wallet_connect_v2 0.1.1

Wallet Connect V2 for Flutter

example/lib/main.dart

import 'dart:convert';

import 'package:bip32/bip32.dart' as bip32;
import 'package:bip39/bip39.dart' as bip39;
import 'package:eth_sig_util/eth_sig_util.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:hex/hex.dart';
import 'package:http/http.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:wallet_connect_v2/wallet_connect_v2.dart';
import 'package:web3dart/crypto.dart';
import 'package:web3dart/web3dart.dart';

void main() {
  runApp(const MainApp());
}

class MainApp extends StatelessWidget {
  const MainApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: HomeView(),
    );
  }
}

class HomeView extends StatefulWidget {
  const HomeView({super.key});

  @override
  State<HomeView> createState() => _HomeViewState();
}

class _HomeViewState extends State<HomeView> with WidgetsBindingObserver {
  static const projectId = '45caf086591c46efb6e9f19b6104d7e8';

  final _walletConnectV2Plugin = WalletConnectV2();
  final _walletMetadata = AppMetadata(
      name: 'Flutter Wallet',
      url: 'https://avacus.cc',
      description: 'Flutter Wallet by Avacus',
      icons: ['https://avacus.cc/apple-icon-180x180.png']);
  final _uriController = TextEditingController();
  final List<Session> _sessions = [];

  late String _privateKey;
  late String _address;

  bool _isLoading = false;
  bool _isInitiated = false;
  bool _isForeground = true;
  bool _isBackground = false;

  @override
  void initState() {
    WidgetsBinding.instance.addObserver(this);
    super.initState();
    _walletConnectV2Plugin.onConnectionStatus = (isConnected) async {
      debugPrint('---: CONNECTED: $isConnected');
      if (_isInitiated) {
        if (!isConnected && _isForeground) {
          _walletConnectV2Plugin.connect();
        }
      } else {
        if (isConnected) {
          setState(() {
            _isLoading = false;
            _isInitiated = true;
          });
          _refreshSessions();
        } else {
          setState(() {
            _isLoading = false;
          });
        }
      }
    };
    _walletConnectV2Plugin.onSessionProposal = (proposal) async {
      setState(() {
        _isLoading = false;
      });
      if (proposal.namespaces.length != 1 ||
          !proposal.namespaces.containsKey('eip155') ||
          int.parse(
                  proposal.namespaces['eip155']!.chains.first.split(':')[1]) !=
              5) {
        _showDialog(
            child: const Text('Please choose GOERLI testnet only to do test!'));
        _walletConnectV2Plugin.rejectSession(proposalId: proposal.id);
        return;
      }
      final isApprove = await _showDialog(
          child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          const Text('Session Proposal'),
          const SizedBox(height: 16),
          Text(proposal.toJson().toString()),
          const SizedBox(height: 16),
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: [
              TextButton(
                  onPressed: () {
                    Navigator.of(context).pop(false);
                  },
                  child: const Text('Reject')),
              TextButton(
                  onPressed: () {
                    Navigator.of(context).pop(true);
                  },
                  child: const Text('Approve')),
            ],
          )
        ],
      ));
      if (isApprove == true) {
        try {
          _walletConnectV2Plugin.approveSession(
              approval: SessionApproval(
                  id: proposal.id,
                  namespaces: proposal.namespaces.map((key, value) => MapEntry(
                      key,
                      SessionNamespace(
                          accounts:
                              value.chains.map((e) => '$e:$_address').toList(),
                          methods: value.methods,
                          events: value.events,
                          extensions: value.extensions)))));
        } catch (e) {
          _showDialog(child: Text('Approve session error: ${e.toString()}'));
        }
      } else {
        try {
          _walletConnectV2Plugin.rejectSession(proposalId: proposal.id);
        } catch (e) {
          _showDialog(child: Text('Reject session error: ${e.toString()}'));
        }
      }
    };

    _walletConnectV2Plugin.onSessionSettle = (session) {
      _refreshSessions();
    };

    _walletConnectV2Plugin.onSessionUpdate = (_) {
      _refreshSessions();
    };

    _walletConnectV2Plugin.onSessionDelete = (_) {
      _refreshSessions();
    };

    _walletConnectV2Plugin.onEventError = (code, message) {
      _showDialog(child: Text(message));
    };

