Question

I’m beta testing my first Android app and have had a few users mention that when they attempt to lookup by GPS it hangs. In order to improve error handling around this I wanted to get the opinion of people who have apps in the wild.

My current activity does the following to kick off the lookup

findViewById(R.id.gpsButton).setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    LocationManager mlocManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
                    MyLocationListener mlocListener = new MyLocationListener();

                    Criteria locationCriteria = new Criteria();
                    locationCriteria.setAccuracy(Criteria.ACCURACY_FINE);

                    mlocManager.requestLocationUpdates(mlocManager.getBestProvider(locationCriteria, true), 0, 0, mlocListener);
                }
            });

The implementation of my custom location lookup class is below

public class MyLocationListener implements LocationListener {
        private boolean alreadyLocatedDevice;
        private ProgressDialog dialog;

        public MyLocationListener() {
            this.dialog = ProgressDialog.show(LocationLookup.this, "", "Loading...");
        }

        @Override
        public void onProviderDisabled(String provider) {
            this.dialog.dismiss();
            DialogHelper.showDialogWithMessageAndTitle("", "You don't currently have location services turned on", LocationLookup.this);
        }

        @Override
        public void onLocationChanged(android.location.Location location) {
            if (!alreadyLocatedDevice) {
                alreadyLocatedDevice = true;
                Location loc = new Location();
                loc.setLng(Double.toString(location.getLongitude()));
                loc.setLat(Double.toString(location.getLatitude()));

                ((AppDelegate) getApplicationContext()).setSelectedLocation(loc);
                Intent findKioskLocation = new Intent(LocationLookup.this, FindKioskLocation.class);

                this.dialog.dismiss();

                startActivity(findKioskLocation);
            }
        }

        @Override
        public void onStatusChanged(String s, int i, Bundle bundle) {
            //To change body of implemented methods use File | Settings | File Templates.
        }

        @Override
        public void onProviderEnabled(String s) {
            //To change body of implemented methods use File | Settings | File Templates.
        }
    }

And finally I’ve added both the ACCESS_FINE_LOCATION and ACCESS_COARSE_LOCATION permissions in my manifest file.

Any help would be much appreciated!

Answer 1

For anyone who might follow this thread -I found a mixture of my own approach (admittedly hackish in this code example) and the one mentioned by @bear to work without any issues (plus the location lookup was fast/accurate and error free)

I found the example listed by @bear to be a little more complex than I needed. For starters I wanted to kick off the GPS lookup when a button was clicked and have a simple async task wrapping this so it would throw up a dialog/etc

Next I wanted the exact latitude and longitude (no need to pass this off to another class because my example was simply to use the lat + lng to locate a resource and plot it)

So if you can follow my untested rather copy/paste approach here goes…

Inside your activity you would spin up the service during an onclick lets say …

LocationManager networkManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
LocationManager gpsManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

LocationService locationProcessor = new LocationService(YourActivityName.this, networkManager, gpsManager, dialog);
locationProcessor.onStartCommand();

Now the location service itself

package com.epicsoftware.android.global;

import android.app.ProgressDialog;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Handler;
import com.epicsoftware.android.activity.LocationLookup;

public class LocationService {
    private LocationManager networkLm;
    private LocationManager gpsLm;
    private LocationListener networkListener;
    private LocationListener gpsListener;

    private boolean isRunning;
    private boolean networkLocDisabled;
    private boolean gpsLocDisabled;
    private Context activity;
    private LocationManager tmpNetworkManager;
    private LocationManager tmpGpsManager;
    private Handler locationHandler;
    private ProgressDialog dialog;
    private boolean gpsUpdated;
    private boolean done;

    public LocationService(final Context activity, LocationManager networkManager, LocationManager gpsManager, ProgressDialog dialog) {
        this.tmpNetworkManager = networkManager;
        this.tmpGpsManager = gpsManager;
        this.activity = activity;
        this.dialog = dialog;
    }

    public void onStartCommand() {
        if (!isRunning) {
            isRunning = true;

            startLocationListeners();

            locationHandler = new Handler();
            getLocationByZip.start();
        }
    }

    private void startLocationListeners() {
        networkListener = new NetworkLocationListener();
        gpsListener = new GpsLocationListener();

        networkLm = tmpNetworkManager;
        gpsLm = tmpGpsManager;

        networkLm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, networkListener);
        gpsLm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, gpsListener);
    }


    private Thread getLocationByZip = new Thread() {
        public void run() {
            try {
                for (int i = 0; i < 15;) {
                    if (!locationDisabled() || !gpsUpdated) {
                        try {
                            Thread.sleep(1000);
                        } catch (Exception e) {
                            break;
                        }
                        i++;
                    } else {
                        break;
                    }
                }

                locationHandler.post(monitorTheNetworkAndGpsProviders);
            } catch (Exception e) {
                killService();
                done = true;
            }
        }
    };

    private Runnable monitorTheNetworkAndGpsProviders = new Runnable() {
        @Override
        public void run() {
            killService();
            dialog.dismiss();
            if (!done) {
                done = true;
                ((LocationLookup) activity).warnUserThatLocationServicesAreDisabledOrFailed();
            }
        }
    };

    private boolean locationDisabled() {
        if (gpsLocDisabled && networkLocDisabled) {
            done = true;
            ((LocationLookup) activity).warnUserThatLocationServicesAreDisabledOrFailed();

            return true;
        } else {
            return false;
        }
    }

    private void updateDb(Double lat, Double lon) {
        done = true;
        ((LocationLookup) activity).setLocationDataAndSpinUpNextActivity(lat, lon);
    }

    public void killService() {
        networkLm.removeUpdates(networkListener);
        gpsLm.removeUpdates(gpsListener);
    }

    public class NetworkLocationListener implements LocationListener {
        @Override
        public void onLocationChanged(Location location) {
            if (location != null) {
                updateDb(location.getLatitude(), location.getLongitude());
            }
        }

        @Override
        public void onProviderDisabled(String provider) {
            networkLocDisabled = true;
        }

        @Override
        public void onProviderEnabled(String provider) {
        }

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {
        }
    }

    public class GpsLocationListener implements LocationListener {
        @Override
        public void onLocationChanged(Location location) {
            if (location != null) {
                gpsUpdated = true;
                updateDb(location.getLatitude(), location.getLongitude());
            }
        }

        @Override
        public void onProviderDisabled(String provider) {
            gpsLocDisabled = true;
        }

        @Override
        public void onProviderEnabled(String provider) {
        }

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {
        }
    }
}