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

Chapter 5: Managing the State of Your Composable Functions

In Chapter 4, Laying Out UI Elements, I showed you how to set the red, green, and blue portions of a color by dragging sliders. We used state to share these values among composable functions. Quite a few other sample apps of the previous chapters dealt with state, too. In fact, reacting to state changes is critical to how modern mobile apps work.

So far, I have described state as data that can change over time. You learned about a few important functions, for example, remember { } and mutableStateOf(). I also briefly touched on a concept called state hoisting.

This chapter builds on these foundations. For example, you will understand the difference between stateless and stateful composables, and when to choose which. Also, I will show you how events should flow in a well-behaving Compose app.

The main sections of this chapter are the following:

  • Understanding stateful and stateless composable functions
  • ...