Events are objects that represent user actions, such as clicking on a button.
When a GUI program is running, the user generates an event by interacting with a GUI component. Here are some ways to generate an event:
For a program to respond to an event there must be an event listener object for it. The event listener object contains listener methods for various types of events.
A program can ignore events. For example, the programs of the previous chapter ignored nearly all events. If there is no listener for an event, the event is ignored.
(Thought question: ) Could an event listener object contain other methods in addition to listener methods?