ColorBoxes2.java


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

//: c14:ColorBoxes2.java
// From 'Thinking in Java, 2nd ed.' by Bruce Eckel
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
// Balancing thread use.
// <applet code=ColorBoxes2 width=600 height=500>
// <param name=grid value="12">
// <param name=pause value="50">
// </applet>
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import com.bruceeckel.swing.*;

class CBox2 extends JPanel {
  private static final Color[] colors = { 
    Color.black, Color.blue, Color.cyan, 
    Color.darkGray, Color.gray, Color.green,
    Color.lightGray, Color.magenta, 
    Color.orange, Color.pink, Color.red, 
    Color.white, Color.yellow 
  };
  private Color cColor = newColor();
  private static final Color newColor() {
    return colors[
      (int)(Math.random() * colors.length)
    ];
  }
  void nextColor() {
    cColor = newColor();
    repaint();
  }
  public void paintComponent(Graphics g) {
    super.paintComponent(g);
    g.setColor(cColor);
    Dimension s = getSize();
    g.fillRect(0, 0, s.width, s.height);
  }
}

class CBoxList 
  extends ArrayList implements Runnable {
  private Thread t;
  private int pause;
  public CBoxList(int pause) {
    this.pause = pause;
    t = new Thread(this);
  }
  public void go() { t.start(); }
  public void run() {
    while(true) {
      int i = (int)(Math.random() * size());
      ((CBox2)get(i)).nextColor();
      try {
        t.sleep(pause);
      } catch(InterruptedException e) {
        System.err.println("Interrupted");
      }
    } 
  }
  public Object last() { return get(size() - 1);}
}

public class ColorBoxes2 extends JApplet {
  private boolean isApplet = true;
  private int grid = 12;
  // Shorter default pause than ColorBoxes:
  private int pause = 50;
  private CBoxList[] v;
  public void init() {
    // Get parameters from Web page:
    if (isApplet) {
      String gsize = getParameter("grid");
      if(gsize != null)
        grid = Integer.parseInt(gsize);
      String pse = getParameter("pause");
      if(pse != null)
        pause = Integer.parseInt(pse);
    }
    Container cp = getContentPane();
    cp.setLayout(new GridLayout(grid, grid));
    v = new CBoxList[grid];
    for(int i = 0; i < grid; i++)
      v[i] = new CBoxList(pause);
    for (int i = 0; i < grid * grid; i++) {
      v[i % grid].add(new CBox2());
      cp.add((CBox2)v[i % grid].last());
    }
    for(int i = 0; i < grid; i++)
      v[i].go();
  }   
  public static void main(String[] args) {
    ColorBoxes2 applet = new ColorBoxes2();
    applet.isApplet = false;
    if(args.length > 0)
      applet.grid = Integer.parseInt(args[0]);
    if(args.length > 1) 
      applet.pause = Integer.parseInt(args[1]);
    Console.run(applet, 500, 400);
  }
} ///:~