The Mediator pattern defines an object that encapsulates how a set of objects interact. It promotes loose coupling by keeping objects from referring to each other explicitly, and it allows their interaction to be varied independently. The pattern defines a mediator interface for communicating with colleague objects. A concrete mediator implements cooperative behavior by coordinating the colleagues. Colleague classes each know their mediator and communicate through it rather than interacting directly.

1. Mediator Design Pattern
(Behavioral)
-Mr.Anuj B. Pawar.
Roll No. 51

2. Intent
Mediator Pattern _ap2
 Object Behavioral an object that encapsulates how a
set of objects, which can interact and refer each other
independently.

3. Motivation
Mediator Pattern _ap3
 Requirement of system –
 A system needs objects to communicate with each other and
should be able to share properties of each other.
 Desired system will have –
 Different objects which can communicate with each other.
 Problem –
 Object structure will have many connections between objects
 Every object ends up knowing about every other.

4. Applicability
Mediator Pattern _ap4
 When one or more objects must interact with several different
objects.
 When simple object need to communicate in complex ways.
 When you want to reuse an object that frequently interacts with
other objects.

5. Example- Problem
Mediator Pattern _ap5

6. Example-Solution
03/04/03CS590L Mediator Pattern6

7. Example-Steps
Mediator Pattern _ap7
 The list box tells its director that it’s changed.
 The director gets the selection from the list box.
 The director passes the selection to the entry field.
 Director takes action.

8. General Structure
Mediator Pattern _ap8

9. Participants
Mediator Pattern _ap9
 Mediator
-defines an interface for communicating with Colleague
objects.
 Concrete Mediator
-implements cooperative behavior by coordinating
Colleague objects.
-knows and maintains its colleagues.
 Colleague classes
-each Colleague class knows its Mediator object.
-each colleague communicates with its mediator
whenever it would have otherwise communicated with
another colleague.

10. Related Patterns
Mediator Pattern _ap10
 Façade
 Observer

11. Mediator Pattern _ap11
Thank You..