Android Push Notifications using Parse.com

We use GCM in our apps to receive push notifications which is little tricky to implement. You can do the same using the free push service provided by Parse.com also. Compared to GCM, using parse is very simple. You can implement and test the push notifications in just 2 mins by following steps mentioned here. But this tutorial is aimed to customize the parse push service as much as possible.

In this tutorial we’ll learn how to customize the default push broadcast receiver, handling the json push messages, using the parse dashboard to send messages, customizing the push icons and lot more.

We’ll also build a simple app with a login and home screen. Login screen prompts users to enter their email address which will be used to send personalized messages individually. Home screen is to show the push messages in a list view. So let’s get started with basic parse setup.

1. Parse Applciation ID, Client Key & parse-x.x.x.jar

To integrate parse in your app, you need Application ID, Client Key and parse jar library. Follow the below steps to get your app keys.

1. Sign Up by entering the details required.

2. Create a new parse app.

3. Once the app is created, go to Settings of the app and grab the Application ID and Client Key.

4. Download latest version of parse-1.9.2.jar. This library contains necessary functions to interact with parse API.

Check out the below video demonstrating the parse setup.

2. Push Notification JSON

While we send push notification, we use json to interact with the android app. Below is the structure of the json which we use in this tutorial. This json structured varies from app to app depending upon the requirement.

is_background – flag decides whether to show the notification or not. This flag will be useful to do any background jobs on receiving push notification. When this flag is set to true, notification won’t to be shown to user.

{
    "data": {
        "message": "Hello! Welcome to parse notifications.",
        "title": "AndroidHive"
    },
    "is_background": false
}

3. Creating Android Project

1. In Android Studio, create a new project by navigating to File ⇒ New Project and fill all the required details.

2. Follow my material design tutorial to convert this app into material app. (But this step is optional)

3. In project’s app ⇒ libs folder, paste the Parse-1.9.2.jar file. You can find this jar file in the downloaded parse library that we have downloaded in above step.

4. Open build.gradle located under app folder and add below dependencies.

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile "com.android.support:appcompat-v7:22.1.1"

    compile 'com.parse.bolts:bolts-android:1.+'
    compile fileTree(dir: 'libs', include: 'Parse-*.jar')
}

5. Open strings.xml and add below string values.

<resources>
    <string name="app_name">Parse Push</string>

    <string name="action_settings">Settings</string>
    <string name="title_activity_login">LoginActivity</string>
    <string name="action_logout">Logout</string>
</resources>

6. Open colors.xml and add below color values. If you did’t find colors.xml, create a new file with the name.

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#218eed</color>
    <color name="colorPrimaryDark">#218eed</color>
    <color name="textColorPrimary">#FFFFFF</color>
    <color name="windowBackground">#FFFFFF</color>
    <color name="navigationBarColor">#000000</color>
    <color name="colorAccent">#8e8e8e</color>
</resources>

7. Under res ⇒ layout, create an xml named toolbar.xml. This adds an action bar to our app.

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:local="http://schemas.android.com/apk/res-auto"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/colorPrimary"
    android:minHeight="?attr/actionBarSize"
    local:popupTheme="@style/ThemeOverlay.AppCompat.Light"
    local:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />

8. Now quickly create 5 packages named activity, app, helper, model and receiver under your project. These packages will helps to you keep your project organized.

9. Under app package, create a class named AppConfig.java and add below configuration. Replace parse keys with your Parse Application Key and Client Id.

The channel name ‘AndroidHive‘ is the channel to which every user will be subscribed to. So that you can send a generic message all the users subscribed to that channel.

package info.androidhive.parsenotifications.app;

/**
 * Created by Ravi on 15/05/15.
 */
public class AppConfig {
    public static final String PARSE_CHANNEL = "AndroidHive";
    public static final String PARSE_APPLICATION_ID = "ZUSZNPfsop5GnsjZPc4ajRittIUj3ilvC8dPLbC0";
    public static final String PARSE_CLIENT_KEY = "3kCVPLxA09hFUCkWB9Hc5isS6lOb6iYtG2gIcf1k";
    public static final int NOTIFICATION_ID = 100;
}

