How to refresh marker in Android Google Maps view? - android

How can I refresh the marker position (for example, when user is moving) on Android maps?
I set up the refresh time for 3 seconds in locationManager.requestLocationUpdates but it seems that it's not working.
Here is my GPSTracker class:
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 50; // 3 seconds
// Declaring a Location Manager
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
} else {
this.canGetLocation = true;
// First get location from Network Provider
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
public void stopUsingGPS() {
if (locationManager != null) {
locationManager.removeUpdates(GPSTracker.this);
}
}
public double getLatitude() {
if (location != null) {
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
public double getLongitude() {
if (location != null) {
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
public boolean canGetLocation() {
return this.canGetLocation;
}
public void showSettingsAlert() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog
.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(
Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
#Override
public void onLocationChanged(Location location) {
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}
And here is my Maps Activity where I create map and add a marker to it:
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
private final static int REQUEST_CODE_ASK_PERMISSIONS = 1;
private static final String[] REQUIRED_SDK_PERMISSIONS = new String[]{
Manifest.permission.ACCESS_FINE_LOCATION,
Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.INTERNET,
Manifest.permission.ACCESS_NETWORK_STATE};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
checkPermissions();
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
#Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mapsCreate();
}
public void mapsCreate() {
GPSTracker tracker = new GPSTracker(MapsActivity.this);
double lat = tracker.getLatitude();
double lng = tracker.getLongitude();
// Add a marker for current location and move the camera
LatLng currentLocation = new LatLng(lat, lng);
mMap.addMarker(new MarkerOptions().position(currentLocation).title("Current Location Marker"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(currentLocation));
}
protected boolean checkPermissions() {
final List<String> missingPermissions = new ArrayList<String>();
// check all required dynamic permissions
for (final String permission : REQUIRED_SDK_PERMISSIONS) {
final int result = ContextCompat.checkSelfPermission(this, permission);
if (result != PackageManager.PERMISSION_GRANTED) {
missingPermissions.add(permission);
}
}
if (!missingPermissions.isEmpty()) {
// request all missing permissions
final String[] permissions = missingPermissions
.toArray(new String[missingPermissions.size()]);
ActivityCompat.requestPermissions(this, permissions, REQUEST_CODE_ASK_PERMISSIONS);
} else {
final int[] grantResults = new int[REQUIRED_SDK_PERMISSIONS.length];
Arrays.fill(grantResults, PackageManager.PERMISSION_GRANTED);
onRequestPermissionsResult(REQUEST_CODE_ASK_PERMISSIONS, REQUIRED_SDK_PERMISSIONS,
grantResults);
return true;
}
return true;
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String permissions[],
#NonNull int[] grantResults) {
switch (requestCode) {
case REQUEST_CODE_ASK_PERMISSIONS:
for (int index = permissions.length - 1; index >= 0; --index) {
if (grantResults[index] != PackageManager.PERMISSION_GRANTED) {
// exit the app if one permission is not granted
Toast.makeText(this, "Required permission '" + permissions[index]
+ "' not granted, exiting", Toast.LENGTH_LONG).show();
finish();
return;
}
}
// all permissions were granted
break;
}
}
Any help would be much appreciated! Thank you

Save the marker object after adding to maps.
myMarker = mMap.addMarker(new MarkerOptions().position(currentLocation).title("Current Location Marker"));
After getting new location in location updates callback update marker's position.
.....
myMarker.setPosition(newLatLng);

