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

Adding the alien's components


Remember that some of the alien's components are the same as some of the other components we have already coded. For example, all the aliens and their laser have a StdGraphicsComponent. In addition, the alien's laser has the same components as the player's laser. The only difference is the specification (that we have already coded) and the need for an AlienLaserSpawner interface.

As all the specifications are completed, everything is in place we can just go ahead and code these remaining classes shown next.

AlienChaseMovementComponent

Create a new class called AlienChaseMovementComponent and then add the following member and constructor method.

class AlienChaseMovementComponent implements MovementComponent {

    private Random mShotRandom = new Random();

    // Gives this class the ability to tell the game engine
    // to spawn a laser
    private AlienLaserSpawner alienLaserSpawner;

    AlienChaseMovementComponent(AlienLaserSpawner als){
        alienLaserSpawner...