Definition:

Write an applet that draws four squares of equal size & of different colors such that they cover up the whole applet area. The applet should operate correctly even if it is resized.

import java.applet.*;
import java.awt.*;

public class rotateSquares extends Applet implements Runnable
{
	Color[] clr = {Color.red, Color.green, Color.pink, Color.blue};
	int cnt = 0;
	Thread t;
	public void init()
	{
		t = new Thread(this);
		t.start();
		setBackground(Color.black);	
	}
	
	public void run()
	{
		try
		{
			while(true)
			{
				
				repaint();
				t.sleep(1000);
				cnt++;	
				if(cnt>3){cnt=0;}
			}
		}
		catch(Exception e)
		{
			System.out.println(e);	
		}
	}
		
	public void paint(Graphics g)
	{
		int w = getWidth();
		int h = getHeight();
		
		int tmp = cnt;
		for(int i=0;i<4;i++)
		{
		 g.setColor(clr[tmp++]);
		 if(tmp>3)tmp=0;
		 
		 if(i==0) g.fillRect(0,0,w/2,h/2);
		 else if(i==1) g.fillRect(w/2,0,w/2,h/2);
		 else if(i==2) g.fillRect(w/2,h/2,w/2,h/2);
		 else if(i==3) g.fillRect(0,h/2,w/2,h/2); 
		}
	}	
	
}

/*
<applet code="rotateSquares" width="500" height="500"></applet>
*/

Output: