1. Stephenson College DP 98 1 Design Patterns by Derek Peacock

2. Stephenson College DP 98 2 Introduction a Designing OO software is hard a Specific enough for current problem a General enough for future requirements a Experts reuse past design solutions a Patterns of classes to solve specific design problems

3. Stephenson College DP 98 3 What is a Pattern Name a A Pattern Name Problem a A Problem (When to apply the pattern) Solution a The Solution (How to solve the problem) a Consequences a Consequences (Space, time, flexibility, portability, extensibility)

4. Stephenson College DP 98 4 Design Patterns a Creational ` Creating objects a Structural ` composition of objects a Behavioural ` Interaction between objects

5. Stephenson College DP 98 5 Creational Patterns a Abstract Factory a Builder a Singleton a Interface for creating families of related objects a Create complex object from representation a Create a only one globally accessible object

6. Stephenson College DP 98 6 Structural Patterns a Composite a Decorator a Façade a Proxy a Part-whole hierarchies a Attach additional responsibilities a Unified interface to subsystems a Provide surrogate for object

7. Stephenson College DP 98 7 Behavioural Patterns a Chain a Interpreter a Iterator a Memento a Provide a message chain a Interpret a language with grammar a Provide access to elements a Capture objects internal states