basicdesktopiconui.java

gcc的组建

  /** The JInternalFrame associated with the JDesktopIcon. */
  protected JInternalFrame frame;

  /** The MouseListener responsible for reacting to MouseEvents on the JDesktopIcon. */
  private transient MouseInputListener mouseHandler;

  /** The Button in the JDesktopIcon responsible for deiconifying it.
   * This is package-private to avoid an accessor method. */
  transient BoundButton button;

  /** The PropertyChangeListener listening to the JDesktopIcon. */
  private transient PropertyChangeListener propertyHandler;
  
  /** The default icon used when no frame icon is given by the JInternalFrame. */
  static Icon defaultIcon = new InternalFrameDefaultMenuIcon();

  /**
   * This is a helper class that is used in JDesktopIcon and gives the Button a predetermined size.
   */
  private class BoundButton extends JButton
  {
    /**
     * Creates a new BoundButton object.
     *
     * @param title The title of the button.
     */
    public BoundButton(String title)
    {
      super(title);
    }

    /**
     * This method returns a standard size (based on the defaults of the JDesktopIcon) and the insets.
     *
     * @return The preferred size of the JDesktopIcon.
     */
    public Dimension getPreferredSize()
    {
      Insets insets = desktopIcon.getInsets();
      return new Dimension(iconWidth - insets.left - insets.right,
                           iconHeight - insets.top - insets.bottom);
    }

    /**
     * This method returns the minimum size of the button.
     *
     * @return The minimum size of the button.
     */
    public Dimension getMinimumSize()
    {
      return getPreferredSize();
    }

    /**
     * This method returns the maximum size of the button.
     *
     * @return The maximum size of the button.
     */
    public Dimension getMaximumSize()
    {
      return getPreferredSize();
    }
  }

  /**
   * Creates a new BasicDesktopIconUI object.
   */
  public BasicDesktopIconUI()
  {
    // Nothing to do here.
  }

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

  /**
   * This method installs the UI for the given JComponent.
   *
   * @param c The JComponent to install this UI for.
   */
  public void installUI(JComponent c)
  {
    if (c instanceof JDesktopIcon)
      {
	desktopIcon = (JDesktopIcon) c;
	desktopIcon.setLayout(new BorderLayout());
	frame = desktopIcon.getInternalFrame();

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

	desktopIcon.setOpaque(true);
      }
  }

  /**
   * This method uninstalls the UI for the given JComponent.
   *
   * @param c The JComponent to uninstall this UI for.
   */
  public void uninstallUI(JComponent c)
  {
    desktopIcon.setOpaque(false);
    
    uninstallListeners();
    uninstallComponents();
    uninstallDefaults();
    
    frame = null;
    desktopIcon.setLayout(null);
    desktopIcon = null;
  }

  /**
   * This method installs the necessary sub components for the JDesktopIcon.
   */
  protected void installComponents()
  {
    // Try to create a button based on what the frame's
    // state is currently
    button = new BoundButton(frame.getTitle());
    button.setHorizontalAlignment(SwingConstants.LEFT);
    button.setHorizontalTextPosition(SwingConstants.TRAILING);

    Icon use = frame.getFrameIcon();
    if (use == null)
      use = defaultIcon;
    button.setIcon(use);

    desktopIcon.add(button, SwingConstants.CENTER);
  }

  /**
   * This method uninstalls the sub components for the JDesktopIcon.
   */
  protected void uninstallComponents()
  {
    desktopIcon.remove(button);
    
    button = null;
  }

  /**
   * This method installs the listeners needed by this UI.
   */
  protected void installListeners()
  {
    mouseHandler = createMouseInputListener();

    desktopIcon.addMouseMotionListener(mouseHandler);
    desktopIcon.addMouseListener(mouseHandler);

    propertyHandler = new PropertyChangeListener()
        {
	  public void propertyChange(PropertyChangeEvent e)
	  {
	    if (e.getPropertyName().equals(JInternalFrame.TITLE_PROPERTY))
	      button.setText(desktopIcon.getInternalFrame().getTitle());
	    else if (e.getPropertyName().equals(JInternalFrame.FRAME_ICON_PROPERTY))
	      {
		Icon use = desktopIcon.getInternalFrame().getFrameIcon();
		if (use == null)
		  use = defaultIcon;
		button.setIcon(use);
	      }
	    desktopIcon.revalidate();
	    desktopIcon.repaint();
	  }
        };
    frame.addPropertyChangeListener(propertyHandler);

    button.addActionListener(new ActionListener()
        {
	  public void actionPerformed(ActionEvent e)
	  {
            deiconize();
	  }
        });
  }

  /**
   * This method uninstalls the listeners needed by the UI.
   */
  protected void uninstallListeners()
  {
    // button is nulled so no need to remove it.
    
    frame.removePropertyChangeListener(propertyHandler);
    propertyHandler = null;
    
    desktopIcon.removeMouseMotionListener(mouseHandler);
    desktopIcon.removeMouseListener(mouseHandler);
  }

  /**
   * This method installs the defaults for the JDesktopIcon.
   */
  protected void installDefaults()
  {
    // FIXME: Move border to defaults.
    desktopIcon.setBorder(new DesktopIconBorder());  
  }

  /**
   * This method uninstalls the defaults for the JDesktopIcon.
   */
  protected void uninstallDefaults()
  {
    desktopIcon.setBorder(null);
  }

  /**
   * This method creates a new MouseInputListener for the JDesktopIcon.
   *
   * @return A new MouseInputListener.
   */
  protected MouseInputListener createMouseInputListener()
  {
    return new MouseInputHandler();
  }

  /**
   * This method returns the preferred size for the given JComponent.
   *
   * @param c The JComponent to find a preferred size for.
   *
   * @return The preferred size.
   */
  public Dimension getPreferredSize(JComponent c)
  {
    return new Dimension(iconWidth, iconHeight);
  }

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

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

  /**
   * This method returns the insets of the given JComponent.
   *
   * @param c The JComponent to find insets for.
   *
   * @return The insets of the given JComponent.
   */
  public Insets getInsets(JComponent c)
  {
    return c.getInsets();
  }

  /**
   * This method deiconizes the JInternalFrame associated with the JDesktopIcon.
   */
  public void deiconize() 
  {
    try
    {
      frame.setIcon(false);
    }
    catch (PropertyVetoException pve)
    {
      // We do nothing if the attempt has been vetoed.
    }
  }
}