/*  Hello4.java
  *
  *  Illustrates Colors, arrays and a method.
  *  Displays lines correctly upon resizing frame (window).
  */

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Hello4 extends JComponent
{
     static int frameWidth  = 200;
     static int frameHeight = 200;

     Color [] lineColors = { Color.black, Color.red,   Color.green,
                             Color.blue,  Color.orange, Color.magenta };

     static int iColor = 0;    // line color index

     public static void main( String[] args )
     {
         JFrame f = new JFrame( "Hello4" );

         //  Exit application when the window is closed
         f.addWindowListener( new WindowAdapter() {
             public void windowClosing( WindowEvent e )
             {  System.exit(0); }
             }
         );

         f.setSize( frameWidth, frameHeight );
         f.getContentPane().add( new Hello4() );
         f.setVisible( true );
     }

     public void paintComponent( Graphics g )
     {
         frameWidth  = getWidth();
         frameHeight = getHeight();

         int xC = frameWidth/2;
         int yC = frameHeight/2;

         g.drawString( "Hello, Java!", xC, yC );

         drawLines( g );
     }

     public void drawLines( Graphics g )
     {
         g.setColor( lineColors[iColor] );

         g.drawLine( 0, 0, frameWidth, frameHeight );
         g.drawLine( 0, frameHeight, frameWidth, 0 );

         if( ++iColor == lineColors.length ) iColor = 0;
     }
}