Events

Question 1

What model is the Java event system based on? Explain the model…

Answer 1

Delegation Model.
Event sources cause an event via changing some state within the program. An event listener then reacts as specified.

Question 2

What are the 2 ways events are implemented?

Answer 2

Polling : Waiting for an indefinite amount of time in a loop for an event to occur via some condition.
Event driven : Create idle code that only executes when a certain event occurs.

Question 3

What are the 3 components of the events framework?

Answer 3

Events : Change of state within the program.
Event Source : An object that generates a state change.
Event Listener : An object that responds to the event in a defined way.

Question 4

Where do all event sources descend from?

Answer 4

Event Object class

Question 5

Where do all event listeners descent from?

Answer 5

Event Listener interface