE);
    g.drawPolyline(bright.xpoints, bright.ypoints, bright.npoints);

    g.setColor(Color.BLACK);
    g.drawPolyline(dark.xpoints, dark.ypoints, dark.npoints);

    g.setColor(Color.GRAY);
    g.fillPolygon(all);

    g.setColor(saved_color);
  }

  /**
   * This method sets the position of the thumbRect.
   *
   * @param x The new x position.
   * @param y The new y position.
   */
  public void setThumbLocation(int x, int y)
  {
    thumbRect.x = x;
    thumbRect.y = y;
  }

  /**
   * This method is used to move the thumb one  block in the direction
   * specified. If the slider  snaps to ticks, this method is responsible for
   * snapping it to a tick after the thumb  has been moved.
   *
   * @param direction The direction to move in.
   */
  public void scrollByBlock(int direction)
  {
    // The direction is -1 for backwards and 1 for forwards.
    int unit = direction * (slider.getMaximum() - slider.getMinimum()) / 10;

    int moveTo = slider.getValue() + unit;

    if (slider.getSnapToTicks())
      moveTo = findClosestTick(moveTo);

    slider.setValue(moveTo);
  }

  /**
   * This method is used to move the thumb one unit in the direction
   * specified. If the slider snaps to ticks, this method is responsible for
   * snapping it to a tick after the thumb has been moved.
   *
   * @param direction The direction to move in.
   */
  public void scrollByUnit(int direction)
  {
    // The direction is -1 for backwards and 1 for forwards.
    int moveTo = slider.getValue() + direction;

    if (slider.getSnapToTicks())
      moveTo = findClosestTick(moveTo);

    slider.setValue(moveTo);
  }

  /**
   * This method is called when there has been a click in the track and the
   * thumb needs to be scrolled  on regular intervals. This method is only
   * responsible  for starting the timer and not for stopping it.
   *
   * @param dir The direction to move in.
   */
  protected void scrollDueToClickInTrack(int dir)
  {
    scrollTimer.stop();

    scrollListener.setDirection(dir);
    scrollListener.setScrollByBlock(true);

    scrollTimer.start();
  }

  /**
   * This method returns the X coordinate for the value passed in.
   *
   * @param value The value to calculate an x coordinate for.
   *
   * @return The x coordinate for the value.
   */
  protected int xPositionForValue(int value)
  {
    int min = slider.getMinimum();
    int max = slider.getMaximum();
    int extent = slider.getExtent();
    int len = trackRect.width;

    int xPos = (max == min) ? 0 : (value - min) * len / (max - min);

    if (! drawInverted())
      xPos += trackRect.x;
    else
      {
	xPos = trackRect.width - xPos;
	xPos += trackRect.x;
      }
    return xPos;
  }

  /**
   * This method returns the y coordinate for the value passed in.
   *
   * @param value The value to calculate a y coordinate for.
   *
   * @return The y coordinate for the value.
   */
  protected int yPositionForValue(int value)
  {
    int min = slider.getMinimum();
    int max = slider.getMaximum();
    int extent = slider.getExtent();
    int len = trackRect.height;

    int yPos = (max == min) ? 0 : (value - min) * len / (max - min);

    if (! drawInverted())
      {
	yPos = trackRect.height - yPos;
	yPos += trackRect.y;
      }
    else
      yPos += trackRect.y;
    return yPos;
  }

  /**
   * This method returns the value in the slider'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.
   */
  public int valueForYPosition(int yPos)
  {
    int min = slider.getMinimum();
    int max = slider.getMaximum();
    int len = trackRect.height;

    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);

    if (! drawInverted())
      value = ((len - (yPos - trackRect.y)) * (max - min) / len + min);
    else
      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 slider'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.
   */
  public int valueForXPosition(int xPos)
  {
    int min = slider.getMinimum();
    int max = slider.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);

    if (! drawInverted())
      value = ((xPos - trackRect.x) * (max - min) / len + min);
    else
      value = ((len - (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;
  }

  /**
   * This method finds the closest value that has a tick associated with it.
   *
   * @param value The value to search from.
   *
   * @return The closest value that has a tick associated with it.
   */
  private int findClosestTick(int value)
  {
    int min = slider.getMinimum();
    int max = slider.getMaximum();
    int majorSpace = slider.getMajorTickSpacing();
    int minorSpace = slider.getMinorTickSpacing();

    // The default value to return is value + minor or
    // value + major. 
    // Initializing at min - value leaves us with a default
    // return value of min, which always has tick marks
    // (if ticks are painted).
    int minor = min - value;
    int major = min - value;

    // If there are no major tick marks or minor tick marks 
    // e.g. snap is set to true but no ticks are set, then
    // we can just return the value.
    if (majorSpace <= 0 && minorSpace <= 0)
      return value;

    // First check the major ticks.
    if (majorSpace > 0)
      {
	int lowerBound = (value - min) / majorSpace;
	int majLower = majorSpace * lowerBound + min;
	int majHigher = majorSpace * (lowerBound + 1) + min;

	if (majHigher <= max && majHigher - value <= value - majLower)
	  major = majHigher - value;
	else
	  major = majLower - value;
      }

    if (minorSpace > 0)
      {
	int lowerBound = value / minorSpace;
	int minLower = minorSpace * lowerBound;
	int minHigher = minorSpace * (lowerBound + 1);

	if (minHigher <= max && minHigher - value <= value - minLower)
	  minor = minHigher - value;
	else
	  minor = minLower - value;
      }

    // Give preference to minor ticks
    if (Math.abs(minor) > Math.abs(major))
      return value + major;
    else
      return value + minor;
  }
}