Whatsapp Stickers Handler

This plugin provides functionality for dynamically adding and updating sticker packs to WhatsApp. It also includes helper functions that support creating valid stickers from user images.

Features

WhatsApp API

The plugin provides the following WhatsApp API functionality:

• Add a sticker pack to WhatsApp
• Update an existing sticker pack
• Check if sticker pack is available in WhatsApp
• Launch WhatsApp
• Check if WhatsApp is installed on device

Sticker Creation and Validation

The plugin provides the following sticker functionality:

• Create and save stickers from images on the users device
  • Convert images to required file types
  • Scaling and compressing to comply with the WhatsApp API
• Sticker pack validation

Usage

A functioning example app can be found here.

WhatsappStickersHandler

class WhatsAppService {
  static WhatsappStickersHandler whatsappStickersHandler =
      WhatsappStickersHandler();

  /// Returns if WhatsApp is installed
  static Future<bool> get isWhatsAppInstalled async {
    return await whatsappStickersHandler.isWhatsAppInstalled;
  }

  /// Launches WhatsApp
  static void launchWhatsApp() {
    whatsappStickersHandler.launchWhatsApp();
  }

  /// Checks if a sticker pack with the given [identifier] is available in
  /// WhatsApp
  static Future<bool> isStickerPackInstalled(String identifier) async {
    return await whatsappStickersHandler.isStickerPackInstalled(identifier);
  }
  
  /// Adds [stickerPack] to the sticker pack list that is exposed to WhatsApp
  /// and sends request to add the pack to Whatsapp
  static Future<void> addStickerPack(StickerPack stickerPack) async {
    await whatsappStickersHandler.addStickerPack(stickerPack);
  }

  /// Updates [stickerPack] in the sticker pack list that is exposed to WhatsApp
  static Future<void> updateStickerPack(StickerPack stickerPack) async {
    await whatsappStickersHandler.updateStickerPack(stickerPack);
  }

  /// Deletes sticker pack from the sticker pack list that is exposed to WhatsApp
  /// The sticker pack still needs to be deleted manually in the WhatsApp UI
  static Future<void> deleteStickerPack(String identifier) async {
    await whatsappStickersHandler.deleteStickerPack(identifier);
  }
}

The sticker pack validation is called automatically and might throw an exception so you should implement exception handling:

try {
  await whatsappStickersHandler.addStickerPack(stickerPack);
} on StickerPackException catch (e) {
  print(e.message);
} on PlatformException catch (e) {
  print(e.message ?? 'An unexpected error occurred');
}

Create stickers and sticker packs

Create a sticker pack

StickerPack stickerPack = StickerPack(
  identifier: 'packIdentifier',
  name: 'packName',
  publisher: 'publisherName',
);

Create stickers

Create .webp stickers from the given image paths and save them to the given directory. You can also create a single sticker with the createStickerFromImage() function.

You can use file_picker or image_picker to get the images from the users phone. You can also use path_provider to get your apps application directory.

List<String> stickerWebpPaths = await StickerPackUtil().createStickersFromImages(
  ['externalDir/sticker1.jpg', 'externalDir/sticker2.png'],
  'myAppDir/myStickerPack',
);

stickerPack.stickers = stickerWebpPaths;

Create a tray image from a sticker

Create a .png from a .webp sticker and save it in the same directory.

String trayPngPath = await StickerPackUtil().saveWebpAsTrayImage(
  'myAppDir/myStickerPack/myStickerName.webp'
);

stickerPack.trayImage = trayPngPath;

Check if a sticker is animated

bool isAnimated = await StickerPackUtil().isStickerAnimated(
  'myAppDir/myStickerPack/myStickerName.webp'
);

Sticker Pack Validation

Validate a sticker pack. This throws an exception if something is invalid.

try {
  StickerPackValidator.validateStickerPack(myStickerPack);
} on StickerPackException catch (e) {
  print(e.message);
}

WhatsApp Stickers API

See the WhatsApp documentation for more information.

Android Platform Code

The docs for the Android platform code can be found here.