offline_navigation #

Drop-in offline turn-by-turn navigation for Flutter, powered by the Organic Maps engine and OpenStreetMap data.

Pass a start and destination; the library takes care of the rest — including automatically downloading the offline map of the country the route is in:

final result = await Navigator.push(context, MaterialPageRoute(
  builder: (_) => OfflineNavigationPage(
    start: NavPoint(latitude: -6.1722, longitude: 35.7395, name: 'Dodoma City'),
    destination: NavPoint(latitude: -6.1841, longitude: 35.9297, name: 'University of Dodoma'),
    travelMode: TravelMode.drive,
    options: NavOptions(voiceGuidance: true),
  ),
));
// result.outcome: arrived | cancelledByUser | failed

The navigation page manages its own flow — engine initialization, map download with progress UI, route preview with distance/ETA, then live turn-by-turn guidance with voice instructions — and pops back to your app with a NavigationResult when done. Everything after the map download works fully offline.

Installation #

1. Add the dependency:

   flutter pub add offline_navigation
   

   The native Organic Maps engine is downloaded automatically as a prebuilt Android library (~80 MB, one-time) during your next Gradle sync.

2. Enable core library desugaring in android/app/build.gradle.kts (required by the engine on minSdkVersion < 26; the build fails with instructions if it is missing):

   android {
     compileOptions {
       isCoreLibraryDesugaringEnabled = true
     }
   }
   dependencies {
     coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.1.5")
   }
   

That's it. Asset packaging (noCompress) is configured automatically.

Permissions #

The plugin declares the location permissions it needs (they merge into your app's manifest automatically) and requests location access at runtime when turn-by-turn guidance starts. No manifest edits are required on your side. Simulated guidance (NavOptions(simulateRoute: true)) needs no location access, which is handy for demos and tests.

Platform support #

How it works #

The Organic Maps map surface is embedded in your widget tree via a platform view, while all navigation UI (instruction banner, lane hints, ETA bar, download and preview screens) is drawn in Flutter and fed by native event streams. The engine — rendering, routing, and map management — is the same C++ core that powers the Organic Maps app, consumed as a prebuilt AAR (io.github.fred-apina:organicmaps-sdk).

License & attribution #

Apache-2.0, built on the Organic Maps engine (Apache-2.0). Map data © OpenStreetMap contributors (ODbL); the map widget shows a permanent attribution notice.