Summary

In this chapter, we learned how to build modern UIs on Android directly in Kotlin by using the Jetpack Compose toolkit. You learned how, in Compose, everything is a composable function and how this new declarative way of defining UIs improves and makes the way we build UIs much easier and less prone to bugs.

We learned that Compose accelerates and greatly simplifies UI development with the help of concise Kotlin APIs and without the need for XML or other additional languages. We then covered the basic concepts behind Compose and the core components that allow you to build UIs.

Finally, we saw how easy it is to build UI with Compose by creating a Compose-based screen that displays a list of restaurants.

In Chapter 2, Handling UI State with Jetpack ViewModel, we will use the fundamentals we've learned in this chapter to revisit the concept of state in Compose and learn how it is represented, as well as how we can correctly manage it with the help of another Jetpack component: ViewModel.

First, we will understand what ViewModel is and why such a component is needed. Then, by continuing working on the Restaurants application that we started in this chapter, we will learn how to define and lift the UI's state in our own ViewModel class.