Related

get user location longitude and latitude

I stuck in this code in week ago I tried every solution in stack overflow and doesn't work in my problem the problem is when I tried to get user longitude and latitude it gives me zero here is my code
public class AppLocationService extends Service implements LocationListener {
private Context mContext = null;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 60000; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
public AppLocationService(Context context) {
this.mContext = context;
getLocation();
}
public AppLocationService() {
//super(context);
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
} else {
this.canGetLocation = true;
// First get location from Network Provider
if (isNetworkEnabled) {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return location;
}
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(AppLocationService.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
#Override
public void onLocationChanged(Location location) {
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}
You should use Google Play services location APIs
Setup your Google play services: https://developers.google.com/android/guides/setup
Add to your manifest
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.google.android.gms.location.sample.basiclocationsample" >
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
</manifest>
Declare the location client
private FusedLocationProviderClient mFusedLocationClient;
// ..
#Override
protected void onCreate(Bundle savedInstanceState) {
// ...
mFusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
}
Getting user last location
mFusedLocationClient.getLastLocation()
.addOnSuccessListener(this, new OnSuccessListener<Location>() {
#Override
public void onSuccess(Location location) {
// Got last known location. In some rare situations this can be null.
if (location != null) {
// ...
}
}
});
Ref:
https://developer.android.com/training/location/retrieve-current.html
Try Calling your methods for getting user longitude and latitude in
#Override
public void onLocationChanged(Location location) {
}

getLastKnownLocation sometimes returns null

Let me start by acknowledging that there are many results when you search for this particular question. Yet, nothing I've tried, according to those answers, works. Sometimes I get the location, sometimes I don't. If I play with the Location enabling/disabling I always get null when calling getLastKnownLocation. If I sometimes manually revoke the Location permission and enable it again, it works. I've tried changing the LocationManager to location = locationManager .getLastKnownLocation(LocationManager.PASSIVE_PROVIDER); but it doesn't work.
Basically, I am doing the following:
public class GPSTracker implements LocationListener {
public static final int LOCATION_SETTINGS_REQUEST_CODE = 109;
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
private static final long MIN_TIME_BW_UPDATES = 1000 * 60;
private static boolean isGpsStatusChanged = false;
private static AlertDialog.Builder alertDialog;
private LocationManager locationManager;
private boolean canGetLocation = false;
private Location location;
private double latitude;
private double longitude;
private NewLocationListener newLocationListener;
public interface NewLocationListener {
void onLocationChanges(Location location);
}
public GPSTracker() {
}
#SuppressWarnings("all")
public Location getLocation() {
try {
locationManager = (LocationManager) BaseApplication.getContext().getSystemService(Context.LOCATION_SERVICE);
// getting GPS status
boolean isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
boolean isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
} else {
this.canGetLocation = true;
// First get location from Network Provider
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPSTracker", "Network");
if (locationManager != null) {
Log.d("GPSTracker", "Network - location manager != null");
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
Log.d("GPSTracker", "Network - last known location != null");
latitude = location.getLatitude();
longitude = location.getLongitude();
newLocationListener.onLocationChanges(location);
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPSTracker", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
Log.d("LastKnownLocation", "Location: " + locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER));
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
newLocationListener.onLocationChanges(location);
}
}
}
}
}
} catch (Exception e) {
Log.e(Constants.TAG, e.getMessage(), e);
}
return location;
}
public static boolean isGpsEnabled() {
LocationManager locationManager = (LocationManager) BaseApplication.getContext().getSystemService(Context
.LOCATION_SERVICE);
return locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
}
#SuppressWarnings("all")
public void stopUsingGPS() {
if (locationManager != null) {
locationManager.removeUpdates(GPSTracker.this);
}
}
public double getLatitude() {
if (location != null) {
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
public double getLongitude() {
if (location != null) {
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
public boolean canGetLocation() {
return this.canGetLocation;
}
public void setNewLocationListener(NewLocationListener newLocationListener) {
this.newLocationListener = newLocationListener;
}
public void removeLocationListener() {
this.newLocationListener = null;
}
#SuppressWarnings("InlinedApi")
public void showSettingsAlert(final Context context) {
if (alertDialog != null) {
return;
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
alertDialog = new AlertDialog.Builder(context, android.R.style.Theme_Material_Light_Dialog_Alert);
} else {
alertDialog = new AlertDialog.Builder(context);
}
alertDialog.setTitle(R.string.gps_window_title);
alertDialog.setMessage(R.string.gps_window_message);
alertDialog.setPositiveButton(R.string.gps_window_button_positive, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
((Activity) context).startActivityForResult(intent, LOCATION_SETTINGS_REQUEST_CODE);
}
});
alertDialog.setNegativeButton(R.string.gps_window_button_negative, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
alertDialog.show().setOnDismissListener(new DialogInterface.OnDismissListener() {
#Override
public void onDismiss(DialogInterface dialog) {
alertDialog = null;
}
});
}
#Override
public void onLocationChanged(Location location) {
if (newLocationListener != null) {
newLocationListener.onLocationChanges(location);
}
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
public static boolean isGpsStatusChanged() {
return isGpsStatusChanged;
}
public static void setIsGpsStatusChanged(boolean isGpsStatusChanged) {
GPSTracker.isGpsStatusChanged = isGpsStatusChanged;
}
}
And then in my fragment:
private void statGPSLocationTracking() {
Log.d(Constants.TAG, "start gps update");
// check if GPS enabled
gpsTracker = new GPSTracker();
gpsTracker.setNewLocationListener(newLocationListener);
gpsTracker.getLocation();
if (!gpsTracker.canGetLocation()) {
Log.d(Constants.TAG, "GPS not enabled, show enable dialog");
// stop the gps tracker(removes the location update listeners)
gpsTracker.stopUsingGPS();
// ask user to enable location
gpsTracker.showSettingsAlert(getActivity());
}
}
private GPSTracker.NewLocationListener newLocationListener = new GPSTracker.NewLocationListener() {
#Override
public void onLocationChanges(Location loc) {
if (getActivity() == null) {
return;
}
// GPS location determined, load the web page and pass the coordinates in the header location section
Log.d(Constants.TAG, "Location listener onLocationChanges: " + loc);
infoManager.setCurrentLocation(loc);
checkRadioInfoNeeded();
// stop the gps tracker(removes the location update listeners)
gpsTracker.stopUsingGPS();
}
};
Without this location permission android.Manifest.permission.ACCESS_FINE_LOCATION the getLastKnownLocation() will always return null.
getLastKnownLocation() does not return location immediately, it takes some time.
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
private static final long MIN_TIME_BW_UPDATES = 1000 * 60;
this to
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 0;
private static final long MIN_TIME_BW_UPDATES = 5 * 1000;
Also remove your code which gets location from network. Go to Google maps and see if maps is able to detect your current location. If your map is able to get location then your code too should get location place breakpoints and see where the real issue is.

