Complete development from <<Abstraction>>

Static diagram :

Strong points :

1. 1. Extensibility
   1. 1.1 Addition or removal of a concrete implementor does not need code modification
   2. 1.2 Addition or removal of a refined abstraction does not need code modification
2. 2. Decoupling between abstraction and implementor
   1. 2.1 Minimal number of concrete implementor
   2. 2.2 Maximal factorization of the link between abstraction and implementor

Spoiled pattern instantiations on different problems

Problem 1 :

Name :

Display platform changing

Problem wording :

Design a system for changing the style of windows on the screen. Three types of window are possible: simple, with menu and transparent. The style of these windows depends on the platform of use. Two platforms are considered, Gnome and XFCE. The client code must be able to be written independently and without prior knowledge of the future execution platform.

Optimal solution :

Static diagram :

In this solution, there is a real separation between the windows style and their content. It is possible to add a new style or a new type without modifying existing code.

Alternative solution :

Static diagram :

Probably the worst case with Implementor under Refined Abstraction