Adding and removing Proximity Alert in Google Map Android API V2 using LocationManager

Proximity alert is an alert which is triggered by Android LocationManager when the device enters a region specified by its center coordinate (latitude, longitude) and radius.

In this article, we will develop an Android application which demonstrates how to add and remove a proximity alert in Google Map Android API V2. The center of the region is specified by clicking (tap) a location in the Google Map. The radius of the region is hard-coded as 20 meters.

On clicking a location in the Google Map, proximity alert is added and on long clicking on the Google Map, the proximity alert is removed.

An extension to this application is available in the article titled “Adding and removing multiple proximity alerts in Google Maps Android API V2“, where, as the title of the article indicates, multiple proximity alerts can be defined in Google Maps Android API V2.

This application is developed in Eclipse (4.2.1) with ADT plugin (21.1.0) and Android SDK (21.1.0) and tested in a real Android device (Android 2.3.6  -  GingerBread).

1. Create a new Android application project namely “ProximityMapV2″

Figure 1 : New Android application project namely "ProximityMapV2"

2. Configure the project

Figure 2 : Configure the application project

3. Design application launcher icon

Figure 3 : Design application launcher icon

4. Create a blank activity

Figure 4 : Create a blank activity

5. Enter MainActivity details

Figure 5 : Enter MainActivity details

6. Download and configure Google Play Services Library in Eclipse

Google Map for Android is now integrated with Google Play Services. So we need to set up Google Play Service Library for developing Google Map application in Android.

Please follow the given below link to setup Google Play Service library in Eclipse.

http://developer.android.com/google/play-services/setup.html

7. Add Google Play Services Library to this project

Figure 6 : Link Google Play Services Library to this project

8. Get the API key for Google Maps Android API V2

We need to get an API key from Google to use Google Maps in Android application.

Please follow the given below link to get the API key for Google Maps Android API v2.

https://developers.google.com/maps/documentation/android/start

9. Add Android Support library to this project

By default, Android support library (android-support-v4.jar ) is added to this project by Eclipse IDE to the directory libs. If it is not added, we can do it manually by doing the following steps :

• Open Project Explorer by Clicking “Window -> Show View -> Project Explorer”
• Right click this project
• Then from popup menu, Click “Android Tools -> Add Support Library “

10. Update the layout 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"
    tools:context=".MainActivity" >

    <fragment
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

11. Create a layout file res/layout/notification.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/tv_notification"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

12. Create the class “NotificationView” in the file src/in/wptrafficanalyzer/proximitymapv2/NotificationView.java

package in.wptrafficanalyzer.proximitymapv2;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class NotificationView extends Activity {
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.notification);

        TextView tv = (TextView) findViewById(R.id.tv_notification);
        Bundle data = getIntent().getExtras();
        tv.setText(data.getString("content"));
    }
}

13. Create the class “ProximityActivity” in the file src/in/wptrafficanalyzer/proximitymapv2/ProximityActivity.java

package in.wptrafficanalyzer.proximitymapv2;

import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.location.LocationManager;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.NotificationCompat;
import android.widget.Toast;

public class ProximityActivity extends Activity {

    String notificationTitle;
    String notificationContent;
    String tickerMessage;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        boolean proximity_entering = getIntent().getBooleanExtra(LocationManager.KEY_PROXIMITY_ENTERING, true);

        if(proximity_entering){
            Toast.makeText(getBaseContext(),"Entering the region"  ,Toast.LENGTH_LONG).show();
            notificationTitle="Proximity - Entry";
            notificationContent="Entered the region";
            tickerMessage = "Entered the region";
        }else{
            Toast.makeText(getBaseContext(),"Exiting the region"  ,Toast.LENGTH_LONG).show();
            notificationTitle="Proximity - Exit";
            notificationContent="Exited the region";
            tickerMessage = "Exited the region";
        }

        Intent notificationIntent = new Intent(getApplicationContext(),NotificationView.class);
        notificationIntent.putExtra("content", notificationContent );

        /** This is needed to make this intent different from its previous intents */
        notificationIntent.setData(Uri.parse("tel:/"+ (int)System.currentTimeMillis()));

