Java Programming Code Examples

Java > Java AWT Code Examples

Demonstrating keystroke events

Demonstrating keystroke events

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

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

	 public KeyDemo()
	 {
		 super( "Demonstrating Keystroke Events" );

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

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

		 getContentPane().add( textArea );

		 setSize( 350, 100 );
		 show();
	 }

	 public void keyPressed( KeyEvent e )
	 {
		 line1 = "Key pressed: " + e.getKeyText( e.getKeyCode() );
		 setLines2and3( e );
	 }

	 public void keyReleased( KeyEvent e )
	 {
		 line1 = "Key released: " + e.getKeyText( e.getKeyCode() );
		 setLines2and3( e );
	 }

	 public void keyTyped( KeyEvent e )
	 {
		 line1 = "Key typed: " + e.getKeyChar();
		 setLines2and3( e );
	 }

	 private void setLines2and3( KeyEvent e )
	 {
		 line2 = "This key is " + ( e.isActionKey() ? "" : "not " ) + "an action key";

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

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

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

	 public static void main( String args[] )
	 {
		 KeyDemo app = new KeyDemo();

		 app.addWindowListener( new WindowAdapter() 
		 {
			 public void windowClosing( WindowEvent e )
			 {
				 System.exit( 0 );
			 }
		 } );
	 }
}