Summary

This chapter introduced you to the key principles of Jetpack Compose. We closely looked at the underlying ideas and concepts of composable functions, and you now know how they are written and used. We also focused on how to create and update the UI, as well as how Jetpack Compose achieves what other frameworks call repainting or updating the screen. When relevant app data changes, the UI changes, or so-called recomposition takes place automatically, this is one of the advantages over the traditional View-based approach, where the developer must imperatively change the component tree.

We then expanded our knowledge of the concept of modifiers. We looked at how modifier chains work and what you need to keep in mind to always get the intended results. For example, to receive clicks inside padding, padding {} must occur after clickable {} in the modifier chain. Finally, you learned how to implement custom modifiers.

In Chapter 4, Laying Out UI Elements, we will examine how...