| Designing reusable object-oriented software applications is hard and challenging. Designing highly flexible and extensible object-oriented frameworks is even harder and more challenging. Object-oriented frameworks are a promising software reuse technique which allow reuse at large scale and have been becoming increasingly popular in contemporary software development. However, they are much more difficult to develop than applications. Design patterns are widely used as building elements to support designing reusable software applications. Flexibility and maintainability features coming with design patterns are exactly what frameworks are pursuing. The objective of this research is to obtain an in-depth understanding of design patterns and object-oriented frameworks, and study the development of frameworks and how to apply design patterns in the development process. For this reason, this thesis studies the essence of design patterns, how they solve problems, the concepts, principles, techniques and process of frameworks development, and the relationship between design patterns and frameworks. This thesis also presents a case study in which I developed an object-oriented framework for genetic algorithms by using design patterns. The experience shows that design patterns are closely related to few essential framework construction patterns and the use of hot spots and design patterns provides a powerful support for achieving flexibility and extensibility of frameworks. |
