android - repeat same location without WiFi connection

Question

I use LocationClient to get Location. With WiFi connection it works fine, but without WiFi, it repeats same location (even with mobile data connection!). I used LocationManager but it didn't work.

I'm wondering how google maps works fine (with mobile data connection) but I can't get the right location.

Using "LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY" or "LocationRequest.PRIORITY_HIGH_ACCURACY" makes same result.

here is my code:

public class LocationTracker implements
    GooglePlayServicesClient.ConnectionCallbacks,
    GooglePlayServicesClient.OnConnectionFailedListener {

LocationClient mLocationClient;
Location mCurrentLocation;
LocationRequest mLocationRequest;
LocationListener locationListener;
Handler handler = new Handler();

private static final int MILLISECONDS_PER_SECOND = 1000;
public static final int UPDATE_INTERVAL_IN_SECONDS = 5;
private static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND
        * UPDATE_INTERVAL_IN_SECONDS;
private static final int FASTEST_INTERVAL_IN_SECONDS = 5;
private static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND
        * FASTEST_INTERVAL_IN_SECONDS;

Context context;

public LocationTracker(Context context) {
    this.context = context;

}

public void getLocation() throws Exception {
    try {
        final int result = GooglePlayServicesUtil
                .isGooglePlayServicesAvailable(context);
        if (result != ConnectionResult.SUCCESS) {
            Toast.makeText(
                    context,
                    "Google Play service is not available (status="
                            + result + ")", Toast.LENGTH_LONG).show();

        }
    } catch (Exception e) {
        throw new Exception(e);
    }    

    mLocationClient = new LocationClient(context, this, this);
    mLocationRequest = LocationRequest.create();
    mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
    mLocationRequest.setInterval(UPDATE_INTERVAL);
    mLocationRequest.setFastestInterval(FASTEST_INTERVAL);

    mLocationClient.connect();

}

private final class MyLocationListener implements LocationListener {
    @Override
    public void onLocationChanged(Location location) {
        mCurrentLocation = location;
    }
}

@Override
public void onConnectionFailed(ConnectionResult arg0) {
    Toast.makeText(context, "Connection Failed", Toast.LENGTH_LONG).show();

}

@Override
public void onConnected(Bundle connectionHint) {

    locationListener = new MyLocationListener();
    mLocationClient.requestLocationUpdates(mLocationRequest,
            locationListener);
    mCurrentLocation = mLocationClient.getLastLocation();

}

@Override
public void onDisconnected() {

}

Answer 1

I resolve it. LocationClient.getLastLocation() returns last cached location. I have to check location in LocationListener.onLocationChanged() and if location is not equal with last cached location, I can use it.

here is the code:

import android.content.Context;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Handler;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesClient;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.location.LocationClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;

public class LocationTracker implements
    GooglePlayServicesClient.ConnectionCallbacks,
    GooglePlayServicesClient.OnConnectionFailedListener {

LocationClient mLocationClient;
Location mCurrentLocation;
LocationRequest mLocationRequest;
LocationListener locationListener;
Handler handler = new Handler();


private static final int MILLISECONDS_PER_SECOND = 1000;
public static final int UPDATE_INTERVAL_IN_SECONDS = 5;
private static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND
        * UPDATE_INTERVAL_IN_SECONDS;
private static final int FASTEST_INTERVAL_IN_SECONDS = 1;
private static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND
        * FASTEST_INTERVAL_IN_SECONDS;

Context context;

public LocationTracker(Context context) {
    this.context = context;

}

public void getLocation() throws Exception {
    try {
        final int result = GooglePlayServicesUtil
                .isGooglePlayServicesAvailable(context);
        if (result != ConnectionResult.SUCCESS) {
            Toast.makeText(
                    context,
                    "Google Play service is not available (status="
                            + result + ")", Toast.LENGTH_LONG).show();

        }
    } catch (Exception e) {
        throw new Exception(e);
    }

    mLocationClient = new LocationClient(context, this, this);
    mLocationRequest = LocationRequest.create();
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    mLocationRequest.setInterval(UPDATE_INTERVAL);
    mLocationRequest.setFastestInterval(FASTEST_INTERVAL);

    mLocationClient.connect();

}

private final class MyLocationListener implements LocationListener {
    @Override
    public void onLocationChanged(Location location) {
        // Report to the UI that the location was updated

        // sendLocation(location);

        if (!(location.getLatitude() == mCurrentLocation.getLatitude() && location
                .getLongitude() == mCurrentLocation.getLongitude())) {

            mLocationClient.removeLocationUpdates(locationListener);
            mLocationClient.disconnect();

            //use location as answer

        }
    }
}

@Override
public void onConnectionFailed(ConnectionResult arg0) {
    Toast.makeText(context, "Connection Failed", Toast.LENGTH_LONG).show();

}

@Override
public void onConnected(Bundle connectionHint) {

    final LocationManager manager = (LocationManager) context
            .getSystemService(Context.LOCATION_SERVICE);

    if (!manager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {

        //GPS provider is not enabled
        return;
    }

    locationListener = new MyLocationListener();
    mLocationClient.requestLocationUpdates(mLocationRequest,
            locationListener);
    mCurrentLocation = mLocationClient.getLastLocation();
    handler.postDelayed(new Runnable() {

        @Override
        public void run() {
            // TODO Auto-generated method stub
            if (mLocationClient.isConnected()) {
                mLocationClient.removeLocationUpdates(locationListener);
                mLocationClient.disconnect();

                //GPS can not find the location

            }
        }
    }, 2 * 60 * 1000);


}


@Override
public void onDisconnected() {

}

}