Book Image

Android UI Development with Jetpack Compose

By : Thomas Künneth
Book Image

Android UI Development with Jetpack Compose

By: Thomas Künneth

Overview of this book

Jetpack Compose is Android’s new framework for building fast, beautiful, and reliable native user interfaces. It simplifies and significantly accelerates UI development on Android using the declarative approach. This book will help developers to get hands-on with Jetpack Compose and adopt a modern way of building Android applications. The book is not an introduction to Android development, but it will build on your knowledge of how Android apps are developed. Complete with hands-on examples, this easy-to-follow guide will get you up to speed with the fundamentals of Jetpack Compose such as state hoisting, unidirectional data flow, and composition over inheritance and help you build your own Android apps using Compose. You'll also cover concepts such as testing, animation, and interoperability with the existing Android UI toolkit. By the end of the book, you'll be able to write your own Android apps using Jetpack Compose.
Table of Contents (16 chapters)
Part 1:Fundamentals of Jetpack Compose
Part 2:Building User Interfaces
Part 3:Advanced Topics

Sharing data between Views and composable functions

State is app data that may change over time. Recomposition occurs when state being used by a composable changes. To achieve something similar in the traditional View world, we need to store data in a way that changes to it can be observed. There are many implementations of the Observable pattern. The Android Architecture Components (and subsequent Jetpack versions) include LiveData and MutableLiveData. Both are frequently used inside ViewModels to store state outside activities.

Revisiting ViewModels

I introduced you to ViewModels in the Surviving configuration changes section of Chapter 5, Managing the State of Your Composable Functions, and the Persisting and retrieving state section of Chapter 7, Tips, Tricks, and Best Practices. Before we look at how to use ViewModels to synchronize data between Views and composable functions, let's briefly recap on key techniques, as follows:

  • To create or get an instance of...