Java Reference
In-Depth Information
LISTING 8.22
continued
//--------------------------------------------------------------
// Provide empty definitions for unused event methods.
//--------------------------------------------------------------
public void keyTyped (KeyEvent event) {}
public void keyReleased (KeyEvent event) {}
}
}
The KeyEvent object passed to the keyPressed method of the listener can be
used to determine which key was pressed. In the example, we call the getKeyCode
method of the event object to get a numeric code that represents the key that was
pressed. We use a switch statement to determine which key was pressed and to
respond accordingly. The KeyEvent class contains constants that correspond to
the numeric code that is returned from the getKeyCode method. If any key other
than an arrow key is pressed, it is ignored.
void keyPressed (KeyEvent event)
Called when a key is pressed.
void keyReleased (KeyEvent event)
Called when a key is released.
void keyTyped (KeyEvent event)
Called when a pressed key or key combination produces
a key character.
FIGURE 8.8 The methods of the KeyListener interface
 
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