Mediator

Intent, Motivation, Applicability, Structure, Participants, Collaborations, Consequences, Implementation, Sample Code, Known Uses, Related Patterns

Applicability

Use the Mediator pattern when

• a set of objects communicate in well-defined but complex ways. The resulting interdependencies are unstructured and difficult to understand.
• reusing an object is difficult because it refers to and communicates with many other objects.
• a behavior that's distributed between several classes should be customizable without a lot of subclassing.

Applicability of Abstract Factory, Adapter, Bridge, Builder, Chain of Responsibility, Command, Composite, Decorator, Facade, Factory Method, Flyweight, Interpreter, Iterator, Mediator, Memento, Observer, Prototype, Proxy, Singleton, State, Strategy, Template Method, Visitor