/* The example draws several moving wadges on a circle. These wedges move with different speeds */
import java.applet.*;
import java.awt.*;
import java.util.*;

public class DrawMultWedges extends Applet {
 Wedges t [] = new Wedges [6];
 Graphics g;

 public void init ()
 {
  g = getGraphics ();

  for (int i = 0; i < t.length; i++)
  {
   if ( i < t.length / 2)
    t [i] = new Wedges (g, 10, 10 + i * 100, 100, 100, 100 * (i + 1));
   else
    t [i] = new Wedges (g, 110, 10 + (i - 3) * 100, 100, 100, 100 * (i + 1));
   t [i].start ();
  }
 }

 public void paint (Graphics g)
 {
 }
}

class Wedges implements Runnable {
 int x, y, width, height, interval;
 Graphics g;
 volatile boolean isSet = true;
 Thread t;

 public Wedges (Graphics g, int x, int y, int width, int height, int interval)
 {
  this.g = g;
  this.x = x;
  this.y = y;
  this.width = width;
  this.height = height;
  this.interval = interval;

  t = new Thread (this);
 }

 public void start ()
 {
  t.start ();
 }

 public void run ()
 {
  int i = 0;

  if (g == null)
  {
   System.out.println ("The reference to Graphics is " + g);
   return;
  }
  g.drawArc (x, y, width, height, 0, 360);  // draw a circle
  while (isSet)
  {
   g.setColor (Color.white);
   g.fillArc (x, y, width, height, i - 45, 45);   // erase a wedge
   g.setColor (Color.black);
   g.drawArc (x, y, width, height, i - 45, 45);   // draw a circle sector
   g.fillArc (x, y, width, height, i, 45);   // draw a wedge
   if (i != 315)
    i += 45;
   else
    i = 0;
   System.out.println (i);
   try
   {
    Thread.sleep (interval);
   } catch (InterruptedException ie)
    {
     System.out.println (ie.getMessage ());
    }
  }
  g.dispose ();
 }

}

Related:

• Interview Questions in Core Java - Part Two
• Java Interview Questions
• Interview Questions in Core Java

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