Is there a way to access the GPS once instead of having a looper that constantly checks for location updates?
In my scenario all I'm interested in is finding the current co-ordinates and not a continuous connection with the GPS satellite. Does anyone have any ideas how this can be done? Thanks in advance.
Dont use the getLastKnownLocation because that could be returning null or old data.
This code Only fetches the location once a button is pressed and not every time. People use to leave the location listener listen in every instance and that kills the battery life so Use the code snippet I have posted by doing lots of research:
// get the text view and buttons from the xml layout
Button button = (Button) findViewById(R.id.btnGetLocation);
final TextView latitude = (TextView) findViewById(R.id.textview4);
final TextView longitude = (TextView) findViewById(R.id.textview5);
final LocationListener locationListener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
mlocation = location;
Log.d("Location Changes", location.toString());
latitude.setText(String.valueOf(location.getLatitude()));
longitude.setText(String.valueOf(location.getLongitude()));
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Log.d("Status Changed", String.valueOf(status));
}
#Override
public void onProviderEnabled(String provider) {
Log.d("Provider Enabled", provider);
}
#Override
public void onProviderDisabled(String provider) {
Log.d("Provider Disabled", provider);
}
};
// Now first make a criteria with your requirements
// this is done to save the battery life of the device
// there are various other other criteria you can search for..
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_COARSE);
criteria.setPowerRequirement(Criteria.POWER_LOW);
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setSpeedRequired(false);
criteria.setCostAllowed(true);
criteria.setHorizontalAccuracy(Criteria.ACCURACY_HIGH);
criteria.setVerticalAccuracy(Criteria.ACCURACY_HIGH);
// Now create a location manager
final LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
// This is the Best And IMPORTANT part
final Looper looper = null;
// Now whenever the button is clicked fetch the location one time
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
locationManager.requestSingleUpdate(criteria, locationListener, looper);
}
});
First check if the last know location is recent. If not, I believe you must to set up onLocationChanged listener, but once you get your first valid location you can always stop the stream of updates.
Addition
public class Example extends Activity implements LocationListener {
LocationManager mLocationManager;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Location location = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(location != null && location.getTime() > Calendar.getInstance().getTimeInMillis() - 2 * 60 * 1000) {
// Do something with the recent location fix
// otherwise wait for the update below
}
else {
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
}
}
public void onLocationChanged(Location location) {
if (location != null) {
Log.v("Location Changed", location.getLatitude() + " and " + location.getLongitude());
mLocationManager.removeUpdates(this);
}
}
// Required functions
public void onProviderDisabled(String arg0) {}
public void onProviderEnabled(String arg0) {}
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {}
}
Related
I have an activity which uses onLocationChanged method and upon performing a parse query it makes a toast. It works fine. However, when I go to another activity (it's a maps activity), if I change the coordinates (I'm using an emulator) the toast pops up. I would like to know why the onLocationChanged method is still running. I thought it may be due to context, but I specified the activity in the context field.
locationManager = (LocationManager) DriverChoicesActivity.this.getSystemService(Context.LOCATION_SERVICE);
locationListener = new LocationListener() {
#Override
public void onLocationChanged(final Location location) {
final ParseGeoPoint parseGeoPoint = new ParseGeoPoint(location.getLatitude(), location.getLongitude());
ParseQuery<ParseUser> query = ParseUser.getQuery();
query.whereEqualTo("username", ParseUser.getCurrentUser().getUsername());
query.findInBackground(new FindCallback<ParseUser>() {
#Override
public void done(List<ParseUser> objects, ParseException e) {
if (e == null && objects.size() > 0) {
for (ParseObject object : objects) {
object.put("driverLocation", parseGeoPoint);
object.saveInBackground();
Toast.makeText(DriverChoicesActivity.this, "User found", Toast.LENGTH_SHORT).show();
}
}
}
});
updateRequestList(location);
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}
};
All that is within onCreate of the original activity (DriverChoicesActivity.class). The other activity (DriverMapActivity.class) has no code in it apart from getting the intent from this activity to collect some latitude and longitude points. Here is the code which makes the intent (also within onCreate)
requestListView.setAdapter(arrayAdapter);
requestListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (requestLatitude.size() > position && requestLongitude.size() > position) {
if (Build.VERSION.SDK_INT < 23 || ContextCompat.checkSelfPermission(DriverChoicesActivity.this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
Location getLastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (getLastKnownLocation != null) {
Intent intent = new Intent(getApplicationContext(), DriverMapActivity.class);
intent.putExtra("requestLatitude", requestLatitude.get(position));
intent.putExtra("requestLongitude", requestLongitude.get(position));
intent.putExtra("driverLatitude", getLastKnownLocation.getLatitude());
intent.putExtra("driverLongitude", getLastKnownLocation.getLongitude());
startActivity(intent);
}
}
}
}
});
I assume my problem is with context somehow. If someone could be kind enough to explain.
