antstatus.java

一个TSP问题的图形演示程序

/*
 *  This code is from the book:
 *
 *    Winder, R and Roberts, G (2000) Developing Java
 *    Software, second edition, John Wiley & Sons.
 *
 *  It is copyright (c) 2000 Russel Winder and Graham Roberts.
 */

import SimFrameWork.* ;
import javax.swing.* ;
/**
 *  This class displays basic status information for the
 *  ant simulation.
 *  By inheriting from Control, the status update is run
 *  as a separate thread.
 *
 *  @version 2.0 March 1999
 *  @author Graham Roberts
 */
public class AntStatus extends Control {
  /**
   *  Use the Grid object to obtain status information and the
   *  JLabel to display it.
   *
   *  @param g grid object providing status information
   *  @param l JLabel used to display information on screen
   */
  public AntStatus(Grid g, JLabel l) {
    grid = g ;
    label = l ;
  }
  /**
   *  Perform the status update. Use the sleep method to wait 1 second
   *  between each update.
   */
  public void update() {
    int count = grid.getTimeCount() ;
    label.setText(" Time steps: " +
                  new Integer(count).toString() +
                  "  (" + (count-lastCount) + " steps per second)") ;
    lastCount = count ;
    try {
      sleep(1000) ;
    }
    catch (InterruptedException e) { }
  }
  /**
   *  The priority of this thread is increased by one, so
   *  that the status thread is guaranteed priority
   *  over the simulation thread. This is needed to ensure
   *  that the status thread will be run on
   *  JVMs that don't support pre-emptive
   *  multi-tasking of threads with the
   *  same priority.
   */
  public void run() {
    setPriority(getPriority()+1) ;
    super.run() ;
  }
  /**
   *  Reference to simulation object holding statistics
   */
  protected Grid grid ;
  /**
   *  Label used as status display.
   */
  JLabel label ;
  /**
   *  Record of number of time steps completed at last update.
   */
  private int lastCount = 0 ;
}