/*
 * File: ThreadsExample.java
 * -------------------------
 * This programs shows an example of threads to simulate running a race.
 */

import acm.program.*;
import acm.graphics.*;
import java.awt.event.*;
import javax.swing.*;

public class ThreadsExample extends GraphicsProgram {

	public void run() {
		racers = new RacingSquare[NUM_RACERS];
		finished = new boolean[NUM_RACERS];
		threads = new Thread[NUM_RACERS];

		// finish line
		add(new GLine(510, 0, 510, 400));
		
		add(new JButton("Start!"), SOUTH);
		addActionListeners();
	}

	public void actionPerformed(ActionEvent e) {
		String cmd = e.getActionCommand();
		if (cmd.equals("Start!")) {
			for(int i = 0; i < NUM_RACERS; i++) {
				// remove the racer, if it previously existed
				if (racers[i] != null) {
					remove(racers[i]);
				}
				
				// create new racer
				racers[i] = new RacingSquare(i, finished);
				add(racers[i], 10, 10 + (40 * i));
				
				// send the new racer along its way 
				// (on a separate thread)
				threads[i] = new Thread(racers[i]);
				threads[i].start();
			}
		}
	}

	/* private instance variables */
	private Thread[] threads;
	private RacingSquare[] racers;
	private boolean[] finished;

	/* constants */
	private static final int NUM_RACERS = 2;
}