Design Patterns Explained

He defines it as part of his constraints:
The system (code and tests together) must communicate
everything you want to communicate.
The system must contain no duplicate code. (1 and 2
together constitute the Once and Only Once rule).
Figure 9-13 illustrates the separation of the Shape abstraction from
the Drawing implementation.
Figure 9-13 Class diagram illustrating separation of abstraction and
implementation.
From a method point of view, this looks fairly similar to the inheritance-based
implementation (such as shown in Figure 9-3). The biggest
difference is that the methods are now located in different
objects.
Chapter 9 The Bridge Pattern 145
The pattern
llustrated
Relating this to the
inheritance-based
design