It seems like if I start an external activity (lik...

# compose

[Afzal Najam]

It seems like if I start an external activity (like the ACTION_VIEW Intent with a Uri) and then press back to come back to my compose-based app, the Composable parts aren't recomposed.

The containing activity gets onStart and onResume called as expected. Does that mean I should be creating my app in onStart instead of onCreate?
Or is there a way to detect this from within composables? I'm expecting a state change upon returning to the app, based on something that happens in the activity's onStop when the app loses focus.

Edit: Is the right way to use LiveData.observeAsState()? It seems like that works.
StateFlow.collectAsState() didn't work as well, seems like some weird race condition in my code.

[Joost Klitsie]

maybe you can try to collectAsState and pass in a coroutine context like AndroidUiDispatcher.Main

[Afzal Najam]

Thanks. I actually had a weird race condition where I was using collectAsState in the Scaffold composable for changing the screen BUT also using the return value of function that emitted the state to also change the screen.

Once I removed the return value usage and used collectAsState in both places, that got fixed. Although, for now, I think I still prefer LiveData due to the lifecycle-awareness.

[Joost Klitsie]

@Afzal Najam you can use coroutine scopes that are lifecycle aware as well. For example, if you get a lifecycleOwner.lifecycleScope you get a scope that dies with the lifecycle. Also they have helper functions like launchWhenResumed/launchWhenCreated etc. to only launch the coroutines when you are at least in that state. The AndroidUiDispatcher.Main I think synchronizes the coroutine with the choreographer of the composition, so I am not sure what happens if the app is in background but perhaps it pauses during the app being in the background automagically as I don't know/think the composition is rendered during that time

[Afzal Najam]

Hmm, thanks! That's great to learn!