// とりあえずバブルソート

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

/*
<applet code="BubbleSort2.class" width="300" height="200">
</applet>
*/

public class BubbleSort2 extends JApplet implements Runnable, ActionListener {
  int[] args = { 10, 3, 46, 7, 23, 34, 8, 12, 4, 45, 44, 52};
  Color[] cs = {Color.RED, Color.ORANGE, Color.GREEN, Color.BLUE};
  Thread thread = null;
  private boolean threadSuspended = true;

  @Override
  public void init() {
    JButton step = new JButton("Step");
    step.addActionListener(this);
    setLayout(new FlowLayout());
    add(step);
  }

  @Override
  public void start() {
    if (thread == null) {
      thread = new Thread(this);
      thread.start();
    }
  }

  @Override
  public void stop() {
    thread = null;
  }

  public synchronized void actionPerformed(ActionEvent e) {
    threadSuspended = false;
    notify();
  }

  @Override
  public void paint(Graphics g) {
    int i;

    super.paint(g);
    for(i = 0; i < args.length; i++) {
      g.setColor(cs[args[i] % cs.length]);
      g.fillRect(0, i * 10 + 50, args[i] * 5, 10);
    }
  }

  public void run() {
    while(true) {
      int i, j;

      for (i = 0; i < args.length - 1; i++) {
        for (j = args.length - 1; j > i; j--) {
          if (args[j - 1] > args[j]) { // スワップする。
            int tmp = args[j - 1];
            args[j - 1] = args[j];
            args[j] = tmp;
          }
          repaint();
              /* repaintの後で止まる */
          try {
            synchronized(this) {
              while (threadSuspended) {
                wait();
               }
               threadSuspended = true;
            }
          } catch (InterruptedException e) {}
        }
      }
    }
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame("");
    JApplet applet = new BubbleSort2();
    applet.setPreferredSize(new Dimension(300, 200));
    frame.add(applet);
    frame.pack();
    frame.setVisible(true);
    applet.init();
    applet.start();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }
}