container.java

gcc的组建

  private void addNotifyContainerChildren()
  {
    synchronized (getTreeLock ())
      {
        for (int i = ncomponents;  --i >= 0; )
          {
            component[i].addNotify();
            if (component[i].isLightweight ())
	      {

                // If we're not lightweight, and we just got a lightweight
                // child, we need a lightweight dispatcher to feed it events.
                if (!this.isLightweight() && dispatcher == null) 
                  dispatcher = new LightweightDispatcher (this);

                if (dispatcher != null)
                  dispatcher.enableEvents(component[i].eventMask);

		enableEvents(component[i].eventMask);
		if (peer != null && !isLightweight ())
		  enableEvents (AWTEvent.PAINT_EVENT_MASK);
	      }
          }
      }
  }

  /**
   * Deserialize this Container:
   * <ol>
   * <li>Read from the stream the default serializable fields.</li>
   * <li>Read a list of serializable ContainerListeners as optional
   * data.  If the list is null, no listeners will be registered.</li>
   * <li>Read this Container's FocusTraversalPolicy as optional data.
   * If this is null, then this Container will use a
   * DefaultFocusTraversalPolicy.</li>
   * </ol>
   *
   * @param s the stream to read from
   * @throws ClassNotFoundException if deserialization fails
   * @throws IOException if the stream fails
   */
  private void readObject (ObjectInputStream s)
    throws ClassNotFoundException, IOException
  {
    s.defaultReadObject ();
    String key = (String) s.readObject ();
    while (key != null)
      {
        Object object = s.readObject ();
        if ("containerL".equals (key))
          addContainerListener((ContainerListener) object);
        // FIXME: under what key is the focus traversal policy stored?
        else if ("focusTraversalPolicy".equals (key))
          setFocusTraversalPolicy ((FocusTraversalPolicy) object);

        key = (String) s.readObject();
      }
  }

  /**
   * Serialize this Container:
   * <ol>
   * <li>Write to the stream the default serializable fields.</li>
   * <li>Write the list of serializable ContainerListeners as optional
   * data.</li>
   * <li>Write this Container's FocusTraversalPolicy as optional data.</li>
   * </ol>
   *
   * @param s the stream to write to
   * @throws IOException if the stream fails
   */
  private void writeObject (ObjectOutputStream s) throws IOException
  {
    s.defaultWriteObject ();
    AWTEventMulticaster.save (s, "containerL", containerListener);
    if (focusTraversalPolicy instanceof Serializable)
      s.writeObject (focusTraversalPolicy);
    else
      s.writeObject (null);
  }

  // Nested classes.

  /* The following classes are used in concert with the
     visitChildren() method to implement all the graphics operations
     that requires traversal of the containment hierarchy. */

  abstract static class GfxVisitor
  {
    public abstract void visit(Component c, Graphics gfx);
  }

  static class GfxPaintVisitor extends GfxVisitor
  {
    public static final GfxVisitor INSTANCE = new GfxPaintVisitor();
    
    public void visit(Component c, Graphics gfx)
    {
      c.paint(gfx);
    }
  }

  static class GfxPrintVisitor extends GfxVisitor
  {
    public static final GfxVisitor INSTANCE = new GfxPrintVisitor();
    
    public void visit(Component c, Graphics gfx)
    {
      c.print(gfx);
    }
  }

  static class GfxPaintAllVisitor extends GfxVisitor
  {
    public static final GfxVisitor INSTANCE = new GfxPaintAllVisitor();

    public void visit(Component c, Graphics gfx)
    {
      c.paintAll(gfx);
    }
  }

  static class GfxPrintAllVisitor extends GfxVisitor
  {
    public static final GfxVisitor INSTANCE = new GfxPrintAllVisitor();

    public void visit(Component c, Graphics gfx)
    {
      c.printAll(gfx);
    }
  }

  /**
   * This class provides accessibility support for subclasses of container.
   *
   * @author Eric Blake ([e-mail])
   *
   * @since 1.3
   */
  protected class AccessibleAWTContainer extends AccessibleAWTComponent
  {
    /**
     * Compatible with JDK 1.4+.
     */
    private static final long serialVersionUID = 5081320404842566097L;

