Android™ Application Development - Bahar Ali Khan

Chapter 7: Maps, Geocoding, and Location-Based Services
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long expiration = -1; // do not expire
Intent intent = new Intent(TREASURE_PROXIMITY_ALERT);
PendingIntent proximityIntent = PendingIntent.getBroadcast(this, -1,
intent,
0);
locationManager.addProximityAlert(lat, lng, radius, expiration,
proximityIntent);}
When the Location Manager detects that you have moved either within or beyond the specifi ed radius, the
packaged Intent will be fi red with an extra keyed as LocationManager.KEY_PROXIMITY_ENTERING
set to true or false accordingly.
To handle proximity alerts, you need to create a BroadcastReceiver, such as the one shown in the
following snippet:
public class ProximityIntentReceiver extends BroadcastReceiver {
}
@Override
public void onReceive (Context context, Intent intent) {
String key = LocationManager.KEY_PROXIMITY_ENTERING;
}
Boolean entering = intent.getBooleanExtra(key, false);
[ ... perform proximity alert actions ... ]
To start listening for them, register your receiver, as shown in the snippet below:
IntentFilter filter = new IntentFilter(TREASURE_PROXIMITY_ALERT);
registerReceiver(new ProximityIntentReceiver(), filter);
Using the Geocoder
Geocoding lets you translate between street addresses and longitude/latitude map coordinates. This
can give you a recognizable context for the locations and coordinates used in location-based services
and map-based Activities.
The Geocoder class provides access to two geocoding functions:
❑ Forward Geocoding Finds the latitude and longitude of an address.
❑ Reverse Geocoding Finds the street address for a given latitude and longitude.
The results from these calls will be contextualized using a locale, where a locale is used to defi ne your
usual location and language. The following snippet shows how you set the locale when creating your
Geocoder. If you don’t specify a locale, it will assume your device’s default.
Geocoder geocoder = new Geocoder(getApplicationContext(),
Locale.getDefault());