flutter_ledger_lib 1.0.0

A Flutter project for interacting with Ledger Nano devices.

example/lib/main.dart

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

import 'package:flutter_ledger_lib/flutter_ledger_lib.dart';

Future<void> main() async {
  runApp(const MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

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

class _MyAppState extends State<MyApp> {
  bool isInit = false;
  LedgerTransport? ledgerTransport;
  final keyNotifier = ValueNotifier<String?>(null);
  int keyIndex = 0;
  String errorText = '';
  List<LedgerDevice> devices = [];

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Plugin example app'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.spaceAround,
            children: [
              ElevatedButton(
                onPressed: getLedgers,
                child: const Text(
                  'Get ledgers',
                ),
              ),
              ...devices
                  .map(
                    (device) => TextButton(
                      onPressed: ledgerTransport == null
                          ? () => connectLedger(
                                device.path,
                              )
                          : null,
                      child: Text(
                        device.name,
                      ),
                    ),
                  )
                  .toList(),
              ValueListenableBuilder<String?>(
                valueListenable: keyNotifier,
                builder: (context, value, _) => SizedBox(
                  height: 50,
                  child: AnimatedSwitcher(
                    duration: const Duration(milliseconds: 200),
                    child: value == null
                        ? const SizedBox()
                        : value.isEmpty
                            ? const CircularProgressIndicator()
                            : Text(value),
                  ),
                ),
              ),
              Text(errorText.isNotEmpty ? 'Error: $errorText' : ''),
              Text('Key index = $keyIndex'),
              Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  IconButton(
                    onPressed: () {
                      setState(() {
                        if (keyIndex > 0) {
                          --keyIndex;
                        }
                      });
                    },
                    icon: const Text('-1'),
                  ),
                  const SizedBox(
                    width: 20,
                  ),
                  IconButton(
                    onPressed: () {
                      setState(() {
                        ++keyIndex;
                      });
                    },
                    icon: const Text('+1'),
                  ),
                ],
              ),
              ElevatedButton(
                onPressed: ledgerTransport != null
                    ? () async {
                        try {
                          keyNotifier.value = '';
                          final key = await ledgerTransport!.getKey(keyIndex);
                          // final key = await ledgerTransport!.signMessage(
                          //   keyIndex: 0,
                          //   address: 'some64LenghtValue',
                          //   destination: '0:some64LenghtValue2',
                          //   decimals: 9,
                          //   amount: 1000000000,
                          //   asset: 'VENOM',
                          // );
                          setState(() {
                            errorText = '';
                          });
                          if (key.isNotEmpty) {
                            keyNotifier.value = key;
                          } else {
                            keyNotifier.value = null;
                          }
                        } catch (err) {
                          _mapError(err);
                        }
                      }
                    : null,
                child: const Text(
                  'Get public key',
                ),
              ),
              ElevatedButton(
                onPressed: ledgerTransport != null ? disconnectLedger : null,
                child: const Text(
                  'Disconnect ledger',
                  style: TextStyle(color: Colors.white),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  void _mapError(Object err) {
    if (err is LedgerError) {
      setState(() {
        keyNotifier.value = null;
        errorText = err.when(
          connectionError: (error) => error,
          responseError: (sw) => sw.toString(),
        );
      });
    }
  }

  Future<void> connectLedger(String path) async {
    try {
      ledgerTransport = await LedgerTransport.create(
        path: path,
        appName: 'Your app name',
      );
      setState(() {});
    } catch (err) {
      _mapError(err);
    }
  }

  Future<void> disconnectLedger() async {
    keyNotifier.value = null;
    setState(() {
      ledgerTransport = null;
    });
  }

  Future<void> getLedgers() async {
    final a = await LedgerTransport.getLedgerDevices();
    setState(() {
      devices = [...a];
    });
  }
}