A Query regarding 'Events' published and 'Event' subscribed

Question

I have a query regarding 'Events' and 'EventHandling' in Java Swing.
Swing in an EVENT based application whereby 'events' are generated
by interacting with the components.
Eg: Clicking on a Button generates an 'ActionEvent' and every event
generated has an associated 'EventListener'.
Now,my question is:
a)When an event is generated,(let's say by clicking a button),
an 'event' is published,right?
That means that there is an 'Event Publisher'.
In the above case,the Button is the 'Publisher' of the event,right?
b) Who are the subscribers for the events generated?
Where do we specify the 'subscibers' to the events generated?(and once
the subscribers get the Event,the subscriber will call the methods
of the event object)
We just say
   addButton.addActionListener(new ButtonHandler);
   private class ButtonHandler implements ActionListener {
        public void actionPerformed(ActionEvent e){
  In the above code :
a) Who is the Event Publisher?
b) Who is the Event Subscriber?
No offence meant for the question.

Answer 1

The 'event publisher' for the mouse click is the ToolKit implementation (translates the OS mouse event to a Java mouse event).
The 'event subscriber' for the mouse click on a button is typically a ButtonUI (you can add a mouse listener directly though).
The 'event publisher' for the action event is the ButtonModel (notified by the ButtonUI when the button is unpressed, etc).
The 'event subscriber' for the action event are the action listeners.