Implement GPS navigation with position, SOG, and COG

2 files changed, 118 insertions, 0 deletions

diff --git a/android-app/app/src/main/kotlin/com/example/androidapp/LocationService.kt b/android-app/app/src/main/kotlin/com/example/androidapp/LocationService.kt
new file mode 100644
index 0000000..346fdfe
--- /dev/null
+++ b/android-app/app/src/main/kotlin/com/example/androidapp/LocationService.kt
@@ -0,0 +1,54 @@
+package com.example.androidapp
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.location.Location
+import android.os.Looper
+import com.google.android.gms.location.*
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
+
+data class GpsData(
+    val latitude: Double,
+    val longitude: Double,
+    val speedOverGround: Float, // m/s
+    val courseOverGround: Float // degrees
+)
+
+class LocationService(private val context: Context) {
+
+    private val fusedLocationClient: FusedLocationProviderClient =
+        LocationServices.getFusedLocationProviderClient(context)
+
+    @SuppressLint("MissingPermission") // Permissions handled by the calling component (Activity/Fragment)
+    fun getLocationUpdates(): Flow<GpsData> = callbackFlow {
+        val locationRequest = LocationRequest.Builder(Priority.PRIORITY_HIGH_ACCURACY, 1000)
+            .setMinUpdateIntervalMillis(500)
+            .build()
+
+        val locationCallback = object : LocationCallback() {
+            override fun onLocationResult(locationResult: LocationResult) {
+                locationResult.lastLocation?.let { location ->
+                    val gpsData = GpsData(
+                        latitude = location.latitude,
+                        longitude = location.longitude,
+                        speedOverGround = location.speed,
+                        courseOverGround = location.bearing
+                    )
+                    trySend(gpsData)
+                }
+            }
+        }
+
+        fusedLocationClient.requestLocationUpdates(
+            locationRequest,
+            locationCallback,
+            Looper.getMainLooper()
+        )
+
+        awaitClose {
+            fusedLocationClient.removeLocationUpdates(locationCallback)
+        }
+    }
+}
diff --git a/android-app/app/src/main/kotlin/com/example/androidapp/MainActivity.kt b/android-app/app/src/main/kotlin/com/example/androidapp/MainActivity.kt
new file mode 100644
index 0000000..1d41f4a
--- /dev/null
+++ b/android-app/app/src/main/kotlin/com/example/androidapp/MainActivity.kt
@@ -0,0 +1,64 @@
+package com.example.androidapp
+
+import android.os.Bundle
+import androidx.appcompat.app.AppCompatActivity
+import org.maplibre.android.MapLibre
+import org.maplibre.android.maps.MapView
+import org.maplibre.android.maps.Style
+
+class MainActivity : AppCompatActivity() {
+
+    private var mapView: MapView? = null
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        // MapLibre access token only needed for Mapbox styles, but good practice to initialize
+        MapLibre.getInstance(this)
+        setContentView(R.layout.activity_main)
+
+        mapView = findViewById(R.id.mapView)
+        mapView?.onCreate(savedInstanceState)
+        mapView?.getMapAsync { maplibreMap ->
+            maplibreMap.setStyle(Style.Builder()
+                .addSource(RasterSource("noaa-enc-source",
+                    TileSet("2.0.0", "asset://noaa_enc.mbtiles")))
+                .addLayer(RasterLayer("noaa-enc-layer", "noaa-enc-source"))
+            )
+        }
+    }
+
+    override fun onStart() {
+        super.onStart()
+        mapView?.onStart()
+    }
+
+    override fun onResume() {
+        super.onResume()
+        mapView?.onResume()
+    }
+
+    override fun onPause() {
+        super.onPause()
+        mapView?.onPause()
+    }
+
+    override fun onStop() {
+        super.onStop()
+        mapView?.onStop()
+    }
+
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        mapView?.onSaveInstanceState(outState)
+    }
+
+    override fun onLowMemory() {
+        super.onLowMemory()
+        mapView?.onLowMemory()
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        mapView?.onDestroy()
+    }
+}