Book Image

Android Programming with Kotlin for Beginners

By : John Horton
5 (1)
Book Image

Android Programming with Kotlin for Beginners

5 (1)
By: John Horton

Overview of this book

Android is the most popular mobile operating system in the world and Kotlin has been declared by Google as a first-class programming language to build Android apps. With the imminent arrival of the most anticipated Android update, Android 10 (Q), this book gets you started building apps compatible with the latest version of Android. It adopts a project-style approach, where we focus on teaching the fundamentals of Android app development and the essentials of Kotlin by building three real-world apps and more than a dozen mini-apps. The book begins by giving you a strong grasp of how Kotlin and Android work together before gradually moving onto exploring the various Android APIs for building stunning apps for Android with ease. You will learn to make your apps more presentable using different layouts. You will dive deep into Kotlin programming concepts such as variables, functions, data structures, Object-Oriented code, and how to connect your Kotlin code to the UI. You will learn to add multilingual text so that your app is accessible to millions of more potential users. You will learn how animation, graphics, and sound effects work and are implemented in your Android app. By the end of the book, you will have sound knowledge about significant Kotlin programming concepts and start building your own fully featured Android apps.
Table of Contents (33 chapters)
Android Programming with Kotlin for Beginners
Contributors
Preface
Index

The Canvas Demo app


First, create a new project to explore the topic of drawing with Canvas. We will reuse what we have 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, and make sure that you choose the Empty Activity template option.

In this app, we will make a change that we have not seen before. We will be using the vanilla version of the Activity class. Therefore, MainActivity will inherit from Activity instead of AppCompatActivity, as has been the case previously. We are doing this because we are not using a layout from an XML file, and so we have no need for the backward compatibility features of AppCompatActivity as we did in all the previous projects.

You should edit the class declaration as follows.

class MainActivity : Activity() {

You will also need to add the following import statement:

import android.app.Activity

Note

The complete code for this app can be found in the download bundle in the Chapter20...