Book Image

Android Programming for Beginners - Third Edition

By : John Horton
Book Image

Android Programming for Beginners - Third Edition

By: John Horton

Overview of this book

Do you want to make a career in programming but don’t know where to start? Do you have a great idea for an app but don't know how to make it a reality? Or are you worried that you’ll have to learn Java programming to become an Android developer? Look no further! This new and expanded third edition of Android Programming for Beginners will be your guide to creating Android applications from scratch. The book starts by introducing you to all the fundamental concepts of programming in an Android context, from the basics of Java to working with the Android API. You’ll learn with the help of examples that use up-to-date API classes and are created within Android Studio, the official Android development environment that helps supercharge your mobile application development process. After a crash course on the key programming concepts, you’ll explore Android programming and get to grips with creating applications with a professional-standard UI using fragments and storing user data with SQLite. This Android Java book also shows you how you can make your apps multilingual, draw on the screen with a finger, and work with graphics, sound, and animations. By the end of this Android programming book, you'll be ready to start building your own custom applications in Android and Java.
Table of Contents (30 chapters)

Understanding the Canvas class

The Canvas class is part of the android.graphics package. In the next two chapters, we will be using all the following import statements from the android.graphics package and one more from the now-familiar View package. They give us access to some powerful drawing methods from the Android API:

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
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 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 consider the specific device our app is running on. It is true that some of this preparation can be slightly counterintuitive, but we will go through it a step at...