import java.applet.Applet;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class Counter1 extends Applet {
  private int count = 0;
  private Button
    onOff = new Button("停止計數"),
    start = new Button("開始計數");
  private TextField t = new TextField(10);
  private boolean runFlag = true;
  public void init() {
    add(t);
    start.addActionListener(new StartL());
    add(start);
    onOff.addActionListener(new OnOffL());
    add(onOff);
  }
  public void go() {
    while (true) {
      try {
        Thread.currentThread().sleep(100);
      } catch (InterruptedException e){}
      if(runFlag) 
        t.setText(Integer.toString(count++));
    }
  }
  class StartL implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      go();
    }
  }
  class OnOffL implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      runFlag = !runFlag;
    }
  }
  public static void main(String[] args) {
    Counter1 applet = new Counter1();
    Frame aFrame = new Frame("計數器");
    aFrame.addWindowListener(
      new WindowAdapter() {
        public void windowClosing(WindowEvent e) {
          System.exit(0);
        }
      });
    aFrame.add(applet, BorderLayout.CENTER);
    aFrame.setSize(300,200);
    applet.init();
    applet.start();
    aFrame.setVisible(true);
  }
}