AAMapState

Focused state holder for Android Auto map display state.

This class manages all state related to the Android Auto map rendering, camera behavior, and user interaction with the map surface:

• Camera following: Whether the map auto-centers on GPS position

• Split screen: Whether the AA display shows a side panel

• Vehicle position: Horizontal center of the visible area for vehicle icon placement

• Day/night: The car head unit's day/night mode, the user's day/night choice (AADayNightMode), and the mode the map is drawn in, which combines the two (isMapDark)

• Zoom: Delegated zoom handlers (routed through SurfaceCallback for live camera state)

• MapView reattach: Callback for re-attaching MapView after Navigation session restart

Why Zoom Is Delegated

The zoom buttons in NavigationScreen only have access to MapController, whose zoomIn()/zoomOut() methods use a stale ViewModel center during guidance tracking (the MSDK moves the camera directly without updating the ViewModel).

By routing zoom through the SurfaceCallback (which has access to the live aaMapView), we can read the actual camera position via getCurrentMapState() and apply zoom at the correct location using MapController.centerOn().

Thread Safety

• StateFlow for all reactive state (inherently thread-safe)

• @Volatile for zoomHandler and zoomToRectHandler (set from main thread, may be invoked from binder thread)

See also