@Pattern(name="Decorator", scope=Object, purpose=Structural, participants={"Component","ConcreteComponent","Decorator","ConcreteDecorator"})

Package dk.rode.thesis.decorator

Implementations and examples of the Decorator design pattern [Gamma95, p.175].

See:
Description

Class Summary

AppenderDecorator	An appender decorator returns the String value from a decorated sequence prefixed and/or postfixed with values supplied at construction time, respectively.
DuplexDecorator	A duplex sequence decorator returns the String value returned by the decorated sequence concatenated with the same value, for example x -> xx.
Main	Decorator tests.
SequenceDecorator<E>	A sequence decorator is a decorator that forwards all request to the decorated Sequence without performing additional operations except for toString().
UppercaseDecorator	An upper-case sequence decorator returns the string value returned by the decorated sequence in upper-case, for example a -> A.

Enum Summary

DecoratedPolicy

Additional policies for formatting decorated sequences into char sequences (not part of the core Decorator implementation).

Package dk.rode.thesis.decorator Description

Implementations and examples of the Decorator design pattern [Gamma95, p.175].

Intent:

Attach additional responsibilities to an object dynamically. Decorators provide a flexible alternative to sub—classing for extending functionality.

Here, the Component participant is represented by the Sequence interface. Any Sequence implementation thus represent the ConcreteComponent participant.

The Decorator participant is represented by the abstract SequenceDecorator class, which also implements the Sequence interface as required. It implements all the basic Sequence functionality by forwarding calls to the decorated sequence. This package defines several decorators that represent the ConcreteDecorator participant, for example AppenderDecorator and DuplexDecorator.

UML Class Diagram:

Implementation notes:
All the decorators defined here only adds behaviour, no additional state.

Author:

Gunni Rode / rode.dk