wallet_connect 1.0.0

Wallet Connect client made in love with dart.

example/lib/main.dart

import 'dart:convert';
import 'dart:typed_data';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_inappwebview/flutter_inappwebview.dart';
import 'package:http/http.dart' as http;
import 'package:shared_preferences/shared_preferences.dart';
import 'package:wallet_connect/wallet_connect.dart';
import 'package:wallet_connect_example/eth_conversions.dart';
import 'package:wallet_connect_example/qr_scan_view.dart';
import 'package:web3dart/crypto.dart';
import 'package:web3dart/web3dart.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Wallet Connect',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Wallet Connect'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

const maticRpcUri =
    'https://rpc-mainnet.maticvigil.com/v1/140d92ff81094f0f3d7babde06603390d7e581be';

enum MenuItems { PREVIOUS_SESSION, KILL_SESSION, SCAN_QR, CLEAR_CACHE }

class _MyHomePageState extends State<MyHomePage> {
  late WCClient _wcClient;
  late SharedPreferences _prefs;
  late InAppWebViewController _webViewController;
  late String walletAddress, privateKey;
  bool connected = false;
  WCSessionStore? _sessionStore;
  final _web3client = Web3Client(
    maticRpcUri,
    http.Client(),
  );

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

  _initialize() async {
    _wcClient = WCClient(
      onSessionRequest: _onSessionRequest,
      onFailure: _onSessionError,
      onDisconnect: _onSessionClosed,
      onEthSign: _onSign,
      onEthSignTransaction: _onSignTransaction,
      onEthSendTransaction: _onSendTransaction,
      onCustomRequest: (_, __) {},
      onConnect: _onConnect,
    );
    // TODO: Mention walletAddress and privateKey while connecting
    walletAddress = '';
    privateKey = '';
    _prefs = await SharedPreferences.getInstance();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
        actions: [
          PopupMenuButton<MenuItems>(
            onSelected: (item) {
              switch (item) {
                case MenuItems.PREVIOUS_SESSION:
                  _connectToPreviousSession();
                  break;
                case MenuItems.KILL_SESSION:
                  _wcClient.killSession();
                  break;
                case MenuItems.SCAN_QR:
                  Navigator.push(
                    context,
                    MaterialPageRoute(builder: (_) => QRScanView()),
                  ).then((value) {
                    if (value != null) {
                      _qrScanHandler(value);
                    }
                  });
                  break;
                case MenuItems.CLEAR_CACHE:
                  _webViewController.clearCache();
                  break;
              }
            },
            itemBuilder: (_) {
              return [
                PopupMenuItem(
                  value: MenuItems.PREVIOUS_SESSION,
                  child: Text('Connect Previous Session'),
                ),
                PopupMenuItem(
                  value: MenuItems.KILL_SESSION,
                  child: Text('Kill Session'),
                ),
                PopupMenuItem(
                  value: MenuItems.SCAN_QR,
                  child: Text('Connect via QR'),
                ),
                PopupMenuItem(
                  value: MenuItems.CLEAR_CACHE,
                  child: Text('Clear Cache'),
                ),
              ];
            },
          ),
        ],
      ),
      body: InAppWebView(
        initialUrlRequest:
            URLRequest(url: Uri.parse('https://example.walletconnect.org')),
        initialOptions: InAppWebViewGroupOptions(
          crossPlatform: InAppWebViewOptions(
            useShouldOverrideUrlLoading: true,
          ),
        ),
        onWebViewCreated: (controller) {
          _webViewController = controller;
        },
        shouldOverrideUrlLoading: (controller, navAction) async {
          final uri = navAction.request.url;
          final url = uri.toString();
          debugPrint('URL $url');
          if (url.startsWith('wc:')) {
            if (url.contains('bridge') && url.contains('key')) {
              _qrScanHandler(url);
            }
            return NavigationActionPolicy.CANCEL;
          } else {
            return NavigationActionPolicy.ALLOW;
          }
        },
      ),
    );
  }

