StateFlow and Android's Lifecycle

Android’s LiveData has a very handy behaviour: it only notify observers if the current Lifecycle is equal to ON_START or ON_RESUME.

Now that we have StateFlow with KMM, and create ViewModels that are platform agnostic (without LiveData). However, I’m struggling to simulate the same behaviour.

Is there a way to manually “pause” a job somehow and continue later in same point? For example, I could add a Lifecycle observer that pauses a Job when Lifecycle is not active (user can see the screen). I could also launch jobs but this could be problematic as I could redraw the UI unnecessary, for example.

I know we Android provides a viewLifecycleOwner.lifecycleScope but this is cancelled only when the view is destroyed…

This behaviour is important as some operations (like Fragment transactions) might crash depending on the current Lifecycle - and it also doesn’t make sense to show a snack bar if the user can’t see it.

Thanks in advance.

1 Like

Sounds like you are looking for LifecycleOwner.whenResumed.

It has some gotcha’s if you change contexts or put in exception handling. The details are documented with Lifecycle.whenStateAtLeast.


Hey @nickallendev, that is exactly what I was looking for. Thanks a lot! :+1: