Develop Reference

What do I see the GPS icon consistently?

I've written my custom location manager to check for an update in the user's location every 30 seconds. The code is working fine i.e. I'm receiving updates in user's location. But the problem is that the GPS icon is always visible on the status bar on top. I'm guessing that it should be visible only once in 30 seconds. Is this normal or I'm doing something wrong?
public volatile Double mLatitude = 0.0;
public volatile Double mLongitude = 0.0;
int minTime = 30000;
float minDistance = 0;
MyLocationListener myLocListener = new MyLocationListener();
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setCostAllowed(true);
criteria.setSpeedRequired(false);
String bestProvider = locationManager.getBestProvider(criteria, false);
locationManager.requestSingleUpdate(criteria, myLocListener, null);
locationManager.requestLocationUpdates(bestProvider, minTime, minDistance, myLocListener);
private class MyLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location loc)
{
if (loc != null) {
//Do something knowing the location changed by the distance you requested
mLatitude = loc.getLatitude();
mLongitude = loc.getLongitude();
Toast.makeText(mContext, "Location Changed! "+Double.toString(mLatitude)+" "+Double.toString(mLongitude), Toast.LENGTH_LONG).show();
}
}
#Override
public void onProviderDisabled(String arg0)
{
//Do something here if you would like to know when the provider is disabled by the user
Toast.makeText(mContext, "Provider Disabled! "+Double.toString(mLatitude)+" "+Double.toString(mLongitude), Toast.LENGTH_LONG).show();
}
#Override
public void onProviderEnabled(String arg0)
{
//Do something here if you would like to know when the provider is enabled by the user
Toast.makeText(mContext, "Provider Enabled! "+Double.toString(mLatitude)+" "+Double.toString(mLongitude), Toast.LENGTH_LONG).show();
}
#Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2)
{
//Do something here if you would like to know when the provider status changes
Toast.makeText(mContext, "Provider Status Changed! "+Double.toString(mLatitude)+" "+Double.toString(mLongitude), Toast.LENGTH_LONG).show();
}
}

As long as 1 or more apps have called requestLocationUpdates for the GPS provider, GPS will stay on. It doesn't turn off between requests. It can't- doing so would cause it to lose satellite lock, which would cause it to have to re-establish. That takes a lot more than 30 seconds sometimes. So GPS will stay on until you unregister for GPS events.

The question is old but still, it would be great to give a better answer.
You need to use a Handler which runs continuously on 5 minutes interval so, you get the location update only once and you release the GPS device, this way your app won't listen to the GPS updates but your handler know when it should be called again to listen the updates.
public static void getLocation(Context context) {
Handler locationHandler = new Handler();
locationHandler.post(new Runnable() {
#Override
public void run() {
LocationManager locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
locationManager.requestSingleUpdate(LocationManager.GPS_PROVIDER, new LocationListener() {
#Override
public void onLocationChanged(Location location) {
// Handle the location update
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}
}, null);
locationHandler.postDelayed(this, 1000 * 60 * 5);
}
});
}

Android how to turn off gps icon after press return back button to home screen ?

I have this problem, I using GPS from my app to get latitude and longitude,when I want to return to home Icon GPS always show from top of my Mobile device,how I can turn off it after return to home screen
my code.
public class doctorlocation extends Activity implements LocationListener {
protected LocationManager locationManager;
protected LocationListener locationListener;
protected Context context;
String lat;
String provider;
protected double latitude,longitude;
protected boolean gps_enabled,network_enabled;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.doctorlocation);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
}
#Override
public void onLocationChanged(Location location) {
//txtLat = (TextView) findViewById(R.id.textview1);
//txtLat.setText("Latitude:" + location.getLatitude() + ", Longitude:" + location.getLongitude());
String str = "Latitude: "+location.getLatitude()+" \nLongitude: "+location.getLongitude();
Toast.makeText(getBaseContext(), str, Toast.LENGTH_LONG).show();
latitude=location.getLatitude();
longitude=location.getLongitude();
}
#Override
public void onProviderDisabled(String provider) {
Log.d("Latitude","disable");
Toast.makeText(getBaseContext(), "Gps turned off ", Toast.LENGTH_LONG).show();
}
#Override
public void onProviderEnabled(String provider) {
Log.d("Latitude","enable");
Toast.makeText(getBaseContext(), "Gps turned on ", Toast.LENGTH_LONG).show();
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Log.d("Latitude","status");
}
}

