The new navigation state restoration changes are g...

# compose

[Jason Ankers]

The new navigation state restoration changes are great. One issue(?) we’ve noticed is LazyColumn scroll position will not be saved if both of these conditions are met:
• A screen with a LazyColumn instantiates a ViewModel with hiltViewModel()
• An item in the LazyColumn references an unstable object (i.e. a navController)
Is this expected?

[julioromano]

The new navigation state restoration changes are great

What exactly are you referring to by this?

[Jason Ankers]

https://developer.android.com/jetpack/androidx/releases/navigation#2.4.0-alpha01

[julioromano]

You mean https://developer.android.com/reference/kotlin/androidx/navigation/NavController#popBackStack(kotlin.String,kotlin.Boolean,kotlin.Boolean) ?

[julioromano]

FYI: https://kotlinlang.slack.com/archives/CJLTWPH7S/p1612449639335400

Hope it helps

[Jason Ankers]

Unfortunately I don’t think this is related. The issue is reproducible without any flows involved. I’m specifically referring to the new saveState and restoreState properties on NavOptionsBuilder

When I set these properties to true while navigating between bottom tabs, I would expect scroll positions to persist across tab changes (which they do, unless the circumstances I described in the OP are met)

[julioromano]

@Ian Lake I wonder if/how this relates to https://twitter.com/ianhlake/status/1388517293005574144?s=21

[Ian Lake]

This is a totally unrelated regression in LazyColumn in beta07: https://kotlinlang.slack.com/archives/CJLTWPH7S/p1621443353261700?thread_ts=1621443353.261700&cid=CJLTWPH7S

[Jason Ankers]

@Ian Lake Does this sound related to this or would you like me to submit a separate issue?

[Ian Lake]

That's the exact bug linked in the first reply in that conversation 🙂