  _qrScanHandler(String value) {
    final session = WCSession.from(value);
    debugPrint('session $session');
    final peerMeta = WCPeerMeta(
      name: "Example Wallet",
      url: "https://example.wallet",
      description: "Example Wallet",
      icons: [
        "https://gblobscdn.gitbook.com/spaces%2F-LJJeCjcLrr53DcT1Ml7%2Favatar.png"
      ],
    );
    _wcClient.connectNewSession(session: session, peerMeta: peerMeta);
  }

  _connectToPreviousSession() {
    final _sessionSaved = _prefs.getString('session');
    debugPrint('_sessionSaved $_sessionSaved');
    _sessionStore = _sessionSaved != null
        ? WCSessionStore.fromJson(jsonDecode(_sessionSaved))
        : null;
    if (_sessionStore != null) {
      debugPrint('_sessionStore $_sessionStore');
      _wcClient.connectFromSessionStore(_sessionStore!);
    } else {
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(
        content: Text('No previous session found.'),
      ));
    }
  }

  _onConnect() {
    setState(() {
      connected = true;
    });
  }

  _onSessionRequest(int id, WCPeerMeta peerMeta) {
    showDialog(
      context: context,
      builder: (_) {
        return SimpleDialog(
          title: Column(
            children: [
              if (peerMeta.icons.isNotEmpty)
                Container(
                  height: 100.0,
                  width: 100.0,
                  padding: const EdgeInsets.only(bottom: 8.0),
                  child: Image.network(peerMeta.icons.first),
                ),
              Text(peerMeta.name),
            ],
          ),
          contentPadding: const EdgeInsets.fromLTRB(16.0, 12.0, 16.0, 16.0),
          children: [
            if (peerMeta.description.isNotEmpty)
              Padding(
                padding: const EdgeInsets.only(bottom: 8.0),
                child: Text(peerMeta.description),
              ),
            if (peerMeta.url.isNotEmpty)
              Padding(
                padding: const EdgeInsets.only(bottom: 8.0),
                child: Text('Connection to ${peerMeta.url}'),
              ),
            Row(
              children: [
                Expanded(
                  child: TextButton(
                    style: TextButton.styleFrom(
                      primary: Colors.white,
                      backgroundColor: Theme.of(context).accentColor,
                    ),
                    onPressed: () async {
                      _wcClient.approveSession(
                        accounts: [walletAddress],
                        // TODO: Mention Chain ID while connecting
                        chainId: 1,
                      );
                      _sessionStore = _wcClient.sessionStore;
                      await _prefs.setString('session',
                          jsonEncode(_wcClient.sessionStore.toJson()));
                      Navigator.pop(context);
                    },
                    child: Text('APPROVE'),
                  ),
                ),
                const SizedBox(width: 16.0),
                Expanded(
                  child: TextButton(
                    style: TextButton.styleFrom(
                      primary: Colors.white,
                      backgroundColor: Theme.of(context).accentColor,
                    ),
                    onPressed: () {
                      _wcClient.rejectSession();
                      Navigator.pop(context);
                    },
                    child: Text('REJECT'),
                  ),
                ),
              ],
            ),
          ],
        );
      },
    );
  }

  _onSessionError(dynamic message) {
    setState(() {
      connected = false;
    });
    showDialog(
      context: context,
      builder: (_) {
        return SimpleDialog(
          title: Text("Error"),
          contentPadding: const EdgeInsets.fromLTRB(16.0, 12.0, 16.0, 16.0),
          children: [
            Padding(
              padding: const EdgeInsets.only(bottom: 8.0),
              child: Text('Some Error Occured. $message'),
            ),
            Row(
              children: [
                TextButton(
                  style: TextButton.styleFrom(
                    primary: Colors.white,
                    backgroundColor: Theme.of(context).accentColor,
                  ),
                  onPressed: () {
                    Navigator.pop(context);
                  },
                  child: Text('CLOSE'),
                ),
              ],
            ),
          ],
        );
      },
    );
  }