Thank you
You must add:
locationManager.removeUpdates(listener);
Before move to next Activity.
and
LocationManager locationManager;
LocationListener locationListener;
on the top, under class declaraction
Hie,
I tried this sample code that one of the person who gave me this in my other question in stack overflow. I tried using this code but when i run the applicationn, it doesnt locate my current device and it doesnt even display a dot of my location .. The code does not give me any red underline errors but i am unable to locate the current location i am at.
What did i miss out? is there anyone who has a sample working source code file that i can download from to get my current device location??
the codes i used is as followed,
This is my MainActivity.class
public class MainActivity extends Activity {
MapView mMapView;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mMapView = (MapView) findViewById(R.id.mapview);
mMapView.addLayer(new ArcGISTiledMapServiceLayer(
"http://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer"));
mMapView = new MapView(this);
LocationResult locationResult = new LocationResult(){
#Override
public void gotLocation(Location loc){
}
};
MyLocation mylocation = new MyLocation();
mylocation.getLocation(this, locationResult);
}
This is MyLocation.java
public class MyLocation {
Timer timer1;
LocationManager lm;
LocationResult locationResult;
boolean gps_enabled=false;
boolean network_enabled=false;
public boolean getLocation(Context context, LocationResult result)
{
//I use LocationResult callback class to pass location value from MyLocation to user code.
locationResult=result;
if(lm==null)
lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
//exceptions will be thrown if provider is not permitted.
try{gps_enabled=lm.isProviderEnabled(LocationManager.GPS_PROVIDER);}catch(Exception ex){}
try{network_enabled=lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);}catch(Exception ex){}
//don't start listeners if no provider is enabled
if(!gps_enabled && !network_enabled)
return false;
if(gps_enabled)
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
if(network_enabled)
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
timer1=new Timer();
timer1.schedule(new GetLastLocation(), 20000);
return true;
}
LocationListener locationListenerGps = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerNetwork);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerGps);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
class GetLastLocation extends TimerTask {
#Override
public void run() {
lm.removeUpdates(locationListenerGps);
lm.removeUpdates(locationListenerNetwork);
Location net_loc=null, gps_loc=null;
if(gps_enabled)
gps_loc=lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(network_enabled)
net_loc=lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
//if there are both values use the latest one
if(gps_loc!=null && net_loc!=null){
if(gps_loc.getTime()>net_loc.getTime())
locationResult.gotLocation(gps_loc);
else
locationResult.gotLocation(net_loc);
return;
}
if(gps_loc!=null){
locationResult.gotLocation(gps_loc);
return;
}
if(net_loc!=null){
locationResult.gotLocation(net_loc);
return;
}
locationResult.gotLocation(null);
}
}
public static abstract class LocationResult{
public abstract void gotLocation(Location location);
}
}
You have to write the code for displaying a red dot in the gotLocation method which is currently empty. That is why you are not getting anything displayed on top of the map.
I am writting code for getting current location (latitude and longitude) of my phone. I display a toast whether Network Location service is provided by the phone or not. This toast doesn't show up ever. The other question is, for getting current location using Network_location, will the app use phone's gprs/internet or not?
