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Not getting location coordinates unless location has changed

Here is what I need to do. I need to launch my application and on the click of a button, I need to display the current coordinates, that is latitude and longitude. I followed this tutorial and used the following code for my purpose:
public class MainActivity extends Activity {
public double latitude;
public double longitude;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener locationListener = new MyLocationListener();
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
}
#Override
protected void onStart() {
super.onStart();
final TextView latValueLabel = (TextView)findViewById(R.id.latLabel);
final TextView lonValueLabel = (TextView)findViewById(R.id.lonLabel);
Button setButton = (Button)findViewById(R.id.set_button);
setButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
latValueLabel.setText(String.valueOf(latitude));
lonValueLabel.setText(String.valueOf(longitude));
}
});
}
private class MyLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
if(location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
(Copy pasted only a part of the code, please ignore any unclosed brackets or anything like that.)
It continuously gets the latitude longitude as location changes and stores it to two double variables latitude and longitude and when the setButton is clicked, it displays the last stored lat-lon value. That would be the user's current location. Now the issue is, I launched the app and while still staying on the exact location from which the app is launched, I clicked the Set Button. But at that time the location is not changed, so the latitude and longitude are displayed as zero, which is the default value of the double variables. I need to take a walk around with the device so that the location is changed before I can get my actual coordinates. How can I get the lat-lon as soon as the app is launched?

You can use getLastKnownLocation(...) to initialise the longitude and latitude values like this:
LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
double longitude = location.getLongitude();
double latitude = location.getLatitude();

This is your total class.
public class MainActivity extends Activity {
public double latitude;
public double longitude;
private TextView latValueLabel,lonValueLabel ;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener locationListener = new MyLocationListener();
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
}
#Override
protected void onStart() {
super.onStart();
latValueLabel = (TextView)findViewById(R.id.latLabel);
lonValueLabel = (TextView)findViewById(R.id.lonLabel);
Button setButton = (Button)findViewById(R.id.set_button);
setButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
latValueLabel.setText(String.valueOf(latitude));
lonValueLabel.setText(String.valueOf(longitude));
}
});
}
private class MyLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location location) {
if(location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
latValueLabel.setText(String.valueOf(latitude));
lonValueLabel.setText(String.valueOf(longitude));
}
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}
}

Print Longitude and Latitude in textbox Android

I have looked about and cannot find any direct threads regarding what I am looking for. I am trying to create an Android application which dials out an emergency number at the push of a button (which I have got working) but cannot get the location (displayed in Longitude and Latitude) to display, I have tried doing it with Toast and EditText boxes. I am new to Android development so wanted to start with something easy, but the LongLat part is being troublesome. Any help would be greatly appreciated.
Below is the code I have been tampering with in order to try and get it to grab the Long and Lat, then in another file I have been trying to use a click listener to assign it to a button so when the button is pressed (in main.xml) it will display the Long and Lat either in a textfield or in toast.
import android.app.Activity;
import android.location.Location;
import android.location.LocationListener;
import android.os.Bundle;
import android.widget.TextView;
import android.content.Context;
import android.location.LocationManager;
import android.location.Criteria;
public class EmergencyLocation extends Activity implements LocationListener {
private TextView latituteField;
private TextView longitudeField;
private LocationManager locationManager;
private String provider;
/** Called when the activity is first created. **/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
latituteField = (TextView) findViewById(R.id.TextView);
longitudeField = (TextView) findViewById(R.id.long_lat);
// Get the location manager
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
// Define the criteria how to select the location provider -> use
// default
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, false);
Location location = locationManager.getLastKnownLocation(provider);
// Initialise the location fields
if (location != null) {
System.out.println("Provider " + provider + " has been selected.");
int lat = (int) (location.getLatitude());
int lng = (int) (location.getLongitude());
latituteField.setText(String.valueOf(lat));
longitudeField.setText(String.valueOf(lng));
} else {
latituteField.setText("Provider not available");
longitudeField.setText("Provider not available");
}
}
private void TextView() {
// TODO Auto-generated method stub
}
#Override
public void onLocationChanged(Location arg0) {
// TODO Auto-generated method stub
}
#Override
public void onProviderDisabled(String arg0) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String arg0) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
// TODO Auto-generated method stub
}}

