basicscrollbarui.java

来自「Mac OS X 10.4.9 for x86 Source Code gcc」· Java 代码 · 共 1,300 行 · 第 1/3 页

  protected Rectangle thumbRect;

  /** Indicates that the decrease highlight should be painted. */
  protected static final int DECREASE_HIGHLIGHT = 1;

  /** Indicates that the increase highlight should be painted. */
  protected static final int INCREASE_HIGHLIGHT = 2;

  /** Indicates that no highlight should be painted. */
  protected static final int NO_HIGHLIGHT = 0;

  /** Indicates that the scrolling direction is positive. */
  private static final int POSITIVE_SCROLL = 1;

  /** Indicates that the scrolling direction is negative. */
  private static final int NEGATIVE_SCROLL = -1;

  /** The cached preferred size for the scrollbar. */
  private transient Dimension preferredSize;

  /** The current highlight status. */
  protected int trackHighlight;

  /** FIXME: Use this for something (presumably mouseDragged) */
  protected boolean isDragging;

  /** The timer used to move the thumb when the mouse is held. */
  protected Timer scrollTimer;

  /** The scrollbar this UI is acting for. */
  protected JScrollBar scrollbar;

  /**
   * This method adds a component to the layout.
   *
   * @param name The name to associate with the component that is added.
   * @param child The Component to add.
   */
  public void addLayoutComponent(String name, Component child)
  {
    // You should not be adding stuff to this component.
    // The contents are fixed.
  }

  /**
   * This method configures the scrollbar's colors. This can be  done by
   * looking up the standard colors from the Look and Feel defaults.
   */
  protected void configureScrollBarColors()
  {
    UIDefaults defaults = UIManager.getLookAndFeelDefaults();

    trackColor = defaults.getColor("ScrollBar.track");
    trackHighlightColor = defaults.getColor("ScrollBar.trackHighlight");
    thumbColor = defaults.getColor("ScrollBar.thumb");
    thumbHighlightColor = defaults.getColor("ScrollBar.thumbHighlight");
    thumbDarkShadowColor = defaults.getColor("ScrollBar.thumbDarkShadow");
    thumbLightShadowColor = defaults.getColor("ScrollBar.thumbLightShadow");
  }

  /**
   * This method creates an ArrowButtonListener.
   *
   * @return A new ArrowButtonListener.
   */
  protected ArrowButtonListener createArrowButtonListener()
  {
    return new ArrowButtonListener();
  }

  /**
   * This method creates a new JButton with the appropriate icon for the
   * orientation.
   *
   * @param orientation The orientation this JButton uses.
   *
   * @return The increase JButton.
   */
  protected JButton createIncreaseButton(int orientation)
  {
    if (incrButton == null)
      incrButton = new BasicArrowButton((orientation == SwingConstants.HORIZONTAL)
                                        ? SwingConstants.EAST
                                        : SwingConstants.SOUTH);
    else
      {
	if (orientation == SwingConstants.HORIZONTAL)
	  ((BasicArrowButton) incrButton).setDirection(SwingConstants.EAST);
	else
	  ((BasicArrowButton) incrButton).setDirection(SwingConstants.SOUTH);
      }
    return incrButton;
  }

  /**
   * This method creates a new JButton with the appropriate icon for the
   * orientation.
   *
   * @param orientation The orientation this JButton uses.
   *
   * @return The decrease JButton.
   */
  protected JButton createDecreaseButton(int orientation)
  {
    if (decrButton == null)
      decrButton = new BasicArrowButton((orientation == SwingConstants.HORIZONTAL)
                                        ? SwingConstants.WEST
                                        : SwingConstants.NORTH);
    else
      {
	if (orientation == SwingConstants.HORIZONTAL)
	  ((BasicArrowButton) decrButton).setDirection(SwingConstants.WEST);
	else
	  ((BasicArrowButton) decrButton).setDirection(SwingConstants.NORTH);
      }
    return decrButton;
  }

  /**
   * This method creates a new ModelListener.
   *
   * @return A new ModelListener.
   */
  protected ModelListener createModelListener()
  {
    return new ModelListener();
  }

