ActionListener is an interface and not a class,
it can be implemented wherever is convenient. For example, an
applet can handle its own events like this:
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class BeepApplet extends Applet implements ActionListener {
public void init () {
// Construct the button
Button beep = new Button("Beep");
// add the button to the layout
this.add(beep);
// specify that action events sent by this
// button should be handled by the applet itself
beep.addActionListener(this);
}
public void actionPerformed(ActionEvent e) {
Toolkit.getDefaultToolkit().beep();
}
}