flutter_p2p_connection

A p2p wifi direct plugin.

Getting Started

Required permissions

Add these permissions to AndroidManifest.xml

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.NEARBY_WIFI_DEVICES" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<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.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />

Add this for android 10:

<!-- add this to your AndroidManifest file application tag -->
   <application
        ...
        android:requestLegacyExternalStorage="true">

Request Permissions

// check if storage permission is granted
FlutterP2pConnection().checkStoragePermission();

// request storage permission
FlutterP2pConnection().askStoragePermission();

// check if location permission is granted
FlutterP2pConnection().checkLocationPermission();

// request location permission
FlutterP2pConnection().askLocationPermission();

// check if location is enabled
FlutterP2pConnection().checkLocationEnabled();

// enable location
FlutterP2pConnection().enableLocationServices();

// check if wifi is enabled
FlutterP2pConnection().checkWifiEnabled();

// enable wifi
FlutterP2pConnection().enableWifiServices();

Register / unregister from WiFi events

To receive notifications for connection changes or device changes (peers discovered etc.) you have to subscribe to the wifiEvents and register the plugin to the native events.

class _MyHomePageState extends State<MyHomePage> with WidgetsBindingObserver {
  final _flutterP2pConnectionPlugin = FlutterP2pConnection();

  StreamSubscription<WifiP2PInfo>? _streamWifiInfo;
  StreamSubscription<List<DiscoveredPeers>>? _streamPeers;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    _init();
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    _flutterP2pConnectionPlugin.unregister();
    super.dispose();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (state == AppLifecycleState.paused) {
      _flutterP2pConnectionPlugin.unregister();
    } else if (state == AppLifecycleState.resumed) {
      _flutterP2pConnectionPlugin.register();
    }
  }

  void _init() async {
    await _flutterP2pConnectionPlugin.initialize();
    await _flutterP2pConnectionPlugin.register();
    _streamWifiInfo = _flutterP2pConnectionPlugin.streamWifiP2PInfo().listen((event) {
      // Handle changes in connection
    });
    _streamPeers = _flutterP2pConnectionPlugin.streamPeers().listen((event) {
      // Handle discovered peers
    });
  }
}

Create Group

final _flutterP2pConnectionPlugin = FlutterP2pConnection();

_flutterP2pConnectionPlugin.createGroup();

Remove Group

final _flutterP2pConnectionPlugin = FlutterP2pConnection();

_flutterP2pConnectionPlugin.removeGroup();

Get Group Info

final _flutterP2pConnectionPlugin = FlutterP2pConnection();

WifiP2PGroupInfo? info = await _flutterP2pConnectionPlugin.groupInfo();

Discover devices

After you subscribed to the events, enable wifi and location with FlutterP2pConnection().enableWifiServices() and FlutterP2pConnection().enableLocationServices() method, then call the FlutterP2pConnection().discover() to discover peers. To stop discovery call the FlutterP2pConnection().stopDiscovery() method.

final _flutterP2pConnectionPlugin = FlutterP2pConnection();
List<DiscoveredPeers> peers = [];

void _init() async {
  ...
  _streamPeers = _flutterP2pConnectionPlugin.streamPeers().listen((event) {
    // handle discovered peers
    setState(() {
      peers = event;
    });
  });
}

void discover() {
  _flutterP2pConnectionPlugin.discover();
}

void stopDiscovery() {
  _flutterP2pConnectionPlugin.stopDiscovery();
}

Connect to a device

Call FlutterP2pConnection().connect(deviceAddress); and listen to the FlutterP2pConnection().streamWifiP2PInfo

final _flutterP2pConnectionPlugin = FlutterP2pConnection();
 WifiP2PInfo? wifiP2PInfo;
 List<DiscoveredPeers> peers = [];

 void _init() async {
    _streamWifiInfo = _flutterP2pConnectionPlugin.streamWifiP2PInfo().listen((event) {
      // Handle changes in connection
      setState(() {
        wifiP2PInfo = event;
      });
    });
    ...
  }

  void connect() async {
    await _flutterP2pConnectionPlugin.connect(peers[0].deviceAddress);
  }

Disconnect from current P2P group

Call FlutterP2pConnection().removeGroup()

final _flutterP2pConnectionPlugin = FlutterP2pConnection();

void _disconnect() async {
  _flutterP2pConnectionPlugin.removeGroup();
}

Transferring data between devices

After you are connected to a device you can transfer data async in both directions (client -> host -> other clients, host -> clients).

