Track Compose Recomposition Part-2

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Track Recomposition Part-2 : You are here
Check out sample project : Github

Avoid using value classes in composable

Value classes are considered unstable even if we annotate with @Stable 👇🏻

value class compose

If you see in above image, TaskyDate is marked stable by compose compiler, but TaskyTime is unstable, the only difference b/w them is TaskyDate is data class and TaskyTime is value class

Optimisation in multi modular project

Let’s suppose we have a class in a non-compose module containing just a integer value, So ideally it should be stable 👇🏻

class in non-compose module

Wondering Why? -

• When analysing any non-compose module, compiler can’t check the stability of a class as compose compiler is not enabled for that module, so it will mark the class unstable

Think of a fix -

• 1st solution — You can enable compose and compose compiler for all modules, so now compose can check for stability of your class

buildFeatures.compose = true
composeOptions {
    kotlinCompilerExtensionVersion = Versions.Compose.Compiler
}

compose report when enabled compose

• 2nd solution — mark all the classes as @Stable, basically you guarantee for the stability of the class and compose will mark it stable

// non-compose module 
@Stable
data class ModelFromCore(val value: Int)

To use @Stable annotation add the dependency
| androidx.compose.runtime:runtime:1.1.0 |

• 3rd solution — create a wrapper for the classes using from any non-compose module

// class from non-compose module
data class ModelFromCore(val value: Int)

// when using in your composable
@Stable
fun StableModelFromCore(val value: ModelFromCore)

Or can create a generic wrapper 👇🏻

@Stable
class StableHolder<T>(val item: T)

@Immutable
class ImmutableHolder<T>(val item: T)

usage: 
fun nonComposeModuleClassUsage(model: StableHolder<ModelFromCore>) {
    val value = model.item
}

Track Recomposition Part-1 : Navigate
Check out sample project : Github