  _onSessionClosed(int? code, String? reason) {
    _prefs.remove('session');
    setState(() {
      connected = false;
    });
    showDialog(
      context: context,
      builder: (_) {
        return SimpleDialog(
          title: Text("Session Ended"),
          contentPadding: const EdgeInsets.fromLTRB(16.0, 12.0, 16.0, 16.0),
          children: [
            Padding(
              padding: const EdgeInsets.only(bottom: 8.0),
              child: Text('Some Error Occured. ERROR CODE: $code'),
            ),
            if (reason != null)
              Padding(
                padding: const EdgeInsets.only(bottom: 8.0),
                child: Text('Failure Reason: $reason'),
              ),
            Row(
              children: [
                TextButton(
                  style: TextButton.styleFrom(
                    primary: Colors.white,
                    backgroundColor: Theme.of(context).accentColor,
                  ),
                  onPressed: () {
                    Navigator.pop(context);
                  },
                  child: Text('CLOSE'),
                ),
              ],
            ),
          ],
        );
      },
    );
  }

  _onSignTransaction(
    int id,
    WCEthereumTransaction ethereumTransaction,
  ) {
    _onTransaction(
      id: id,
      ethereumTransaction: ethereumTransaction,
      title: 'Sign Transaction',
      onConfirm: () async {
        final creds = EthPrivateKey.fromHex(privateKey);
        final tx = await _web3client.signTransaction(
          creds,
          _wcEthTxToWeb3Tx(ethereumTransaction),
          chainId: _wcClient.chainId!,
        );
        // final txhash = await _web3client.sendRawTransaction(tx);
        // debugPrint('txhash $txhash');
        _wcClient.approveRequest<String>(
          id: id,
          result: bytesToHex(tx),
        );
        Navigator.pop(context);
      },
      onReject: () {
        _wcClient.rejectRequest(id: id);
        Navigator.pop(context);
      },
    );
  }

  _onSendTransaction(
    int id,
    WCEthereumTransaction ethereumTransaction,
  ) {
    _onTransaction(
      id: id,
      ethereumTransaction: ethereumTransaction,
      title: 'Send Transaction',
      onConfirm: () async {
        final creds = EthPrivateKey.fromHex(privateKey);
        final txhash = await _web3client.sendTransaction(
          creds,
          _wcEthTxToWeb3Tx(ethereumTransaction),
          chainId: _wcClient.chainId!,
        );
        debugPrint('txhash $txhash');
        _wcClient.approveRequest<String>(
          id: id,
          result: txhash,
        );
        Navigator.pop(context);
      },
      onReject: () {
        _wcClient.rejectRequest(id: id);
        Navigator.pop(context);
      },
    );
  }

