WiFi Direct Plugin #

A comprehensive Flutter plugin for WiFi Direct (P2P) communication, enabling direct device-to-device connections without requiring internet access. Perfect for building offline chat applications, file sharing tools, and collaborative apps.

🚀 Features #

✨ Core Functionality #

• 📱 Cross-Platform Support: Android (WiFi Direct) & iOS (MultipeerConnectivity)
• 🔗 P2P Connection: Direct device-to-device communication without internet
• 💬 Real-time Messaging: Instant text message exchange
• 📁 File Transfer: Send any file type with progress tracking
• 📸 Image Sharing: Camera capture and gallery selection
• 🔄 Auto-Discovery: Automatic peer detection and connection

⚡ Advanced Features #

• 📊 Progress Tracking: Real-time upload/download progress for both sender and receiver
• 🔒 Data Integrity: MD5 checksum verification for file transfers
• 💾 Smart Storage: Automatic saving to Downloads folder with duplicate handling
• 🔄 Auto-Reconnection: Intelligent connection recovery mechanisms
• 🎯 Connection Management: Host/Client roles with seamless switching
• ⚠️ Error Handling: Comprehensive error detection and recovery

📱 Platform Support #

🏗️ Installation #

Add this to your package's pubspec.yaml file:

dependencies:
  wifi_direct_plugin: ^0.0.1

Then run:

flutter pub get

⚙️ Setup #

Android Configuration #

Add the following permissions to your android/app/src/main/AndroidManifest.xml:

    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.NEARBY_WIFI_DEVICES" android:usesPermissionFlags="neverForLocation" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
    <uses-permission android:name="android.permission.READ_MEDIA_AUDIO" />
    <uses-permission android:name="android.permission.READ_MEDIA_VIDEO" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-feature android:name="android.hardware.wifi.direct" android:required="true" />

iOS Configuration #

Add the following to your ios/Runner/Info.plist:

<key>NSLocalNetworkUsageDescription</key>
<string>This app needs to access your local network for WiFi Direct communication</string>
<key>NSBonjourServices</key>
<array>
    <string>_wifi-direct._tcp</string>
    <string>_wifi-direct._udp</string>
</array>

🚀 Quick Start #

1. Initialize the Plugin #

import 'package:wifi_direct_plugin/wifi_direct_plugin.dart';

// Initialize WiFi Direct
bool success = await WifiDirectPlugin.initialize();
if (success) {
  print('WiFi Direct initialized successfully!');
}

2. Start as Host (Server) #

// Start as host to create a group
bool started = await WifiDirectPlugin.startAsServer(
  deviceName: "My Awesome Device"
);

if (started) {
  print('Host started! Waiting for connections...');
}

3. Join as Client #

// Start as client and discover devices
await WifiDirectPlugin.startAsClient(deviceName: "Client Device");
await WifiDirectPlugin.startDiscovery();

// Listen for discovered peers
WifiDirectPlugin.peersStream.listen((peers) {
  for (var peer in peers) {
    print('Found device: ${peer.deviceName}');
  }
});

// Connect to a device
await WifiDirectPlugin.connect(deviceAddress);

4. Send Messages and Files #

// Send text message
await WifiDirectPlugin.sendText("Hello, World!");

// Send file
await WifiDirectPlugin.sendFile("/path/to/document.pdf");

// Send image
await WifiDirectPlugin.sendImage("/path/to/photo.jpg");

5. Handle Incoming Data #

// Set up callbacks for received data
WifiDirectPlugin.onTextReceived = (text) {
  print('Received message: $text');
};

WifiDirectPlugin.onFileReceived = (file) {
  print('Received file: ${file.path}');
};

WifiDirectPlugin.onImageReceived = (image) {
  print('Received image: ${image.path}');
};

// Track transfer progress
WifiDirectPlugin.onFileProgress = (fileName, progress) {
  print('Receiving $fileName: ${(progress * 100).toInt()}%');
};

WifiDirectPlugin.onSendProgress = (fileName, progress) {
  print('Sending $fileName: ${(progress * 100).toInt()}%');
};

🎯 Complete Example #

Here's a complete example of a simple chat application:

import 'package:flutter/material.dart';
import 'package:wifi_direct_plugin/wifi_direct_plugin.dart';

class ChatScreen extends StatefulWidget {
  @override
  _ChatScreenState createState() => _ChatScreenState();
}

class _ChatScreenState extends State<ChatScreen> {
  final TextEditingController _messageController = TextEditingController();
  final List<String> _messages = [];
  bool _isConnected = false;

  @override
  void initState() {
    super.initState();
    _initializeWifiDirect();
  }

  Future<void> _initializeWifiDirect() async {
    await WifiDirectPlugin.initialize();

    // Set up message receiver
    WifiDirectPlugin.onTextReceived = (text) {
      setState(() {
        _messages.add('Received: $text');
      });
    };

    // Listen for connection changes
    WifiDirectPlugin.connectionStream.listen((info) {
      setState(() {
        _isConnected = info.isConnected;
      });
    });
  }

