Can we have some tooling to count recompositions by screen areas?

# compose

[Daniele Segato]

Can we have some tooling to count recompositions by screen areas?

[Daniele Segato]

Thinking of something similar to overdraw that show in colors where you overdraw too much, in this case it would should where recomposing too much

[Cicero]

This would be quite a rich improvement in understanding what’s going on in your code could maybe a Modifier be created for this?

[Cicero]

@Composable
fun Modifier.countRecomposition() = this.composed{
    var counter by rememberSaveable() {
        mutableStateOf(0)
    }
    counter++
    Text(text = counter.toString())
    this
}

Works but obviously creates an infinite loop 😂

[Cicero]

Maybe a combintion of dataStore and this might do the trick as I need something for persistance

[Adam Powell]

There are some ideas around tooling for tracing and visualizing this in some early design phases but nothing to play with just yet

[Cicero]

I got to present something in a very clunky way with data store but definitely it would be good to be able to write a Modifier with some implementation of listenToRecomposition and some sort of rememberSaveable that does not activates recomposition, even then just writing this sounds like a very big feature braking thing

[Cicero]

val android.content.Context.dataStore: DataStore<Preferences> by preferencesDataStore(name = "settings")

@Composable
fun Modifier.countRecomposition() = this.composed{
    val context = LocalContext.current
    val EXAMPLE_COUNTER = intPreferencesKey("example_counter")
    var value = context.dataStore.data
        .map { preferences ->
            // No type safety.
            preferences[EXAMPLE_COUNTER] ?: 0
        }.collectAsState(initial = null)

    GlobalScope.async {
        context.dataStore.edit { settings ->
            val currentCounterValue = settings[EXAMPLE_COUNTER] ?: 0
            settings[EXAMPLE_COUNTER] = currentCounterValue + 1
        }
    }

    Text(text = value.value.toString())
    this
}

[Cicero]

If you just run it it will just look empty and if you try to collect as state you will fall victim of recomposition tornado

[Cicero]

I could probably manage something acceptable with some more hours and using some compose side-effects

[Cicero]

🙂

[steelahhh]

chrisbanes/tivi/Debug snippet is an option with just a counter