// 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.addWindowListener(new WindowAdapter()

{ public void windowClosing( WindowEvent event )

{

System.exit( 0 );

}

}

);

}

} // end class KeyDemo