  Future<void> _sendMessage() async {
    final message = _messageController.text.trim();
    if (message.isNotEmpty && _isConnected) {
      await WifiDirectPlugin.sendText(message);
      setState(() {
        _messages.add('Sent: $message');
        _messageController.clear();
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(_isConnected ? 'Connected' : 'Disconnected'),
        backgroundColor: _isConnected ? Colors.green : Colors.red,
      ),
      body: Column(
        children: [
          // Connection buttons
          if (!_isConnected) ...[
            Row(
              children: [
                Expanded(
                  child: ElevatedButton(
                    onPressed: () => WifiDirectPlugin.startAsServer(),
                    child: Text('Host'),
                  ),
                ),
                SizedBox(width: 8),
                Expanded(
                  child: ElevatedButton(
                    onPressed: () async {
                      await WifiDirectPlugin.startAsClient();
                      await WifiDirectPlugin.startDiscovery();
                    },
                    child: Text('Join'),
                  ),
                ),
              ],
            ),
          ],

          // Messages list
          Expanded(
            child: ListView.builder(
              itemCount: _messages.length,
              itemBuilder: (context, index) {
                return ListTile(
                  title: Text(_messages[index]),
                );
              },
            ),
          ),

          // Message input
          if (_isConnected)
            Padding(
              padding: EdgeInsets.all(8.0),
              child: Row(
                children: [
                  Expanded(
                    child: TextField(
                      controller: _messageController,
                      decoration: InputDecoration(
                        hintText: 'Type a message...',
                        border: OutlineInputBorder(),
                      ),
                      onSubmitted: (_) => _sendMessage(),
                    ),
                  ),
                  SizedBox(width: 8),
                  IconButton(
                    onPressed: _sendMessage,
                    icon: Icon(Icons.send),
                  ),
                ],
              ),
            ),
        ],
      ),
    );
  }

  @override
  void dispose() {
    WifiDirectPlugin.dispose();
    super.dispose();
  }
}

📚 API Reference #

Core Methods #

Messaging & Transfer #

Event Streams #

Callbacks #

🔧 Advanced Configuration #

Connection Management #

// Monitor connection state
WifiDirectPlugin.connectionStream.listen((info) {
  print('Connected: ${info.isConnected}');
  print('Is Group Owner: ${info.isGroupOwner}');
  print('Group Owner Address: ${info.groupOwnerAddress}');
});

// Handle peer discovery
WifiDirectPlugin.peersStream.listen((peers) {
  for (var peer in peers) {
    print('Device: ${peer.deviceName} (${peer.deviceAddress})');
  }
});

File Transfer with Progress #

// Track upload progress
WifiDirectPlugin.onSendProgress = (fileName, progress) {
  print('Uploading $fileName: ${(progress * 100).toInt()}%');
};

// Track download progress
WifiDirectPlugin.onFileProgress = (fileName, progress) {
  print('Downloading $fileName: ${(progress * 100).toInt()}%');
};

// Handle completed transfers
WifiDirectPlugin.onFileReceived = (file) async {
  // Save to Downloads folder
  String? savedPath = await FileService.saveFileToDownloads(
    file,
    file.path.split('/').last
  );
  print('File saved to: $savedPath');
};

🎨 UI Components #

The plugin includes pre-built UI components for quick integration:

• ConnectionInfo: Shows current connection status
• PeerList: Displays discovered devices
• FileProgress: Shows transfer progress
• MessageBubble: Chat message display
• InputArea: Message input with file/image buttons

⚠️ Important Notes #

Android Considerations #

• Permissions: Location permission is required for WiFi Direct discovery
• WiFi State: Device WiFi must be enabled
• Background: File transfers may be interrupted if app goes to background
• Device Compatibility: Some manufacturers may have WiFi Direct limitations

iOS Considerations #

• Proximity: Devices must be in close proximity for MultipeerConnectivity
• Privacy: Users will see connection prompts
• Background: Limited background execution capabilities

Performance Tips #

• File Size: Large files are automatically chunked for efficient transfer
• Network Quality: Transfer speed depends on WiFi Direct connection quality
• Memory: Plugin efficiently manages memory for large file transfers
• Battery: Continuous discovery can drain battery

🐛 Troubleshooting #

Common Issues #

Connection fails on Android:

• Ensure location permission is granted
• Check if WiFi is enabled
• Try restarting WiFi Direct discovery

iOS devices not discovering each other:

• Ensure devices are close to each other
• Check Bluetooth and WiFi are enabled
• Restart the app if needed

File transfer is slow:

• WiFi Direct speed varies by device and distance
• Close other network-intensive apps
• Ensure devices are close to each other

Permission errors:

• Check all required permissions are added to AndroidManifest.xml
• Request runtime permissions properly
• Test on different Android versions

🤝 Contributing #

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

📄 License #

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments #

• Flutter team for the excellent plugin architecture
• Android WiFi Direct API documentation
• iOS MultipeerConnectivity framework
• Open source community for inspiration and feedback

📞 Support #

• Examples: Check the /example folder for complete sample apps

Made with ❤️ for the Flutter community