Is there anything like `RecyclerView`’s

StateRestorationPolicy.PREVENT_WHEN_EMPTY

for

LazyColumn

?

LazyColumn

doesn’t currently restore the scroll position if the list’s data is fed using something like

val myList by aFlow.collectAsState(emptyList())

. For example during configuration changes (like rotation, dark/light theme switch, etc.) the flow will be resubscribed to and so

aFlow

will temporarily emit

emptyList()

causing the saved scroll position to be discarded. This is a workaround I found but I was hoping it could be handled better:

if (myList.isNotEmpty()) {
    LazyColumn() {
       // .....
    }
}

Generally, you should avoid the latency of requerying from scratch in the first place by using

shareIn

inside a ViewModel, thus ensuring that your last data is immediately available after a config change, skipping the whole empty list problem entirely

Definitely, although

ViewModel

only helps for configuration changes but not for system initiated process death (SIPD). I was looking for a solution that could encompass both. Throwing in a ViewModel to optimize the configuration change part is always a nice to have and can be done with little effort. In other words: if one solves the SIPD side, the configuration change side gets taken care of implicitly.

could you file a bug for this feedback? so at least we consider this in the future. but in general I don’t think the solution with if is that bad

@Ian Lake I don't think

shareIn

works because when using

collectAsState()

on flows other than `StateFlow`s you always have to specify an initial value and that initial value will always be used even if the flow emits immediately. In my app I'm using

collectAsState()

on a flow produced by transforming the value of

StateFlow

in a ViewModel and I'm facing the same problem. I have tried

shareIn

and it didn't work.

Sure, you can use

stateIn

then