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

Spicing up transitions through visual effects

So far, I have shown you animations that modify certain aspects of a UI element, like its color, size, or visibility. But sometimes you may want to exchange parts of your UI. Then, Crossfade() comes in handy. It allows you to switch between two composable functions with a crossfade animation. Let's look at my CrossfadeAnimationDemo() sample (Figure 8.2), part of the AnimationDemo project, to see how this works:

Figure 8.2 – The AnimationDemo sample showing CrossfadeAnimationDemo()

A switch toggles between two screens. As we are focusing on animation, I kept the Screen()composable very simple, just a box with customizable background color, and a big text centered inside. You can find its source code in AnimationDemoActivity.kt.

Crossfading composable functions

Like most examples in this chapter, CrossfadeAnimationDemo() uses a Column() as the root element. The column contains a switch, and the screen...