10. Now we’ll quickly create three helper classes required for this project. Create a class named ParseUtils.java under helper package. This class contains utility methods to interact with parse API like initializing the parse, subscribing using email to send individual notifications.

package info.androidhive.parsenotifications.helper;

import android.app.Activity;
import android.content.Context;
import android.text.TextUtils;
import android.util.Log;
import android.widget.Toast;

import com.parse.Parse;
import com.parse.ParseException;
import com.parse.ParseInstallation;
import com.parse.ParsePush;
import com.parse.SaveCallback;

import info.androidhive.parsenotifications.app.AppConfig;

/**
 * Created by Ravi on 01/06/15.
 */
public class ParseUtils {

    private static String TAG = ParseUtils.class.getSimpleName();

    public static void verifyParseConfiguration(Context context) {
        if (TextUtils.isEmpty(AppConfig.PARSE_APPLICATION_ID) || TextUtils.isEmpty(AppConfig.PARSE_CLIENT_KEY)) {
            Toast.makeText(context, "Please configure your Parse Application ID and Client Key in AppConfig.java", Toast.LENGTH_LONG).show();
            ((Activity) context).finish();
        }
    }

    public static void registerParse(Context context) {
        // initializing parse library
        Parse.initialize(context, AppConfig.PARSE_APPLICATION_ID, AppConfig.PARSE_CLIENT_KEY);
        ParseInstallation.getCurrentInstallation().saveInBackground();

        ParsePush.subscribeInBackground(AppConfig.PARSE_CHANNEL, new SaveCallback() {
            @Override
            public void done(ParseException e) {
                Log.e(TAG, "Successfully subscribed to Parse!");
            }
        });
    }

    public static void subscribeWithEmail(String email) {
        ParseInstallation installation = ParseInstallation.getCurrentInstallation();

        installation.put("email", email);

        installation.saveInBackground();
    }
}

11. Create a class named NotificationUtils.java under helper package. This class contains below useful methods to handle the notifications.

> showNotificationMessage() – shows the notification in notification area by setting appropriate title, message, icon and intent.

> isAppIsInBackground() – checks whether your app is in background or foreground.

package info.androidhive.parsenotifications.helper;

import android.app.ActivityManager;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.graphics.BitmapFactory;
import android.media.RingtoneManager;
import android.os.Build;
import android.support.v4.app.NotificationCompat;
import android.text.TextUtils;
import android.widget.Toast;

import java.util.List;

import info.androidhive.parsenotifications.R;
import info.androidhive.parsenotifications.activity.MainActivity;
import info.androidhive.parsenotifications.app.AppConfig;

/**
 * Created by Ravi on 01/06/15.
 */
public class NotificationUtils {

    private String TAG = NotificationUtils.class.getSimpleName();

    private Context mContext;

    public NotificationUtils() {
    }

    public NotificationUtils(Context mContext) {
        this.mContext = mContext;
    }

    public void showNotificationMessage(String title, String message, Intent intent) {

        // Check for empty push message
        if (TextUtils.isEmpty(message))
            return;

        if (isAppIsInBackground(mContext)) {
            // notification icon
            int icon = R.mipmap.ic_launcher;

            int mNotificationId = AppConfig.NOTIFICATION_ID;

            PendingIntent resultPendingIntent =
                    PendingIntent.getActivity(
                            mContext,
                            0,
                            intent,
                            PendingIntent.FLAG_CANCEL_CURRENT
                    );

            NotificationCompat.InboxStyle inboxStyle = new NotificationCompat.InboxStyle();

            NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(
                    mContext);
            Notification notification = mBuilder.setSmallIcon(icon).setTicker(title).setWhen(0)
                    .setAutoCancel(true)
                    .setContentTitle(title)
                    .setStyle(inboxStyle)
                    .setContentIntent(resultPendingIntent)
                    .setSound(RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION))
                    .setLargeIcon(BitmapFactory.decodeResource(mContext.getResources(), icon))
                    .setContentText(message)
                    .build();