First, you need to set up a LocationManager:
LocationManager manager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
// set preferred provider based on the best accuracy possible
Criteria fineAccuracyCriteria = new Criteria();
fineAccuracyCriteria.setAccuracy(Criteria.ACCURACY_FINE);
String preferredProvider = manager.getBestProvider(fineAccuracyCriteria, true);
Now, you have to create a LocationListener. In this case, it calls the method updateLocation():
LocationListener listener = new LocationListener() {
public void onLocationChanged(Location location) {
// called when a new location is found by the network location provider.
updateLocation(location);
}
public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
public void onProviderDisabled(String provider) {}
};
EDIT:
Then, you have to register the listener with your LocationManager (and try to get the cached location):
manager.requestLocationUpdates(preferredProvider, 0, 0, listener);
// get a fast fix - cached version
updateLocation(manager.getLastKnownLocation());
And finally, the updateLocation() method:
private void updateLocation(Location location) {
if (location == null)
return;
// save location details
latitude = (float) location.getLatitude();
longitude = (float) location.getLongitude();
}
EDIT2:
OK, just saw your code. In order to make it work, just move around a few bits:
/** Called when the activity is first created. **/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
latituteField = (TextView) findViewById(R.id.TextView);
longitudeField = (TextView) findViewById(R.id.long_lat);
// Get the location manager
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
// Define the criteria how to select the location provider -> use
// default
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, false);
locationManager.requestLocationUpdates(provider, 0, 0, this);
Location location = locationManager.getLastKnownLocation(provider);
onLocationChanged(location);
}
#Override
protected void onDestroy() {
super.onDestroy();
locationManager.removeUpdates(this);
}
#Override
public void onLocationChanged(Location location) {
if (location != null) {
System.out.println("Provider " + provider + " has been selected.");
int lat = (int) (location.getLatitude());
int lng = (int) (location.getLongitude());
latituteField.setText(String.valueOf(lat));
longitudeField.setText(String.valueOf(lng));
} else {
latituteField.setText("Provider not available");
longitudeField.setText("Provider not available");
}
}
Hope it helps!

Quite easy. I use the locationListener as an attribute inside a Location class. Here's how I do it:
package com.rifsoft.android.helper.location;
import com.rifsoft.android.helper.IListener;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
public class Location implements IListener
{
public final static int IDX_LATITIDE = 0;
public final static int IDX_LONGITUDE = 1;
private double[] lastLocation = {0.0, 0.0};
private LocationManager locationManager = null;
private ILocation activity = null;
private LocationListener locationListener = new LocationListener()
{
public void onLocationChanged(android.location.Location location)
{
// TODO: http://developer.android.com/guide/topics/location/obtaining-user-location.html#BestEstimate
lastLocation[IDX_LATITIDE] = location.getLatitude();
lastLocation[IDX_LONGITUDE] = location.getLongitude();
activity.onLocationChange();
}
public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
public void onProviderDisabled(String provider) {}
};
/**
* Constructor, needs LocationManager
* #param activity Activity that will receive the notification when location has changed
* #param locationManager LocationManager
*/
public Location(final ILocation act, LocationManager lm) throws LocationException
{
if (lm == null)
{
throw new LocationException(LocationException.ERR_NULL_LOCATION_MANAGER);
}
if (act == null)
{
throw new LocationException(LocationException.ERR_NULL_ILOCATION);
}
locationManager = lm;
activity = act;
registerListener();
android.location.Location lastCachedLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (lastCachedLocation != null)
{
lastLocation[IDX_LATITIDE] = lastCachedLocation.getLatitude();
lastLocation[IDX_LONGITUDE] = lastCachedLocation.getLatitude();
}
}
/**
* Retuns last known most accurate location as latitude, longitude
* #return Latitude, Longitude
*/
public double[] getLastLocation()
{
return lastLocation;
}
#Override
public void registerListener()
{
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
}
#Override
public void unRegisterListener()
{
locationManager.removeUpdates(locationListener);
}
}
Then the activity.onLocationChange() goes like
public void onLocationChange()
{
locationUpdated = true;
double[] coordinates = location.getLastLocation();
EditText lon = (EditText) activity.findViewById(R.id.longitude_value);
lon.setText(String.valueOf(coordinates[Location.IDX_LONGITUDE]));
EditText lat = (EditText) activity.findViewById(R.id.latitude_value);
lat.setText(String.valueOf(coordinates[Location.IDX_LATITIDE]));
}

