container.java

来自「Mac OS X 10.4.9 for x86 Source Code gcc」· Java 代码 · 共 2,024 行 · 第 1/4 页

          gfx.translate (-bounds.x, -bounds.y);
        if (clipped)
          gfx.setClip (oldClip.x, oldClip.y, oldClip.width, oldClip.height);
      }
  }

  void dispatchEventImpl(AWTEvent e)
  {
    // Give lightweight dispatcher a chance to handle it.
    if (eventTypeEnabled (e.id)
        && dispatcher != null 
        && dispatcher.handleEvent (e))
      return;
    
    if ((e.id <= ContainerEvent.CONTAINER_LAST
             && e.id >= ContainerEvent.CONTAINER_FIRST)
        && (containerListener != null
            || (eventMask & AWTEvent.CONTAINER_EVENT_MASK) != 0))
      processEvent(e);
    else
      super.dispatchEventImpl(e);
  }

  // This is used to implement Component.transferFocus.
  Component findNextFocusComponent(Component child)
  {
    synchronized (getTreeLock ())
      {
        int start, end;
        if (child != null)
          {
            for (start = 0; start < ncomponents; ++start)
              {
                if (component[start] == child)
                  break;
              }
            end = start;
            // This special case lets us be sure to terminate.
            if (end == 0)
              end = ncomponents;
            ++start;
          }
        else
          {
            start = 0;
            end = ncomponents;
          }

        for (int j = start; j != end; ++j)
          {
            if (j >= ncomponents)
              {
                // The JCL says that we should wrap here.  However, that
                // seems wrong.  To me it seems that focus order should be
                // global within in given window.  So instead if we reach
                // the end we try to look in our parent, if we have one.
                if (parent != null)
                  return parent.findNextFocusComponent(this);
                j -= ncomponents;
              }
            if (component[j] instanceof Container)
              {
                Component c = component[j];
                c = c.findNextFocusComponent(null);
                if (c != null)
                  return c;
              }
            else if (component[j].isFocusTraversable())
              return component[j];
          }

        return null;
      }
  }

  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()) 
                  {
                    if (dispatcher == null)
                      dispatcher = new LightweightDispatcher (this);
                  }	
	  

		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()
      {
      }

      /**
       * 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 mouseEventTarget;
  private transient Component pressedComponent;
  private transient Component lastComponentEntered;
  private transient int pressCount;
  
  LightweightDispatcher(Container c)
  {
    nativeContainer = c;
  }

  void acquireComponentForMouseEvent(MouseEvent me)
  {
    int x = me.getX ();
    int y = me.getY ();

    // Find the candidate which should receive this event.
    Component parent = nativeContainer;
    Component candidate = null;
    Point p = me.getPoint();
    while (candidate == null && parent != null)
      {
        candidate =
          SwingUtilities.getDeepestComponentAt(parent, p.x, p.y);
        if (candidate == null || (candidate.eventMask & me.getID()) == 0)
        {
          candidate = null;
          p = SwingUtilities.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 (SwingUtilities.isDescendingFrom(lastComponentEntered, nativeContainer))
        {
          Point tp = 
            SwingUtilities.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 = SwingUtilities.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);
          }
      }

    if (me.getID() == MouseEvent.MOUSE_RELEASED
        || me.getID() == MouseEvent.MOUSE_PRESSED && pressCount > 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_RELEASED
      //   - MOUSE_PRESSED: another button pressed while the first is held down
      //   - MOUSE_DRAGGED
      if (SwingUtilities.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;
        else if (pressCount == 0)
          pressedComponent = null;
      }
  }

  boolean handleEvent(AWTEvent e)
  {
    if (e instanceof MouseEvent)
      {
        MouseEvent me = (MouseEvent) e;

        acquireComponentForMouseEvent(me);
	
        // Avoid dispatching ENTERED and EXITED events twice.
        if (mouseEventTarget != null
            && mouseEventTarget.isShowing()
            && e.getID() != MouseEvent.MOUSE_ENTERED
            && e.getID() != MouseEvent.MOUSE_EXITED)
          {
            MouseEvent newEvt = 
              SwingUtilities.convertMouseEvent(nativeContainer, me, 
                                               mouseEventTarget);
            mouseEventTarget.dispatchEvent(newEvt);

            switch (e.getID())
              {
                case MouseEvent.MOUSE_PRESSED:
                  if (pressCount++ == 0)
                    pressedComponent = mouseEventTarget;
                  break;

                case MouseEvent.MOUSE_RELEASED:
                  // Clear our memory of the original PRESSED event, only if
                  // we're not expecting a CLICKED event after this. If
                  // there is a CLICKED event after this, it will do clean up.
                  if (--pressCount == 0
                      && mouseEventTarget != pressedComponent)
                    pressedComponent = null;
                  break;
              }
              if (newEvt.isConsumed())
                e.consume();
          }
      }
    
    return e.isConsumed();
  }

} // class LightweightDispatcher