        /** Creating different tasks for each notification. See the flag Intent.FLAG_ACTIVITY_NEW_TASK */
        PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(), 0, notificationIntent, Intent.FLAG_ACTIVITY_NEW_TASK);

        /** Getting the System service NotificationManager */
        NotificationManager nManager = (NotificationManager) getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);

        /** Configuring notification builder to create a notification */
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(getApplicationContext())
                .setWhen(System.currentTimeMillis())
                .setContentText(notificationContent)
                .setContentTitle(notificationTitle)
                .setSmallIcon(R.drawable.ic_launcher)
                .setAutoCancel(true)
                .setTicker(tickerMessage)
                .setContentIntent(pendingIntent);

        /** Creating a notification from the notification builder */
        Notification notification = notificationBuilder.build();

        /** Sending the notification to system.
        * The first argument ensures that each notification is having a unique id
        * If two notifications share same notification id, then the last notification replaces the first notification
        * */
        nManager.notify((int)System.currentTimeMillis(), notification);

        /** Finishes the execution of this activity */
        finish();
    }
}

14. Update the class “MainActivity” in the file src/in/wptrafficanalyzer/proximitymapv2/MainActivity.java

package in.wptrafficanalyzer.proximitymapv2;

import android.app.Dialog;
import android.app.PendingIntent;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Color;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMapClickListener;
import com.google.android.gms.maps.GoogleMap.OnMapLongClickListener;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.CircleOptions;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

public class MainActivity extends FragmentActivity {

    GoogleMap googleMap;
    LocationManager locationManager;
    PendingIntent pendingIntent;
    SharedPreferences sharedPreferences;

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

        // Getting Google Play availability status
        int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getBaseContext());

        // Showing status
        if(status!=ConnectionResult.SUCCESS){ // Google Play Services are not available

            int requestCode = 10;
            Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, this, requestCode);
            dialog.show();

        }else { // Google Play Services are available

            // Getting reference to the SupportMapFragment of activity_main.xml
            SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);

            // Getting GoogleMap object from the fragment
            googleMap = fm.getMap();

            // Enabling MyLocation Layer of Google Map
            googleMap.setMyLocationEnabled(true);

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

            // Opening the sharedPreferences object
            sharedPreferences = getSharedPreferences("location", 0);

            // Getting stored latitude if exists else return 0
            String lat = sharedPreferences.getString("lat", "0");

            // Getting stored longitude if exists else return 0
            String lng = sharedPreferences.getString("lng", "0");

            // Getting stored zoom level if exists else return 0
            String zoom = sharedPreferences.getString("zoom", "0");

            // If coordinates are stored earlier
            if(!lat.equals("0")){

                // Drawing circle on the map
                drawCircle(new LatLng(Double.parseDouble(lat), Double.parseDouble(lng)));

                // Drawing marker on the map
                drawMarker(new LatLng(Double.parseDouble(lat), Double.parseDouble(lng)));

                // Moving CameraPosition to previously clicked position
                googleMap.moveCamera(CameraUpdateFactory.newLatLng(new LatLng(Double.parseDouble(lat), Double.parseDouble(lng))));

                // Setting the zoom level in the map
                googleMap.animateCamera(CameraUpdateFactory.zoomTo(Float.parseFloat(zoom)));

            }

            googleMap.setOnMapClickListener(new OnMapClickListener() {

                @Override
                public void onMapClick(LatLng point) {

                    // Removes the existing marker from the Google Map
                    googleMap.clear();

                    // Drawing marker on the map
                    drawMarker(point);

                    // Drawing circle on the map
                    drawCircle(point);

                    // This intent will call the activity ProximityActivity
                    Intent proximityIntent = new Intent("in.wptrafficanalyzer.activity.proximity");

                    // Creating a pending intent which will be invoked by LocationManager when the specified region is
                    // entered or exited
                    pendingIntent = PendingIntent.getActivity(getBaseContext(), 0, proximityIntent,Intent.FLAG_ACTIVITY_NEW_TASK);

                    // Setting proximity alert
                    // The pending intent will be invoked when the device enters or exits the region 20 meters
                    // away from the marked point
                    // The -1 indicates that, the monitor will not be expired
                    locationManager.addProximityAlert(point.latitude, point.longitude, 20, -1, pendingIntent);

