The authors have come up with some ingenious ways to solve some common vexations among object-oriented programmers. Want to build a page-layout program that embeds inline images among characters of various sizes? How about building a program that converts files of one format to another? Chances are, some programmer already has thought of a better solution than you will and the recipes you need are here. Solutions are presented in generalised diagrams of data and logic structures. The idea is that you can take the concepts presented here and adapt them--in whatever language you use--to your individual situation. You may have to read some of the chapters several times before you fully understand them, but when you find a solution in this book, it will make your job easier and your results more elegant. --Jake Bond

• Capturing a wealth of experience about the design of object-oriented software, four top-notch designers present a catalog of simple and succinct solutions to commonly occurring design problems. Previously undocumented, these 23 patterns allow designers to create more flexible, elegant, and ultimately reusable designs without having to rediscover the design solutions themselves.
• The authors begin by describing what patterns are and how they can help you design object-oriented software. They then go on to systematically name, explain, evaluate, and catalog recurring designs in object-oriented systems. With Design Patterns as your guide, you will learn how these important patterns fit into the software development process, and how you can leverage them to solve your own design problems most efficiently.

Capturing a wealth of experience about the design of object-oriented software, four top-notch designers present a catalog of simple and succinct solutions to commonly occurring design problems. Previously undocumented, these 23 patterns allow designers to create more flexible, elegant, and ultimately reusable designs without having to rediscover the design solutions themselves.

The authors begin by describing what patterns are and how they can help you design object-oriented software. They then go on to systematically name, explain, evaluate, and catalog recurring designs in object-oriented systems. With Design Patterns as your guide, you will learn how these important patterns fit into the software development process, and how you can leverage them to solve your own design problems most efficiently.

Each pattern describes the circumstances in which it is applicable, when it can be applied in view of other design constraints, and the consequences and trade-offs of using the pattern within a larger design. All patterns are compiled from real systems and are based on real-world examples. Each pattern also includes code that demonstrates how it may be implemented in object-oriented programming languages like C++ or Smalltalk.

0201633612B07092001

Dr. Erich Gamma is technical director at the Software Technology Center of Object Technology International in Zurich, Switzerland. Dr. Richard Helm is a member of the Object Technology Practice Group in the IBM Consulting Group in Sydney, Australia. Dr. Ralph Johnson is a faculty member at the University of Illinois at Urbana-Champaign's Computer Science Department.

John Vlissides is a member of the research staff at the IBM T. J. Watson Research Center in Hawthorne, New York. He has practiced object-oriented technology for more than a decade as a designer, implementer, researcher, lecturer, and consultant. In addition to co-authoring Design Patterns: Elements of Reusable Object-Oriented Software, he is co-editor of the book Pattern Languages of Program Design 2 (both from Addison-Wesley). He and the other co-authors of Design Patterns are recipients of the 1998 Dr. Dobb's Journal Excellence in Programming Award.

Capturing a wealth of experience about the design of object-oriented software, four top-notch designers present a catalog of

simple and succinct solutions to commonly occurring design problems. Previously undocumented, these 23 patterns allow

designers to create more flexible, elegant, and ultimately reusable designs without having to rediscover the design solutions themselves.

The authors begin by describing what patterns are and how they can help you design object-oriented software. They then go on to systematically name,

explain, evaluate, and catalog recurring designs in object-oriented systems. With Design Patterns as your guide, you will learn how these important patterns fit

into the software development process, and how you can leverage them to solve your own design problems most efficiently.

Each pattern describes the circumstances in which it is applicable, when it can be applied in view of other design constraints, and the consequences and

trade-offs of using the pattern within a larger design. All patterns are compiled from real systems and are based on real-world examples. Each pattern also

includes code that demonstrates how it may be implemented in object-oriented programming languages like C++ or Smalltalk. Table of Contents

Preface

Foreword

Guide to Readers

1. Introduction

What Is a Design Pattern? * Design Patterns in Smalltalk MVC * Describing Design Patterns * The Catalog of Design Patterns * Organizing the Catalog *

How Design Patterns Solve Design Problems * How to Select a Design Pattern * How to Use a Design Pattern

2. A Case Study: Designing a Document Editor

Design Problems * Document Structure * Formatting * Embellishing the User Interface * Supporting Multiple Look-and-Feel Standards * Supporting

Multiple Window Systems * User Operations * Spelling Checking and Hyphenation * Summary

Design Pattern Catalog

3. Creational Patterns

Abstract Factory * Builder * Factory Method * Prototype * Singleton * Discussion of Creational Patterns

4. Structural Pattern

Adapter * Bridge * Composite * Decorator * Facade * Flyweight * Proxy * Discussion of Structural Patterns

5. Behavioral Patterns

Chain of Responsibility * Command * Interpreter * Iterator * Mediator * Memento * Observer * State * Strategy * Template Method * I have tested the scripts both on LINUX (Redhat) and on AIX, and some scripts have also been tested on Data Generals. I hope you enjoy the book, not only as a learning tool but also as a reference tool. Enjoy and have fun. Stand-by to stand-to. Any comments, or just to say hello, e-mail me at dtansley@my-Deja.com.

2008-01-31 All current comments are valid