Whatsapp Sticker App (Offline) with Admob and OneSignal Push Notification for Android

Introduction

WhatsApp Sticker App is a popular feature that allows users to send and receive stickers in their conversations. In this tutorial, we will create a complete WhatsApp Sticker App for Android that uses AdMob for monetization and OneSignal for push notifications. We will also cover how to use the WhatsApp Sticker App offline, making it a seamless experience for users.

Prerequisites

Before we begin, make sure you have the following:

• Android Studio installed on your computer
• Basic knowledge of Java or Kotlin programming language
• AdMob account and OneSignal account
• WhatsApp Sticker App API key

Step 1: Create a New Project in Android Studio

Open Android Studio and create a new project. Choose "Empty Activity" and name your project "WhatsApp Sticker App".

Step 2: Add WhatsApp Sticker App API Key

Add the WhatsApp Sticker App API key to your project. You can obtain the API key from the WhatsApp Sticker App website.

Step 3: Add AdMob to Your Project

Add AdMob to your project by following these steps:

• Open the project structure and navigate to the "app" folder
• Create a new folder called "ads"
• Inside the "ads" folder, create a new file called "AdMob.java"
• Add the following code to the "AdMob.java" file:

  
  import com.google.android.gms.ads.AdRequest;
  import com.google.android.gms.ads.AdView;
  import com.google.android.gms.ads.MobileAds;

public class AdMob { private AdView adView;

public AdMob(Context context) {
    MobileAds.initialize(context, new OnInitializationCompleteListener() {
        @Override
        public void onInitializationComplete() {
            // AdMob initialization complete
        }
    });
    adView = new AdView(context);
    adView.setAdSize(AdSize.BANNER);
    adView.setAdUnitId("YOUR_AD_UNIT_ID");
}

public void loadAd() {
    AdRequest adRequest = new AdRequest.Builder().build();
    adView.loadAd(adRequest);
}

public void showAd() {
    if (adView!= null) {
        adView.setVisibility(View.VISIBLE);
    }
}

public void hideAd() {
    if (adView!= null) {
        adView.setVisibility(View.GONE);
    }
}

}

Replace "YOUR_AD_UNIT_ID" with your actual AdMob ad unit ID.

**Step 4: Add OneSignal to Your Project**

Add OneSignal to your project by following these steps:

* Open the project structure and navigate to the "app" folder
* Create a new folder called "onesignal"
* Inside the "onesignal" folder, create a new file called "OneSignal.java"
* Add the following code to the "OneSignal.java" file:
```java
import com.onesignal.OneSignal;

public class OneSignal {
    public static void init(Context context) {
        OneSignal.init(context, "YOUR_ONESIGNAL_APP_ID");
    }

    public static void sendNotification(String message) {
        OneSignal.sendNotification(context, message);
    }
}

Replace "YOUR_ONESIGNAL_APP_ID" with your actual OneSignal app ID.

Step 5: Create a Sticker Pack

Create a sticker pack by following these steps:

• Open the project structure and navigate to the "app" folder
• Create a new folder called "stickers"
• Inside the "stickers" folder, create a new file called "sticker_pack.json"
• Add the following code to the "sticker_pack.json" file:

  {
  "pack": {
  "name": "WhatsApp Sticker App",
  "description": "A sticker pack for WhatsApp",
  "author": "Your Name",
  "version": "1.0"
  },
  "stickers": [
  {
    "id": "sticker1",
    "image": "sticker1.png",
    "name": "Sticker 1"
  },
  {
    "id": "sticker2",
    "image": "sticker2.png",
    "name": "Sticker 2"
  },
  ...
  ]
  }

  Replace the "sticker1.png", "sticker2.png", etc. with the actual images of your stickers.

Step 6: Add Sticker Pack to Your App

Add the sticker pack to your app by following these steps:

• Open the project structure and navigate to the "app" folder
• Create a new file called "StickerPack.java"
• Add the following code to the "StickerPack.java" file:

  
  import android.content.Context;
  import android.graphics.Bitmap;
  import android.graphics.drawable.BitmapDrawable;
  import android.os.Bundle;
  import android.view.View;
  import android.widget.ImageView;
  import android.widget.Toast;

import com.whatsapp.stickerpack.StickerPack; import com.whatsapp.stickerpack.StickerPackManager;

public class StickerPack { private Context context; private StickerPackManager stickerPackManager;

public StickerPack(Context context) {
    this.context = context;
    stickerPackManager = new StickerPackManager(context);
}

public void loadStickerPack() {
    stickerPackManager.loadStickerPack("sticker_pack.json");
}

public void sendSticker(String stickerId) {
    stickerPackManager.sendSticker(stickerId);
}

}

**Step 7: Use the Sticker Pack in Your App**

Use the sticker pack in your app by following these steps:

* Open the project structure and navigate to the "activity_main.xml" file
* Add the following code to the "activity_main.xml" file:
```xml
<?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">

