jpopupmenu.java

gcc的组建

    return ((PopupMenuListener[]) listenerList.getListeners(PopupMenuListener.class));
  }

  /**
   * This method calls popupMenuWillBecomeVisible() of popup menu's
   * PopupMenuListeners. This method is invoked just before popup menu
   * will appear on the screen.
   */
  protected void firePopupMenuWillBecomeVisible()
  {
    EventListener[] ll = listenerList.getListeners(PopupMenuListener.class);

    for (int i = 0; i < ll.length; i++)
      ((PopupMenuListener) ll[i]).popupMenuWillBecomeVisible(new PopupMenuEvent(this));
  }

  /**
   * This method calls popupMenuWillBecomeInvisible() of popup
   * menu's PopupMenuListeners. This method is invoked just before popup
   * menu will disappear from the screen
   */
  protected void firePopupMenuWillBecomeInvisible()
  {
    EventListener[] ll = listenerList.getListeners(PopupMenuListener.class);

    for (int i = 0; i < ll.length; i++)
      ((PopupMenuListener) ll[i]).popupMenuWillBecomeInvisible(new PopupMenuEvent(this));
  }

  /**
   * This method calls popupMenuCanceled() of popup menu's PopupMenuListeners.
   * This method is invoked just before popup menu is cancelled. This happens
   * when popup menu is closed without selecting any of its menu items. This
   * usually happens when the top-level window is resized or moved.
   */
  protected void firePopupMenuCanceled()
  {
    EventListener[] ll = listenerList.getListeners(PopupMenuListener.class);

    for (int i = 0; i < ll.length; i++)
      ((PopupMenuListener) ll[i]).popupMenuCanceled(new PopupMenuEvent(this));
  }

  /**
   * This methods sets popup menu's size to its' preferred size. If the
   * popup menu's size is previously set it will be ignored.
   */
  public void pack()
  {
    // Hook up this call so that it gets executed on the event thread in order
    // to avoid synchronization problems when calling the layout manager.
    if (! SwingUtilities.isEventDispatchThread())
      {
        SwingUtilities.invokeLater(new Runnable()
          {
            public void run()
            {
              show();
            }
          });
      }

    setSize(getPreferredSize());
  }

  /**
   * Return visibility of the popup menu
   *
   * @return true if popup menu is visible on the screen and false otherwise.
   */
  public boolean isVisible()
  {
    return visible;
  }

  /**
   * Sets visibility property of this popup menu. If the property is
   * set to true then popup menu will be dispayed and popup menu will
   * hide itself if visible property is set to false.
   *
   * @param visible true if popup menu will become visible and false otherwise.
   */
  public void setVisible(final boolean visible)
  {
    // Hook up this call so that it gets executed on the event thread in order
    // to avoid synchronization problems when calling the layout manager.
    if (! SwingUtilities.isEventDispatchThread())
      {
        SwingUtilities.invokeLater(new Runnable()
          {
            public void run()
            {
              setVisible(visible);
            }
          });
      }

    if (visible == isVisible())
      return;

    boolean old = isVisible();
    this.visible = visible;
    if (old != isVisible())
      {
        firePropertyChange("visible", old, isVisible());
        if (visible)
          {
            firePopupMenuWillBecomeVisible();

            PopupFactory pf = PopupFactory.getSharedInstance();
            pack();
            popup = pf.getPopup(invoker, this, popupLocationX, popupLocationY);
            popup.show();
          }
        else
          {
            firePopupMenuWillBecomeInvisible();
            popup.hide();
          }
      }
  }

  /**
   * Sets location of the popup menu.
   *
   * @param x X coordinate of the popup menu's location
   * @param y Y coordinate of the popup menu's location
   */
  public void setLocation(int x, int y)
  {
    popupLocationX = x;
    popupLocationY = y;
    // Handle the case when the popup is already showing. In this case we need
    // to fetch a new popup from PopupFactory and use this. See the general
    // contract of the PopupFactory.
  }

  /**
   * Returns popup menu's invoker.
   *
   * @return popup menu's invoker
   */
  public Component getInvoker()
  {
    return invoker;
  }

  /**
   * Sets popup menu's invoker.
   *
   * @param component The new invoker of this popup menu
   */
  public void setInvoker(Component component)
  {
    invoker = component;
  }

  /**
   * This method displays JPopupMenu on the screen at the specified
   * location. Note that x and y coordinates given to this method
   * should be expressed in terms of the popup menus' invoker.
   *
   * @param component Invoker for this popup menu
   * @param x x-coordinate of the popup menu relative to the specified invoker
   * @param y y-coordiate of the popup menu relative to the specified invoker
   */
  public void show(Component component, int x, int y)
  {
    if (component.isShowing())
      {
        setInvoker(component);
        Point p = new Point(x, y);
        SwingUtilities.convertPointToScreen(p, component);
        setLocation(p.x, p.y);
        setVisible(true);
      }
  }

  /**
   * Returns component located at the specified index in the popup menu
   *
   * @param index index of the component to return
   *
   * @return component located at the specified index in the popup menu
   *
   * @deprecated Replaced by getComponent(int)
   */
  public Component getComponentAtIndex(int index)
  {
    return getComponent(index);
  }

  /**
   * Returns index of the specified component in the popup menu
   *
   * @param component Component to look for
   *
   * @return index of the specified component in the popup menu
   */
  public int getComponentIndex(Component component)
  {
    Component[] items = getComponents();

    for (int i = 0; i < items.length; i++)
      {
	if (items[i].equals(component))
	  return i;
      }

    return -1;
  }

  /**
   * Sets size of the popup
   *
   * @param size Dimensions representing new size of the popup menu
   */
  public void setPopupSize(Dimension size)
  {
    super.setSize(size);
  }

