import java.awt.*;
import java.util.*;
import java.applet.*;
/*
<APPLET CODE="Animation.java" WIDTH=400 HEIGHT=300>
</APPLET>
*/
//The basic applet class.The applet shows 4 cars crossing each other at a square.
public class Animation extends Applet implements Runnable
{
Thread t;
//4 variables used to vary the car's positions.
int x1=0,x2=380,y1=50,y2=250;
public void start()
{
if(t==null)
{
t=new Thread(this,"New Thread");//New side Thread created on start of applet.
t.start();
}
}
public void stop()
{
if(t!=null)
{
t=null;//On stop of applet the created thread is destroyed.
}
}
//Implementation of method run() of Runnable interface.
public void run()
{
Thread t1=Thread.currentThread();
while(t==t1)
{
repaint();
try
{
Thread.sleep(100);
}
catch(Exception e)
{ }
}
}
public void paint(Graphics g)
{
setBackground(Color.cyan);
g.setColor(Color.BLACK);
x1=(x1+16)%400;
x2=x2-16;
y1=(y1+12)%300;
y2=y2-12;
if(y2<0)
y2=288;
if(x2<0)
x2=384;
//Draw the roads using 2 filled rectangles using black color.
g.fillRect(0,130,400,40);
g.fillRect(180,0,40,305);
//Draw the white colored lines.
g.setColor(Color.white);
for(int i=0;i<20;i++)
{
if(i!=9 && i!=10)
g.drawLine(i*20,150,i*20+10,150);
}
for(int j=0;j<15;j++)
{
if(j!=7 && j!=8)
g.drawLine(200,j*20,200,j*20+10);
}
//Draw 4 colored cars using filled round rectangles.
g.setColor(Color.red);
g.fillRoundRect(x2,152,20,8,2,2);
g.fillRoundRect(x1,140,20,8,2,2);
g.fillRoundRect(190,y1,8,20,2,2);
g.fillRoundRect(202,y2,8,20,2,2);
}
}