  _onTransaction({
    required int id,
    required WCEthereumTransaction ethereumTransaction,
    required String title,
    required VoidCallback onConfirm,
    required VoidCallback onReject,
  }) async {
    ContractFunction? contractFunction;
    BigInt gasPrice = BigInt.parse(ethereumTransaction.gasPrice ?? '0');
    try {
      final abiUrl =
          'https://api.polygonscan.com/api?module=contract&action=getabi&address=${ethereumTransaction.to}&apikey=BCER1MXNFHP1TVE93CMNVKC5J4FV8R4CPR';
      final res = await http.get(Uri.parse(abiUrl));
      final Map<String, dynamic> resMap = jsonDecode(res.body);
      final abi = ContractAbi.fromJson(resMap['result'], '');
      final contract = DeployedContract(
          abi, EthereumAddress.fromHex(ethereumTransaction.to));
      final dataBytes = hexToBytes(ethereumTransaction.data);
      final funcBytes = dataBytes.take(4).toList();
      debugPrint("funcBytes $funcBytes");
      final maibiFunctions = contract.functions
          .where((element) => listEquals<int>(element.selector, funcBytes));
      if (maibiFunctions.isNotEmpty) {
        debugPrint("isNotEmpty");
        contractFunction = maibiFunctions.first;
        debugPrint("function ${contractFunction.name}");
        // contractFunction.parameters.forEach((element) {
        //   debugPrint("params ${element.name} ${element.type.name}");
        // });
        // final params = dataBytes.sublist(4).toList();
        // debugPrint("params $params ${params.length}");
      }
      if (gasPrice == BigInt.zero) {
        gasPrice = await _web3client.estimateGas();
      }
    } catch (e, trace) {
      debugPrint("failed to decode\n$e\n$trace");
    }
    showDialog(
      context: context,
      builder: (_) {
        return SimpleDialog(
          title: Column(
            children: [
              if (_wcClient.remotePeerMeta!.icons.isNotEmpty)
                Container(
                  height: 100.0,
                  width: 100.0,
                  padding: const EdgeInsets.only(bottom: 8.0),
                  child: Image.network(_wcClient.remotePeerMeta!.icons.first),
                ),
              Text(
                _wcClient.remotePeerMeta!.name,
                style: TextStyle(
                  fontWeight: FontWeight.normal,
                  fontSize: 20.0,
                ),
              ),
            ],
          ),
          contentPadding: const EdgeInsets.fromLTRB(16.0, 12.0, 16.0, 16.0),
          children: [
            Container(
              alignment: Alignment.center,
              padding: const EdgeInsets.only(bottom: 8.0),
              child: Text(
                title,
                style: TextStyle(
                  fontWeight: FontWeight.bold,
                  fontSize: 18.0,
                ),
              ),
            ),
            Padding(
              padding: const EdgeInsets.only(bottom: 8.0),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    'Receipient',
                    style: TextStyle(
                      fontWeight: FontWeight.bold,
                      fontSize: 16.0,
                    ),
                  ),
                  const SizedBox(height: 8.0),
                  Text(
                    '${ethereumTransaction.to}',
                    style: TextStyle(fontSize: 16.0),
                  ),
                ],
              ),
            ),
            Padding(
              padding: const EdgeInsets.only(bottom: 8.0),
              child: Row(
                children: [
                  Expanded(
                    flex: 2,
                    child: Text(
                      'Transaction Fee',
                      style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 16.0,
                      ),
                    ),
                  ),
                  Expanded(
                    child: Text(
                      '${EthConversions.weiToEthUnTrimmed(gasPrice * BigInt.parse(ethereumTransaction.gas), 18)} MATIC',
                      style: TextStyle(fontSize: 16.0),
                    ),
                  ),
                ],
              ),
            ),
            Padding(
              padding: const EdgeInsets.only(bottom: 8.0),
              child: Row(
                children: [
                  Expanded(
                    flex: 2,
                    child: Text(
                      'Transaction Amount',
                      style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 16.0,
                      ),
                    ),
                  ),
                  Expanded(
                    child: Text(
                      '${EthConversions.weiToEthUnTrimmed(BigInt.parse(ethereumTransaction.value ?? '0'), 18)} MATIC',
                      style: TextStyle(fontSize: 16.0),
                    ),
                  ),
                ],
              ),
            ),
            if (contractFunction != null)
              Padding(
                padding: const EdgeInsets.only(bottom: 8.0),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      'Function',
                      style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 16.0,
                      ),
                    ),
                    const SizedBox(height: 8.0),
                    Text(
                      '${contractFunction.name}',
                      style: TextStyle(fontSize: 16.0),
                    ),
                  ],
                ),
              ),
            Theme(
              data:
                  Theme.of(context).copyWith(dividerColor: Colors.transparent),
              child: Padding(
                padding: const EdgeInsets.only(bottom: 8.0),
                child: ExpansionTile(
                  tilePadding: EdgeInsets.zero,
                  title: Text(
                    'Data',
                    style: TextStyle(
                      fontWeight: FontWeight.bold,
                      fontSize: 16.0,
                    ),
                  ),
                  children: [
                    Text(
                      '${ethereumTransaction.data}',
                      style: TextStyle(fontSize: 16.0),
                    ),
                  ],
                ),
              ),
            ),
            Row(
              children: [
                Expanded(
                  child: TextButton(
                    style: TextButton.styleFrom(
                      primary: Colors.white,
                      backgroundColor: Theme.of(context).accentColor,
                    ),
                    onPressed: onConfirm,
                    child: Text('CONFIRM'),
                  ),
                ),
                const SizedBox(width: 16.0),
                Expanded(
                  child: TextButton(
                    style: TextButton.styleFrom(
                      primary: Colors.white,
                      backgroundColor: Theme.of(context).accentColor,
                    ),
                    onPressed: onReject,
                    child: Text('REJECT'),
                  ),
                ),
              ],
            ),
          ],
        );
      },
    );
  }

