Detecting GPS on/off switch in Android phones

As I have found out the best way to do this is to attach to the

<action android:name="android.location.PROVIDERS_CHANGED" />

intent.

For instance:

<receiver android:name=".gps.GpsLocationReceiver">
        <intent-filter>
            <action android:name="android.location.PROVIDERS_CHANGED" />
            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </receiver>

And then in the code:

public class GpsLocationReceiver extends BroadcastReceiver implements LocationListener 
...

@Override
public void onReceive(Context context, Intent intent)
{
        if (intent.getAction().matches("android.location.PROVIDERS_CHANGED"))
        { 
            // react on GPS provider change action 
        }
}

Here is a code sample for a BroadcastReceiver detecting GPS location ON/OFF events:

private BroadcastReceiver locationSwitchStateReceiver = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {

            if (LocationManager.PROVIDERS_CHANGED_ACTION.equals(intent.getAction())) {

                LocationManager locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
                boolean isGpsEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
                boolean isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

                if (isGpsEnabled || isNetworkEnabled) {
                    //location is enabled
                } else {
                    //location is disabled
                }
            }
        }
    };

Instead of changing your manifest file, you can register your BroadcastReceiver dynamically:

IntentFilter filter = new IntentFilter(LocationManager.PROVIDERS_CHANGED_ACTION);
filter.addAction(Intent.ACTION_PROVIDER_CHANGED);
mActivity.registerReceiver(locationSwitchStateReceiver, filter);

Don't forget to unregister the receiver in your onPause() method:

mActivity.unregisterReceiver(locationSwitchStateReceiver);