    _walletConnectV2Plugin.onSessionRequest = (request) async {
      final isApprove = await _showDialog(
          child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          const Text('Session Request'),
          const SizedBox(height: 16),
          Text(request.toJson().toString()),
          const SizedBox(height: 16),
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
            children: [
              TextButton(
                  onPressed: () {
                    Navigator.of(context).pop(false);
                  },
                  child: const Text('Reject')),
              TextButton(
                  onPressed: () {
                    Navigator.of(context).pop(true);
                  },
                  child: const Text('Approve')),
            ],
          )
        ],
      ));
      if (isApprove) {
        switch (request.method) {
          case 'eth_sendTransaction':
          case 'eth_signTransaction':
            try {
              final object = request.params.first as Map;
              final gasLimit = object['gasLimit'] != null
                  ? BigInt.tryParse(object['gasLimit'])
                  : null;
              final gasPrice = object['gasPrice'] != null
                  ? EtherAmount.fromUnitAndValue(
                      EtherUnit.wei, object['gasPrice'])
                  : null;
              final value = object['value'] != null
                  ? EtherAmount.fromUnitAndValue(EtherUnit.wei, object['value'])
                  : null;
              final from = object['from'] != null
                  ? EthereumAddress.fromHex(object['from'])
                  : null;
              final to = object['to'] != null
                  ? EthereumAddress.fromHex(object['to'])
                  : null;
              final data =
                  object['data'] != null ? hexToBytes(object['data']) : null;
              final tx = Transaction(
                from: from,
                data: data,
                value: value,
                maxGas: gasLimit?.toInt(),
                to: to,
                gasPrice: gasPrice,
              );
              final client =
                  Web3Client('https://rpc.ankr.com/eth_goerli', Client());
              final signature = await client.signTransaction(
                  EthPrivateKey.fromHex(_privateKey), tx);
              await _walletConnectV2Plugin.approveRequest(
                  topic: request.topic,
                  requestId: request.id,
                  result: bytesToHex(signature, include0x: true));
            } catch (e) {
              _showDialog(child: Text('Sign error: ${e.toString()}'));
            }
            break;
          case 'personal_sign':
          case 'eth_sign':
            try {
              final message =
                  request.params.firstWhere((element) => element != _address);
              final signature = EthSigUtil.signPersonalMessage(
                  message: hexToBytes(message), privateKey: _privateKey);
              await _walletConnectV2Plugin.approveRequest(
                  topic: request.topic,
                  requestId: request.id,
                  result: signature);
            } catch (e) {
              _showDialog(child: Text('Approve error: ${e.toString()}'));
            }
            break;
          case 'eth_signTypedData':
            try {
              final message =
                  request.params.firstWhere((element) => element != _address);
              final jsonData = message is Map ? jsonEncode(message) : message;
              final signature = EthSigUtil.signTypedData(
                  jsonData: jsonData.toString(),
                  privateKey: _privateKey,
                  version: TypedDataVersion.V4);
              await _walletConnectV2Plugin.approveRequest(
                  topic: request.topic,
                  requestId: request.id,
                  result: signature);
            } catch (e) {
              _showDialog(
                  child: Text('Approve request error: ${e.toString()}'));
            }
            break;
          default:
            _showDialog(child: Text('Unhandled method ${request.method}'));
            break;
        }
      } else {
        try {
          await _walletConnectV2Plugin.rejectRequest(
              topic: request.topic, requestId: request.id);
        } catch (e) {
          _showDialog(child: Text('Reject request error: ${e.toString()}'));
        }
      }
    };
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      resizeToAvoidBottomInset: false,
      appBar: AppBar(
        title: const Text('Wallet Connect Flutter V2'),
      ),
      body: SafeArea(
        child: Center(
          child: _isLoading
              ? const CupertinoActivityIndicator()
              : _isInitiated
                  ? Padding(
                      padding: const EdgeInsets.all(16),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          const Text('Sessions:'),
                          Expanded(
                              child: _sessions.isEmpty
                                  ? const Center(
                                      child: Text(
                                          'No sessions\n\nPair wallet connect uri and approve to have session',
                                          textAlign: TextAlign.center))
                                  : ListView.separated(
                                      padding: const EdgeInsets.symmetric(
                                          vertical: 16),
                                      itemBuilder: (_, index) {
                                        final session = _sessions[index];
                                        return Container(
                                          padding: const EdgeInsets.all(16),
                                          decoration: BoxDecoration(
                                              borderRadius:
                                                  BorderRadius.circular(12),
                                              border: Border.all(
                                                  width: 1,
                                                  color: Colors.grey)),
                                          child: Column(
                                            mainAxisSize: MainAxisSize.min,
                                            children: [
                                              Text(session.toJson().toString()),
                                              TextButton(
                                                  onPressed: () async {
                                                    try {
                                                      await _walletConnectV2Plugin
                                                          .disconnectSession(
                                                              topic: session
                                                                  .topic);
                                                      _refreshSessions();
                                                    } catch (e) {
                                                      _showDialog(
                                                          child: Text(
                                                              'Disconnect session error: ${e.toString()}'));
                                                    }
                                                  },
                                                  child:
                                                      const Text('Disconnect'))
                                            ],
                                          ),
                                        );
                                      },
                                      separatorBuilder: (_, __) =>
                                          const SizedBox(height: 16),
                                      itemCount: _sessions.length)),
                          Container(
                              width: double.infinity,
                              height: 1,
                              color: Colors.grey,
                              margin: const EdgeInsets.symmetric(vertical: 16)),
                          Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              const Text('Account:'),
                              const SizedBox(height: 8),
                              Text('Private Key: $_privateKey'),
                              const SizedBox(height: 8),
                              Text('Address: $_address'),
                              const SizedBox(height: 8),
                              const Text(
                                  'PLEASE CHOOSE GOERLI NETWORK ONLY TO PAIR!',
                                  style: TextStyle(color: Colors.redAccent)),
                              const SizedBox(height: 8),
                              Container(
                                padding:
                                    const EdgeInsets.symmetric(horizontal: 16),
                                width: double.infinity,
                                height: 56,
                                decoration: BoxDecoration(
                                    borderRadius: BorderRadius.circular(12),
                                    border: Border.all(
                                        width: 1, color: Colors.grey)),
                                child: TextFormField(
                                    controller: _uriController,
                                    maxLines: 1,
                                    maxLength: 512,
                                    cursorWidth: 2,
                                    cursorColor: Colors.grey,
                                    decoration: const InputDecoration(
                                        border: InputBorder.none,
                                        hintText: "Enter wallet connect URI",
                                        counterText: '')),
                              ),
                              const SizedBox(height: 8),
                              Row(
                                mainAxisAlignment:
                                    MainAxisAlignment.spaceEvenly,
                                children: [
                                  TextButton(
                                      onPressed: () {
                                        Clipboard.getData('text/plain')
                                            .then((data) {
                                          if (data?.text == null) return;
                                          _uriController.text = data!.text!;
                                        });
                                      },
                                      child: const Text('Paste')),
                                  TextButton(
                                      onPressed: () async {
                                        try {
                                          setState(() {
                                            _isLoading = true;
                                          });
                                          final uri = _uriController.text;
                                          if (uri.trim().isEmpty) {
                                            _showDialog(
                                                child: const Text(
                                                    'Please paste the WalletConnect V2 URI then do Pair'));
                                            return;
                                          }
                                          _uriController.clear();
                                          await _walletConnectV2Plugin.pair(
                                              uri: uri);
                                        } catch (e) {
                                          _showDialog(
                                              child: Text(
                                                  'Pair error: ${e.toString()}'));
                                        } finally {
                                          setState(() {
                                            _isLoading = false;
                                          });
                                        }
                                      },
                                      child: const Text('Pair'))
                                ],
                              )
                            ],
                          ),
                        ],
                      ),
                    )
                  : TextButton(
                      onPressed: () async {
                        setState(() {
                          _isLoading = true;
                        });
                        await _initWallet();
                        await _walletConnectV2Plugin.init(
                            projectId: projectId, appMetadata: _walletMetadata);
                        await _walletConnectV2Plugin.connect();
                      },
                      child: const Text('Init WalletConnect')),
        ),
      ),
    );
  }

