Customize GPX export.

app/build.gradle.kts

@@ -26,8 +26,8 @@ android {
         }
     }
     compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_1_8
-        targetCompatibility = JavaVersion.VERSION_1_8
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
     }
 }
 
@@ -50,4 +50,9 @@ dependencies {
 
     // optional - Guava support for Room, including Optional and ListenableFuture
     implementation("androidx.room:room-guava:$room_version")
+
+    implementation("io.jenetics:jpx:3.1.0")
+    // https://mvnrepository.com/artifact/org.codehaus.woodstox/woodstox-core-asl
+    implementation("org.codehaus.woodstox:woodstox-core-asl:4.4.1")
+
 }

app/src/main/AndroidManifest.xml

@@ -5,6 +5,10 @@
     <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_LOCATION"/>
+
 
     <application
         android:allowBackup="true"
@@ -19,7 +23,9 @@
         <service
             android:name=".LocationLoggingService"
             android:enabled="true"
-            android:exported="true"></service>
+            android:exported="true"
+            android:foregroundServiceType="location"
+            />
 
         <activity
             android:name=".MainActivity"

app/src/main/java/com/proculite/logmylocation/LocationDao.java

@@ -2,9 +2,15 @@ package com.proculite.logmylocation;
 
 import androidx.room.Dao;
 import androidx.room.Insert;
+import androidx.room.Query;
+
+import java.util.List;
 
 @Dao
 public interface LocationDao {
     @Insert
     void insert(LocationEntity location);
+
+    @Query("SELECT * FROM locationentity")
+    List<LocationEntity> getAll();
 }

app/src/main/java/com/proculite/logmylocation/LocationDatabase.java

@@ -3,7 +3,7 @@ package com.proculite.logmylocation;
 import androidx.room.Database;
 import androidx.room.RoomDatabase;
 
-@Database(entities = {LocationEntity.class}, version = 2)
+@Database(entities = {LocationEntity.class}, version = 3)
 public abstract class LocationDatabase extends RoomDatabase {
     public abstract LocationDao locationDao();
 }

app/src/main/java/com/proculite/logmylocation/LocationEntity.java

@@ -27,6 +27,9 @@ public class LocationEntity {
     @ColumnInfo(name = "bearing")
     public Float bearing;
 
+    @ColumnInfo(name = "bearing_accuracy")
+    public Float bearingAccuracy;
+
     @ColumnInfo(name = "latitude")
     public double latitude;
 
@@ -42,6 +45,9 @@ public class LocationEntity {
     @ColumnInfo(name = "unix_time")
     public long unixTime;
 
+    @ColumnInfo(name = "elapsed_realtime_age")
+    public Long elapsedRealtimeAge;
+
     @ColumnInfo(name = "is_mock")
-    public boolean isMock;
+    public Boolean isMock;
 }

app/src/main/java/com/proculite/logmylocation/LocationLoggingService.java

@@ -1,8 +1,11 @@
 package com.proculite.logmylocation;
 
 import android.annotation.SuppressLint;
+import android.app.NotificationChannel;
+import android.app.NotificationManager;
 import android.app.Service;
 import android.content.Intent;
+import android.content.pm.ServiceInfo;
 import android.location.Location;
 import android.location.LocationListener;
 import android.location.LocationManager;
@@ -12,6 +15,8 @@ import android.os.IBinder;
 import android.util.Log;
 
 import androidx.annotation.NonNull;
+import androidx.core.app.NotificationCompat;
+import androidx.core.app.ServiceCompat;
 import androidx.core.location.LocationManagerCompat;
 import androidx.room.Room;
 
@@ -33,6 +38,21 @@ public class LocationLoggingService extends Service implements LocationListener
     public int onStartCommand(Intent intent, int flags, int startId) {
         Log.d(TAG, "Service started.");
 
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            NotificationChannel notificationChannel = new NotificationChannel(
+                    "Foreground",
+                    "Foreground",
+                    NotificationManager.IMPORTANCE_DEFAULT
+            );
+            NotificationManager notificationManager = getSystemService(NotificationManager.class);
+            notificationManager.createNotificationChannel(notificationChannel);
+            NotificationCompat.Builder builder = new NotificationCompat.Builder(this, notificationChannel.getId());
+            builder.setSmallIcon(R.drawable.ic_launcher_foreground);
+            builder.setContentText("Started service in foreground.");
+
+            ServiceCompat.startForeground(this,3784583, builder.build(), ServiceInfo.FOREGROUND_SERVICE_TYPE_LOCATION);
+        }
+
         LocationDatabase database = Room
                 .databaseBuilder(getApplicationContext(), LocationDatabase.class, "location")
                 .fallbackToDestructiveMigration()
@@ -45,6 +65,10 @@ public class LocationLoggingService extends Service implements LocationListener
         return super.onStartCommand(intent, flags, startId);
     }
 