            NotificationManager notificationManager = (NotificationManager) mContext.getSystemService(Context.NOTIFICATION_SERVICE);
            notificationManager.notify(mNotificationId, notification);
        } else {
            intent.putExtra("title", title);
            intent.putExtra("message", message);
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_SINGLE_TOP);
            mContext.startActivity(intent);
        }
    }

    /**
     * Method checks if the app is in background or not
     *
     * @param context
     * @return
     */
    public static boolean isAppIsInBackground(Context context) {
        boolean isInBackground = true;
        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT_WATCH) {
            List<ActivityManager.RunningAppProcessInfo> runningProcesses = am.getRunningAppProcesses();
            for (ActivityManager.RunningAppProcessInfo processInfo : runningProcesses) {
                if (processInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
                    for (String activeProcess : processInfo.pkgList) {
                        if (activeProcess.equals(context.getPackageName())) {
                            isInBackground = false;
                        }
                    }
                }
            }
        } else {
            List<ActivityManager.RunningTaskInfo> taskInfo = am.getRunningTasks(1);
            ComponentName componentInfo = taskInfo.get(0).topActivity;
            if (componentInfo.getPackageName().equals(context.getPackageName())) {
                isInBackground = false;
            }
        }

        return isInBackground;
    }
}

12. Create another class named PrefManager.java under helper package. This class handles the user’s session with the help of shared preferences.

package info.androidhive.parsenotifications.helper;

import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;

/**
 * Created by Ravi on 01/06/15.
 */
public class PrefManager {
    // Shared Preferences
    SharedPreferences pref;

    // Editor for Shared preferences
    Editor editor;

    // Context
    Context _context;

    // Shared pref mode
    int PRIVATE_MODE = 0;

    // Shared pref file name
    private static final String PREF_NAME = "AndroidHive";

    // All Shared Preferences Keys
    private static final String IS_LOGIN = "IsLoggedIn";

    // Email address
    private static final String KEY_EMAIL = "email";

    // Constructor
    public PrefManager(Context context) {
        this._context = context;
        pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
        editor = pref.edit();
    }

    /**
     * Create login session
     */
    public void createLoginSession(String email) {
        // Storing login value as TRUE
        editor.putBoolean(IS_LOGIN, true);

        // Storing email in pref
        editor.putString(KEY_EMAIL, email);

        // commit changes
        editor.commit();
    }

    public String getEmail() {
        return pref.getString(KEY_EMAIL, null);
    }

    public boolean isLoggedIn() {
        return pref.getBoolean(IS_LOGIN, false);
    }

    public void logout() {
        editor.clear();
        editor.commit();
    }
}

13. Now under app package, create another class named MyApplication.java and add below code. This is an Application class which will be executed on app launch. So we initialize the parse by calling ParseUtils.registerParse() method which initializes the parse and subscribe the user to AndroidHive channel.

package info.androidhive.parsenotifications.app;


import android.app.Application;

import info.androidhive.parsenotifications.helper.ParseUtils;

public class MyApplication extends Application {

    private static MyApplication mInstance;

    @Override
    public void onCreate() {
        super.onCreate();
        mInstance = this;

        // register with parse
        ParseUtils.registerParse(this);
    }


    public static synchronized MyApplication getInstance() {
        return mInstance;
    }
}

3.1 Creating Custom Parse Push Receiver

Parse comes with a default broadcast push receiver, but the options are limited. If you want to fully utilize the parse notifications, the best option is create a custom broad cast receiver.

14. Under receiver package, create a class named CustomPushReceiver.java which extends ParsePushBroadcastReceiver.

onPushReceive() – method will be called whenever push message is received. In this message the json message will be parsed and shown to user.

package info.androidhive.parsenotifications.receiver;

import android.content.Context;
import android.content.Intent;
import android.util.Log;

import com.parse.ParsePushBroadcastReceiver;

import org.json.JSONException;
import org.json.JSONObject;

import info.androidhive.parsenotifications.activity.MainActivity;
import info.androidhive.parsenotifications.helper.NotificationUtils;