    /**
     * The handler to fire PropertyChange when children are added or removed.
     *
     * @serial the handler for property changes
     */
    protected ContainerListener accessibleContainerHandler
      = new AccessibleContainerHandler();

    /**
     * The default constructor.
     */
    protected AccessibleAWTContainer()
    {
      Container.this.addContainerListener(accessibleContainerHandler);
    }

    /**
     * Return the number of accessible children of the containing accessible
     * object (at most the total number of its children).
     *
     * @return the number of accessible children
     */
    public int getAccessibleChildrenCount()
    {
      synchronized (getTreeLock ())
        {
          int count = 0;
          int i = component == null ? 0 : component.length;
          while (--i >= 0)
            if (component[i] instanceof Accessible)
              count++;
          return count;
        }
    }

    /**
     * Return the nth accessible child of the containing accessible object.
     *
     * @param i the child to grab, zero-based
     * @return the accessible child, or null
     */
    public Accessible getAccessibleChild(int i)
    {
      synchronized (getTreeLock ())
        {
          if (component == null)
            return null;
          int index = -1;
          while (i >= 0 && ++index < component.length)
            if (component[index] instanceof Accessible)
              i--;
          if (i < 0)
            return (Accessible) component[index];
          return null;
        }
    }

    /**
     * Return the accessible child located at point (in the parent's
     * coordinates), if one exists.
     *
     * @param p the point to look at
     *
     * @return an accessible object at that point, or null
     *
     * @throws NullPointerException if p is null
     */
    public Accessible getAccessibleAt(Point p)
    {
      Component c = getComponentAt(p.x, p.y);
      return c != Container.this && c instanceof Accessible ? (Accessible) c
        : null;
    }

    /**
     * This class fires a <code>PropertyChange</code> listener, if registered,
     * when children are added or removed from the enclosing accessible object.
     *
     * @author Eric Blake ([e-mail])
     *
     * @since 1.3
     */
    protected class AccessibleContainerHandler implements ContainerListener
    {
      /**
       * Default constructor.
       */
      protected AccessibleContainerHandler()
      {
        // Nothing to do here.
      }

      /**
       * Fired when a component is added; forwards to the PropertyChange
       * listener.
       *
       * @param e the container event for adding
       */
      public void componentAdded(ContainerEvent e)
      {
        AccessibleAWTContainer.this.firePropertyChange
          (ACCESSIBLE_CHILD_PROPERTY, null, e.getChild());
      }

      /**
       * Fired when a component is removed; forwards to the PropertyChange
       * listener.
       *
       * @param e the container event for removing
       */
      public void componentRemoved(ContainerEvent e)
      {
        AccessibleAWTContainer.this.firePropertyChange
          (ACCESSIBLE_CHILD_PROPERTY, e.getChild(), null);
      }
    } // class AccessibleContainerHandler
  } // class AccessibleAWTContainer
} // class Container

/**
 * There is a helper class implied from stack traces called
 * LightweightDispatcher, but since it is not part of the public API,
 * rather than mimic it exactly we write something which does "roughly
 * the same thing".
 */
class LightweightDispatcher implements Serializable
{
  private static final long serialVersionUID = 5184291520170872969L;
  private Container nativeContainer;
  private Cursor nativeCursor;
  private long eventMask;
  
  private transient Component pressedComponent;
  private transient Component lastComponentEntered;
  private transient int pressCount;
  
  LightweightDispatcher(Container c)
  {
    nativeContainer = c;
  }

  void enableEvents(long l)
  {
    eventMask |= l;
  }

  /**
   * Returns the deepest visible descendent of parent that contains the 
   * specified location and that is not transparent and MouseListener-less.
   * @param parent the root component to begin the search
   * @param x the x coordinate
   * @param y the y coordinate
   * @return null if <code>parent</code> doesn't contain the location, 
   * parent if parent is not a container or has no child that contains the
   * location, otherwise the appropriate component from the conditions
   * above.
   */
  Component getDeepestComponentForMouseEventAt(Component parent, int x, int y)
  {
    if (parent == null || (! parent.contains(x, y)))
      return null;

    if (! (parent instanceof Container))
      return parent;

    Container c = (Container) parent;
    return c.findComponentForMouseEventAt(x, y);
  }
  
  Component acquireComponentForMouseEvent(MouseEvent me)
  {
    int x = me.getX ();
    int y = me.getY ();

