AssistedInject HiltViewModels for Compose Navigation

FactoryViewModels.kt

// Screen VM
class ScreenOneViewModel @AssistedInject constructor(
    // deviceManager is scoped to a flow's sub-NavGraph
    @Assisted private val deviceManager: SomeBLEDeviceManager,
    @Assisted private val someIdArg: Int,
    logger: Logger,
    otherThing: SomeOtherDependency,
) : CoroutineViewModel<ViewState, UiAction> { ... }


// Screen Composable - Compose Destination
@Destination
@Composable
fun ScreenOne(
    navigator: MyFlowNavigator,
    deviceManager: SomeBLEDeviceManager,
    someIdArg: Int, // NavArg
) {
    val factory = hiltViewModel<FactoriesViewModel>().screenOneVmFactory
    val viewModel: ScreenOneViewModel = viewModelByFactory { factory.create(deviceManager, someIdArg) }

    BackHandler { navigator.popBackStack() }

    val state by viewModel.viewStateStream().collectAsState() 

    ...
}

// utility to grab a viewModel() for an Assisted.Factory
@Composable
inline fun <reified VM : ViewModel, T> viewModelByFactory(crossinline creator: () -> T): VM {
    @Suppress("UNCHECKED_CAST")
    val vmFactory = object : ViewModelProvider.Factory {
        override fun <T : ViewModel> create(modelClass: Class<T>): T {
            return creator.invoke() as T
        }
    }
    return viewModel(factory = vmFactory)
}

// HiltViewModel as the glue between Dagger and Compose NavGraph
@HiltViewModel
class FactoriesViewModel @Inject constructor(
    val screen1VmFactory: ScreenOneViewModel.Factory,
    val screen2VmFactory: ScreenTwoViewModel.Factory,
    val screen3VmFactory: ScreenThreeViewModel.Factory,
) : ViewModel()

// NavGraph-scoped dependencies
@Module
@InstallIn(ViewModelComponent::class)
interface DeviceFlowModule {
    @Binds
    fun bindDeviceManager(deviceManagerImpl: SomeBLEDeviceManagerImpl): SomeBLEDeviceManager
}

@AssistedInject et al are expect/actual in KMM, typealias to Dagger.