A doubt in SWING event handling

Question

Hi all,
I'm a beginner in JAVA studying SWING. I learned that if we want to handle an event for a event source(say JButton) we should implement corresponding Event Listener(say ActionListener) .
I also understood that we should register the Listener with that event source.
With that knowledge I tried this program
import javax.swing.*;
import java.awt.event.*;
public class SimpleGui2 implements MouseListener,ActionListener {
   SimpleGui2 insGui;
   JButton button= new JButton("Click me");
     public static void main(String[] args) {
          SimpleGui2 gui = new SimpleGui2();
          gui.start();
   public void start() {
        JFrame frame = new JFrame();
        //button.addMouseListener(this);   
        //button.addActionListener(this);
        button.addActionListener(insGui);
        frame.getContentPane().add(button);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300,300);
        frame.setVisible(true);
   public void actionPerformed(ActionEvent ae) {
        button.setText("Triggered");
   public void mouseClicked(MouseEvent me) {
      button.setText("I have been clicked");
   public void mouseEntered(MouseEvent me) { }
   public void mouseExited(MouseEvent me) { }
   public void mousePressed(MouseEvent me) { }
   public void mouseReleased(MouseEvent me) { }  
}but It's is not working as I expected.
or precisely why when we clicked the actionPerformed/mouseClicked method is not invoked ?
if i change the same with argument "this" it's working .
I guess "this" refers to current object (which is also of type SimpleGui2 which implemented ActionListener)
Can any one please clarify me what happens behind the scenes ?
Thanks in advance

Answer 1

first of all, you never initialize insGui. YOu just declare it, and never use it.
SimpleGui2 insGui;However, you dont need it anyways. As you suspected, using 'this' when you add your actionListener is what you need.
button.addActionListener(insGui);
Can any one please clarify me what happens behind the scenes ?Well my professor always said it was 'black magic'. All I know is that you click a button with an event listener, and an event is fired doing whatever you want it to do. For example, if I want my event to print "Hey" then when I click the button, "Hey" is printed. Simple enough eh? You will probably find a better answer using Google though. It's amazing.