  void _refreshSessions() async {
    try {
      final sessions = await _walletConnectV2Plugin.getActivatedSessions();
      setState(() {
        this._sessions.clear();
        this._sessions.addAll(sessions);
      });
    } catch (e) {
      _showDialog(child: Text('Refresh sessions error: ${e.toString()}'));
    }
  }

  Future _showDialog({required Widget child}) {
    return showDialog(
        context: context,
        builder: (context) {
          return Dialog(
            insetPadding: const EdgeInsets.symmetric(horizontal: 16),
            backgroundColor: Colors.transparent,
            child: Card(
              clipBehavior: Clip.antiAlias,
              color: Colors.white,
              shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(12)),
              child: Container(
                padding: const EdgeInsets.all(16),
                child: child,
              ),
            ),
          );
        });
  }

  Future _initWallet() async {
    final sp = await SharedPreferences.getInstance();
    final mnemonic = sp.getString('mnemonic') ?? bip39.generateMnemonic();
    if (!sp.containsKey('mnemonic')) {
      await sp.setString('mnemonic', mnemonic);
    }
    final seed = bip39.mnemonicToSeed(mnemonic);
    final wallet = bip32.BIP32.fromSeed(seed);
    final pathWallet = wallet.derivePath('''m/44'/60'/0'/0/0''');
    _privateKey = HEX.encode(pathWallet.privateKey!);
    final private = EthPrivateKey.fromHex(_privateKey);
    _address = (await private.extractAddress()).hexEip55;
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    super.didChangeAppLifecycleState(state);
    switch (state) {
      case AppLifecycleState.resumed:
        _isBackground = false;
        _isForeground = true;
        debugPrint('---: DO CONNECT');
        if (_isInitiated) {
          _walletConnectV2Plugin.connect();
        }
        break;
      case AppLifecycleState.inactive:
        _isForeground = false;
        if (!_isBackground) {
          debugPrint('---: DO DISCONNECT');
          if (_isInitiated) {
            _walletConnectV2Plugin.disconnect();
          }
        }
        break;
      case AppLifecycleState.paused:
        _isForeground = false;
        _isBackground = true;
        break;
      case AppLifecycleState.detached:
      default:
        break;
    }
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    _walletConnectV2Plugin.dispose();
    super.dispose();
  }
}