Uml Model Of The Observer Pattern. Swing and net are extensively using the observer pattern for implementing the events mechanism. Observer pattern uses three actor classes.
Event management this is one of the domains where the observer patterns is extensively used. In the design pattern dialog box select observer from the list of patterns. Besides other well known patterns such as the visitor pattern or the singleton pattern the observer pattern belongs to this collection of practical design patterns.
When subject changes its state all the observers are notified automatically.
The observable sends all information about the change to the observers using an object and it s up to observer to decide what information to use. Swing and net are extensively using the observer pattern for implementing the events mechanism. Subject represents the core or independent or common or engine abstraction. Model view controller pattern the observer pattern is used in the model view controller mvc architectural pattern.