/**
 * Created by Ravi on 01/06/15.
 */
public class CustomPushReceiver extends ParsePushBroadcastReceiver {
    private final String TAG = CustomPushReceiver.class.getSimpleName();

    private NotificationUtils notificationUtils;

    private Intent parseIntent;

    public CustomPushReceiver() {
        super();
    }

    @Override
    protected void onPushReceive(Context context, Intent intent) {
        super.onPushReceive(context, intent);

        if (intent == null)
            return;

        try {
            JSONObject json = new JSONObject(intent.getExtras().getString("com.parse.Data"));

            Log.e(TAG, "Push received: " + json);

            parseIntent = intent;

            parsePushJson(context, json);

        } catch (JSONException e) {
            Log.e(TAG, "Push message json exception: " + e.getMessage());
        }
    }

    @Override
    protected void onPushDismiss(Context context, Intent intent) {
        super.onPushDismiss(context, intent);
    }

    @Override
    protected void onPushOpen(Context context, Intent intent) {
        super.onPushOpen(context, intent);
    }

    /**
     * Parses the push notification json
     *
     * @param context
     * @param json
     */
    private void parsePushJson(Context context, JSONObject json) {
        try {
            boolean isBackground = json.getBoolean("is_background");
            JSONObject data = json.getJSONObject("data");
            String title = data.getString("title");
            String message = data.getString("message");

            if (!isBackground) {
                Intent resultIntent = new Intent(context, MainActivity.class);
                showNotificationMessage(context, title, message, resultIntent);
            }

        } catch (JSONException e) {
            Log.e(TAG, "Push message json exception: " + e.getMessage());
        }
    }


    /**
     * Shows the notification message in the notification bar
     * If the app is in background, launches the app
     *
     * @param context
     * @param title
     * @param message
     * @param intent
     */
    private void showNotificationMessage(Context context, String title, String message, Intent intent) {

        notificationUtils = new NotificationUtils(context);

        intent.putExtras(parseIntent.getExtras());

        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);

        notificationUtils.showNotificationMessage(title, message, intent);
    }
}

15. Now we have all the helper classes required. Open AndroidManifest.xml and do the below changes.

> Add MyApplication to your <application> tag

> Make LoginActivity as launcher activity. We’ll create this activity shortly.

> Replace info.androidhive.parsenotifications with your project’s package name.

> Add the custom receiver class CustomPushReceiver using <receiver> tag.

> Add the necessary permissions mentioned.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="info.androidhive.parsenotifications">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WAKE_LOCK" />
    <uses-permission android:name="android.permission.VIBRATE" />
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
    <uses-permission android:name="android.permission.GET_ACCOUNTS" />
    <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />

    <!--
      IMPORTANT: Change "info.androidhive.parsenotifications.permission.C2D_MESSAGE" in the lines below
      to match your app's package name + ".permission.C2D_MESSAGE".
    -->
    <permission
        android:name="info.androidhive.parsenotifications.permission.C2D_MESSAGE"
        android:protectionLevel="signature" />

    <uses-permission android:name="info.androidhive.parsenotifications.permission.C2D_MESSAGE" />

    <application
        android:name=".app.MyApplication"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/MyMaterialTheme">
        <activity
            android:name=".activity.LoginActivity"
            android:label="@string/app_name"
            android:windowSoftInputMode="stateHidden|adjustResize">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

        <!-- Added for Parse push notifications -->

        <service android:name="com.parse.PushService" />

        <receiver
            android:name=".receiver.CustomPushReceiver"
            android:exported="false">
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED" />
                <action android:name="android.intent.action.USER_PRESENT" />
                <action android:name="com.parse.push.intent.RECEIVE" />
                <action android:name="com.parse.push.intent.DELETE" />
                <action android:name="com.parse.push.intent.OPEN" />
            </intent-filter>
        </receiver>
        <receiver
            android:name="com.parse.GcmBroadcastReceiver"
            android:permission="com.google.android.c2dm.permission.SEND">
            <intent-filter>
                <action android:name="com.google.android.c2dm.intent.RECEIVE" />
                <action android:name="com.google.android.c2dm.intent.REGISTRATION" />

                <!-- IMPORTANT: Change "info.androidhive.parsenotifications" to match your app's package name. -->
                <category android:name="info.androidhive.parsenotifications" />
            </intent-filter>
        </receiver>

        <!-- /Added for Parse push notifications -->
    </application>

</manifest>

3.1 Creating Login Activity

Now we’ll add the login screen to our app. This will be the launcher activity which prompts user to enter the email to login. Using this email address, we’ll subscribe the user to parse channel email.