android -LocationManager return 0.0 for latitude and longitude

I want to get current latitude and longitude when user clicks on a button . to do so ,I've written these codes :
LocationManager mlocManager=null;
LocationListener mlocListener;
mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
if (mlocManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){
Log.v("this",MyLocationListener.latitude+ " lat");
if(MyLocationListener.latitude>0){
in = new Intent(DrawerActivity.this, Barbers.class);
in.putExtra("w", "nearest");
in.putExtra("latitude",Double.toString(MyLocationListener.latitude));
in.putExtra("longitude",Double.toString(MyLocationListener.longitude));
startActivity(in);
}else{
MyToast.makeText(DrawerActivity.this, Z_Farsi.Convert(getString(R.string.gpsfinding)));
}
} else {
MyToast.makeText(DrawerActivity.this, Z_Farsi.Convert(getString(R.string.gpsoffline)));
}
The gps is on and the current location is showing on google map perfectly .
What is the problem ? why it returns 0.0 ?
how to solve this ?
getLastKnownLocation is missing. You should have something like this :
Location location = null;
if (mlocManager!= null) {
location = mlocManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
This file will do the work for you. It will get the data from network-operator or GPS.
GPSTracker.java
public class GpsTracker extends Service implements LocationListener {
private final Context mContext;
boolean isGPSEnabled = false;
boolean isNetworkEnabled = false;
boolean canGetLocation = false;
Location location;
double latitude;
double longitude;
private final long MIN_DISTANCE = 10;
private final long MIN_TIME = 30;
protected LocationManager locationManager;
public GpsTracker(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider enabled
} else {
this.canGetLocation = true;
// first get location from network provider
if (isNetworkEnabled) {
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return null;
}
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME, MIN_DISTANCE, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS enabled get lat/long using GPS provider
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME, MIN_DISTANCE, this);
Log.d("GPS provider", "GPS provider");
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
/* Stop using GPS listener
* calling this function will stop using GPS in your app*/
public void stopUsingGPS() {
if (locationManager != null) {
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
locationManager.removeUpdates(GpsTracker.this);
}
}
// functions to get latitude and longitude
public double getLatitude()
{
if(location != null){
latitude = location.getLatitude();
}
return latitude;
}
public double getLongitude()
{
if(location != null){
longitude = location.getLongitude();
}
return longitude;
}
// function to check whether GPS/WiFi is enabled
public boolean canGetLocation()
{
return this.canGetLocation;
}
/* Function to show alert dialog
* on pressing settings button will launch settings options */
public void showAlertDialog()
{
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
alertDialog.setTitle("GPS Settings").setMessage("GPS not Enabled. /n Want to enable it ? ").setCancelable(false);
alertDialog.setPositiveButton("Settings", new OnClickListener() {
#Override
public void onClick(DialogInterface arg0, int arg1) {
// Implicit intent
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
alertDialog.setNegativeButton("No", new OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int arg1) {
dialog.cancel();
}
});
alertDialog.show();
}
#Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
#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
}
}
Try like this
manager.requestLocationUpdates("gps", 10, 10, new LocationListener() {
#Override
public void onLocationChanged(Location location) {
double lat=location.getLatitude();
double lon=location.getLognitude()
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}
});
What I have come to notice with location features is that you cannot acquire a user location instantly. You have to wait for the device to give you the location.
Normally, I would have my code in my Application class then for example when a user clicks the button, you call a method inside the application class and let the user know (through a progress dialog??) that they should wait for the latitude and longitude to be acquired.
Next thing would be to use an event to notify the activity or fragment of the location availability then dismissing the progress dialog once you have your data.
Just know that you cannot easily get the current location when you want like immediately. Sometimes, when indoors, it doesn't even work as expected.
Good luck!

