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)

Understanding the Canvas class

The Canvas class is part of the android.graphics package. If you look at the import statements at the top of the Sub' Hunter code, you will see the following lines of code:

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.view.Display;
import android.widget.ImageView;

First, let's talk about Bitmap, Canvas, and ImageView, as highlighted in the previous code.

Getting started drawing with Bitmap, Canvas, and ImageView

As Android is designed to run on all types of mobile apps, we can't immediately start typing our drawing code and expect it to work. We need to do a bit of preparation (coding) to get things working. It is true that some of this preparation can be slightly counterintuitive, but we will go through it a step at a time.

Canvas and Bitmap

Depending on how you use the Canvas class, the term...