MAPS and LOCATION SERVICE TUTORIAL

MAPS and LOCATION SERVICE TUTORIAL

Maps and Location tutorial

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MAPS and LOCATION SERVICE TUTORIAL

To implement Google Maps V2 The following are the steps to be followed.

1. Download and configure the Google Play services SDK, which includes the Google Maps Android API. If you use the Google Maps Mobile SDK for Businessyou must download and configure the Google Maps Mobile SDK for Business static library.
2. Obtain an API key. To do this, you will need to register a project in the Google APIs Console, and get a signing certificate for your app.
3. Add the required settings in your application's manifest.
4. Add a map to your application

Step 1:
a.Open Eclipse ⇒ Windows ⇒ Android SDK Manager and ensure you have already downloaded Google Play Services or not under Extras section. If not  installed then select google   play services and install the package.

b. Importing Google Play Services into Eclipse

After downloading play services we need to import it to Eclipse which will be used as a library for our maps project.In Eclipse navigate to  File ⇒ Import ⇒ Android ⇒ Existing Android Code Into Workspace

c. Click on Browse and select Google Play Services project from your android sdk folder. You can locate play services library project from android-sdk-windows\extras\google\ google_play_services\ libproject\google-play-services_lib.Select the checkbox .Copy projects into work space option as shown in the below image.

d.Ensure that the project is library project by checking is Library option is selected




Step 2:

Getting the Google Maps API key

a. Same as in maps v1 we need to generate SHA-1 fingerprint using java keytool. Open your terminal and execute the following command to generate SHA-1 fingerprint.

On Windows

keytool -list -v -keystore "%USERPROFILE%\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android




b. Similarly you can generate SH1 print through eclipse IDE as shown in figure below after selecting the debug store location


Step 3:

a.Now open Google API Console. Select Services on left side and turn on Google Maps Android API v2 If you haven't used the Google APIs Console before, you're prompted to create a project that you use to track your usage of the Google Maps Android API. Click Create Project; the Console creates a new project called API Project. On the next page, this name appears in the upper left hand corner. To rename or otherwise manage the project, click on its name.If you're already using the Google APIs Console, you will immediately see a list of your existing projects and the available services. It's still a good idea to use a new project for Google Maps Android API, so select the project name in the upper left hand corner and then click Create.

b.Navigate to your project in the Google APIs Console.
c.In the resulting page, click Create New Android Key....
d.In the resulting dialog, enter the SHA-1 fingerprint, then a semicolon, then your application's package name

.For example:BB:0D:AC:74:D3:21:E1:43:67:71:9B:62:91:AF:A1:66:6E:44:5D:75;com.example.android.mapexample

e.Click create button The Google APIs Console responds by displaying Key for Android apps (with certificates) followed by a forty-character API key, for example:AIzaSyBdVl-cTICSwYKrZ95SuvNw7dbMuDt1KG0

Step 4;Add the API key to your application

Follow the steps below to include the API key in your application's manifest, contained in the file AndroidManifest.xml. From there, the Maps API reads the key value and passes it to the Google Maps server, which then confirms that you have access to Google Maps data.

a.In AndroidManifest.xml, add the following element as a child of the <application> element, by inserting it just before the closing tag</application>:

<meta-data

    android:name="com.google.android.maps.v2.API_KEY"

    android:value="API_KEY"/>

Substitute your API key for API_KEY. This element sets the key com.google.android.maps.v2.API_KEY to the value API_KEY and makes the API key visible to any MapFragment in your application.

b.Save AndroidManifest.xml and re-build your application.

1.Create  Android project with details as listed in the table below.

Property name	Property value
Project name	SRM_MapTutorial
Package name	in.ac.srmuniv.maptutorial
Activity name	SRM_MapActivity
Layout xml name	activity_main

2. To use Google Play Services project as a library in our project SRM_MapTutorial, right click on project and select properties. In the properties window on left side select Android. On the right you can see Add button under library section. Click it and select google play services project which we imported previously.

Click add button then select google-play-services library and click apply and ok button.

