Does anyone know if there is a way to keep `rememb...

# compose

[Isaac Udy]

Does anyone know if there is a way to keep remember state alive between calls to movableContentOf?

I currently have a situation where I am doing something like this:

val moveable = remember { moveableState { DrawAnItem() } }
if(visible) moveable.invoke()

The problem is that when “visible” gets toggled, all `remember`ed state inside DrawAnItem is reset.

However, if I do this:

val moveable = remember { moveableState { DrawAnItem() } }
if(visible) moveable.invoke()
else {
    Box(modifier = Modifier.alpha(0f)) {
        moveable.invoke()
    }
}

the `remember`ed items are properly remembered in between calls to “visible”. This obviously isn’t a very good solution, but I’m trying to figure out how to keep a composable “alive” when I know that I’m going to render it again in the not-too-distant future.

[Filip Wiesner]

The cop out answer would be to hoist your remembered state outside of the DrawAnItem composable 😄 But that does not really answer your question

[Filip Wiesner]

(As a side note, DrawAnItem naming goes against the compose naming conventions)

[Isaac Udy]

Yes, unfortunately hoisting state isn’t possible for my use case - this is for a generic screen animation and themeing system, so “DrawAnItem”, in my codebase, would actually render one of n full screens, which are meant to encapsulate their logic completely.

This isn’t “real” code, I just threw it together as a sample (hence the “DrawAnItem” not really being good naming!)

[Zoltan Demant]

What kind of state are you looking to keep around? For example, LazyListState is remembered using rememberSaveable and will be restored rather than recreated if your content (DrawAnItem) is wrapped with SaveableStateHolder.SaveableStateProvider under a given key. Maybe this is not the answer youre looking for as well, but many navigation frameworks use this approach under the hood so I thought Id at least mention it 🙂

[Isaac Udy]

I don’t know what might be kind of state might be remembered there - I won’t be the person who’s writing the remember calls. I was hoping to get remember working, but I think that rememberSaveable will probably be enough.

However, rememberSaveable wasn’t working correctly for me until I moved some of my Composable logic around (where some onDispose calls were, where the SaveableStateHolder was being used, etc), but it all appears to be working now with rememberSaveable. Thanks for your help.