On the host:

final _flutterP2pConnectionPlugin = FlutterP2pConnection();
WifiP2PInfo? wifiP2PInfo;

// create a socket
Future startSocket() async {
  if (wifiP2PInfo != null) {
    await _flutterP2pConnectionPlugin.startSocket(
      groupOwnerAddress: wifiP2PInfo!.groupOwnerAddress!,
      // downloadPath is the directory where received file will be stored
      downloadPath: "/storage/emulated/0/Download/",
      // the max number of downloads at a time. Default is 2.
      maxConcurrentDownloads: 2,
      // delete incomplete transfered file
      deleteOnError: true,
      // handle connections to socket
      onConnect: (name, address) {
        print("$name connected to socket with address: $address");
      },
      // receive transfer updates for both sending and receiving.
      transferUpdate: (transfer) {
        // transfer.count is the amount of bytes transfered
        // transfer.total is the file size in bytes
        // if transfer.receiving is true, you are receiving the file, else you're sending the file.
        // call `transfer.cancelToken?.cancel()` to cancel transfer. This method is only applicable to receiving transfers.
        print(
            "ID: ${transfer.id}, FILENAME: ${transfer.filename}, PATH: ${transfer.path}, COUNT: ${transfer.count}, TOTAL: ${transfer.total}, COMPLETED: ${transfer.completed}, FAILED: ${transfer.failed}, RECEIVING: ${transfer.receiving}");
      },
      // handle string transfer from server
      receiveString: (req) async {
        print(req);
      },
      // runs when the socket is closed: `_flutterP2pConnectionPlugin.closeSocket()`
      onCloseSocket: () {
        print("closed socket");
      },
    );
  }
}

On the client:

final _flutterP2pConnectionPlugin = FlutterP2pConnection();
WifiP2PInfo? wifiP2PInfo;

// Connect to socket
Future connectToSocket() async {
  if (wifiP2PInfo != null) {
    await _flutterP2pConnectionPlugin.connectToSocket(
      groupOwnerAddress: wifiP2PInfo!.groupOwnerAddress!,
      // downloadPath is the directory where received file will be stored
      downloadPath: "/storage/emulated/0/Download/",
      // the max number of downloads at a time. Default is 2.
      maxConcurrentDownloads: 2,
      // delete incomplete transfered file
      deleteOnError: true,
      // on connected to socket
      onConnect: (address) {
        print("connected to socket: $address");
      },
      // receive transfer updates for both sending and receiving.
      transferUpdate: (transfer) {
        // transfer.count is the amount of bytes transfered
        // transfer.total is the file size in bytes
        // if transfer.receiving is true, you are receiving the file, else you're sending the file.
        // call `transfer.cancelToken?.cancel()` to cancel transfer. This method is only applicable to receiving transfers.
        print(
            "ID: ${transfer.id}, FILENAME: ${transfer.filename}, PATH: ${transfer.path}, COUNT: ${transfer.count}, TOTAL: ${transfer.total}, COMPLETED: ${transfer.completed}, FAILED: ${transfer.failed}, RECEIVING: ${transfer.receiving}");
      },
      // handle string transfer from server
      receiveString: (req) async {
        print(req);
      },
      // runs when the socket is closed: `_flutterP2pConnectionPlugin.closeSocket()`
      onCloseSocket: () {
        print("closed socket");
      },
    );
  }
}

To transfer a string/text: This method returns a bool.

_flutterP2pConnectionPlugin.sendStringToSocket("message");

To transfer file: This method returns a list of transferUpdates. if it returns null, the transfer failed!

List<TransferUpdate>? updates = _flutterP2pConnectionPlugin.sendFiletoSocket(["filePath1","filePath2","filePath3"]);
// Transfered files will be stored in the downloadPath you gave in the `startSocket` or `connectToSocket` method.

To close socket:

_flutterP2pConnectionPlugin.closeSocket();