Use this code on onPause() of that Activity.
#Override
protected void onPause() {
Log.i("onPause", "inside onPause");
super.onPause();
locationManager.removeUpdates(myLocationListener);//locationManager.removeUpdates(this) ;
locationManager = null;
}

Enabling and Disabling the GPS is in the hands of the user. You can show him a Dialog to inform him about disabling the GPS. Keep two buttons on the dialog in that case - one for "Settings" and another one for "ok" or "cancel".
public static void promptForGPS(
final Activity activity)
{
final AlertDialog.Builder builder =
new AlertDialog.Builder(activity);
final String action = Settings.ACTION_LOCATION_SOURCE_SETTINGS;
final String message = "Disable GPS....Message here"
+ " Click OK to go to"
+ " location services settings to let you do so.";
builder.setMessage(message)
.setPositiveButton("OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface d, int id) {
activity.startActivity(new Intent(action));
d.dismiss();
}
})
.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface d, int id) {
d.cancel();
}
});
builder.create().show();
}

The best I have found is
onResume()
{
// Request for GPS Location
//location.requestLocationUpdates()
}
and
onPause()
{
// Remove location
// location.removeUpdates()
}
By calls removeUpdates() method it will stop GPS whenever your Activity is not in forground. This way you can stop GPS as well as it will stop draining your battery.

You need to tell the LocationManager that you no longer need location updates when your App enters into background, by using
locationManager.removeUpdates(this);
in your onPause() method.
You should also move your call to
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
to onResume(); so that location updates will resume once you re-enter your App.

Wait for current location - GPS - Android Dev

I have to wait to get the current location, just like when you are in Google maps and it requests for your location. If it can't get any location inform the error and do nothing.
I read the answers here and in web but all say that I have to use getLastKnownLocation method, but I don't need this, I just need the current location. If not, I don't do anything.

Read this from yesterday: GPS Android - get positioning only once
But here is how you can get the current location:
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);
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
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
// if it is less than two minutes old,
// otherwise wait for the update below
}
}
public void onLocationChanged(Location location) {
if (location != null) {
Log.v("Location Changed", location.getLatitude() + " and " + location.getLongitude());
// You need to call this whenever you are done:
// mLocationManager.removeUpdates(this);
}
}
// Required functions
public void onProviderDisabled(String arg0) {}
public void onProviderEnabled(String arg0) {}
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {}
}

Stop LocationManager Updates

I'm trying to have GPS coordinates sent to a text message. This code works, but every time the GPS updates location, it tries to send a new text message. I can't figure out how to stop the location updates. This is what I have currently...I realize it may not be the most efficient way to do it.
Any help would be appreciated!
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
}
public void GPSDisable() {
LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener mlocListener = new MyLocationListener();
mlocManager.removeUpdates(mlocListener);
}
public class MyLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location loc) {
loc.getLatitude();
loc.getLongitude();
double latitude = loc.getLatitude();
double longitude = loc.getLongitude();
Intent smsIntent = new Intent(Intent.ACTION_VIEW);
smsIntent.setType("vnd.android-dir/mms-sms");
smsIntent.putExtra("address", "5555555555");
smsIntent.putExtra("sms_body", "Location:"+latitude+","+longitude);
GPSDisable();
startActivity(smsIntent);
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras)
{
}
#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 onLocationChanged(Location location) {
// TODO Auto-generated method stub
}
#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
}
}