Android GPS tracks wrong location

In my app I want to show user's current location and if location is changed it will show an alert message to change the location. The problem is that it shows location chahnge message even when the phone's GPS is off. What might be the reason?
Here's my code:
protected void onResume() {
/**
* get saved Location from shared preference
*
*/
SharedPreferences sPrefs = PreferenceManager
.getDefaultSharedPreferences(Activity_Home.this);
String getL = sPrefs.getString(Utility.KEY_USER_LAT, "0.000000");
String getLo = sPrefs.getString(Utility.KEY_USER_LONG, "0.000000");
getLat = Double.parseDouble(getL);
getLog = Double.parseDouble(getLo);
gps = new GpsTracker(Activity_Home.this);
/**
* Get user current latitude and longitude and match them to stored
* latitude and longitude if distance between these latitude then Pop up
* will be show
*
* #author Ankit
*/
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
System.out.println("Latitude is " + getLat);
if (getLat > 0.0) {
Location locationA = new Location("point A");
locationA.setLatitude(getLat);
locationA.setLongitude(getLog);
Location locationB = new Location("point B");
locationB.setLatitude(latitude);
locationB.setLongitude(longitude);
distance = locationA.distanceTo(locationB);
// Toast.makeText(Activity_Home.this,
// "Distance is :"+Double.toString(distance),
// Toast.LENGTH_LONG).show();
distance = distance / 1000000;
int getDistance = (int) (distance * 1000000);
System.out.println("Distance is " + getDistance);
if (getDistance > 100) {
showWarningMessage();
}
}
String lat = String.valueOf(latitude);
String lon = String.valueOf(longitude);
SharedPreferences sPref = PreferenceManager
.getDefaultSharedPreferences(Activity_Home.this);
SharedPreferences.Editor sEdit = sPref.edit();
sEdit.putString(Utility.KEY_USER_LAT, lat);
sEdit.putString(Utility.KEY_USER_LONG, lon);
sEdit.commit();
} else {
gps.showSettingsAlert();
}
super.onResume();
}
// Method for show an Alert dialog for user if user's location changed''
public void showWarningMessage() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(
Activity_Home.this);
alertDialog.setCancelable(false);
// Setting Dialog Title
alertDialog.setTitle("Location Changed");
// Setting Dialog Message
alertDialog
.setMessage("It seems your location has changed, would you like to change the Branch now?");
// On pressing Settings button
alertDialog.setPositiveButton("Yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Activity_Home.this,
Activity_Settings.class);
startActivity(intent);
dialog.cancel();
}
});
// on pressing cancel button
alertDialog.setNegativeButton("No",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
public class GpsTracker extends Service implements LocationListener {
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 100; // 100 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
public GpsTracker(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
System.out.println("=====isGPSEnabled:
"+isGPSEnabled+"====isNetworkEnabled: "+isNetworkEnabled);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
System.out.println("=====notgps");
} else {
this.canGetLocation = true;
// First get location from Network Provider
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GpsTracker.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
alertDialog.setCancelable(false);
// Setting Dialog Title
alertDialog.setTitle("Enable GPS");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to
settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new
DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new
Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new
DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
// alertDialog.;
}
#Override
public void onLocationChanged(Location location) {
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}
Here is one sample code for find location check this if it works for you
public static void LocationFind() {
try {
if (Skyhook) {
_xps.getXPSLocation(null,
// note we convert _period to seconds
(int) (_period / 1000), _desiredXpsAccuracy, _callback);
// _xps.getLocation(null, _streetAddressLookup, _callback);
} else {
Criteria criteria = new Criteria();