16. Create an xml layout named activity_login.xml under res ⇒ layout folder.

<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"
    android:background="#ffffff"
    tools:context="info.androidhive.parsenotifications.activity.LoginActivity">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:gravity="center"
        android:orientation="vertical"
        android:paddingBottom="10dp"
        android:paddingTop="10dp">

        <TextView
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:fontFamily="sans-serif-light"
            android:gravity="center_horizontal"
            android:text="Parse Notifications"
            android:textColor="#218eed"
            android:textSize="24dp" />

        <TextView
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="20dp"
            android:fontFamily="sans-serif-light"
            android:gravity="center_horizontal"
            android:paddingLeft="20dp"
            android:paddingRight="20dp"
            android:text="Enter your email address to subscribe to parse channel!"
            android:textColor="#9d9d9d"
            android:textSize="16dp" />

        <EditText
            android:id="@+id/email"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginLeft="40dp"
            android:layout_marginRight="40dp"
            android:background="@android:color/white"
            android:hint="Your email address"
            android:gravity="center_horizontal"
            android:inputType="textEmailAddress"
            android:padding="10dp"
            android:textColor="#444444"
            android:textColorHint="#888888"
            android:textSize="18dp" />

        <View
            android:layout_width="fill_parent"
            android:layout_height="1dp"
            android:layout_marginLeft="40dp"
            android:layout_marginRight="40dp"
            android:background="#dedede"/>

        <Button
            android:id="@+id/btnLogin"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginLeft="40dp"
            android:layout_marginRight="40dp"
            android:layout_marginTop="20dp"
            android:background="#218eed"
            android:text="Login"
            android:textColor="@android:color/white" />
    </LinearLayout>


</RelativeLayout>

17. Under activity package, create a new activity named LoginActivity.java and add below code. This activity get the email address and stores it in shared preferences.

package info.androidhive.parsenotifications.activity;

import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import info.androidhive.parsenotifications.R;
import info.androidhive.parsenotifications.app.AppConfig;
import info.androidhive.parsenotifications.helper.ParseUtils;
import info.androidhive.parsenotifications.helper.PrefManager;

public class LoginActivity extends ActionBarActivity implements View.OnClickListener {

    private EditText inputEmail;
    private Button btnLogin;
    private PrefManager pref;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Verifying parse configuration. This is method is for developers only.
        ParseUtils.verifyParseConfiguration(this);

        pref = new PrefManager(getApplicationContext());
        if (pref.isLoggedIn()) {
            Intent intent = new Intent(LoginActivity.this, MainActivity.class);
            startActivity(intent);

            finish();
        }

        setContentView(R.layout.activity_login);

        inputEmail = (EditText) findViewById(R.id.email);
        btnLogin = (Button) findViewById(R.id.btnLogin);

        btnLogin.setOnClickListener(this);
    }


    private void login() {
        String email = inputEmail.getText().toString();

        if (isValidEmail(email)) {

            pref.createLoginSession(email);

            Intent intent = new Intent(LoginActivity.this, MainActivity.class);
            startActivity(intent);

            finish();
        } else {
            Toast.makeText(getApplicationContext(), "Please enter valid email address!", Toast.LENGTH_LONG).show();
        }
    }

    public final static boolean isValidEmail(CharSequence target) {
        return !TextUtils.isEmpty(target) && android.util.Patterns.EMAIL_ADDRESS.matcher(target).matches();
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btnLogin:
                login();
                break;
            default:
        }
    }
}

3.2 Showing the Push Messages in List View

18. Under model package, create a class named Message.java. This class is used to pass the message objects to list adapter.

package info.androidhive.parsenotifications.model;

