Lecture 15 - Events

Question 1

Where are events mainly used?

Answer 1

Events are mainly used in GUI’s.

Question 2

Mode of delegation

Answer 2

There is a source, event and listener. Starts at the source, ends at the listener.

Question 3

Listeners and Sources

Answer 3

There can be more than one listener registered to a source, even if it reacts to the same event.
(A button can have 2 listeners where when clicked, one listener plays a music and another takes care of opening a GUI page.) The event is MouseEvent, the source is the MousePointer but there 2 listeners attached to the MousePointer.

Question 4

Class XEvent

Answer 4

If there is a class XEvent, there is an interface XListener. If interface contains more than one method, then class XAdapter exists.