criteria.setBearingRequired(false);
criteria.setCostAllowed(true);
criteria.setPowerRequirement(Criteria.POWER_LOW);
criteria.setAltitudeRequired(false);
criteria.setAccuracy(Criteria.ACCURACY_FINE);
LocationManager locationManager = (LocationManager) mcontext.getSystemService(Context.LOCATION_SERVICE);
isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
// Getting network status
isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, locationListener);
// Log.d("Network", "Network");
if (locationManager != null) {
lastknownlocations = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (lastknownlocations != null) {
lat = lastknownlocations.getLatitude();
lng = lastknownlocations.getLongitude();
}
}
}
if (isGPSEnabled) {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, locationListener);
// Log.d("Network", "Network");
if (locationManager != null) {
lastknownlocations = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (lastknownlocations != null) {
lat = lastknownlocations.getLatitude();
lng = lastknownlocations.getLongitude();
}
}
}
if (lat == 0.0 && lng == 0.0) {
lng = lastknownlocations.getLongitude();
lat = lastknownlocations.getLatitude();
}
getAddressFromLatLong(lat, lng);
}
} catch (Exception e) {
e.printStackTrace();
}
}
Try out with this service class. This sends updates to method sendLocationDataToProcess(Location location) whenever there is a different of 10 meters with respect to last location
public class AppLocationService extends Service implements GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener,
LocationListener{
private LocationRequest locationRequest;
private GoogleApiClient googleApiClient;
private Context appContext;
private boolean currentlyProcessingLocation = false;
private int mInterval=0;
private final int CONNTIMEOUT=50000;
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
appContext=getApplicationContext();
Toast.makeText(getBaseContext(), "Location Service Started", Toast.LENGTH_SHORT)
.show();
if (!currentlyProcessingLocation) {
currentlyProcessingLocation = true;
startTracking();
}
return START_STICKY;
}
private void startTracking() {
if (GooglePlayServicesUtil.isGooglePlayServicesAvailable(this) == ConnectionResult.SUCCESS) {
Log.v(Constants.BLL_LOG, "ConnectionResult SUCCESS");
googleApiClient = new GoogleApiClient.Builder(this)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
if (!googleApiClient.isConnected() || !googleApiClient.isConnecting()) {
googleApiClient.connect();
}else{
Log.v(Constants.BLL_LOG, "NOT connected googleApiClient.connect()");
}
} else {
Log.v(Constants.BLL_LOG, "unable to connect to google play services.");
}
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
public AppLocationService() {
}
#Override
public void onConnected(Bundle bundle) {
Log.v(Constants.BLL_LOG,"onConnected");
locationRequest = LocationRequest.create();
locationRequest.setInterval(mInterval * 1000); // milliseconds
locationRequest.setFastestInterval(mInterval * 1000);
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
locationRequest.setSmallestDisplacement(MIN_DISTANCE_CHANGE_FOR_UPDATES);//dostance change
int permissionCheck = ContextCompat.checkSelfPermission(appContext, Manifest.permission.ACCESS_COARSE_LOCATION);
if (permissionCheck!= PackageManager.PERMISSION_DENIED)
LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient, locationRequest, this);
}
#Override
public void onConnectionSuspended(int i) {
Log.v(Constants.BLL_LOG,"onConnectionSuspended");
}
#Override
public void onLocationChanged(Location location) {
Log.v(Constants.BLL_LOG, "onLocationChanged position: " + location.getLatitude() + ", " + location.getLongitude() + " accuracy: " + location.getAccuracy());
Log.v(Constants.BLL_LOG, "onLocationChanged position: location.getAccuracy()= "+location.getAccuracy());
sendLocationDataToProcess(location);
}
#Override
public void onConnectionFailed(ConnectionResult connectionResult) {
Log.v(Constants.BLL_LOG,"onConnectionFailed");
}
void sendLocationDataToProcess(Location location){
//Do your logic with Location data
}
#Override
public void onDestroy() {
super.onDestroy();
if (googleApiClient != null && googleApiClient.isConnected()) {
googleApiClient.disconnect();
}
}
}

