1. Composite
Design Pattern By
Aravind Reddy Patlola.

2. Composite Design Pattern
What is it?
Compose objects into tree structures to represent
part-whole hierarchies.
Composite lets clients treat individual objects and
compositions of objects uniformly.

3. Participants
Component – An abstract base class that declares the interface for objects in the composition.
Client – Manipulates objects in the composition thru component interface
Leaf – A subclass that defines behavior of primitive objects in the composition
Composite – A subclass that defines behavior for components having children.

4. Structural Representation of a Participants

5. Example

6. General Structure of Composite

7. Node Structure

8. Object Structure

9. When to use Composite?
When you want to represent part-whole hierarchies of objects.
When you want client to ignore the difference between compositions of objects and primitive objects

10. Advantages
Makes the client simple, by treating primitive and composite objects uniformly.
Makes it easier to add components.
Disadvantages
Makes design overly general i.e., components of a composite cannot be restricted.

11. References:
Design Patterns – Elements of Reusable Object Oriented
Software by Erich Gamma, Richard Helm, Ralph Johnson,
John Vlissides.
composite/composite.PDF