Is there a way to have a special

BackHandler

that consumes back calls before the inner most composable? My use case is I have a

BottomSheetScaffold

at the root of my app (Theme>BottomSheet>Home>NavHost) and I want to close the sheet on back clicks. But BackHandler defined in BottomSheet doesn't get invoked until all back handlers deeper in the tree are used (in my case, NavHost consumes before BottomSheet, until the first destination is reached / nav stack cleared).

There's probably a way to do this using the

enabled

parameter to

BackHandler

but it can probably get complex managing that across your tree

I'm already using

enabled

to only handle back clicks when the sheet is expanded. It's not checked before inner back handlers are used.

I meant something along the lines of setting

enabled = false

on the inner ones when you want to outer one to have control

Yeah but I can only do that to my own defined BackHandlers, not the ones defined by libraries like navigation

The correct answer is to only add your BackHandler on demand, not have it added all the time - the last added still wins, which is exactly what you need for an "overlay" style component that you want to dismiss

@Berkeli Alashov if HalfExpanded is your problem you can use

animateTo(Expanded)

which is what expand() uses under the hood

I didn't know about the "last added wins" part. I will try adding it when it's expanded

@Ian Lake last added in the context of time or depth of the tree?

The upcoming Accompanist Navigation Material only goes between expanded and collapsed, it never opens to only half expanded AFAIK

Thanks @Ian Lake, worked like a charm.

So if the

NavHost

is a child wouldn't that always get "added last" in this case (I guess not because OP said it worked, but I guess I'm missing something)

I'd give the Accompanist Navigation Material library a try when it comes out - the back button works exactly as you'd want it to out of the box 😄

Because it's happening in recomposition?

Because it is happening from a user's action, which is by necessity after the first composition completes

Sounds like it could lead to subtle race conditions in more complex scenarios, but I haven't met a back handling solution that didn't have that issue 😅 Thanks!

Keeping things based solely on your hierarchy and using

enabled

is absolutely the best way to do things when they aren't a temporary overlay

Yeah, +1 on Accompanist Navigation Material 🙂 Shouldn't be long!