+    public List<LocationEntity> allLocations(){
+        return locationDao.getAll();
+    }
+
     @SuppressLint("MissingPermission")
     public void subscribeToLocationUpdates(LocationListener locationListener)
     {
@@ -84,6 +108,8 @@ public class LocationLoggingService extends Service implements LocationListener
 
             locationEntity.latitude = location.getLatitude();
             locationEntity.longitude = location.getLongitude();
+            locationEntity.unixTime = location.getTime();
+
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
                 locationEntity.isMock = location.isMock();
             }
@@ -98,9 +124,17 @@ public class LocationLoggingService extends Service implements LocationListener
                 locationEntity.altitude = location.getAltitude();
             }
 
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+                locationEntity.elapsedRealtimeAge = location.getElapsedRealtimeAgeMillis();
+            }
+
             if(location.hasBearing())
             {
                 locationEntity.bearing = location.getBearing();
+                if(location.hasBearingAccuracy())
+                {
+                    locationEntity.bearingAccuracy = location.getBearingAccuracyDegrees();
+                }
             }
 
             if(location.hasSpeed())

app/src/main/java/com/proculite/logmylocation/LocationLoggingServiceBinder.java

@@ -3,6 +3,8 @@ package com.proculite.logmylocation;
 import android.location.LocationListener;
 import android.os.Binder;
 
+import java.util.List;
+
 public class LocationLoggingServiceBinder extends Binder {
     private final LocationLoggingService service;
 
@@ -17,4 +19,8 @@ public class LocationLoggingServiceBinder extends Binder {
     public void subscribeToLocationUpdates(LocationListener locationListener){
         this.service.subscribeToLocationUpdates(locationListener);
     }
+
+    public List<LocationEntity> allLocations(){
+        return this.service.allLocations();
+    }
 }

app/src/main/java/com/proculite/logmylocation/MainActivity.java

@@ -9,6 +9,7 @@ import android.location.LocationListener;
 import android.os.Bundle;
 import android.os.IBinder;
 import android.util.Log;
+import android.widget.Button;
 import android.widget.TextView;
 
 import androidx.activity.EdgeToEdge;
@@ -18,15 +19,31 @@ import androidx.core.graphics.Insets;
 import androidx.core.view.ViewCompat;
 import androidx.core.view.WindowInsetsCompat;
 
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.PipedInputStream;
+import java.io.PipedOutputStream;
+import java.io.Writer;
+
+import io.jenetics.jpx.GPX;
+import io.jenetics.jpx.WayPoint;
+
 public class MainActivity extends AppCompatActivity implements LocationListener, ServiceConnection {
     private final String TAG = MainActivity.class.getName();
+    private Button exportButton;
+    private WriteToFile writeToFile;
+    private static boolean includeComments = false;
+    private static Double accuracyThreshold = 2.0;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
+        writeToFile = new WriteToFile(this,"application/gpx");
+
         Intent serviceIntent = new Intent(this, LocationLoggingService.class);
-        startService(serviceIntent);
+        startForegroundService(serviceIntent);
 
         EdgeToEdge.enable(this);
         setContentView(R.layout.activity_main);
@@ -35,6 +52,8 @@ public class MainActivity extends AppCompatActivity implements LocationListener,
             v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
             return insets;
         });
+
+        exportButton = findViewById(R.id.buttonExport);
     }
 
     @Override
@@ -69,6 +88,89 @@ public class MainActivity extends AppCompatActivity implements LocationListener,
 