                    /** Opening the editor object to write data to sharedPreferences */
                    SharedPreferences.Editor editor = sharedPreferences.edit();

                    /** Storing the latitude of the current location to the shared preferences */
                    editor.putString("lat", Double.toString(point.latitude));

                    /** Storing the longitude of the current location to the shared preferences */
                    editor.putString("lng", Double.toString(point.longitude));

                    /** Storing the zoom level to the shared preferences */
                    editor.putString("zoom", Float.toString(googleMap.getCameraPosition().zoom));

                    /** Saving the values stored in the shared preferences */
                    editor.commit();

                    Toast.makeText(getBaseContext(), "Proximity Alert is added", Toast.LENGTH_SHORT).show();

                }
            });

            googleMap.setOnMapLongClickListener(new OnMapLongClickListener() {
                @Override
                public void onMapLongClick(LatLng point) {
                    Intent proximityIntent = new Intent("in.wptrafficanalyzer.activity.proximity");

                    pendingIntent = PendingIntent.getActivity(getBaseContext(), 0, proximityIntent,Intent.FLAG_ACTIVITY_NEW_TASK);

                    // Removing the proximity alert
                    locationManager.removeProximityAlert(pendingIntent);

                    // Removing the marker and circle from the Google Map
                    googleMap.clear();

                    // Opening the editor object to delete data from sharedPreferences
                    SharedPreferences.Editor editor = sharedPreferences.edit();

                    // Clearing the editor
                    editor.clear();

                    // Committing the changes
                    editor.commit();

                    Toast.makeText(getBaseContext(), "Proximity Alert is removed", Toast.LENGTH_LONG).show();
                }
            });
        }
    }

    private void drawMarker(LatLng point){
        // Creating an instance of MarkerOptions
        MarkerOptions markerOptions = new MarkerOptions();

        // Setting latitude and longitude for the marker
        markerOptions.position(point);

        // Adding marker on the Google Map
        googleMap.addMarker(markerOptions);
    }

    private void drawCircle(LatLng point){

        // Instantiating CircleOptions to draw a circle around the marker
        CircleOptions circleOptions = new CircleOptions();

        // Specifying the center of the circle
        circleOptions.center(point);

        // Radius of the circle
        circleOptions.radius(20);

        // Border color of the circle
        circleOptions.strokeColor(Color.BLACK);

        // Fill color of the circle
        circleOptions.fillColor(0x30ff0000);

        // Border width of the circle
        circleOptions.strokeWidth(2);

        // Adding the circle to the GoogleMap
        googleMap.addCircle(circleOptions);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

15. Update the file AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="in.wptrafficanalyzer.proximitymapv2"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <permission
        android:name="in.wptrafficanalyzer.proximitymapv2.permission.MAPS_RECEIVE"
        android:protectionLevel="signature"/>

    <uses-permission android:name="in.wptrafficanalyzer.proximitymapv2.permission.MAPS_RECEIVE"/>

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

    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="in.wptrafficanalyzer.proximitymapv2.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity
            android:name=".ProximityActivity"
            android:label="@string/app_name" >
            <intent-filter >
                <action android:name="in.wptrafficanalyzer.activity.proximity"/>
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>

        <activity
            android:name=".NotificationView"
            android:label="@string/app_name" >
            <intent-filter >
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>

        <meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="YOUR_ANDROID_API_KEY"/>
    </application>

</manifest>

Note : Replace “YOUR_ANDROID_API_KEY” at line 60 with the API Key obtained in Step 8.

16. Screenshot of the application

Figure 7 : Proximity Alerts in Notification List

Figure 8 : Entering into the Proximity region

Figure 9 : Proximity Alert is removed

17. Download the source code

Adding and removing Proximity Alert in Google Map Android API V2 using LocationManager - R1 362.20 KB

Download Full Source Code

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: Circle, CircleOptions, Google Map, Google Map Android API V2, location, LocationManager, LOCATION_SERVICE, map, marker, MarkerOptions, ProximityAlert, shared preferences, SupportMapFragment