MSDKSession

Base Session class for MSDK-based Android Auto apps.

Handles all the generic session infrastructure that any MSDK client needs:

• Session lifecycle (connect, start, stop, disconnect)

• Phone state observation with deferred surface allocation

• Loading state transitions (IDLE → STARTING → ONBOARDING → INITIALIZING → MAP_READY)

• Car day/night mode: read from CarContext.isDarkMode when the session is created, started and re-opened (onNewIntent), and on every onCarConfigurationChanged

• Phone app launch when AA starts first

• Screen navigation via AANavigationCoordinator with state machine validation

• SurfaceCallback registration/unregistration

• Phone state sync after map is ready

State Access

This class accesses Android Auto state through focused sub-holders:

• connectionState (AAConnectionState): Connection lifecycle, phone state, callbacks

• screenState (AAScreenStateHolder): Screen state, loading state, guidance session

• mapState (AAMapState): The car's dark mode (read when the session is created, started and re-opened, and on car configuration changes)

Surface holder access (MapController, providers) remains via AndroidAutoSurfaceManager since AndroidAutoSurfaceHolder management is a separate concern.

What subclasses implement

• createMainScreen: Root screen for the AA app

• createSurfaceCallback: App-specific SurfaceCallback (with map rendering, overlays)

• createScreenFactory: Factory for creating app-specific screens (search, route preview, navigation)

Screen Navigation

Phone-to-AA screen navigation is handled by AANavigationCoordinator which uses AAScreenFactory to create screens and AANavigationStateMachine to validate transitions. The subclass only provides the factory — the coordinator handles all push/pop logic and state tracking.

Lifecycle Flow

onCreate → read car dark mode → create coordinator → setAAConnected(true) → launch phone app → start observer
  ↓ (phone signals READY)
ensureInfrastructureReady → registerSurfaceCallback → MAP_READY
  ↓ (MapView ready)
syncToPhoneState (via coordinator) → push screens to match phone
  ↓ (user disconnects)
onDestroy → reset coordinator → cancel jobs → unregister callbacks → setAAConnected(false)

See also