Action Listener

• Definition: http://journals.ecs.soton.ac.uk/java/tutorial/post1.0/ui/actionlistener.html
  • Simple Example: http://journals.ecs.soton.ac.uk/java/tutorial/post1.0/ui/eventintro.html#example1

This example emphasizes an event registration, but forgets event unregistration, therefore possibly leading to a MemoryLeak. This is the typical kind of code that teaches very bad habits to developers.

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• Api: http://java.sun.com/j2se/1.4.2/docs/api/java/awt/event/ActionListener.html

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An ActionListener is a sub-interface of EventListener?

• It allows an EventSource? to know about all Listeners which want to be informed

When a user

• clicks a button
• doubleclicks a list item
• chooses a menu item
• presses return in a text field

example

  button.addActionListener(this);

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ActionListeners in JavaSwing implement the ActionListener interface with an ActionListener.actionPerformed(ActionEvent e) method defined which is called when an event (clicking a button, etc) takes place. They sort-of represent the controller in ModelViewController. -- BrianMcCallister

In what way would you say they differ from the MVC controller?

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Listeners are MethodObjects.

They don't have to be.