// Fig. 13.22: KeyDemo.java // Demonstrating keystroke events. import java.awt.*; import java.awt.event.*; import javax.swing.*; public class KeyDemo extends JFrame implements KeyListener { private String line1 = "", line2 = "", 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 ); textArea.setDisabledTextColor( Color.BLACK ); getContentPane().add( textArea ); addKeyListener( this ); // allow frame to process Key events setSize( 350, 100 ); setVisible( true ); } // end KeyDemo constructor // 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" ); } public static void main( String args[] ) { KeyDemo application = new KeyDemo(); application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); } } // end class KeyDemo /************************************************************************** * (C) Copyright 1992-2003 by Deitel & Associates, Inc. and * * Prentice Hall. All Rights Reserved. * * * * DISCLAIMER: The authors and publisher of this book have used their * * best efforts in preparing the book. These efforts include the * * development, research, and testing of the theories and programs * * to determine their effectiveness. The authors and publisher make * * no warranty of any kind, expressed or implied, with regard to these * * programs or to the documentation contained in these books. The authors * * and publisher shall not be liable in any event for incidental or * * consequential damages in connection with, or arising out of, the * * furnishing, performance, or use of these programs. * *************************************************************************/