borderlayoutdemo.java

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// Fig. 13.25: BorderLayoutDemo.java
// Demonstrating BorderLayout.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class BorderLayoutDemo extends JFrame implements ActionListener {
   private JButton buttons[];
   private final String names[] = { "Hide North", "Hide South", 
      "Hide East", "Hide West", "Hide Center" };
   private BorderLayout layout;

   // set up GUI and event handling
   public BorderLayoutDemo()
   {
      super( "BorderLayout Demo" );

      layout = new BorderLayout( 5, 5 ); // 5 pixel gaps

      // get content pane and set its layout
      Container container = getContentPane();
      container.setLayout( layout );

      // instantiate button objects
      buttons = new JButton[ names.length ];

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

      // place buttons in BorderLayout; order not important
      container.add( buttons[ 0 ], BorderLayout.NORTH ); 
      container.add( buttons[ 1 ], BorderLayout.SOUTH ); 
      container.add( buttons[ 2 ], BorderLayout.EAST );  
      container.add( buttons[ 3 ], BorderLayout.WEST );  
      container.add( buttons[ 4 ], BorderLayout.CENTER ); 

      setSize( 300, 200 );
      setVisible( true );

   } // end constructor BorderLayoutDemo

   // handle button events
   public void actionPerformed( ActionEvent event )
   {
      for ( int count = 0; count < buttons.length; count++ )

         if ( event.getSource() == buttons[ count ] )
            buttons[ count ].setVisible( false );
         else
            buttons[ count ].setVisible( true );

      // re-layout the content pane
      layout.layoutContainer( getContentPane() );
   }

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

} // end class BorderLayoutDemo