Book Image

Android UI Development with Jetpack Compose - Second Edition

By : Thomas Künneth
5 (1)
Book Image

Android UI Development with Jetpack Compose - Second Edition

5 (1)
By: Thomas Künneth

Overview of this book

Compose has caused a paradigm shift in Android development, introducing a variety of new concepts that are essential to an Android developer’s learning journey. It solves a lot of pain points associated with Android development and is touted to become the default way to building Android apps over the next few years. This second edition has been thoroughly updated to reflect all changes and additions that were made by Google since the initial stable release, and all examples are based on Material 3 (also called Material You). This book uses practical examples to help you understand the fundamental concepts of Jetpack Compose and how to use them when you are building your own Android applications. You’ll begin by getting an in-depth explanation of the declarative approach, along with its differences from and advantages over traditional user interface (UI) frameworks. Having laid this foundation, the next set of chapters take a practical approach to show you how to write your first composable function. The chapters will also help you master layouts, an important core component of every UI framework, and then move to more advanced topics such as animation, testing, and architectural best practices. By the end of this book, you’ll be able to write your own Android apps using Jetpack Compose and Material Design.
Table of Contents (18 chapters)
Part 1: Fundamentals of Jetpack Compose
Part 2: Building User Interfaces
Part 3: Advanced Topics

Surviving configuration changes

Recall that our definition of state as data that may change over time is quite broad. For example, we do not specify where the data is stored. If it resides in a database, a file, or some backend in the cloud, the app should include a dedicated persistence layer. However, until Google introduced Android Architecture Components back in 2017, there had been practically no guidance for developers on how to structure their apps. Consequently, persistence code, UI logic, and domain logic were often crammed into one activity. Such code was difficult to maintain and often prone to errors. To make matters a little more complicated, there are situations when an activity is destroyed and recreated shortly after. For example, this happens when a user rotates a device. Certainly, data should then be remembered.

The Activity class has a few methods to handle this. For example, onSaveInstanceState() is invoked when the activity is (temporarily) destroyed. Its counterpart...