/**
 * ArrowRoller.java  1.00 97/07/09 Merlin Hughes
 *
 * Copyright (c) 1997 Merlin Hughes, 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/                         ego@merlin.org
 */

package org.merlin.beans.arrow;

class ArrowRoller extends Thread {
  private static final int DELAY_MS = 400, REPEAT_MS = 100;
  
  ArrowRoller () {
    super ("ArrowRoller");
    start ();
  }

  private ArrowBean target;
  private int state;

  synchronized void abort () {
    stop ();
    notify ();
    target = null;
    ++ state;
  }

  synchronized void addTarget (ArrowBean t) {
    target = t;
    ++ state;
    notify ();
  }

   synchronized void removeTarget (ArrowBean t) {
    if (target == t) {
      target = null;
      ++ state;
    }
  }

  public void run () {
    while (true) {
      try {
        ArrowBean target;
        int state;
        synchronized (this) {
          while ((target = this.target) == null)
            wait ();
          state = this.state;
        }
        sleep (DELAY_MS);
        while (state == this.state) {
          target.fireActionEvent ();
          sleep (REPEAT_MS);
        }
      } catch (InterruptedException ex) {
      }
    }
  }
}