Recomposition Scopes in Jetpack Compose
Learn how recomposition scopes make Jetpack Compose smart, efficient, and fast. Complete guide with working examples for Android developers.
If you're learning Jetpack Compose or taking an Android course, you've probably heard a lot about recomposition. But there's a part of it that's often left out in beginner material: recomposition scopes.
These are what make Compose smart, efficient, and fast. They let your UI update only when and where it needs to.
Let's break it down in simple terms, with working examples.
What is Recomposition?
In Compose, recomposition means re-running parts of your UI when state changes. Compose skips the parts that didn't depend on the changed state.
This is the core idea behind how Compose works. It tracks state reads and re-executes only the relevant code.
What is a Recomposition Scope?
Every time you write a Composable, Compose sets up a recomposition scope behind the scenes. That's a part of the UI that can be updated independently of the rest.
But it goes deeper than that.
Internally, when the Compose compiler sees your Composable, it wraps it in what's called a restart group. This group tells the Composer
where recomposition should start and end. For each of these restart groups, the Composer
creates a RecomposeScope
.
This is the building block that allows fine-grained UI updates.
How it works under the hood
Read the full post in 👉 https://composeinternals.com/compose-recomposition-scopes