Book Image

Learning Java by Building Android Games - Third Edition

By : John Horton
5 (1)
Book Image

Learning Java by Building Android Games - Third Edition

5 (1)
By: John Horton

Overview of this book

Android is one of the most popular mobile operating systems today. It uses the most popular programming language, Java, as one of the primary languages for building apps of all types. Unlike most other Android books, this book doesn’t assume that you have any prior knowledge of Java programming, instead helps you get started with building Android games as a beginner. This new, improved, and updated third edition of Learning Java by Building Android Games helps you to build Android games from scratch. Once you've got to grips with the fundamentals, the difficulty level increases steadily as you explore key Java topics, such as variables, loops, methods, object-oriented programming (OOP), and design patterns while working with up-to-date code and supporting examples. At each stage, you'll be able to test your understanding by implementing the concepts that you’ve learned to develop a game. Toward the end, you’ll build games such as Sub Hunter, Retro Pong, Bullet Hell, Classic Snake, and Scrolling Shooter. By the end of this Java book, you'll not only have a solid understanding of Java and Android basics but will also have developed five cool games for the Android platform.
Table of Contents (24 chapters)

Coding the PongGame class

The first thing we will do is solve the problem of our PongGame class not being of the View type. Update the class declaration as highlighted, like this:

class PongGame extends SurfaceView {

You will need to import the android.view.SurfaceView class as shown next so that Android Studio knows about the SurfaceView class. You can add the line of code after the package declaration in the PongGame.java file or use the Alt + Enter keyboard combination as we have done before.

SurfaceView is a descendant of View and now PongGame is, by inheritance, also a type of View. Look again at the import statement that has been added. This relationship is made clear as highlighted next:

android.view.SurfaceView

Tip

Remember that it is because of polymorphism that we can send descendants of View to the setContentView method in the PongActivity class and it is because of inheritance that PongGame is a type of SurfaceView.

There are quite a few descendants...