Orb example

orb_example.dart

import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:web3modal_flutter/web3modal_flutter.dart';

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

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

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> with WidgetsBindingObserver {
  W3MService? _w3mService;

  @override
  void initState() {
    super.initState();
    _initializeW3MService();
  }

  void _initializeW3MService() async {
    _w3mService = W3MService(
      projectId: '*************',
      logLevel: LogLevel.error,
      metadata: const PairingMetadata(
        name: 'Orb Example',
        description: 'Orb Example',
        url: 'https://www.orb.ac',
        icons: [
          'https://play-lh.googleusercontent.com/F7vuFJeNqT-NyNAHextoMwj4zs_oiQ4MozcjuR-IZQJZuMM-Q4SSBfcoAQa_O0Kk7BM=w600-h300-pc0xffffff-pd'
        ],
        redirect: Redirect(
          native: 'flutterdapp://',
          universal: 'https://www.orb.ac',
        ),
      ),
    );

    _w3mService?.addListener(_onServiceUpdate);
    _w3mService?.web3App?.onSessionConnect.subscribe(_onSessionConnect);

    await _w3mService?.init();
  }

  @override
  void dispose() {
    _w3mService?.removeListener(_onServiceUpdate);
    _w3mService?.web3App?.onSessionConnect.unsubscribe(_onSessionConnect);
    super.dispose();
  }

  void _onSessionConnect(SessionConnect? event) async {
    debugPrint('[$runtimeType] _onSessionConnect $event');
    await _switchToPolygonIfNeeded();
  }

  Future<void> _switchToPolygonIfNeeded() async {
    final approvedChains = _w3mService?.getApprovedChains() ?? [];
    final polygonChain = W3MChainPresets.chains['137']!;
    if (!approvedChains.contains(polygonChain.namespace)) {
      if (_w3mService?.selectedChain?.namespace == polygonChain.namespace) {
        final firstChainId = approvedChains.first.split(':')[1];
        final firstChain = W3MChainPresets.chains[firstChainId]!;
        await _w3mService?.selectChain(firstChain);
      }
      Future.delayed(const Duration(milliseconds: 500), () async {
        await _w3mService?.selectChain(polygonChain, switchChain: true);
      });
    }
  }

  void _onServiceUpdate() {
    debugPrint('[$runtimeType] isConnected: ${_w3mService?.isConnected}');
    debugPrint('[$runtimeType] address: ${_w3mService?.address}');
    debugPrint(
        '[$runtimeType] current chain: ${_w3mService?.selectedChain?.namespace}');
    debugPrint(
        '[$runtimeType] approved chains ${_w3mService?.getApprovedChains()}');
    setState(() {
      result =
          'Approved methods:\n${_w3mService?.session?.namespaces['eip155']?.methods.join(', ')}';
    });
  }

  Future<dynamic> signMessage({
    required String message,
    required String method,
  }) async {
    final web3App = _w3mService!.web3App;
    final address = _w3mService!.address?.toLowerCase() ?? '';
    final messageToUse = message;
    final methodToUse = method;
    final topic = _w3mService!.session!.topic;

    _w3mService?.launchConnectedWallet();
    web3App?.request(
      topic: topic,
      chainId: 'eip155:137',
      request: SessionRequestParams(
        method: methodToUse,
        params: [address, messageToUse],
      ),
    );

    return null;
  }

  String result = '';
  void _signMessage() async {
    final chainId = _w3mService!.selectedChain?.chainId ?? '1';
    signMessage(
      message: typedDataV4(int.parse(chainId)),
      method: 'eth_signTypedData_v4',
    );
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Orb Demo',
      home: Builder(
        builder: (context) {
          if (_w3mService == null) {
            return const CircularProgressIndicator.adaptive();
          }
          return Scaffold(
            appBar: AppBar(
              title: const Text('Orb Demo'),
            ),
            body: Container(
              constraints: const BoxConstraints.expand(),
              padding: const EdgeInsets.all(12.0),
              child: Column(
                children: !_w3mService!.isConnected
                    ? [
                        W3MNetworkSelectButton(service: _w3mService!),
                        W3MConnectWalletButton(service: _w3mService!),
                      ]
                    : [
                        W3MConnectWalletButton(service: _w3mService!),
                        const SizedBox.square(dimension: 8.0),
                        ElevatedButton(
                          onPressed: _signMessage,
                          child: const Text('Sign message'),
                        ),
                        const SizedBox.square(dimension: 8.0),
                        if (result.isNotEmpty)
                          Text(
                            result,
                            style: const TextStyle(color: Colors.grey),
                          ),
                      ],
              ),
            ),
          );
        },
      ),
    );
  }
}

String typedDataV4(int chainId) => jsonEncode({
      "types": {
        "EIP712Domain": [
          {"name": "name", "type": "string"},
          {"name": "version", "type": "string"},
          {"name": "chainId", "type": "uint256"},
          {"name": "verifyingContract", "type": "address"}
        ],
        "Person": [
          {"name": "name", "type": "string"},
          {"name": "wallet", "type": "address"}
        ],
        "Mail": [
          {"name": "from", "type": "Person"},
          {"name": "to", "type": "Person"},
          {"name": "contents", "type": "string"}
        ]
      },
      "primaryType": "Mail",
      "domain": {
        "name": "Ether Mail",
        "version": "1",
        "chainId": chainId,
        "verifyingContract": "0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC"
      },
      "message": {
        "from": {
          "name": "Cow",
          "wallet": "0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826"
        },
        "to": {
          "name": "Bob",
          "wallet": "0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB"
        },
        "contents": "Hello, Bob!"
      }
    });