/**
 * ColorEventMulticaster.java  1.00 97/04/12 Merlin Hughes
 *
 * Copyright (c) 1997 Prominence Dot Com, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * for commercial and non-commercial purposes and without fee is
 * hereby granted provided that this copyright notice appears in
 * all copies.
 *
 * http://prominence.com/                  merlin@prominence.com
 */
class ColorEventMulticaster implements ColorListener {
  protected ColorListener a, b;

  protected ColorEventMulticaster (ColorListener a, ColorListener b) {
    this.a = a;
    this.b = b;
  }

  public void colorPicked (ColorEvent e) {
    a.colorPicked (e);
    b.colorPicked (e);
  }

  static ColorListener add (ColorListener a, ColorListener b) {
    if (a == null)
      return b;
    else if (b == null)
      return a;
    else
      return new ColorEventMulticaster (a, b);
  }

  static ColorListener remove (ColorListener a, ColorListener b) {
    if ((a == null) || (a == b))
      return null;
    else if (a instanceof ColorEventMulticaster)
      return add (remove (((ColorEventMulticaster) a).a, b),
                  remove (((ColorEventMulticaster) a).b, b));
    else
      return a;
  }
}