Suspend.java


</COMMENT> No Java 2 support for APPLET!!

//: c14:Suspend.java
// From 'Thinking in Java, 2nd ed.' by Bruce Eckel
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
// The alternative approach to using suspend()
// and resume(), which are deprecated in Java 2.
// <applet code=Suspend width=300 height=100>
// </applet>
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import com.bruceeckel.swing.*;

public class Suspend extends JApplet {
  private JTextField t = new JTextField(10);
  private JButton 
    suspend = new JButton("Suspend"),
    resume = new JButton("Resume");
  private Suspendable ss = new Suspendable();
  class Suspendable extends Thread {
    private int count = 0;
    private boolean suspended = false;
    public Suspendable() { start(); }
    public void fauxSuspend() { 
      suspended = true;
    }
    public synchronized void fauxResume() {
      suspended = false;
      notify();
    }
    public void run() {
      while (true) {
        try {
          sleep(100);
          synchronized(this) {
            while(suspended)
              wait();
          }
        } catch(InterruptedException e) {
          System.err.println("Interrupted");
        }
        t.setText(Integer.toString(count++));
      }
    }
  } 
  public void init() {
    Container cp = getContentPane();
    cp.setLayout(new FlowLayout());
    cp.add(t);
    suspend.addActionListener(
      new ActionListener() {
        public 
        void actionPerformed(ActionEvent e) {
          ss.fauxSuspend();
        }
      });
    cp.add(suspend);
    resume.addActionListener(
      new ActionListener() {
        public 
        void actionPerformed(ActionEvent e) {
          ss.fauxResume();
        }
      });
    cp.add(resume);
  }
  public static void main(String[] args) {
    Console.run(new Suspend(), 300, 100);
  }
} ///:~