         LocationLoggingServiceBinder binder = (LocationLoggingServiceBinder) iBinder;
         binder.subscribeToLocationUpdates(this);
+
+        if(exportButton != null){
+            exportButton.setOnClickListener(v -> {
+                Log.d(TAG, "Export button clicked.");
+                new Thread(() -> {
+                    GPX gpx = GPX.builder().addTrack(track -> track.addSegment(segment -> {
+                        for(LocationEntity location : binder.allLocations()){
+                            WayPoint wayPoint = locationToWayPoint(location);
+                            if(wayPoint != null) {
+                                segment.addPoint(wayPoint);
+                            }
+                        }
+                    })).build();
+                    Log.d(TAG, "Built GPX.");
+
+                    writeToFile.write("output.gpx", outputStream -> {
+                        try {
+                        GPX.Writer.of(GPX.Writer.Indent.SPACE4).write(gpx, outputStream);
+                        } catch (IOException e) {
+                            Log.e(TAG, "Failed to write.");
+                        }
+                    });
+                }).start();
+            });
+        }
+    }
+
+    private static WayPoint locationToWayPoint(LocationEntity location) {
+        if(accuracyThreshold != null)
+        {
+            if(location.accuracy == null) {
+                return null;
+            }
+
+            if(location.accuracy > accuracyThreshold) {
+                return null;
+            }
+        }
+
+        WayPoint.Builder builder = WayPoint.builder()
+                .lat(location.latitude)
+                .lon(location.longitude)
+                .time(location.unixTime);
+
+        if(location.speed != null){
+            builder.speed(location.speed);
+        }
+
+        if(location.bearing != null){
+            builder.course(location.bearing);
+        }
+
+        if(location.altitude != null){
+            builder.ele(location.altitude);
+        }
+
+        if(includeComments) {
+            StringBuilder commentBuilder = new StringBuilder();
+
+            if (location.isMock) {
+                commentBuilder.append("Location is mock.\n");
+            }
+
+            if (location.accuracy != null) {
+                commentBuilder.append(String.format("Accuracy is expected to be within %s meters.\n", location.accuracy));
+            }
+
+            if (location.altitudeAccuracy != null) {
+                commentBuilder.append(String.format("Altitude accuracy is expected to be within %s meters.\n", location.altitudeAccuracy));
+            }
+
+            if (location.bearingAccuracy != null) {
+                commentBuilder.append(String.format("Bearing accuracy is expected to be within %s degrees.\n", location.bearingAccuracy));
+            }
+
+            if (location.speedAccuracy != null) {
+                commentBuilder.append(String.format("Speed accuracy is expected to be within %s meters per second.\n", location.speedAccuracy));
+            }
+
+            builder.cmt(commentBuilder.toString());
+        }
+
+        return builder.build();
     }
 
     @Override

app/src/main/java/com/proculite/logmylocation/WriteToFile.java

@@ -0,0 +1,58 @@
+package com.proculite.logmylocation;
+
+import android.net.Uri;
+import android.os.ParcelFileDescriptor;
+import android.util.Log;
+
+import androidx.activity.result.ActivityResultCallback;
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts;
+import androidx.appcompat.app.AppCompatActivity;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.function.Consumer;
+
+public class WriteToFile implements ActivityResultCallback<Uri> {
+    private final String TAG = WriteToFile.class.getName();
+    private Consumer<OutputStream> fileConsumer;
+    private final AppCompatActivity activityCompat;
+    private final ActivityResultLauncher<String> launcher;
+
+    public WriteToFile(AppCompatActivity activity, String fileMimeType)
+    {
+        this.activityCompat = activity;
+        this.launcher = activity.registerForActivityResult(
+                new ActivityResultContracts.CreateDocument(fileMimeType), this);
+    }
+
+    @Override
+    public void onActivityResult(Uri o) {
+        if(o == null || o.getPath() == null)
+        {
+            Log.d(TAG, "Attempting to write to null path.");
+            return;
+        }
+
+        Log.d(TAG, String.format("Writing to file: %s", o.getPath()));
+
+        try {
+            try (ParcelFileDescriptor fileDescriptor = this.activityCompat.getContentResolver().openFileDescriptor(o, "w")) {
+                if (fileDescriptor == null) {
+                    Log.e(TAG, "Parcel file descriptor is null.");
+                    return;
+                }
+                try (FileOutputStream fileOutputStream = new FileOutputStream(fileDescriptor.getFileDescriptor())) {
+                    fileConsumer.accept(fileOutputStream);
+                }
+            }
+        }  catch (IOException e) {
+            Log.e(TAG, "Failed to write to file.");
+        }
+    }
+
+    public void write(String fileName, Consumer<OutputStream> fileConsumer){
+        this.fileConsumer = fileConsumer;
+        launcher.launch(fileName);
+    }
+}

app/src/main/res/layout/activity_main.xml

@@ -18,4 +18,13 @@
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent" />
 
+    <Button
+        android:id="@+id/buttonExport"
+        app:layout_constraintTop_toBottomOf="@+id/textViewMain"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        android:text="Export"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content" />
+
 </androidx.constraintlayout.widget.ConstraintLayout>