<<< Observer     Index     Observer Usage >>>

61. Observer Structure


    Observer UML Class Diagram
  • Subject is an abstract class that provides an interface for attaching and detaching Observers.

  • Subject::Notify operation notifies each Observer by calling Observer::Update operation, known as raising the state change event.

  • Observer is the interface for all observers who receive notifications from the Subject.


<<< Observer     Index     Observer Usage >>>