android onLocationChanged never called

I've implemented code that should return present location.
First the code:
public static double[] getLocation(Context context) {
double[] result;
lm = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
MyLocationListener ll = new MyLocationListener();
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, ll);
while(!hasLocation) { }
result = ll.getResult();
return result;
}
private static class MyLocationListener implements LocationListener {
double[] result = new double[2];
public double[] getResult() {
return result;
}
#Override
public void onLocationChanged(Location location) {
if(location.getAccuracy() != 0.0 && location.getAccuracy() < 100) {
result[0] = location.getLatitude();
result[1] = location.getLongitude();
hasLocation = true;
lm.removeUpdates(this);
}
}
#Override
public void onProviderDisabled(String provider) {}
#Override
public void onProviderEnabled(String provider) {}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
}
The problem is that all stopps on 'while' statement. WHen I've tried to debug this setting breakpoint on the first line in onLocationChanged() nothing happens, but Logcat was showing some logs like:
loc_eng_report_position: vertical_accuracy = 64.000000
DEBUG/libloc(1292): date:2011-08-11, time:10:51:03.372, raw_sec=1313052663, raw_sec2=1313052663,raw_msec=1313052663372
Any ideas?

The while(!hasLocation) {} is blocking your application from doing anything. You'll either need to deal with the location in the callback onLocationChanged, or you'll need to start the location manager a lot earlier and hope that you have a result by the time you need it. You can't busy-wait for the answer.

Listening to bound location service from an activity

I've got a location service to have an updated location in my app. I bind it to every activity requiring location data, and now I'd like to know in these activities when the location listener in the service receives events such as onLocationChanged, onProviderEnabled... How can I do that?
In my activities
private ServiceConnection mConnection;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Bind location service
bindService(new Intent(this, LocationService.class), mConnection, Context.BIND_AUTO_CREATE);
// Activity stuff...
}
#Override
protected void onDestroy() {
super.onDestroy();
// Unbind LocationService
context.unbindService(mConnection);
}
LocationService.java
public class LocationService extends Service implements LocationListener {
LocationManager locationManager;
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onCreate() {
locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){
// Update after minimum 5 minutes and if user has moved at least 100 meters.
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5 * 60 * 1000, 100, this);
Location loc = getBestLocation(locationManager);
if(loc!=null){
GlobalVars.lat = (Double) (loc.getLatitude());
GlobalVars.lng = (Double) (loc.getLongitude());
}
}
}
public void onLocationChanged(Location loc) {
GlobalVars.lat = (Double) (loc.getLatitude());
GlobalVars.lng = (Double) (loc.getLongitude());
}
public static Location getBestLocation(LocationManager locationManager) {
Location location_gps = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
Location location_network = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
// If both are available, get the most recent
if(location_gps!=null && location_network !=null) {
return (location_gps.getTime() > location_network.getTime())?location_gps:location_network;
}
else if(location_gps==null && location_network ==null){
return null;
}
else
return (location_gps==null)?location_network:location_gps;
}
public void onProviderEnabled(String s){
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5 * 60 * 1000, 0, this);
}
public void onProviderDisabled(String s){
locationManager.removeUpdates(this);
GlobalVars.lat = null;
GlobalVars.lng = null;
}
public void onStatusChanged(String s, int i, Bundle b){}
#Override
public void onDestroy() {
locationManager.removeUpdates(this);
}
}

