Containers and Components

• Containers collect GUI components
• Sometimes, want to add a container to another container
• Container should be a component
• Composite design pattern
• Composite method typically invoke component methods
• E.g. Container.getPreferredSize invokes getPreferredSize of components

Composite Pattern

Context

1. Primitive objects can be combined to composite objects
2. Clients treat a composite object as a primitive object
   

Solution

1. Define an interface type that is an abstraction for the primitive objects
2. Composite object collects primitive objects
   
3. Composite and primitive classes implement same interface type.
4. When implementing a method from the interface type, the composite class applies the method to its primitive objects and combines the results

Composite Pattern

Composite Pattern

Maintained by John Loomis, last updated 25 February 2007