Improving app stability and performance is crucial for delivering a smooth user experience, especially when working with modern UI frameworks like Jetpack Compose. One of the key mechanisms that Jetpack Compose uses to optimize rendering is recomposition, which ensures that only the necessary parts of your UI update in response to state changes. However, without proper management of stability, recomposition can lead to unnecessary work and degrade performance.
What Is Recomposition in Jetpack Compose?
Recomposition is the process by which Jetpack Compose updates the UI when state changes. Instead of redrawing the entire screen, Compose intelligently re-executes only the composables that are affected by the changed state. This selective updating helps reduce resource consumption and improves efficiency .
However, recomposition can become inefficient if Compose cannot determine whether an object’s state has meaningfully changed. That’s where stability comes into play.
Understanding Stability
Stability refers to whether a class’s properties can change in a way that affects recomposition. If a class is stable, Compose can safely skip recomposition for composables that depend on it when its instance hasn’t changed. On the other hand, unstable classes force Compose to re-execute dependent composables even if the actual data hasn’t changed in a meaningful way .
Jetpack Compose provides annotations like @Stable and @Immutable to explicitly declare how your data types should be treated during recomposition:
@Stable: Indicates that the object’s properties may change, but Compose can track them efficiently.@Immutable: Tells Compose that the object will never change, allowing further optimizations.
Using these annotations appropriately helps Compose make better decisions about when and how to recompose, ultimately improving performance .
How to Optimize Stability for Better Performance
-
Use
@StableWisely: Apply this annotation to classes whose properties change infrequently or in predictable ways. This allows Compose to skip unnecessary recompositions when the object reference remains the same . -
Mark Immutable Data as
@Immutable: For data models that do not change after creation (e.g., data fetched from a database), marking them as immutable enables stronger skipping behavior, reducing the number of composable functions that need to be re-evaluated . -
Avoid Unstable Lambdas: Inline lambdas passed into composables can cause unnecessary recompositions if they’re recreated every time. Use
rememberor move logic outside of lambdas where possible to stabilize callbacks . -
Leverage Strong Skipping Mode: Introduced in newer versions of Compose, strong skipping mode enforces stricter rules around class stability, giving developers more control over optimization strategies. It helps ensure that only truly relevant changes trigger recomposition .
-
Diagnose Stability Issues: Android Studio provides tools to detect instability in your codebase. Use the Layout Inspector and recomposition counters to identify problematic areas where excessive recomposition is occurring due to unstable types .
Conclusion
Mastering recomposition through stability management is essential for building high-performance apps with Jetpack Compose. By carefully designing your data models and using Compose’s built-in annotations, you can significantly reduce unnecessary UI updates and enhance overall app responsiveness. As Jetpack Compose continues to evolve, staying updated with best practices—like the new strong skipping mode—will help you stay ahead in delivering efficient and stable applications .