    Component mouseEventTarget = null;
    // Find the candidate which should receive this event.
    Component parent = nativeContainer;
    Component candidate = null;
    Point p = me.getPoint();
    while (candidate == null && parent != null)
      {
        candidate = getDeepestComponentForMouseEventAt(parent, p.x, p.y);
        if (candidate == null || (candidate.eventMask & me.getID()) == 0)
          {
            candidate = null;
            p = AWTUtilities.convertPoint(parent, p.x, p.y, parent.parent);
            parent = parent.parent;
          }
      }

    // If the only candidate we found was the native container itself,
    // don't dispatch any event at all.  We only care about the lightweight
    // children here.
    if (candidate == nativeContainer)
      candidate = null;

    // If our candidate is new, inform the old target we're leaving.
    if (lastComponentEntered != null
        && lastComponentEntered.isShowing()
        && lastComponentEntered != candidate)
      {
        // Old candidate could have been removed from 
        // the nativeContainer so we check first.
        if (AWTUtilities.isDescendingFrom(lastComponentEntered,
                                          nativeContainer))
          {
            Point tp = AWTUtilities.convertPoint(nativeContainer, 
                                                 x, y, lastComponentEntered);
            MouseEvent exited = new MouseEvent (lastComponentEntered, 
                                                MouseEvent.MOUSE_EXITED,
                                                me.getWhen (), 
                                                me.getModifiersEx (), 
                                                tp.x, tp.y,
                                                me.getClickCount (),
                                                me.isPopupTrigger (),
                                                me.getButton ());
            lastComponentEntered.dispatchEvent (exited); 
          }
        lastComponentEntered = null;
      }

    // If we have a candidate, maybe enter it.
    if (candidate != null)
      {
        mouseEventTarget = candidate;
        if (candidate.isLightweight() 
            && candidate.isShowing()
            && candidate != nativeContainer
            && candidate != lastComponentEntered)
	  {
            lastComponentEntered = mouseEventTarget;
            Point cp = AWTUtilities.convertPoint(nativeContainer, 
                                                 x, y, lastComponentEntered);
            MouseEvent entered = new MouseEvent (lastComponentEntered, 
                                                 MouseEvent.MOUSE_ENTERED,
                                                 me.getWhen (), 
                                                 me.getModifiersEx (), 
                                                 cp.x, cp.y,
                                                 me.getClickCount (),
                                                 me.isPopupTrigger (),
                                                 me.getButton ());
            lastComponentEntered.dispatchEvent (entered);
          }
      }

    // Check which buttons where pressed except the last button that
    // changed state.
    int modifiers = me.getModifiersEx() & (MouseEvent.BUTTON1_DOWN_MASK
                                           | MouseEvent.BUTTON2_DOWN_MASK
                                           | MouseEvent.BUTTON3_DOWN_MASK);
    switch(me.getButton())
      {
      case MouseEvent.BUTTON1:
        modifiers &= ~MouseEvent.BUTTON1_DOWN_MASK;
        break;
      case MouseEvent.BUTTON2:
        modifiers &= ~MouseEvent.BUTTON2_DOWN_MASK;
        break;
      case MouseEvent.BUTTON3:
        modifiers &= ~MouseEvent.BUTTON3_DOWN_MASK;
        break;
      }

    if (me.getID() == MouseEvent.MOUSE_PRESSED && modifiers > 0
        || me.getID() == MouseEvent.MOUSE_DRAGGED)
      {
        // If any of the following events occur while a button is held down,
        // they should be dispatched to the same component to which the
        // original MOUSE_PRESSED event was dispatched:
        //   - MOUSE_PRESSED: another button pressed while the first is held
        //     down
        //   - MOUSE_DRAGGED
        if (AWTUtilities.isDescendingFrom(pressedComponent, nativeContainer))
          mouseEventTarget = pressedComponent;
      }
    else if (me.getID() == MouseEvent.MOUSE_CLICKED)
      {
        // Don't dispatch CLICKED events whose target is not the same as the
        // target for the original PRESSED event.
        if (candidate != pressedComponent)
          {
            mouseEventTarget = null;
            pressCount = 0;
          }
        else if (pressCount == 0)
          pressedComponent = null;