Not getting current location properly

I am new to android. I am developing an application which displays users current latitude and longitude even without using internet.
It works fine but the latitude and longitude changes everytime i refersh or start the app again... Please help me.. Why is it so?/
This is my GPSTracker class
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 5 minutes
// Declaring a Location Manager
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
} else {
this.canGetLocation = true;
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS() {
if (locationManager != null) {
// if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// public void requestPermissions(#NonNull String[] permissions, int requestCode)
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for Activity#requestPermissions for more details.
return;
}
locationManager.removeUpdates(GPSTracker.this);
// }
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
#Override
public void onLocationChanged(Location location) {
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}
and in MainActivity
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.app_bar);
toolbar.setTitle("PWD_GPSFinder");
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
lat1 = (TextView) findViewById(R.id.latitude);
long1 = (TextView) findViewById(R.id.longitude);
exit = (Button) findViewById(R.id.button);
exit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
finish();
}
});
refresh = (Button) findViewById(R.id.buttonRefresh);
refresh.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
gps = new GPSTracker(MainActivity.this);
// check if GPS enabled
if(gps.canGetLocation()){
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
lat1.setText(""+latitude);
long1.setText(""+longitude);
}else{
// can't get location
// GPS or Network is not enabled
// Ask user to enable GPS/network in settings
gps.showSettingsAlert();
}
}
});
gps = new GPSTracker(MainActivity.this);
// check if GPS enabled
if(gps.canGetLocation()){
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
lat1.setText(""+latitude);
long1.setText(""+longitude);
// \n is for new line
//Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
}else{
// can't get location
// GPS or Network is not enabled
// Ask user to enable GPS/network in settings
gps.showSettingsAlert();
}
}
Have a look at http://developer.android.com/guide/topics/location/strategies.html ... it helped me understand geolocation states in Android recently.

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