Book Image

Learning Java by Building Android Games - Second Edition

By : John Horton
Book Image

Learning Java by Building Android Games - Second Edition

By: John Horton

Overview of this book

Android is one of the most popular mobile operating systems presently. It uses the most popular programming language, Java, as the primary language for building apps of all types. However, this book is unlike other Android books in that it doesn’t assume that you already have Java proficiency. This new and expanded second edition of Learning Java by Building Android Games shows you how to start building Android games from scratch. The difficulty level will grow steadily as you explore key Java topics, such as variables, loops, methods, object oriented programming, and design patterns, including code and examples that are written for Java 9 and Android P. At each stage, you will put what you’ve learned into practice by developing a game. You will build games such as Minesweeper, Retro Pong, Bullet Hell, and Classic Snake and Scrolling Shooter games. In the later chapters, you will create a time-trial, open-world platform game. By the end of the book, you will not only have grasped Java and Android but will also have developed six cool games for the Android platform.
Table of Contents (30 chapters)
Learning Java by Building Android Games Second Edition
Contributors
Preface
Index

Chapter 18. Introduction to Design Patterns and much more!

Since the second project, we have been using objects. You might have noticed that many of the objects have things in common. Things like variables for speed and direction, a RectF for handling collisions and more besides.

As our objects have more in common we should start taking advantage of OOP, inheritance, polymorphism and a concept we will now introduce design patterns.

Inheritance, polymorphism and design patterns will enable us to fashion a suitable hierarchy to try and avoid writing duplicate code and avoid sprawling classes with hundreds of lines. This type of disorganised code is hard to read, debug or extend. The bigger the game project and the more object types, the more of a problem this would become.

This project and the next will explore many ways that we can structure our Java code to make our code efficient, reusable and less buggy. When we write code to a specific, previously devised solution/structure we are using...