Design Patterns: MORE Examples. Based on Design Patterns: Elements of reusable Object-Oriented software by gamma, helm, johnson , and Vlissides , Addison- wesley , 1995. . Recall What a design pattern is.
Based on Design Patterns: Elements of reusable Object-Oriented software by gamma, helm, johnson, and Vlissides, Addison-wesley, 1995.
“Each pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice.” – Christopher Alexander, et al. A Pattern Language, Oxford Univ. Press, New York, 1977.
An OO design pattern names, explains, and evaluates an important, recurring design in OO systems.
Creating an object by specifying a class explicitly.
Dependence on specific operations.
Dependence on hardware and software platform.
Dependence on object representations or implementations.
Extending functionality by subclassing.
Inability to alter classes conveniently.
Concerned with algorithms and the assignment of responsibilities between objects
Describes the patterns of communication between objects.
Characterizes complex control flow.
Behavioral class patterns use inheritance to distribute behavior between classes.
Behavioral object patterns use composition.