Android Programming: The Big Nerd Ranch Guide, 5th Edition

Building Screens with Composables

You have seen a number of composables up to this point, with a range of complexity. On the simple end, you have seen atomic components like Row and Text. And you have built ToppingCell, a more complex composable that is built on top of other composables.

It is also possible to create a composable that renders the entire screen. In fact, the setContent function you called in MainActivity is a lambda that does just that. Because there are no limitations about what a single composable can do, you do not need another component like a Fragment to perform navigation. (You can, however, enlist the help of the AndroidX Navigation library, which has a Jetpack Compose flavor.)

Under Jetpack Compose, composables ...