  /**
   * This method creates a new PropertyChangeListener.
   *
   * @return A new PropertyChangeListener.
   */
  protected PropertyChangeListener createPropertyChangeListener()
  {
    return new PropertyChangeHandler();
  }

  /**
   * This method creates a new ScrollListener.
   *
   * @return A new ScrollListener.
   */
  protected ScrollListener createScrollListener()
  {
    return new ScrollListener();
  }

  /**
   * This method creates a new TrackListener.
   *
   * @return A new TrackListener.
   */
  protected TrackListener createTrackListener()
  {
    return new TrackListener();
  }

  /**
   * This method returns a new BasicScrollBarUI.
   *
   * @param c The JComponent to create a UI for.
   *
   * @return A new BasicScrollBarUI.
   */
  public static ComponentUI createUI(JComponent c)
  {
    return new BasicScrollBarUI();
  }

  /**
   * This method returns the maximum size for this JComponent.
   *
   * @param c The JComponent to measure the maximum size for.
   *
   * @return The maximum size for the component.
   */
  public Dimension getMaximumSize(JComponent c)
  {
    return getPreferredSize(c);
  }

  /**
   * This method returns the maximum thumb size.
   *
   * @return The maximum thumb size.
   */
  protected Dimension getMaximumThumbSize()
  {
    return maximumThumbSize;
  }

  /**
   * This method returns the minimum size for this JComponent.
   *
   * @param c The JComponent to measure the minimum size for.
   *
   * @return The minimum size for the component.
   */
  public Dimension getMinimumSize(JComponent c)
  {
    return getPreferredSize(c);
  }

  /**
   * This method returns the minimum thumb size.
   *
   * @return The minimum thumb size.
   */
  protected Dimension getMinimumThumbSize()
  {
    return minimumThumbSize;
  }

  /**
   * This method calculates the preferred size since calling
   * getPreferredSize() returns a cached value.
   */
  private void calculatePreferredSize()
  {
    // System.err.println(this + ".calculatePreferredSize()");
    int height;
    int width;
    height = width = 0;

    if (scrollbar.getOrientation() == SwingConstants.HORIZONTAL)
      {
	width += incrButton.getPreferredSize().getWidth();
	width += decrButton.getPreferredSize().getWidth();

	width += (scrollbar.getMaximum() - scrollbar.getMinimum());

	height = Math.max(incrButton.getPreferredSize().height,
	                  decrButton.getPreferredSize().height);
	height = Math.max(getMinimumThumbSize().height, height);
	height = Math.max(20, height);
	height = Math.min(getMaximumThumbSize().height, height);
      }
    else
      {
	height += incrButton.getPreferredSize().getHeight();
	height += decrButton.getPreferredSize().getHeight();

	height += (scrollbar.getMaximum() - scrollbar.getMinimum());

	width = Math.max(incrButton.getPreferredSize().width,
	                 decrButton.getPreferredSize().width);
	width = Math.max(getMinimumThumbSize().width, width);
	width = Math.max(20, width);
	width = Math.min(getMaximumThumbSize().width, width);
      }

    Insets insets = scrollbar.getInsets();

    height += insets.top + insets.bottom;
    width += insets.left + insets.right;

    preferredSize = new Dimension(width, height);
  }

  /**
   * This method returns a cached value of the preferredSize. The only
   * restrictions are: If the scrollbar is horizontal, the height should be
   * the maximum of the height of the JButtons and  the minimum width of the
   * thumb. For vertical scrollbars, the  calculation is similar (swap width
   * for height and vice versa).
   *
   * @param c The JComponent to measure.
   *
   * @return The preferredSize.
   */
  public Dimension getPreferredSize(JComponent c)
  {
    calculatePreferredSize();
    return preferredSize;
  }

  /**
   * This method returns the thumb's bounds based on the  current value of the
   * scrollbar. This method updates the cached value and returns that.
   *
   * @return The thumb bounds.
   */
  protected Rectangle getThumbBounds()
  {
    int max = scrollbar.getMaximum();
    int min = scrollbar.getMinimum();
    int value = scrollbar.getValue();
    int extent = scrollbar.getVisibleAmount();

