I have filed a bug with Accompanist re: navigation...

# compose

[Chris Fillmore]

I have filed a bug with Accompanist re: navigation-material
https://github.com/google/accompanist/issues/617

[Ian Lake]

Can you explain what user experience you're trying to accomplish by putting a bottom sheet over an empty screen (since there's no destination below the bottom sheet)?

[jossiwolf]

Apart from that - the issue here is the bottom sheet being empty 🙂

[Chris Fillmore]

My use case is in a camera Activity. The camera preview is on the screen at all times, so it sits outside the NavHost, like this:

setContent {
  CameraPreview()
  NavHost(...) {
    ...
  }
}

[Chris Fillmore]

Aha, Jossi is right. That didn’t occur to me, because in my actual app I have a bunch of stuff in the bottom sheet. But the code amounted to something like this:

bottomSheet(...) {
  for (item in <empty list>) {
    ...
  }
}

My bad.

[Chris Fillmore]

Jossi, is it practical to add support for bottom sheets as start destinations?
I see the issue now that, without being able to pop the stack, dismissing the modal would go nowhere. perhaps the BottomSheetNavigator.Destination could accept a fallback route to navigate to, in cases where the bottom sheet is itself at the bottom of the stack?

Or, instead, add some behaviour where the bottom sheet can be set as startDestination, with another destination underneath?

Reason I ask is, on iOS we have roughly this capability, by opening a bottom-sheet-style modal in a viewDidLoad callback. I’d like to have some similar capability on Android, so that I can open a bottom sheet when an Activity initially starts.

[jossiwolf]

I don't think that makes a ton of sense. BottomSheetNavigator is only aware of entries on its state's back stack, which means there are only entries with `BottomSheetNavigator.Destination`s on there.
The NavController keeps track of the global back stack but the navigator isn't aware of the NavController. I think it would make more sense to have your Activity (or whatever is under the sheet) as startDestination and then navigate when the Activity starts.
But cc @Ian Lake cause I'd love to hear his thoughts about FloatingWindow destinations as start destinations

[Chris Fillmore]

Thanks for the feedback. Yeah I’m open to suggestions on how to handle this use case

[Ian Lake]

It sounds like your CameraPreview should be the start destination of your graph