android-compose-ui

Define a Contract file with an @Immutable State data class plus sealed Event and Effect classes, implement a ViewModel exposing StateFlow and Channel<Effect>, then build a root Composable that collects state with collectAsStateWithLifecycle and effects inside LaunchedEffect(Unit).

collectAsState keeps receiving StateFlow updates while the app is in the background, wasting CPU and battery. collectAsStateWithLifecycle stops collection when the lifecycle is not active, and is the required approach in this playbook.

Use a Channel<Effect> with BUFFERED capacity in the ViewModel and expose it via receiveAsFlow. Collect it once in LaunchedEffect(Unit) in the root Composable instead of storing boolean flags in State, which causes zombie state on recomposition.

Yes, Navigation Compose 2.8+ supports routes defined as @Serializable objects and data classes. Use composable<Route> in the NavHost and backStackEntry.toRoute() to retrieve arguments, avoiding string-based routes entirely.

State stored in remember { mutableStateOf(...) } is lost during configuration changes and process death. Use rememberSaveable { mutableStateOf(...) } for user inputs and UI flags, with a custom Saver for complex objects.

No, screens should receive navigation lambdas like onNavigateToTask: (String) -> Unit. Navigation is triggered via Effects from the ViewModel, keeping screens testable and free of navigation logic.