I have created the instance of this class in the main activity and then get data using Latitude and Longitude variables of this class, in another class which extends broadcast reciever .
public class GpsClass extends Activity{
public static String Latitude="";
public static String Longitude="";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LocationManager manager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
LocationListener listener = new LocationListener() { // anonymous class
#Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String arg0) {
// TODO Auto-generated method stub
}
#Override
public void onProviderDisabled(String arg0) {
// TODO Auto-generated method stub
}
#Override
public void onLocationChanged(Location currentLocation) {
double lat= currentLocation.getLatitude();
Latitude = Double.toString(lat);
double longt= currentLocation.getLongitude();
Longitude = Double.toString(longt);
}
};
manager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, listener);
if(manager.isProviderEnabled(LocationManager.NETWORK_PROVIDER))
{
Toast.makeText(getApplicationContext(), "Network enabled", 0).show();
}
else
Toast.makeText(getApplicationContext(), "Network not enabled", 0).show();
}
}
Is there anything I am doing wrong?
Regards
I think the problem is that you are passing 0 for duration i.e. last parameter of makeText() method.
Try passing Toast.LENGTH_SHORT or Toast.LENGTH_LONG.
if(manager.isProviderEnabled(LocationManager.NETWORK_PROVIDER))
{
Toast.makeText(getApplicationContext(), "Network enabled", Toast.LENGTH_LONG).show();
}
else
Toast.makeText(getApplicationContext(), "Network not enabled", Toast.LENGTH_LONG).show();
This can help you to get answer to your first question.
The answer to your second question is - No, the app will not use phone's gprs/internet for getting location through network provider.
The problem is setting 0 for duration.
This is a sample example:
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationListener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
currentLocation = new GeoPoint(location.getLatitude(), location.getLongitude());
// Set Toast Here To Diplay location
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}
};
if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
//10000 means request update every 10 sec
//10 tell listener that if location change more than 10m then run locationChanged method
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10000, 10, locationListener);
} else {
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 10000, 10, locationListener);
}
I am new to android, and reverse-engineering my way into learning java.
Having got as far using the code below, i have a few problems needing to be resolved while customising it to suit my inentions.
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
/* Use the LocationManager class to obtain GPS locations */
LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
}
/* Class My Location Listener */
public class MyLocationListener implements LocationListener
{
#Override
public void onLocationChanged(Location loc)
{
loc.getLatitude();
loc.getLongitude();
String Text = “My current location is: “ +
“Latitud = “ + loc.getLatitude() +
“Longitud = “ + loc.getLongitude();
Toast.makeText( getApplicationContext(),
Text,
Toast.LENGTH_SHORT).show();
}
#Override
public void onProviderDisabled(String provider)
{
Toast.makeText( getApplicationContext(),
“Gps Disabled”,
Toast.LENGTH_SHORT ).show();
}
#Override
public void onProviderEnabled(String provider)
{
Toast.makeText( getApplicationContext(),
“Gps Enabled”,
Toast.LENGTH_SHORT).show();
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras)
{
The problem is my (android) home screen starts with a checkboxed page showing two choices (checboxes);
GPS On (Enabled)
GPS Off (Disabled)
Now, question is, i have no idea how to write the 'if else' statement/method which could which could help direct the 'On' scenario to the next stage of getting my location, and for directing the 'Off' scenario back to beginning (Home screen).
Where/how in the code do i declare/insert the checkbox code?
Any assistance welcome please.
