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

Keeping your composables responsive

When implementing composable functions, you should always keep in mind that their main purpose is to declare the UI and to handle user interactions. Ideally, anything needed to achieve this is passed to the composable, including state and logic (such as click handlers), making it stateless. If state is needed only inside a composable, the function may keep state temporarily using remember {}. Such composables are called stateful. If data is kept in a ViewModel, composables must interact with it. So, the ViewModel code must be fast, too.

Communicating with ViewModel instances

Data inside a ViewModel should be observable. ComposeUnitConverter uses LiveData and MutableLiveData from the Android Architecture Components to achieve this. You can choose other implementations of the Observer pattern, provided there is a way to obtain State or MutableState instances that are updated upon changes in the ViewModel. This is beyond the scope of this book...