What parameters are used when .addActionListener() is called?
<p>I've been learning quite a lot in Java recently but something has been really bugging me. I learned / was taught how to use ActionListeners when the program involves a constuctor, for example,</p>

<pre><code>public class test extends JFrame implements ActionListener {
JButton button;

public test 
{
setLayout(null);
setSize(1920,1080);
setTitle("test");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
button = new JButton("");
button.setBounds(x,x,x,x);
button.AddActionListener(this); //What can replace the this parameter here.
button.setVisible(true);
add(button);
}
public static void main(String[] args) {
    test testprogram = new test();
    test.setVisible(true);
}
@Override
    public void actionPerformed(ActionEvent clickevent) {
    if (clickevent.GetSource() == button) { 
      //DoSomething
    }
}
</code></pre>