Thanks
Basic checkbox check:
final CheckBox cbGPS = (CheckBox) findViewById(R.id.checkBox1);
cbGPS.setOnCheckedChangeListener(new OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
// TODO Auto-generated method stub
if (buttonView.isChecked()) {
// do this if checked
StartGPSMethod();
} else {
// if not checked do this
// do nothing or
EndGPSMethod();
}
}
});
My code is supposed to find out the users location and place a marker on the map upon entering the application. My location value always equals null, and never receives a value.
if (location != null) {
lat = (int) (location.getLatitude() * 1E6);
longi = (int) (location.getLongitude() * 1E6);
GeoPoint ourLocation = new GeoPoint(lat, longi);
OverlayItem overlayItem = new OverlayItem(ourLocation, "AYO",
"Whats good yo");
CustomPinpoint custom = new CustomPinpoint(d, CampusMap.this);
custom.insertPinpoint(overlayItem);
overlayList.add(custom);
} else {
Toast.makeText(CampusMap.this, "Couldn't get provider",
Toast.LENGTH_SHORT).show();
}
}
I've had a relatively similar issue with a GPS RPG I was working on and here are some things I noticed:
Firstly, it can take a while for your location to initially be found, which would cause that issue since you're only checking if the location is null.
You may also want to make sure the device's location services are actually enabled before doing anything:
private boolean doLocationsCheck(){
if(!checkLocationEnabled()){
final CharSequence[] items = {"Yes", "No"};
AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
builder.setCancelable(false);
builder.setTitle("Location must be enabled to play this game! Would you like to enable it now?");
builder.setItems(items, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int item) {
final int i = item;
runOnUiThread(new Runnable() {
public void run() {
if(i == 0){
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
quit();
}
else{
quit();
}
}
});
}
}).show();
AlertDialog alert = builder.create();
return false;
}
else {
return true;
}
}
private boolean checkLocationEnabled(){
LocationManager service = (LocationManager) getSystemService(LOCATION_SERVICE);
boolean enabled = service.isProviderEnabled(LocationManager.GPS_PROVIDER) || service.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
return enabled;
}
After I've made sure the providers are available I setup a connection like so:
private void setupLocation() {
LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(final Location location) {
runOnUiThread(new Runnable() {
public void run() {
mLocation = location;
//Log.d(TAG, "Latitude: " + location.getLatitude() + " - Longitude: " + location.getLongitude());
saveLocation();
}
});
}
public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
public void onProviderDisabled(String provider) {}
};
//Can set to GPS or network, whichever is available
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
}
The location is then set in a global variable whenever it's updated, and then saved to the preferences. This way, in the event that the providers are enabled, but are taking a while to retrieve the location, the user can still continue to use the application with their last known location that the app stored (does not apply to the first time the program is run).
I know I left out a lot there, but I figured it wasn't really necessary since it was either self-explanatory or already explained in a previous answer.
Cheers~
/*
* getting the best location using the location manager
* Constants.MINIMUM_TIME_BETWEEN_UPDATES = 1000 Constants.MINIMUM_TIME_BETWEEN_UPDATES = 1
*/
LocationManager mLocation;
private String mBestProvider;
// in your onCreate() do the following
mLocation = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
mBestProvider = mLocation.getBestProvider(criteria, false);
Location location = mLocation.getLastKnownLocation(mBestProvider);
mLocation.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
Constants.MINIMUM_TIME_BETWEEN_UPDATES,
Constants.MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
new LocationListenerManager()
);
// and use the following locationListener inner class
private class LocationListenerManager implements LocationListener {
public void onLocationChanged(Location location) {
String message = String.format(
"New Location \n Longitude: %1$s \n Latitude: %2$s",
location.getLongitude(), location.getLatitude()
);
latitude = location.getLatitude();
longitude = location.getLongitude();
Toast.makeText(MapViewActivity.this, message, Toast.LENGTH_LONG).show();
Log.v("poiint=====", ""+message);
}
public void onStatusChanged(String s, int i, Bundle b) {
Toast.makeText(MapViewActivity.this, "Provider status changed",
Toast.LENGTH_LONG).show();
}
public void onProviderDisabled(String s) {
Toast.makeText(MapViewActivity.this,
"Provider disabled by the user. GPS turned off",
Toast.LENGTH_LONG).show();
}
public void onProviderEnabled(String s) {
Toast.makeText(MapViewActivity.this,
"Provider enabled by the user. GPS turned on",
Toast.LENGTH_LONG).show();
}
}
You have to initialize the locationlistener in the onstartActivity before on create so that it location obtain the location value before onCreate.