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

Theming in Compose

In the previous section, we learned how to handle user actions and how to manage the state of a particular screen. But how do we keep our application’s user interface elements consistent across the entire application? In this section, we will look at how we can create reusable elements that are linked to the application’s theme.

You may have noticed, when you carried out the previous exercises, that Android Studio created some files in a ui.theme package. This is because Jetpack Compose is built upon the Material Design library and will assign a theme to your application that is built on Material Design. The approach taken is the following:

  1. In the Color.kt file, all the colors of the application are declared:
    val Purple200 = Color(0xFFBB86FC)
    val Purple500 = Color(0xFF6200EE)
    val Purple700 = Color(0xFF3700B3)
    val Teal200 = Color(0xFF03DAC5)

In the preceding example, we have the color hexadecimal names.

  1. In Shape.kt, the following...