Location Open Source Tracker for Android
LOST is a drop-in replacement for Google Play Services FusedLocationProviderApi that makes calls directly to the LocationManger.
This project seeks to provide an open source alternative to the Fused Location Provider that depends only on the Android SDK. Operations supported at this time include getting the last known location and registering for location updates.
Connecting to the LOST API Client
When using LOST, GoogleApiClient is replaced by LostApiClient. Connecting to LOST is even easier since there are no ConnectionCallbacks or OnConnectionFailedListener objects to manage.
LostApiClient lostApiClient = new LostApiClient.Builder(this).build();
lostApiClient.connect();LOST instantly connects to the LocationManager and can immediately retrieve that last known location or begin sending location updates.
Getting the Last Known Location
Once connected you can request the last known location. The actual logic to determine the best most recent location is based this classic blog post by Reto Meier.
Location location = LocationServices.FusedLocationApi.getLastLocation();
if (location != null) {
// Do stuff
}Requesting Location Updates
LOST also provides the ability to request ongoing location updates. You can specify the update interval, minimum displacement, and priority. The priority determines which location providers will be activated.
LocationRequest request = LocationRequest.create()
.setInterval(5000)
.setSmallestDisplacement(10)
.setPriority(LocationRequest.PRIORITY_LOW_POWER);
LocationListener listener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
// Do stuff
}
};
LocationServices.FusedLocationApi.requestLocationUpdates(request, listener);Currently location updates can only be requested with a LocationListener object. In the future we are planning to add location updates via a PendingIntent as well.
Mock Locations
With LOST you can mock not just individual locations but also entire routes. By loading a GPX trace file onto the device you can configure LOST to replay locations from the trace file including latitude, longitude, speed, and bearing.
Mocking a single location
To mock a single location with LOST you must first enable mock mode. Then you simply create a mock location object and pass it to the API.
Location mockLocation = new Location("mock");
mockLocation.setLatitude(40.7484);
mockLocation.setLongitude(-73.9857);
LocationServices.FusedLocationApi.setMockMode(true);
LocationServices.FusedLocationApi.setMockLocation(mockLocation);The mock location object you set will be immediately returned to all registered listeners and will be returned the next time getLastLocation() is called.
Mocking an entire route
To mock an entire route you must first transfer a GPX trace file to the device using adb. Sample GPX traces can be found on the public GPS traces page for OpenStreetMap. Once the trace file is loaded on the device you can tell LOST to replay the locations in the trace at the requested update interval.
File file = new File(Environment.getExternalStorageDirectory(), "mock_track.gpx");
LocationServices.FusedLocationApi.setMockMode(true);
LocationServices.FusedLocationApi.setMockTrace(file);For more in-depth examples, please refer to the sample application.
This api is a drop in replacement for Google Play Services' corresponding [SettingsApi] 5. It can be used to check whether location and bluetooth settings are satisfied as well as provide a mechanism for resolving unsatisfied settings.
First create and connect a LostApiClient for use:
LostApiClient apiClient = new LostApiClient.Builder(this).build();
apiClient.connect();Next, create a LocationSettingsRequest specifying the location priority and whether or not the user needs BLE:
ArrayList<LocationRequest> requests = new ArrayList<>();
LocationRequest highAccuracy = LocationRequest.create().setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
requests.add(highAccuracy);
boolean needBle = false;
LocationSettingsRequest request = new LocationSettingsRequest.Builder()
.addAllLocationRequests(requests)
.setNeedBle(needBle)
.build();Then, use the SettingsApi to get a PendingResult:
PendingResult<LocationSettingsResult> result = LocationServices.SettingsApi.checkLocationSettings(apiClient, request);Once you have a PendingResult, invoke either await() or setResultCallback(ResultCallback) to obtain a LocationSettingsResult. With this object, access the LocationSettingsStates to determine whether or not location settings have been satisfied:
private static final int REQUEST_CHECK_SETTINGS = 100;
LocationSettingsResult locationSettingsResult = result.await();
LocationSettingsStates states = locationSettingsResult.getLocationSettingsStates();
Status status = locationSettingsResult.getStatus();
switch (status.getStatusCode()) {
case Status.SUCCESS:
// All location and BLE settings are satisfied. The client can initialize location
// requests here.
break;
case Status.RESOLUTION_REQUIRED:
// Location settings are not satisfied but can be resolved by show the user the Location Settings activity
status.startResolutionForResult(SettingsApiActivity.this, REQUEST_CHECK_SETTINGS);
break;
case Status.INTERNAL_ERROR:
case Status.INTERRUPTED:
case Status.TIMEOUT:
case Status.CANCELLED:
// Location settings are not satisfied but cannot be resolved
break;
default:
break;
}If the status code is RESOLUTION_REQUIRED, the client can call startResolutionForResult(Activity, int) to bring up an Activity, asking for user's permission to modify the location settings to satisfy those requests. The result of the Activity will be returned via onActivityResult(int, int, Intent).
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case REQUEST_CHECK_SETTINGS:
// Check the location settings again and continue
break;
default:
break;
}
}When using this API, you must declare that your app uses the Bluetooth permission:
<uses-permission android:name="android.permission.BLUETOOTH"/>And if your app requires Bluetooth, you must also request the Bluetooth admin permission:
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>Download Jar
Download the latest JAR.
Maven
Include dependency using Maven.
<dependency>
<groupId>com.mapzen.android</groupId>
<artifactId>lost</artifactId>
<version>1.1.1</version>
</dependency>Gradle
Include dependency using Gradle.
compile 'com.mapzen.android:lost:1.1.1'