/**
 * Created by Ravi on 01/06/15.
 */
public class Message {
    private String message;
    private long timestamp;

    public Message() {
    }

    public Message(String message, long timestamp) {
        this.message = message;
        this.timestamp = timestamp;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public long getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(long timestamp) {
        this.timestamp = timestamp;
    }
}

19. Create an xml layout named list_row.xml. This layout renders the single list item row.

<?xml version="1.0" encoding="utf-8"?>
<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/message"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="5dp"
        android:paddingLeft="10dp"
        android:paddingRight="10dp"
        android:paddingTop="10dp"
        android:textSize="16dp" />

    <TextView
        android:id="@+id/timestamp"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="15dp"
        android:paddingLeft="10dp"
        android:paddingRight="10dp"
        android:textColor="#666666" />

</LinearLayout>

20. Open layout file of main activity (activity_main.xml) and add a ListView.

<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <include
            android:id="@+id/toolbar"
            layout="@layout/toolbar" />
    </LinearLayout>

    <ListView
        android:id="@+id/list_view"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"></ListView>

</LinearLayout>

21. Finally open your main activity class MainActivity.java and do the below changes. Here onNewIntent() method will be called whenever a new push message is received. We’ll add the new message to list data source and refresh the list view.

package info.androidhive.parsenotifications.activity;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.text.format.DateUtils;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

import info.androidhive.parsenotifications.R;
import info.androidhive.parsenotifications.helper.ParseUtils;
import info.androidhive.parsenotifications.helper.PrefManager;
import info.androidhive.parsenotifications.model.Message;


public class MainActivity extends AppCompatActivity {

    private static String TAG = MainActivity.class.getSimpleName();

    private Toolbar mToolbar;
    private ListView listView;
    private List<Message> listMessages = new ArrayList<>();
    private MessageAdapter adapter;
    private PrefManager pref;

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

        listView = (ListView) findViewById(R.id.list_view);
        mToolbar = (Toolbar) findViewById(R.id.toolbar);

        setSupportActionBar(mToolbar);
        getSupportActionBar().setDisplayShowHomeEnabled(true);

        adapter = new MessageAdapter(this);
        pref = new PrefManager(getApplicationContext());

        listView.setAdapter(adapter);

        Intent intent = getIntent();

        String email = intent.getStringExtra("email");

        if (email != null) {
            ParseUtils.subscribeWithEmail(pref.getEmail());
        }
    }

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        String message = intent.getStringExtra("message");

        Message m = new Message(message, System.currentTimeMillis());
        listMessages.add(0, m);
        adapter.notifyDataSetChanged();
    }

    private class MessageAdapter extends BaseAdapter {

        LayoutInflater inflater;

        public MessageAdapter(Activity activity) {
            inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }

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

        @Override
        public Object getItem(int position) {
            return listMessages.get(position);
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View view = convertView;
            if (view == null) {
                view = inflater.inflate(R.layout.list_row, null);
            }

            TextView txtMessage = (TextView) view.findViewById(R.id.message);
            TextView txtTimestamp = (TextView) view.findViewById(R.id.timestamp);

            Message message = listMessages.get(position);
            txtMessage.setText(message.getMessage());

            CharSequence ago = DateUtils.getRelativeTimeSpanString(message.getTimestamp(), System.currentTimeMillis(),
                    0L, DateUtils.FORMAT_ABBREV_ALL);

            txtTimestamp.setText(String.valueOf(ago));

            return view;
        }
    }

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

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_logout) {
            pref.logout();
            Intent intent = new Intent(MainActivity.this, LoginActivity.class);
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
            startActivity(intent);
            finish();
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

This completes the android part. Now we’ll learn how to use the parse dashboard to send push messages.

4. Sending Messages using Parse Dashboard

Parse provides the push dashboard to send messages to all your app users. Login to parse, select the app and click on + Send a push. You can find necessary filters to send push notifications like by platform, channel etc., Checkout the demo video above demonstrating sending the push messages to all users, by a channel or by email.

5. Sending Messages using Parse REST API

Parse also provides a REST API for various languages to send the messages from your server directly instead of using the parse dashboard. This REST API is very useful when you want to automate the push messages when user is interacting with the android app.

Go through the REST API guide to integrate the API with the language you choose.