Android: Location Updates with the FusedLocationApi

If you want to retrieve the user’s location in your Android application you can take advantage of Google’s FusedLocationApi. Essentially you establish a connection to the GoogleApiClient and then set up a LocationRequest.  It’s up to you to configure the rate at which you would like to receive updates.  Here is an example of using the API:

import android.app.Activity;
import android.content.Intent;
import android.location.Location;
import android.net.Uri;
import android.os.Bundle;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;

import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class MainActivity extends Activity implements
                                           LocationListener,
                                           GoogleApiClient.ConnectionCallbacks,
                                           GoogleApiClient.OnConnectionFailedListener {

    private static final long ONE_MIN = 1000 * 60;
    private static final long TWO_MIN = ONE_MIN * 2;
    private static final long FIVE_MIN = ONE_MIN * 5;
    private static final long POLLING_FREQ = 1000 * 30;
    private static final long FASTEST_UPDATE_FREQ = 1000 * 5;
    private static final float MIN_ACCURACY = 25.0f;
    private static final float MIN_LAST_READ_ACCURACY = 500.0f;

    private LocationRequest mLocationRequest;
    private Location mBestReading;

    private GoogleApiClient mGoogleApiClient;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if (!servicesAvailable()) {
            finish();
        }

        setContentView(R.layout.activity_main);

        mLocationRequest = LocationRequest.create();
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        mLocationRequest.setInterval(POLLING_FREQ);
        mLocationRequest.setFastestInterval(FASTEST_UPDATE_FREQ);

        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addApi(LocationServices.API)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .build();
    }

    @Override
    protected void onResume() {
        super.onResume();

        if (mGoogleApiClient != null) {
            mGoogleApiClient.connect();
        }
    }

    @Override
    protected void onPause() {
        super.onPause();

        if (mGoogleApiClient != null && mGoogleApiClient.isConnected()) {
            mGoogleApiClient.disconnect();
        }
    }

    @Override
    public void onLocationChanged(Location location) {
        // Determine whether new location is better than current best
        // estimate
        if (null == mBestReading || location.getAccuracy() < mBestReading.getAccuracy()) {
            mBestReading = location;

            if (mBestReading.getAccuracy() < MIN_ACCURACY) {
                LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
            }
        }
    }

    @Override
    public void onConnected(Bundle dataBundle) {
        // Get first reading. Get additional location updates if necessary
        if (servicesAvailable()) {
            // Get best last location measurement meeting criteria
            mBestReading = bestLastKnownLocation(MIN_LAST_READ_ACCURACY, FIVE_MIN);

            if (null == mBestReading
                    || mBestReading.getAccuracy() > MIN_LAST_READ_ACCURACY
                    || mBestReading.getTime() < System.currentTimeMillis() - TWO_MIN) {

                LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
                
                // Schedule a runnable to unregister location listeners
                Executors.newScheduledThreadPool(1).schedule(new Runnable() {

                    @Override
                    public void run() {
                        LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, MainActivity.this);
                    }

                }, ONE_MIN, TimeUnit.MILLISECONDS);
            }
        }
    }

    @Override
    public void onConnectionSuspended(int i) {
        
    }

    private Location bestLastKnownLocation(float minAccuracy, long minTime) {
        Location bestResult = null;
        float bestAccuracy = Float.MAX_VALUE;
        long bestTime = Long.MIN_VALUE;

        // Get the best most recent location currently available
        Location mCurrentLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);

        if (mCurrentLocation != null) {
            float accuracy = mCurrentLocation.getAccuracy();
            long time = mCurrentLocation.getTime();

            if (accuracy < bestAccuracy) {
                bestResult = mCurrentLocation;
                bestAccuracy = accuracy;
                bestTime = time;
            }
        }

        // Return best reading or null
        if (bestAccuracy > minAccuracy || bestTime < minTime) {
            return null;
        }
        else {
            return bestResult;
        }
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        
    }

    private boolean servicesAvailable() {
        int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);

        if (ConnectionResult.SUCCESS == resultCode) {
            return true;
        }
        else {
            GooglePlayServicesUtil.getErrorDialog(resultCode, this, 0).show();
            return false;
        }
    }
}