I would do it on this way:
Create LocationListener class..
Each time i get a new location, send broadcast message with specific predefined ACTION and in extras put lat and lon.
Each activity creates broadcast listener for this message with intentFilter(Action);
Get extras from the intent.

LocationListener InSide AsyncTask

Hi I am New to android programming and currently developing an application that uses location manager to get user location and place a marker on a map. i am attempting to use AsyncTask to run the LocationListener and Constantly update the marker when the user location has changed.
this is the class i am working on...
public class IncidentActivity extends MapActivity{
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
this.setContentView(R.layout.incidentactivity);
mapView = (MapView)findViewById(R.id.mapView);
mapView.setBuiltInZoomControls(true);
mapView.setTraffic(true);
mapController = mapView.getController();
String coordinates[] = {"-26.167004","27.965505"};
double lat = Double.parseDouble(coordinates[0]);
double lng = Double.parseDouble(coordinates[1]);
geoPoint = new GeoPoint((int)(lat*1E6), (int)(lng*1E6));
mapController.animateTo(geoPoint);
mapController.setZoom(16);
mapView.invalidate();
new MyLocationAsyncTask().execute();
}
private class MyLocationAsyncTask extends AsyncTask<Void, Location, Void> implements LocationListener{
private double latLocation;
private Location l;
//location management variables to track and maintain user location
protected LocationManager locationManager;
protected LocationListener locationListener;
#Override
protected Void doInBackground(Void... arg0) {
Looper.prepare();
locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 1, locationListener);
this.publishProgress(l);
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
}
#Override
protected void onProgressUpdate(Location... values) {
super.onProgressUpdate(values);
}
//this method is never executed i dont know why...?
public void onLocationChanged(Location location) {
if (location != null){
latLocation = location.getLatitude();
Toast.makeText(getBaseContext(), " Your latLocation :" + latLocation, Toast.LENGTH_LONG).show();
//Log.d("Your Location", ""+latLocation);
}
}
public void onProviderDisabled(String provider) {
}
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
}

I've just implemented such AsyncTask:
class GetPositionTask extends AsyncTask<Void, Void, Location> implements LocationListener
{
final long TWO_MINUTES = 2*60*1000;
private Location location;
private LocationManager lm;
protected void onPreExecute()
{
// Configure location manager - I'm using just the network provider in this example
lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 1000, 0, this);
nearProgress.setVisibility(View.VISIBLE);
}
protected Location doInBackground(Void... params)
{
// Try to use the last known position
Location lastLocation = lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
// If it's too old, get a new one by location manager
if (System.currentTimeMillis() - lastLocation.getTime() > TWO_MINUTES)
{
while (location == null)
try { Thread.sleep(100); } catch (Exception ex) {}
return location;
}
return lastLocation;
}
protected void onPostExecute(Location location)
{
nearProgress.setVisibility(View.GONE);
lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
lm.removeUpdates(this);
// HERE USE THE LOCATION
}
#Override
public void onLocationChanged(Location newLocation)
{
location = newLocation;
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
}

From what I have read and tried, you cannot use a looper (which is needed by the locationlistener), inside an ASyncTask. Click Here
Actually it mean the two threading models are not compatible, so you can't
use these together. Looper expects to to own the thread that you associate
it with, while AsyncTask owns the thread it creates for you to run in the
background. They thus conflict with each other, and can't be used together.
Dianne Hackborn suggested using a HandlerThread, but I succeeded in getting mine to work inside of an IntentService. I will admit that my code is still a bit of a hack.