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

Code the SoundEngine


Fortunately, the SoundEngine class holds no surprises. This is essentially the exact same class as we coded in the Scrolling Shooter project. The only exceptions are that we load different sound effects and the methods which play the sound effects have different names and play different sounds. We have also made it a Singleton to avoid the long parameter lists that we had in the previous project when we passed a SoundEngine reference into so many other classes/methods.

Add the following code for the member variables and the getInstance method.

import android.content.Context;
import android.content.res.AssetFileDescriptor;
import android.content.res.AssetManager;
import android.media.AudioAttributes;
import android.media.AudioManager;
import android.media.SoundPool;
import android.os.Build;

import java.io.IOException;

class SoundEngine {
    // for playing sound effects
    private static SoundPool mSP;
    private static int mJump_ID = -1;
    private static int mReach_Objective_ID...