import java.awt.*;		// for Graphics, Color
import javax.swing.*;	// for JFrame, JPanel

public class Ch13_3		// draw a Checkerboard
{
	public static void main(String[] args)	
	{
		JFrame frame=new JFrame("Exercise12_1");				// establish title for JFrame
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);	// establish what to do if JFrame is closed
		frame.setSize(340,360);									// set size to something reasonable for this GUI
		CheckerPanel p1=new CheckerPanel();
		frame.add(p1);					// add the JPanel to this JFrame and make the JFrame visible
		frame.setVisible(true);		
	}
	
	public static class CheckerPanel extends JPanel
	{
		public void paintComponent(Graphics g)
		{
			for(int i=0;i<8;i++)
				for(int j=0;j<8;j++)
				{
					if((i+j)%2==0) g.setColor(Color.red);
					else g.setColor(Color.black);
					g.fillRect(i*40,j*40,40,40);
				}
		}
	}
}