2.Copy the code  to the file main.xml in res/layout folder

<RelativeLayout xmlns:tools="http://schemas.android.com/tools"

    xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".MainActivity" >

    <fragment

        android:id="@+id/map"

        android:name="com.google.android.gms.maps.MapFragment"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:layout_below="@+id/radioGroup1" />

    <RadioGroup

        android:id="@+id/radioGroup1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignLeft="@+id/fragment1"

        android:layout_alignParentTop="true"

        android:orientation="horizontal" >

        <RadioButton

            android:id="@+id/radio0"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:checked="true"

            android:text="Satellite" />

        <RadioButton

            android:id="@+id/radio1"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="Terrain" />

        <RadioButton

            android:id="@+id/radio2"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="Normal" />

        <RadioButton

            android:id="@+id/radio3"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:text="Hybrid" />

    </RadioGroup>

</RelativeLayout>

3.Copy the code in SRM_MapActivity.java. Activity.

package in.srmuniv.ac.in;

import in.srmuniv.ac.in.R;

importandroid.annotation.SuppressLint;

importandroid.app.Activity;

import android.content.Context;

importandroid.location.Criteria;

importandroid.location.Location;

importandroid.location.LocationListener;

importandroid.location.LocationManager;

import android.os.Bundle;

import android.view.View;

importandroid.widget.RadioGroup;

importandroid.widget.RadioGroup.OnCheckedChangeListener;

importcom.google.android.gms.maps.CameraUpdate;

importcom.google.android.gms.maps.CameraUpdateFactory;

importcom.google.android.gms.maps.GoogleMap;

importcom.google.android.gms.maps.MapFragment;

importcom.google.android.gms.maps.model.BitmapDescriptorFactory;

importcom.google.android.gms.maps.model.LatLng;

importcom.google.android.gms.maps.model.MarkerOptions;

public class SRM_MapActivity extends Activity implements LocationListener {

    GoogleMap map;

    MarkerOptions marker;

    @SuppressLint("NewApi")

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map))

                .getMap();

        // map.setMapType(GoogleMap.MAP_TYPE_HYBRID);

        // map.setMapType(GoogleMap.MAP_TYPE_NONE);

        // map.setMapType(GoogleMap.MAP_TYPE_NORMAL);

        map.setMapType(GoogleMap.MAP_TYPE_SATELLITE);

        // map.setMapType(GoogleMap.MAP_TYPE_TERRAIN);

        // Getting LocationManager object from System Service LOCATION_SERVICE

        // Showing / hiding your current location

        map.setMyLocationEnabled(true);

        // Enable / Disable zooming controls

        map.getUiSettings().setZoomControlsEnabled(true);

        // Enable / Disable my location button

        map.getUiSettings().setMyLocationButtonEnabled(true);

        // Enable / Disable Compass icon

        map.getUiSettings().setCompassEnabled(true);

        // Enable / Disable Rotate gesture

        map.getUiSettings().setRotateGesturesEnabled(true);

        // Enable / Disable zooming functionality

        map.getUiSettings().setZoomGesturesEnabled(true);

        marker=new MarkerOptions();

        marker.icon(BitmapDescriptorFactory

                .defaultMarker(BitmapDescriptorFactory.HUE_AZURE));

        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);

        RadioGroup radioGroup = (RadioGroup) findViewById(R.id.radioGroup1);

        radioGroup.setOnCheckedChangeListener(newOnCheckedChangeListener() {

            @Override

            public voidonCheckedChanged(RadioGroup group, int checkedId) {

                switch (checkedId) {

                case R.id.radio0:

                    map.setMapType(GoogleMap.MAP_TYPE_SATELLITE);

                    break;

                case R.id.radio1:

                    map.setMapType(GoogleMap.MAP_TYPE_TERRAIN);

                    break;

                case R.id.radio2:

                    map.setMapType(GoogleMap.MAP_TYPE_NORMAL);

                    break;

                case R.id.radio3:

                    map.setMapType(GoogleMap.MAP_TYPE_HYBRID);

                    break;

                }

            }

        });

    }

    @Override

    public voidonLocationChanged(Location location) {

        // Getting latitude

        double latitude = location.getLatitude();

        // Getting longitude

        double longitude = location.getLongitude();

        final LatLng LOCATION = new LatLng(latitude, longitude);

        CameraUpdate update = CameraUpdateFactory.newLatLngZoom(LOCATION, 16);

        map.animateCamera(update);

        marker.position(LOCATION).title("I am K.Nawin Find me here!");

        map.addMarker(marker);

    }

    @Override

    public voidonProviderDisabled(String provider) {

        // TODO Auto-generated method stub

    }

    @Override

    public voidonProviderEnabled(String provider) {

        // TODO Auto-generated method stub

    }

    @Override

    public voidonStatusChanged(String provider, int status, Bundle extras) {

        // TODO Auto-generated method stub

    }

}

4. Modify Androidmanifest.xml as shown below

<?xml version="1.0"encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="in.srmuniv.ac.in"

    android:versionCode="1"

    android:versionName="1.0" >

    <uses-sdk

        android:minSdkVersion="8"

        android:targetSdkVersion="17" />

    <uses-feature

        android:glEsVersion="0x00020000"

        android:required="true" />

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

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

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

    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>

    <!--

     The following two permissions are not required to use

     Google Maps Android API v2, but are recommended.

