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)

Canvas demo app

We will create a new project just to explore the topic of drawing with Canvas. We will reuse what we have just learned and this time, we will also draw to the Bitmap instance.

Creating a new project

Create a new project and call it Canvas Demo. Choose the Empty Activity template.

In addition, we are going to be using the vanilla version of the Activity class and the MainActivity class will therefore extend Activity instead of AppCompatActivity as we have been using previously. This is simply because we no longer need the extra features provided by the AppCompatActivity class.

Note

The complete code for this app can be found in the download bundle in the Chapter 20/Canvas Demo folder.

Coding the Canvas demo app

To get started, edit the code in MainActivity.java, including adding the import directives and changing the version of the Activity class that the MainActivity class inherits from. Also notice in the next code that the call to the setContentView...