More techniques and tips - JavaTech: An Introduction to Scientific and Technical Computing with Java - page 401

*andamessage printed in the text area.
**/
KeyTestPanel () {
setLayout (new GridLayout (2,1));
JPanel canvas = new JPanel ();
add (canvas, BorderLayout.NORTH);
canvas.setBackground (Color.YELLOW);
fTextArea = new JTextArea ();
fTextArea.setEditable (false);
// Add to a scrollpanesothatalonglistof
// keyinputs can be seen.
JScrollPane area - scroll - pane = new JScrollPane
(fTextArea);
add (area - scroll - pane, BorderLayout.CENTER);
// Add to the panel an anonymous KeyAdapter that will
// respond to key strokes.
canvas.addKeyListener (
new KeyAdapter () {
public void keyTyped (KeyEvent e) {
saySomething ( " got " +e.getKeyChar (), e);
}
} // end anonymous class
); // end method call
// Let the canvas panel get the focus.
canvas.setFocusable (true);
} // ctor
/** Display a message in text area about the key
event. **/
void saySomething (String eventDescription, KeyEvent e) {
fTextArea.append (eventDescription + " on "
+e.getComponent ().getClass ().getName ()
+ "\ n " );
}
} // class KeyTestPanel
The KeyListener interface also has the keyPressed() , keyReleased() ,
and keyTyped() methods that fire a KeyEvent when a key is pressed, released,