// Fig. 12.22: KeyDemo.java
// Demonstrating keystroke events.

// Java core packages
import java.awt.*;
import java.awt.event.*;

// Java extension packages
import javax.swing.*;

public class KeyDemo extends JFrame implements KeyListener {
   private String line1 = "", line2 = "";
   private String line3 = "";
   private JTextArea textArea;

   // set up GUI
   public KeyDemo()
   {
      super( "Demonstrating Keystroke Events" );

      // set up JTextArea
      textArea = new JTextArea( 10, 15 );
      textArea.setText( "Press any key on the keyboard..." );
      textArea.setEnabled( false );
      getContentPane().add( textArea );

      // allow frame to process Key events
      addKeyListener( this );

      setSize( 350, 100 );
      setVisible( true );
   }

   // handle press of any key
   public void keyPressed( KeyEvent event )
   {
      line1 = "Key pressed: " + 
         event.getKeyText( event.getKeyCode() );
      setLines2and3( event );
   }

   // handle release of any key
   public void keyReleased( KeyEvent event )
   {
      line1 = "Key released: " +
         event.getKeyText( event.getKeyCode() );
      setLines2and3( event );
   }

   // handle press of an action key
   public void keyTyped( KeyEvent event )
   {
      line1 = "Key typed: " + event.getKeyChar();
      setLines2and3( event );
   }

   // set second and third lines of output
   private void setLines2and3( KeyEvent event )
   {
      line2 = "This key is " +
         ( event.isActionKey() ? "" : "not " ) +
         "an action key";

      String temp = 
         event.getKeyModifiersText( event.getModifiers() );

      line3 = "Modifier keys pressed: " +
         ( temp.equals( "" ) ? "none" : temp );

      textArea.setText( 
         line1 + "\n" + line2 + "\n" + line3 + "\n" );
   }

   // execute application
   public static void main( String args[] )
   {
      KeyDemo application = new KeyDemo();

      application.setDefaultCloseOperation(
         JFrame.EXIT_ON_CLOSE );
   }

}  // end class KeyDemo


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 * (C) Copyright 2002 by Deitel & Associates, Inc. and Prentice Hall.     *
 * All Rights Reserved.                                                   *
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