Showing current location in Google Maps with GPS and LocationManager in Android

In this article, we will create an Android application which will display latitude and longitude of the current location in a text view and corresponding location in the Google Map. The current location will be retrieved using GPS and LocationManager API of the Android.

This application is developed in Eclipse ( 4.2.0) with ADT plugin ( 20.0.3 ) and Android SDK ( R20.0.3 ).

Update : A upgraded version of this application ( using Google maps Android API V2 ) is discussed in the article titled “Showing current location in Google Maps using API V2 with SupportMapFragment” .

1. Create a new Android application project namely “LocationInGoogleMap”

Figure 1 : New Andriod Application Project

2. Design application launcher icon

Figure 2 : Design application launcher Icon

3. Create a blank activity to define the class MainActivity

Figure 3 : Create a blank activity

4. Enter MainActivity details

Figure 4 : Enter MainActivity Details

5. Delete Android’s backward compatibility support library from this project, if exists

By default Eclipse ( 4.2.0) adds Android Support Library to  Android application project. For this application, we don’t need to use this support library. So the library file libs/android-support-v4.jar may be removed manually via ProjectExplorer by simply right click on the file and then clicking the menu item “delete”.

6. Obtain Google’s Map Key

Google’s Map Key for the Android application will be available here.

The map key obtained has to be entered as the value of the attribute android:apiKey in the layout file res/layout/activity_main.

7. Create a new folder namely drawable under the folder “res”

8. Download the given below image file namely “cur_position.png” to the folder “res/drawable”

Google Map - Location Marker Image 0.88 KB

Download Location Marker Image

9. Update the file res/values/strings.xml

<resources>
    <string name="app_name">LocationInGoogleMap</string>
    <string name="hello_world">Hello world!</string>
    <string name="menu_settings">Settings</string>
    <string name="title_activity_main">Current Location in Google Map</string>
</resources>

10. Update the file res/layout/activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <TextView
        android:id="@+id/tv_location"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true" />

    <com.google.android.maps.MapView
        android:id="@+id/map_view"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:apiKey="0u7AJChI1NV8vCpj21C0Cq8YnNMrB6YMgigu0GA"
        android:clickable="true"
        android:layout_below="@id/tv_location" />

</RelativeLayout>

Note : Replace the value of android:apiKey with the Google Map Key obtained in Step 6

11. Create the class CurrentLocationOverlay in the file src/in/wptrafficanalyzer/locationingooglemap/CurrentLocationOverlay.java

package in.wptrafficanalyzer.locationingooglemap;

import java.util.ArrayList;

import android.graphics.drawable.Drawable;
import android.util.Log;

import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.OverlayItem;

public class CurrentLocationOverlay extends ItemizedOverlay<OverlayItem> {

    private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();

    public CurrentLocationOverlay(Drawable defaultMarker) {
        super(boundCenterBottom(defaultMarker));
    }

    // Executed, when populate() method is called
    @Override
    protected OverlayItem createItem(int arg0) {
        return mOverlays.get(arg0);
    }

    @Override
    public int size() {
        return mOverlays.size();
    }

    public void addOverlay(OverlayItem overlay){
        mOverlays.add(overlay);
        populate(); // Calls the method createItem()
    }

    @Override
    protected boolean onTap(int arg0) {
        Log.d("Tapped", mOverlays.get(arg0).getSnippet());
        return true;
    }
}

12. Update the class MainActivity in the file src/in/wptrafficanalyzer/locationingooglemap/MainActivity.java

package in.wptrafficanalyzer.locationingooglemap;

import java.util.List;

import android.graphics.drawable.Drawable;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.Menu;
import android.widget.TextView;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;

public class MainActivity extends MapActivity implements LocationListener {

    private MapView mapView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Getting reference to MapView
        mapView = (MapView) findViewById(R.id.map_view);

        // Setting Zoom Controls on MapView
        mapView.setBuiltInZoomControls(true);

        // Getting LocationManager object from System Service LOCATION_SERVICE
        LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

        // Creating a criteria object to retrieve provider
        Criteria criteria = new Criteria();

        // Getting the name of the best provider
        String provider = locationManager.getBestProvider(criteria, true);

        // Getting Current Location
        Location location = locationManager.getLastKnownLocation(provider);

        if(location!=null){
            onLocationChanged(location);
        }

        locationManager.requestLocationUpdates(provider, 20000, 0, this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    @Override
    protected boolean isRouteDisplayed() {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public void onLocationChanged(Location location) {
        TextView tvLocation = (TextView) findViewById(R.id.tv_location);

        // Getting latitude
        double latitude = location.getLatitude();

        // Getting longitude
        double longitude = location.getLongitude();

        // Setting latitude and longitude in the TextView tv_location
        tvLocation.setText("Latitude:" +  latitude  + ", Longitude:"+ longitude );

        // Creating an instance of GeoPoint corresponding to latitude and longitude
        GeoPoint point = new GeoPoint((int)(latitude * 1E6), (int)(longitude*1E6));

        // Getting MapController
        MapController mapController = mapView.getController();

        // Locating the Geographical point in the Map
        mapController.animateTo(point);

        // Applying a zoom
        mapController.setZoom(15);

        // Redraw the map
        mapView.invalidate();

        // Getting list of overlays available in the map
        List<Overlay> mapOverlays = mapView.getOverlays();

        // Creating a drawable object to represent the image of mark in the map
        Drawable drawable = this.getResources().getDrawable(R.drawable.cur_position);

        // Creating an instance of ItemizedOverlay to mark the current location in the map
        CurrentLocationOverlay currentLocationOverlay = new CurrentLocationOverlay(drawable);

        // Creating an item to represent a mark in the overlay
        OverlayItem currentLocation = new OverlayItem(point, "Current Location", "Latitude : " + latitude + ", Longitude:" + longitude);

        // Adding the mark to the overlay
        currentLocationOverlay.addOverlay(currentLocation);

        // Clear Existing overlays in the map
        mapOverlays.clear();

        // Adding new overlay to map overlay
        mapOverlays.add(currentLocationOverlay);

    }

    @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
    }
}

13. Update the file AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="in.wptrafficanalyzer.locationingooglemap"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="4"
        android:targetSdkVersion="15" />

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

        <uses-library android:name="com.google.android.maps" />

        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
        </activity>
    </application>
</manifest>

14. Enable GPS in the emulator or device from Settings

Figure 5 : Enabling GPS in Google APIs emulator for API Level 4

15. Set Latitude and Longitude of the location in Eclipse -> DDMS ( Perspective ) to run  this application in the emulator

Figure 6 : Setting Latitude and Longitude in Eclipse -> DDMS

16. Screenshot the application

Figure 7 : Screenshot of the application executed in Google APIs emulator for API Level 4

17. Download

Showing current location in Google Maps with GPS and LocationManager in Android 402.50 KB

Download Full Source Code

18. Reference

http://developer.android.com/guide/index.html

How to hire me?

I am George Mathew, working as software architect and Android app developer at wptrafficanalyzer.in

You can hire me on hourly basis or on project basis for Android applications development.

For hiring me, please mail your requirements to info@wptrafficanalyzer.in.

My other blogs
store4js.blogspot.com

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Tags: Google Map, gps, ItemizedOverlay, location, LocationManager, LOCATION_SERVICE, map, MapActivity, OverlayItem, System Service