ViewModels & Compose

ViewModels are entry points

The processor sees the ViewModel supertype and generates a <name>ViewModel() adapter for Activities and Fragments. androidx's ViewModelStore owns the instance — rotation retention, onCleared — and the graph fills the constructor. Graph scopes never apply, because the store is already the cache.

class CounterViewModel(private val analytics: Analytics) : ViewModel() {
    var clicks = 0; private set
    fun onFabClick() { clicks++; analytics.track("fab_clicks:$clicks") }
}

class MainActivity : AppCompatActivity() {
    private val counter: CounterViewModel by counterViewModel()   // generated, survives rotation
}

Runtime arguments need no "assisted injection"

A ViewModel parameter the graph cannot provide simply becomes a parameter of the generated adapter. SavedStateHandle is supplied automatically:

class CheckoutViewModel(
    flow: CheckoutFlow,
    orderId: String,
    saved: SavedStateHandle,
) : ViewModel()

// in the fragment:
private val vm by checkoutViewModel(orderId = args.orderId)

There is no @AssistedInject, no factory interface and no @AssistedFactory — the concept does not exist because the adapter is generated from the constructor that already describes the split.

Compose

Apply the Compose compiler plugin as usual; the Kite plugin notices and does the rest — it adds the Compose helpers and gives every ViewModel adapter a @Composable remember… form. Same graph, no extra concepts:

@Composable
fun SecondScreen() {
    val analytics = injected<Analytics>()                       // graph value, host Activity's scope
    val greeting = rememberGreetingViewModel(name = "Compose")  // generated; store-retained
    val taps by greeting.taps.collectAsState()
    Button(onClick = { greeting.onTap(); analytics.track("tap") }) {
        Text("Taps: $taps")
    }
}

The nearest LocalViewModelStoreOwner — a NavBackStackEntry, a Fragment, the Activity — retains the ViewModel. SavedStateHandle and runtime arguments work exactly as they do in the Activity and Fragment adapters.

In a @Preview there is no Activity, so injected() falls back to the app scope.