feat!: Application outline

app/src/main/java/eu/ztsh/garmin/mapbox/LocationObserver.kt

@@ -0,0 +1,46 @@
+package eu.ztsh.garmin.mapbox
+
+import com.mapbox.common.location.Location
+import com.mapbox.navigation.core.trip.session.LocationMatcherResult
+import com.mapbox.navigation.core.trip.session.LocationObserver
+import com.mapbox.navigation.ui.maps.camera.transition.NavigationCameraTransitionOptions
+
+class LocationObserver(private val mapControl: MapControl) : LocationObserver {
+
+    /**
+     * Gets notified with location updates.
+     *
+     * Exposes raw updates coming directly from the location services
+     * and the updates enhanced by the Navigation SDK (cleaned up and matched to the road).
+     */
+    private var firstLocationUpdateReceived = false
+
+    override fun onNewRawLocation(rawLocation: Location) {
+        // not handled
+    }
+
+    override fun onNewLocationMatcherResult(locationMatcherResult: LocationMatcherResult) {
+        val enhancedLocation = locationMatcherResult.enhancedLocation
+        // update location puck's position on the map
+        mapControl.navigationLocationProvider.changePosition(
+            location = enhancedLocation,
+            keyPoints = locationMatcherResult.keyPoints,
+        )
+
+        // update camera position to account for new location
+        mapControl.viewportDataSource.onLocationChanged(enhancedLocation)
+        mapControl.viewportDataSource.evaluate()
+
+        // if this is the first location update the activity has received,
+        // it's best to immediately move the camera to the current user location
+        if (!firstLocationUpdateReceived) {
+            firstLocationUpdateReceived = true
+            mapControl.navigationCamera.requestNavigationCameraToOverview(
+                stateTransitionOptions = NavigationCameraTransitionOptions.Builder()
+                    .maxDuration(0) // instant transition
+                    .build()
+            )
+        }
+    }
+
+}