I would set two global variables latitude and longitude.
This variables would be updated every onLocationChanged. You cannot change this comportament, but you can get out from there the sending of sms.
I would send the sms on a timer after 5 seconds let's say.
new java.util.Timer().schedule(
new java.util.TimerTask() {
#Override
public void run() {
Intent smsIntent = new Intent(Intent.ACTION_VIEW);
smsIntent.setType("vnd.android-dir/mms-sms");
smsIntent.putExtra("address", "5555555555");
smsIntent.putExtra("sms_body", "Location:"+latitude+","+longitude);
startActivity(smsIntent);
}
},
5000 );
And your onlocation changed could look like this
#Override
public void onLocationChanged(Location loc) {
loc.getLatitude();
loc.getLongitude();
latitude = loc.getLatitude();
longitude = loc.getLongitude();
}

First I would advise you to have a look at this article.
Having said this, generally you should "unsubscribe" from the location manager when you do not need any more updates. Typically, you subscribe for location updates in "onCreate" and unsubscribe in "onDestroy" when you need updates for as long as your Activity is 'alive'.
Even better is to subscribe/unsubscribe when your activity is getting visible or hidden respectively (via "onResume"/"onPause" respectively). Have a look here for details on the Activity's lifecycle.
Now, about your specific problem, it is not clear what is your desired behavior. Do you want to send an SMS message every time the location changes? Or only when some time passes?
Assuming what you need is to send SMS whenever your location changes but not too often, I would suggest the following:
1. Register for location updates in "onResume" and unregister in "onPause".
2. Maintain some local variables that tell you which was the last time you sent an SMS message and what were the coordinates in it. These variables should probably persist Activity lifecycle events (e.g. when the Activity is destroyed, you should "store" these values, and restore them when you recreate it).
3. Whenever there is a new location update, check if it is too soon or too close (compared to the previous SMS) and if not send another message, updating the variables.
Having said these, please note that this will work for as long as your Activity is visible. If you need a similar functionality that does not require you to keep the Activity visible, I would suggest you use a BroadcastReceiver.

How to get user's GPS coordinates by clicking a button

i want to make application like this :
User clicks the button
The application show the user's coordinates (Latitude and Longitude)
i'm following the steps here
// Acquire a reference to the system Location Manager
LocationManager locationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
// Define a listener that responds to location updates
LocationListener locationListener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
// Called when a new location is found by the network location provider.
double glat = location.getLatitude();
double glong = location.getLongitude();
Toast.makeText(getApplicationContext(), "Your position\n"+glat+"\n"+glong, Toast.LENGTH_LONG).show();
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
#Override
public void onProviderEnabled(String provider) {}
#Override
public void onProviderDisabled(String provider) {}
};
// Register the listener with the Location Manager to receive location updates
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
how to implement it to button click event?
if the user clicks the button, the toast appear showing the position :)
UPDATE
I implement it using startActivityForResult() but the result is empty or null
here's my code :
this is the code on the button that i want to click
btn_obj_useKor.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
Intent intent = new Intent(getApplicationContext(), MyLocationListener.class);
startActivityForResult(intent, 0);
}
});
and this is my MyLocationListener class :
public class MyLocationListener extends Activity{
Intent intent;
String output = "";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Intent intent = getIntent();
LocationManager locationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
LocationListener locationListener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
double glat = location.getLatitude();
double glong = location.getLongitude();
output = glat+","+glong;
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
#Override
public void onProviderEnabled(String provider) {}
#Override
public void onProviderDisabled(String provider) {}
};
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
intent.putExtra("returnedData", output);
setResult(RESULT_OK, intent);
finish();
}
}
When i click the button it showing WTF! that means the result is null or empty.
what's the problem and what should i do then?

It wont return a result immediately since it takes time for the GPS provider to start and find your location. This is why you listen for a callback event.
Currently your code is listening for the network location, which is not very accurate. Change the LocationManager to GPS_Provider (on your last line) to use GPS if it is enabled.

Responding to an onClick is a user event, the LocationListener onLocationChanged is also an event. If you trigger the user event before the LocationListener event, there will be no position available to display.
My suggestion is to call startActivityForResult on another activity in the button onClick handler, the 2nd activity has all the LocationManager & LocationListener code in it, in the onLocationChanged event handler you pass the position back to the 1st activity.