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

Building the GameObjectFactory


It is the job of the GameObjectFactory to use the ObjectSpec based classes to assemble GameObject instances with the correct components.

Create a new class called GameObjectFactory and add the following members and constructor shown next.

class GameObjectFactory {
    private Context mContext;
    private PointF mScreenSize;
    private GameEngine mGameEngineReference;

    GameObjectFactory(Context c, PointF screenSize, 
                      GameEngine gameEngine) {
        
        this.mContext = c;
        this.mScreenSize = screenSize;
        mGameEngineReference = gameEngine;
    }
}

We have a Context object, a PointF to hold the screen resolution and a GameEngine object to hold a reference to the GameEngine class. In the constructor all these member variables are initialized. It is the Level class that will create and use a reference to this class. It is the GameEngine class that will create an instance of the Level class and supply the necessary references...