awteventmulticaster.java

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   *
   * @param a the "a" listener, may be null
   * @param b the "b" listener, may be null
   * @return latest entry in the chain
   * @since 1.2
   */
  public static InputMethodListener add(InputMethodListener a,
                                        InputMethodListener b)
  {
    return (InputMethodListener) addInternal(a, b);
  }

  /**
   * Chain <code>HierarchyListener</code> a and b.
   *
   * @param a the "a" listener, may be null
   * @param b the "b" listener, may be null
   * @return latest entry in the chain
   * @since 1.3
   */
  public static HierarchyListener add(HierarchyListener a, HierarchyListener b)
  {
    return (HierarchyListener) addInternal(a, b);
  }

  /**
   * Chain <code>HierarchyBoundsListener</code> a and b.
   *
   * @param a the "a" listener, may be null
   * @param b the "b" listener, may be null
   * @return latest entry in the chain
   * @since 1.3
   */
  public static HierarchyBoundsListener add(HierarchyBoundsListener a,
                                            HierarchyBoundsListener b)
  {
    return (HierarchyBoundsListener) addInternal(a, b);
  }

  /**
   * Chain <code>MouseWheelListener</code> a and b.
   *
   * @param a the "a" listener, may be null
   * @param b the "b" listener, may be null
   * @return latest entry in the chain
   * @since 1.4
   */
  public static MouseWheelListener add(MouseWheelListener a,
                                       MouseWheelListener b)
  {
    return (MouseWheelListener) addInternal(a, b);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  public static ComponentListener remove(ComponentListener l,
                                         ComponentListener oldl)
  {
    return (ComponentListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  public static ContainerListener remove(ContainerListener l,
                                         ContainerListener oldl)
  {
    return (ContainerListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  public static FocusListener remove(FocusListener l, FocusListener oldl)
  {
    return (FocusListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  public static KeyListener remove(KeyListener l, KeyListener oldl)
  {
    return (KeyListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  public static MouseListener remove(MouseListener l, MouseListener oldl)
  {
    return (MouseListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  public static MouseMotionListener remove(MouseMotionListener l,
                                           MouseMotionListener oldl)
  {
    return (MouseMotionListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  public static WindowListener remove(WindowListener l, WindowListener oldl)
  {
    return (WindowListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   * @since 1.4
   */
  public static WindowStateListener remove(WindowStateListener l,
                                           WindowStateListener oldl)
  {
    return (WindowStateListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   * @since 1.4
   */
  public static WindowFocusListener remove(WindowFocusListener l,
                                           WindowFocusListener oldl)
  {
    return (WindowFocusListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  public static ActionListener remove(ActionListener l, ActionListener oldl)
  {
    return (ActionListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  public static ItemListener remove(ItemListener l, ItemListener oldl)
  {
    return (ItemListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  public static AdjustmentListener remove(AdjustmentListener l,
                                          AdjustmentListener oldl)
  {
    return (AdjustmentListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  public static TextListener remove(TextListener l, TextListener oldl)
  {
    return (TextListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   * @since 1.2
   */
  public static InputMethodListener remove(InputMethodListener l,
                                           InputMethodListener oldl)
  {
    return (InputMethodListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   * @since 1.3
   */
  public static HierarchyListener remove(HierarchyListener l,
                                         HierarchyListener oldl)
  {
    return (HierarchyListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   * @since 1.3
   */
  public static HierarchyBoundsListener remove(HierarchyBoundsListener l,
                                               HierarchyBoundsListener oldl)
  {
    return (HierarchyBoundsListener) removeInternal(l, oldl);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   * @since 1.4
   */
  public static MouseWheelListener remove(MouseWheelListener l,
                                          MouseWheelListener oldl)
  {
    return (MouseWheelListener) removeInternal(l, oldl);
  }

  /**
   * Chain <code>EventListener</code> a and b.
   *
   * @param a the "a" listener, may be null
   * @param b the "b" listener, may be null 
   * @return latest entry in the chain
   */
  protected static EventListener addInternal(EventListener a, EventListener b)
  {
    if (a == null)
      return b;
    if (b == null)
      return a;
    return new AWTEventMulticaster(a, b);
  }

  /**
   * Removes the listener <code>oldl</code> from the listener <code>l</code>.
   *
   * @param l the listener chain to reduce
   * @param oldl the listener to remove
   * @return the resulting listener chain
   */
  protected static EventListener removeInternal(EventListener l,
                                                EventListener oldl)
  {
    if (l == oldl)
      return null;
    if (l instanceof AWTEventMulticaster)
      return ((AWTEventMulticaster) l).remove(oldl);
    return l;
  }

  /**
   * Saves all Serializable listeners to a serialization stream.
   *
   * @param s the stream to save to
   * @param k a prefix stream put before each serializable listener
   * @throws IOException if serialization fails
   */
  protected void saveInternal(ObjectOutputStream s, String k)
    throws IOException
  {
    // This is not documented by Sun, but I think it is correct.
    if (a instanceof AWTEventMulticaster)
      ((AWTEventMulticaster) a).saveInternal(s, k);
    else if (a instanceof Serializable)
      {
        s.writeObject(k);
        s.writeObject(a);
      }
    if (b instanceof AWTEventMulticaster)
      ((AWTEventMulticaster) b).saveInternal(s, k);
    else if (b instanceof Serializable)
      {
        s.writeObject(k);
        s.writeObject(b);
      }
  }

  /**
   * Saves a Serializable listener chain to a serialization stream.
   *
   * @param s the stream to save to
   * @param k a prefix stream put before each serializable listener
   * @param l the listener chain to save
   * @throws IOException if serialization fails
   */
  protected static void save(ObjectOutputStream s, String k, EventListener l)
    throws IOException
  {
    // This is not documented by Sun, but I think it is correct.
    if (l instanceof AWTEventMulticaster)
      ((AWTEventMulticaster) l).saveInternal(s, k);
    else if (l instanceof Serializable)
      {
        s.writeObject(k);
        s.writeObject(l);
      }
  }

  /**
   * Returns an array of all chained listeners of the specified type in the
   * given chain. A null listener returns an empty array, and a listener
   * which is not an AWTEventMulticaster returns an array of one element. If
   * no listeners in the chain are of the specified type, an empty array is
   * returned.
   *
   * @param l the listener chain to convert to an array
   * @param type the type of listeners to collect
   * @return an array of the listeners of that type in the chain
   * @throws ClassCastException if type is not assignable from EventListener
   * @throws NullPointerException if type is null
   * @throws IllegalArgumentException if type is Void.TYPE
   * @since 1.4
   */
  public static EventListener[] getListeners(EventListener l, Class type)
  {
    ArrayList list = new ArrayList();
    if (l instanceof AWTEventMulticaster)
      ((AWTEventMulticaster) l).getListeners(list, type);
    else if (type.isInstance(l))
      list.add(l);
    EventListener[] r = (EventListener[]) Array.newInstance(type, list.size());
    list.toArray(r);
    return r;
  }

  /**
   * Collects all instances of the given type in the chain into the list.
   *
   * @param l the list to collect into
   * @param type the type of listeners to collect
   * @throws NullPointerException if type is null
   * @see #getListeners(EventListener, Class)
   */
  private void getListeners(ArrayList l, Class type)
  {
    if (a instanceof AWTEventMulticaster)
      ((AWTEventMulticaster) a).getListeners(l, type);
    else if (type.isInstance(a))
      l.add(a);
    if (b instanceof AWTEventMulticaster)
      ((AWTEventMulticaster) b).getListeners(l, type);
    else if (type.isInstance(b))
      l.add(b);
  }
} // class AWTEventMulticaster