Uses some patterns and OO principles to provide an example of some patterns. These are detailed below, and a pretty huge SVG image of the class diagram is below.

Disclaimer; I am a programmer, therefore I make mistakes.

The factory method pattern is used to produce different implementations of a factory

Pizzas can be decorated by a decorator to add new ingredients.

• These are added after the base ingredients in the prepare() method of the DecoratedPizza.
• DecoratedPizzas can be decorated again, adding more ingredients.

A special factory is responsible for creating decorated pizzas.

• A decorated pizza is more expensive than a 'normal' one; Margherita pizzas constructed via your own list of ingredients cost more!

The margherita factory only produces one kind of pizza and no instance variables are required. It is a shame to create more than one.

• The specific implementation is thread safe.

Use the zoom functionality on your browser to navigate an isolate specific parts of the diagram.

Can you spot all the patterns above?