  _onSign(
    int id,
    WCEthereumSignMessage ethereumSignMessage,
  ) {
    final decoded = (ethereumSignMessage.type == WCSignType.TYPED_MESSAGE)
        ? ethereumSignMessage.data!
        : ascii.decode(hexToBytes(ethereumSignMessage.data!));
    showDialog(
      context: context,
      builder: (_) {
        return SimpleDialog(
          title: Column(
            children: [
              if (_wcClient.remotePeerMeta!.icons.isNotEmpty)
                Container(
                  height: 100.0,
                  width: 100.0,
                  padding: const EdgeInsets.only(bottom: 8.0),
                  child: Image.network(_wcClient.remotePeerMeta!.icons.first),
                ),
              Text(
                _wcClient.remotePeerMeta!.name,
                style: TextStyle(
                  fontWeight: FontWeight.normal,
                  fontSize: 20.0,
                ),
              ),
            ],
          ),
          contentPadding: const EdgeInsets.fromLTRB(16.0, 12.0, 16.0, 16.0),
          children: [
            Container(
              alignment: Alignment.center,
              padding: const EdgeInsets.only(bottom: 8.0),
              child: Text(
                'Sign Message',
                style: TextStyle(
                  fontWeight: FontWeight.bold,
                  fontSize: 18.0,
                ),
              ),
            ),
            Theme(
              data:
                  Theme.of(context).copyWith(dividerColor: Colors.transparent),
              child: Padding(
                padding: const EdgeInsets.only(bottom: 8.0),
                child: ExpansionTile(
                  tilePadding: EdgeInsets.zero,
                  title: Text(
                    'Message',
                    style: TextStyle(
                      fontWeight: FontWeight.bold,
                      fontSize: 16.0,
                    ),
                  ),
                  children: [
                    Text(
                      decoded,
                      style: TextStyle(fontSize: 16.0),
                    ),
                  ],
                ),
              ),
            ),
            Row(
              children: [
                Expanded(
                  child: TextButton(
                    style: TextButton.styleFrom(
                      primary: Colors.white,
                      backgroundColor: Theme.of(context).accentColor,
                    ),
                    onPressed: () async {
                      final creds = EthPrivateKey.fromHex(privateKey);
                      final signedData = await creds.signPersonalMessage(
                          Uint8List.fromList(
                              utf8.encode(ethereumSignMessage.data!)));
                      final signedDataHex =
                          bytesToHex(signedData, include0x: true);
                      debugPrint('SIGNED $signedDataHex');
                      _wcClient.approveRequest<String>(
                        id: id,
                        result: signedDataHex,
                      );
                      Navigator.pop(context);
                    },
                    child: Text('SIGN'),
                  ),
                ),
                const SizedBox(width: 16.0),
                Expanded(
                  child: TextButton(
                    style: TextButton.styleFrom(
                      primary: Colors.white,
                      backgroundColor: Theme.of(context).accentColor,
                    ),
                    onPressed: () {
                      _wcClient.rejectRequest(id: id);
                      Navigator.pop(context);
                    },
                    child: Text('REJECT'),
                  ),
                ),
              ],
            ),
          ],
        );
      },
    );
  }

  Transaction _wcEthTxToWeb3Tx(WCEthereumTransaction ethereumTransaction) {
    return Transaction(
      from: EthereumAddress.fromHex(ethereumTransaction.from),
      to: EthereumAddress.fromHex(ethereumTransaction.to),
      maxGas: ethereumTransaction.gasLimit != null
          ? int.tryParse(ethereumTransaction.gasLimit!)
          : null,
      gasPrice: ethereumTransaction.gasPrice != null
          ? EtherAmount.inWei(BigInt.parse(ethereumTransaction.gasPrice!))
          : null,
      value: EtherAmount.inWei(BigInt.parse(ethereumTransaction.value ?? '0')),
      data: hexToBytes(ethereumTransaction.data),
      nonce: ethereumTransaction.nonce != null
          ? int.tryParse(ethereumTransaction.nonce!)
          : null,
    );
  }
}