    <ImageView
        android:id="@+id/sticker_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/sticker1" />

    <Button
        android:id="@+id/send_sticker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Send Sticker" />

</LinearLayout>

• Open the "MainActivity.java" file and add the following code:

  
  import android.os.Bundle;
  import android.view.View;
  import android.widget.Button;
  import android.widget.ImageView;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity { private StickerPack stickerPack; private ImageView stickerImageView; private Button sendStickerButton;

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

    stickerPack = new StickerPack(this);
    stickerImageView = findViewById(R.id.sticker_image);
    sendStickerButton = findViewById(R.id.send_sticker);

    stickerPack.loadStickerPack();

    sendStickerButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String stickerId = "sticker1";
            stickerPack.sendSticker(stickerId);
        }
    });
}

}

**Step 8: Add Offline Support**

Add offline support to your app by following these steps:

* Open the "StickerPack.java" file and add the following code:
```java
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;

import com.whatsapp.stickerpack.StickerPack;
import com.whatsapp.stickerpack.StickerPackManager;

public class StickerPack {
    private Context context;
    private StickerPackManager stickerPackManager;
    private Bitmap stickerBitmap;

    public StickerPack(Context context) {
        this.context = context;
        stickerPackManager = new StickerPackManager(context);
    }

    public void loadStickerPack() {
        stickerPackManager.loadStickerPack("sticker_pack.json");
    }

    public void sendSticker(String stickerId) {
        stickerPackManager.sendSticker(stickerId);
    }

    public void getStickerBitmap(String stickerId) {
        stickerBitmap = stickerPackManager.getStickerBitmap(stickerId);
    }

    public void showStickerBitmap() {
        if (stickerBitmap!= null) {
            ImageView stickerImageView = findViewById(R.id.sticker_image);
            stickerImageView.setImageBitmap(stickerBitmap);
        } else {
            Toast.makeText(context, "Sticker not found", Toast.LENGTH_SHORT).show();
        }
    }
}

• Open the "MainActivity.java" file and add the following code:

  
  import android.os.Bundle;
  import android.view.View;
  import android.widget.Button;
  import android.widget.ImageView;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity { private StickerPack stickerPack; private ImageView stickerImageView; private Button sendStickerButton;

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

    stickerPack = new StickerPack(this);
    stickerImageView = findViewById(R.id.sticker_image);
    sendStickerButton = findViewById(R.id.send_sticker);

    stickerPack.loadStickerPack();

    sendStickerButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String stickerId = "sticker1";
            stickerPack.getStickerBitmap(stickerId);
            stickerPack.showStickerBitmap();
        }
    });
}

}

**Step 9: Test Your App**

Test your app by running it on an emulator or a physical device. Make sure to test the app offline by disconnecting from the internet.

**Conclusion**

In this tutorial, we have created a complete WhatsApp Sticker App for Android that uses AdMob for monetization and OneSignal for push notifications. We have also covered how to use the WhatsApp Sticker App offline, making it a seamless experience for users.