  /**
   * Sets size of the popup menu
   *
   * @param width width for the new size
   * @param height height for the new size
   */
  public void setPopupSize(int width, int height)
  {
    super.setSize(width, height);
  }

  /**
   * Selects specified component in this popup menu.
   *
   * @param selected component to select
   */
  public void setSelected(Component selected)
  {
    int index = getComponentIndex(selected);
    selectionModel.setSelectedIndex(index);
  }

  /**
   * Checks if this popup menu paints its border.
   *
   * @return true if this popup menu paints its border and false otherwise.
   */
  public boolean isBorderPainted()
  {
    return borderPainted;
  }

  /**
   * Sets if the border of the popup menu should be
   * painter or not.
   *
   * @param painted true if the border should be painted and false otherwise
   */
  public void setBorderPainted(boolean painted)
  {
    borderPainted = painted;
  }

  /**
   * Returns margin for this popup menu.
   *
   * @return margin for this popup menu.
   */
  public Insets getMargin()
  {
    return margin;
  }

  /**
   * A string that describes this JPopupMenu. Normally only used
   * for debugging.
   *
   * @return A string describing this JMenuItem
   */
  protected String paramString()
  {
    StringBuffer sb = new StringBuffer();
    sb.append(super.paramString());
    sb.append(",label=");
    if (getLabel() != null)
      sb.append(getLabel());
    sb.append(",lightWeightPopupEnabled=").append(isLightWeightPopupEnabled());
    sb.append(",margin=");
    if (getMargin() != null)
      sb.append(margin);
    sb.append(",paintBorder=").append(isBorderPainted());
    return sb.toString();
  }

  /**
  * Process mouse events forwarded from MenuSelectionManager. This method 
  * doesn't do anything. It is here to conform to the MenuElement interface.
  *
  * @param event event forwarded from MenuSelectionManager
  * @param path path to the menu element from which event was generated
  * @param manager MenuSelectionManager for the current menu hierarchy
  */
  public void processMouseEvent(MouseEvent event, MenuElement[] path,
                                MenuSelectionManager manager)
  {
    // Empty Implementation. This method is needed for the implementation
    // of MenuElement interface
  }

  /**
   * Process key events forwarded from MenuSelectionManager. This method
   * doesn't do anything. It is here to conform to the MenuElement interface.
   *
   * @param event event forwarded from MenuSelectionManager
   * @param path path to the menu element from which event was generated
   * @param manager MenuSelectionManager for the current menu hierarchy
   *
   */
  public void processKeyEvent(KeyEvent event, MenuElement[] path,
                              MenuSelectionManager manager)
  {
    // Empty Implementation. This method is needed for the implementation
    // of MenuElement interface
  }

  /**
   * Method of MenuElement Interface. It is invoked when
   * popupMenu's selection has changed
   *
   * @param changed true if this popupMenu is part of current menu
   * hierarchy and false otherwise.
   */
  public void menuSelectionChanged(boolean changed)
  {
    if (! changed)
      setVisible(false);
  }

  /**
   * Return subcomonents of this popup menu. This method returns only
   * components that implement the <code>MenuElement</code> interface.
   *
   * @return array of menu items belonging to this popup menu
   */
  public MenuElement[] getSubElements()
  {
    Component[] items = getComponents();
    ArrayList subElements = new ArrayList();

    for (int i = 0; i < items.length; i++)
      if (items[i] instanceof MenuElement)
	subElements.add(items[i]);

    return (MenuElement[])
      subElements.toArray(new MenuElement[subElements.size()]);
  }

  /**
   * Method of the MenuElement interface. Returns reference to itself.
   *
   * @return Returns reference to itself
   */
  public Component getComponent()
  {
    return this;
  }

  /**
   * Checks if observing mouse event should trigger popup
   * menu to show on the screen.
   *
   * @param event MouseEvent to check
   *
   * @return true if the observing mouse event is popup trigger and false otherwise
   */
  public boolean isPopupTrigger(MouseEvent event)
  {
    return ((PopupMenuUI) getUI()).isPopupTrigger(event);
  }

  /**
   * DOCUMENT ME!
   *
   * @return DOCUMENT ME!
   */
  public AccessibleContext getAccessibleContext()
  {
    if (accessibleContext == null)
      accessibleContext = new AccessibleJPopupMenu();

    return accessibleContext;
  }

  /**
   * This is the separator that can be used in popup menu.
   */
  public static class Separator extends JSeparator
  {
    public Separator()
    {
      super();
    }

    public String getUIClassID()
    {
      return "PopupMenuSeparatorUI";
    }
  }

  protected class AccessibleJPopupMenu extends AccessibleJComponent
  {
    private static final long serialVersionUID = 7423261328879849768L;

    protected AccessibleJPopupMenu()
    {
      // Nothing to do here.
    }

    public AccessibleRole getAccessibleRole()
    {
      return AccessibleRole.POPUP_MENU;
    }
  }

  /* This class resizes popup menu and repaints popup menu appropriately if one
   of item's action has changed */
  protected class ActionChangeListener implements PropertyChangeListener
  {
    public void propertyChange(PropertyChangeEvent evt)
    {
      // We used to have a revalidate() and repaint() call here. However I think
      // this is not needed. Instead, a new Popup has to be fetched from the
      // PopupFactory and used here.
    }
  }
}