Code to Access GPS in Android Phones

GET !!! SET !! GO..!!!!!!!!

Location Based Services (LBS) have become very popular in past few years after the advent of GPS enabled smartphone devices . In this post, we shall see how a LBS application for Android works.

Simply speaking map navigation is possible in  following ways:

1. Using the GPS device in built in mobile-    Easier and precise.
2. Using the ID of the Cell that the user is currently served by

How to code?
We can give dummy values as GPS co-ordiantes for a location(i.e., Longitude and Latitude) .Another way to emulate location is to including .gpx files. Although it is not very flexible , it can give better performance.

Pre-requisite

First include this code fragment in AndroidManifest.xml to access GPS:
 
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS"/>
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION"/>
<uses-permission android:name="android.permission.CONTROL_LOCATION_UPDATES"/>
<uses-permission android:name="android.permission.INTERNET"/>




Application Code


 import com.GPS_project.android.lbs.R;
import android.app.Activity;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class gps extends Activity {

private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 1; // in Meters
private static final long MINIMUM_TIME_BETWEEN_UPDATES = 1000; // in Milliseconds

protected LocationManager locationManager;

protected Button retrieveLocationButton;

@Override
public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);
setContentView(R.layout.main);

retrieveLocationButton = (Button)findViewById(R.id.retrieve_location_button);

locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
 locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MINIMUM_TIME_BETWEEN_UPDATES,
MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
new MyLocationListener()
);
retrieveLocationButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
showCurrentLocation();
}
});

}

protected void showCurrentLocation() {

Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

if (location != null) {
String message = String.format(
"Current Location \n Longitude: %1$s \n Latitude: %2$s",
location.getLongitude(), location.getLatitude());

Toast.makeText(gps.this, message,
Toast.LENGTH_LONG).show();
}
if (location == null)
{
Toast.makeText(gps.this, "No Location Available ", Toast.LENGTH_LONG).show();
}

}

private class MyLocationListener 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()
);
Toast.makeText(gps.this, message, Toast.LENGTH_LONG).show();
}

public void onStatusChanged(String s, int i, Bundle b) {
Toast.makeText(gps.this, "Provider status changed",
Toast.LENGTH_LONG).show();
}

public void onProviderDisabled(String s) {
Toast.makeText(gps.this,
"Provider disabled by the user. GPS turned off",
Toast.LENGTH_LONG).show();
}

public void onProviderEnabled(String s) {
Toast.makeText(gps.this,
"Provider enabled by the user. GPS turned on",
Toast.LENGTH_LONG).show();
}

}

}