13.26.java.java

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


public class Main extends JFrame implements ActionListener {
  private JButton buttons[];
  private final String names[] = 
    { "one", "two", "three", "four", "five", "six" };
  private boolean toggle = true;
  private Container container;
  private GridLayout grid1, grid2;


  public Main()
{
  super( "GridLayout Demo" );

  grid1 = new GridLayout( 2, 3, 5, 5 );
  grid2 = new GridLayout( 3, 2 ); 

  container = getContentPane();
  container.setLayout( grid1 );


buttons = new JButton[ names.length ];
 
for ( int count = 0; count < names.length; count++ ) {
  buttons[ count ] = new JButton( names[ count ] );
  buttons[ count ].addActionListener( this );
  container.add( buttons[ count ] );
}

setSize( 300, 150 );
setVisible( true );

}

public void main( ActionEvent event )
{ 
if ( toggle ) 
  container.setLayout( grid2 );
else 
  container.setLayout( grid1 );

toggle = !toggle; 
container.validate();
}

public static void main( String args[] )
 {
Main application = new Main();
application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
} 

}