    // System.err.println(this + ".getThumbBounds()");
    if (max == min)
      {
	thumbRect.x = trackRect.x;
	thumbRect.y = trackRect.y;
	if (scrollbar.getOrientation() == HORIZONTAL)
	  {
	    thumbRect.width = getMinimumThumbSize().width;
	    thumbRect.height = trackRect.height;
	  }
	else
	  {
	    thumbRect.width = trackRect.width;
	    thumbRect.height = getMinimumThumbSize().height;
	  }
	return thumbRect;
      }

    if (scrollbar.getOrientation() == HORIZONTAL)
      {
	thumbRect.x = trackRect.x;
	thumbRect.x += (value - min) * trackRect.width / (max - min);
	thumbRect.y = trackRect.y;

	thumbRect.width = extent * trackRect.width / (max - min);
	thumbRect.height = trackRect.height;
      }
    else
      {
	thumbRect.x = trackRect.x;
	thumbRect.y = trackRect.y + value * trackRect.height / (max - min);

	thumbRect.width = trackRect.width;
	thumbRect.height = extent * trackRect.height / (max - min);
      }
    return thumbRect;
  }

  /**
   * This method calculates the bounds of the track. This method updates the
   * cached value and returns it.
   *
   * @return The track's bounds.
   */
  protected Rectangle getTrackBounds()
  {
    SwingUtilities.calculateInnerArea(scrollbar, trackRect);

    if (scrollbar.getOrientation() == SwingConstants.HORIZONTAL)
      {
	trackRect.width -= incrButton.getPreferredSize().getWidth();
	trackRect.width -= decrButton.getPreferredSize().getWidth();

	trackRect.x += decrButton.getPreferredSize().getWidth();
      }
    else
      {
	trackRect.height -= incrButton.getPreferredSize().getHeight();
	trackRect.height -= decrButton.getPreferredSize().getHeight();

	trackRect.y += incrButton.getPreferredSize().getHeight();
      }
    return trackRect;
  }

  /**
   * This method installs any addition Components that  are a part of or
   * related to this scrollbar.
   */
  protected void installComponents()
  {
    incrButton = createIncreaseButton(scrollbar.getOrientation());
    scrollbar.add(incrButton);
    decrButton = createDecreaseButton(scrollbar.getOrientation());
    scrollbar.add(decrButton);
  }

  /**
   * This method installs the defaults for the scrollbar specified by the
   * Basic Look and Feel.
   */
  protected void installDefaults()
  {
    UIDefaults defaults = UIManager.getLookAndFeelDefaults();

    scrollbar.setForeground(defaults.getColor("ScrollBar.foreground"));
    scrollbar.setBackground(defaults.getColor("ScrollBar.background"));
    scrollbar.setBorder(defaults.getBorder("ScrollBar.border"));
    scrollbar.setOpaque(true);

    maximumThumbSize = defaults.getDimension("ScrollBar.maximumThumbSize");
    minimumThumbSize = defaults.getDimension("ScrollBar.minimumThumbSize");
  }

  /**
   * This method installs the keyboard actions for the scrollbar.
   */
  protected void installKeyboardActions()
  {
    // FIXME: implement.
  }

  /**
   * This method installs any listeners for the scrollbar. This method also
   * installs listeners for things such as the JButtons and the timer.
   */
  protected void installListeners()
  {
    scrollListener = createScrollListener();
    trackListener = createTrackListener();
    buttonListener = createArrowButtonListener();
    modelListener = createModelListener();
    propertyChangeListener = createPropertyChangeListener();

    scrollbar.addMouseMotionListener(trackListener);
    scrollbar.addMouseListener(trackListener);

    incrButton.addMouseListener(buttonListener);
    decrButton.addMouseListener(buttonListener);

    scrollbar.addPropertyChangeListener(propertyChangeListener);
    scrollbar.getModel().addChangeListener(modelListener);

    scrollTimer.addActionListener(scrollListener);
  }

  /**
   * This method installs the UI for the component. This can include setting
   * up listeners, defaults,  and components. This also includes initializing
   * any data objects.
   *
   * @param c The JComponent to install.
   */
  public void installUI(JComponent c)
  {
    super.installUI(c);
    if (c instanceof JScrollBar)
      {
	scrollbar = (JScrollBar) c;

	trackRect = new Rectangle();
	thumbRect = new Rectangle();

	scrollTimer = new Timer(200, null);