Book Image

How to Build Android Apps with Kotlin - Second Edition

By : Alex Forrester, Eran Boudjnah, Alexandru Dumbravan, Jomar Tigcal
5 (1)
Book Image

How to Build Android Apps with Kotlin - Second Edition

5 (1)
By: Alex Forrester, Eran Boudjnah, Alexandru Dumbravan, Jomar Tigcal

Overview of this book

Looking to kick-start your app development journey with Android 13, but don’t know where to start? How to Build Android Apps with Kotlin is a comprehensive guide that will help jump-start your Android development practice. This book starts with the fundamentals of app development, enabling you to utilize Android Studio and Kotlin to get started with building Android projects. You'll learn how to create apps and run them on virtual devices through guided exercises. Progressing through the chapters, you'll delve into Android's RecyclerView to make the most of lists, images, and maps, and see how to fetch data from a web service. You'll also get to grips with testing, learning how to keep your architecture clean, understanding how to persist data, and gaining basic knowledge of the dependency injection pattern. Finally, you'll see how to publish your apps on the Google Play store. You'll work on realistic projects that are split up into bitesize exercises and activities, allowing you to challenge yourself in an enjoyable and attainable way. You'll build apps to create quizzes, read news articles, check weather reports, store recipes, retrieve movie information, and remind you where you parked your car. By the end of this book, you'll have the skills and confidence to build your own creative Android applications using Kotlin.
Table of Contents (24 chapters)
1
Part 1: Android Foundation
6
Part 2: Displaying Network Calls
12
Part 3: Testing and Code Structure
17
Part 4: Polishing and Publishing an App

Scoped storage

Since Android 10 and with further updates in Android 11, the notion of scoped storage was introduced. The main idea behind this is to allow apps to gain more control of their files in external storage and prevent other apps from accessing these files.

The consequences of this mean that READ_EXTERNAL_STORAGE and WRITE_EXTERNAL_STORAGE will only apply to files a user interacts with (such as media files). This discourages apps from creating their own directories in external storage, instead sticking with the one already provided to them through Context.getExternalFilesDir.

FileProviders and the SAF are a good way of making your app comply with scoped storage practices, with one allowing the app to use Context.getExternalFilesDir and the other using the built-in File Explorer app, which will now avoid files from other applications in the Android/data and Android/obb folders in external storage.

Camera and media storage

Android offers a variety of ways to interact...