    -->

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

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

    <permission

        android:name="in.srmuniv.ac.in.permission.MAPS_RECEIVE"

        android:protectionLevel="signature" />

    <uses-permission android:name="in.srmuniv.ac.in.permission.MAPS_RECEIVE"/>

    <application

        android:allowBackup="true"

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <activity

            android:name="in.srmuniv.ac.in.SRM_MapActivity"

            android:label="@string/app_name" >

            <intent-filter>

                <action android:name="android.intent.action.MAIN"/>

                <category android:name="android.intent.category.LAUNCHER"/>

            </intent-filter>

        </activity>

        <meta-data

            android:name="com.google.android.maps.v2.API_KEY"

            android:value="AIzaSyCMUyepRQ2vawvkOgpC_TNhyWNMguFH-o8"/>

    </application>

</manifest>

5.Run the application in the emulator/device. 

Figure1  Shows Hybrid Map View

Figure2 Shows Normal Map View

Figure3  Shows Terrain Map View

Figure4  Shows Satellite Map View

CODE EXPLANATION:

Most Android devices allow to determine the current geolocation. This can be done via a GPS (Global Positioning System) module, via cell tower triangulation or via wifi networks.

Android contains the android.location package which provides the API to determine the current geo position.

 LocationManager

The LocationManager class provides access to the Android location service. This services allows to access location providers, to register location update listeners and proximity alerts and more.

 LocationProvider

The LocationProvider class is the superclass of the different location providers which deliver the information about the current location. This information is stored in the Location class.

The Android device might have several LocationProvider available and you can select which one you want to use. In most cases you have the followng LocationProvider available.

Table 1. LocationProvider

LocationProvider	Description
network	Uses the mobile network or WI-Fi to determine the best location. Might have a higher precision in closed rooms then GPS.
gps	Use the GPS receiver in the Android device to determine the best location via satellites. Usually better precision than network.
passive	Allows to participate in location of updates of other components to save energy

AndroidManifest.xml needs the following permissions and features for Google maps 

ACCESS_NETWORK_STATE – To check network state whether data can be downloaded or not
INTERNET – To check internet connection status
WRITE_EXTERNAL_STORAGE – To write to external storage as google maps store map data in external storage
ACCESS_COARSE_LOCATION – To determine user’s location using WiFi and mobile cell data
ACCESS_FINE_LOCATION – To determine user’s location using GPS
OpenGL ES V2 – Required for Google Maps V2

READ_GSERVICES- To get geo location services

 AndroidManifest.xml Replace the package name with your project package

Google provides 4 kinds of map types Normal, Hybrid, Satellite and Terrain. You can toggle to any kind of map using googleMap.setMapType() method.

map.setMapType(GoogleMap.MAP_TYPE_NORMAL);

map.setMapType(GoogleMap.MAP_TYPE_HYBRID);

map.setMapType(GoogleMap.MAP_TYPE_SATELLITE);

map.setMapType(GoogleMap.MAP_TYPE_TERRAIN);

map.setMapType(GoogleMap.MAP_TYPE_NONE);

Showing Current Location

You can show user’s current location on the map by calling setMyLocationEnabled(). Pass true / false to enable or disable this feature

googleMap.setMyLocationEnabled(true); // false to disable

Zooming Buttons

You can call setZoomControlsEnabled() function to get rid of those zooming

controls on the map. By disabling these buttons map zooming functionality still work by pinching gesture.

googleMap.getUiSettings().setZoomControlsEnabled(false); //true to enable

Zooming Functionality

You can disable zooming gesture functionality by calling setZoomGesturesEnabled()

googleMap.getUiSettings().setZoomGesturesEnabled(false);
Compass Functionality

Compass can be disabled by calling setCompassEnabled() function

googleMap.getUiSettings().setCompassEnabled(true);
My Location Button

My location button will be used to move map to your current location. This button can be shown / hidden by calling setMyLocationButtonEnabled() function

googleMap.getUiSettings().setMyLocationButtonEnabled(true);
Map Rotate Gesture
My rotate gesture can be enabled or disabled

by calling setRotateGesturesEnabled() method
googleMap.getUiSettings().setRotateGesturesEnabled(true);