1 / 10

Introduction to Design Patterns

Introduction to Design Patterns. For CSE 3902 By: Matt Boggus. Outline. Why design? Patterns (in general) Design patterns. Design. Design is the creation of a plan or convention for the construction of an object or a system. Poor Planning. Design quotes – Make it Simple!.

ceana
Download Presentation

Introduction to Design Patterns

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction to Design Patterns For CSE 3902 By: Matt Boggus

  2. Outline • Why design? • Patterns (in general) • Design patterns

  3. Design • Design is the creation of a plan or convention for the construction of an object or a system

  4. Poor Planning

  5. Design quotes – Make it Simple! • A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away - Antoine de Saint-Exupery • If you can't explain it to a six year old, you don't understand it yourself - Albert Einstein • Simplicity is the ultimate sophistication - Leonardo da Vinci • Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius and a lot of courage to move in the opposite direction- E.F. Schumacher

  6. Patterns • “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

  7. Design Pattern • “A design pattern names, abstracts, and identifies key aspects of a common design structure that makes it useful for creating a reusable object-oriented design.” • Gang of Four (Design Patterns: Elements of Reusable Object-Oriented Software)

  8. Why use Design Patterns? A developer might say "Let's use an ADAPTER.“ rather than "How about a superclass with a getTemperature method and then subclass that with classes that reference instances of the vendor-supplied classes for...."

  9. Four essential elements to a Pattern • Pattern Name • Having a concise, meaningful name for a pattern improves communication among developers • Problem • What is the problem and context where we would use this pattern? • What are the conditions that must be met before this pattern should be used? • Solution • A description of the elements that make up the design pattern • Emphasizes their relationships, responsibilities and collaborations • Not a concrete design or implementation; rather an abstract description • Consequences • The pros and cons of using the pattern • Includes impacts on reusability, portability, extensibility

  10. UML Notation • Design patterns in UML paper http://en.wikipedia.org/wiki/File:Command_Design_Pattern_Class_Diagram.png

More Related