posix_sdk 0.0.3

Posix SDK is a bluetooth plugin for Flutter, a new app SDK to help developers build modern multi-platform apps. Using the Posix SDK instance, you can scan for and check LED to nearby devices.

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:flutter_blue/flutter_blue.dart';
import 'package:posix_sdk/posix_sdk.dart';


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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      color: Colors.lightBlue,
      home: StreamBuilder<BluetoothState>(
          stream: FlutterBlue.instance.state,
          initialData: BluetoothState.unknown,
          builder: (c, snapshot) {
            final state = snapshot.data;
            if (state == BluetoothState.on) {
              return ListDevicesScreen();
            }
            return BluetoothOffScreen(state: state);
          }),
    );
  }
}

class ListDevicesScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    PosixSdk posixSdk = PosixSdk.instance;
    return Scaffold(
      appBar: AppBar(
        title: const Text('Find Devices'),
      ),
      body: RefreshIndicator(
        onRefresh: () =>
            FlutterBlue.instance.startScan(scanMode: ScanMode.opportunistic, timeout: const Duration(seconds: 30)),
        child: SingleChildScrollView(
          child: Column(
            children: <Widget>[
              StreamBuilder<List<ScanResult>>(
                stream: FlutterBlue.instance.scanResults,
                initialData: [],
                builder: (c, snapshot) => Column(
                  children: snapshot.data!
                      .map(
                        (r) => ScanResultTile(
                      result: r,
                      onTap: () => {
                        FlutterBlue.instance.stopScan(),
                        posixSdk.connect(device: r.device)
                      },
                    ),
                  )
                      .toList(),
                ),
              ),
            ],
          ),
        ),
      ),
      floatingActionButton: StreamBuilder<bool>(
        stream: FlutterBlue.instance.isScanning,
        initialData: false,
        builder: (c, snapshot) {
          if (snapshot.data!) {
            return FloatingActionButton(
              child: const Icon(Icons.stop),
              onPressed: () => FlutterBlue.instance.stopScan(),
              backgroundColor: Colors.red,
            );
          } else {
            return FloatingActionButton(
                child: const Icon(Icons.search),
                onPressed: () => FlutterBlue.instance
                    .startScan(timeout: const Duration(seconds: 60)));
          }
        },
      ),
    );
  }
}

class ScanResultTile extends StatelessWidget {
  const ScanResultTile({Key? key, required this.result, this.onTap})
      : super(key: key);

  final ScanResult result;
  final VoidCallback? onTap;

  Widget _buildTitle(BuildContext context) {
    if (result.device.name.length > 0) {
      return Column(
        mainAxisAlignment: MainAxisAlignment.start,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Text(
            result.device.name,
            overflow: TextOverflow.ellipsis,
          ),
          Text(
            result.device.id.toString(),
            style: Theme.of(context).textTheme.caption,
          )
        ],
      );
    } else {
      return Text(result.device.id.toString());
    }
  }

  Widget _buildAdvRow(BuildContext context, String title, String value) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16.0, vertical: 4.0),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Text(title, style: Theme.of(context).textTheme.caption),
          const SizedBox(
            width: 12.0,
          ),
          Expanded(
            child: Text(
              value,
              style: Theme.of(context)
                  .textTheme
                  .caption
                  ?.apply(color: Colors.black),
              softWrap: true,
            ),
          ),
        ],
      ),
    );
  }

  String getNiceHexArray(List<int> bytes) {
    return '[${bytes.map((i) => i.toRadixString(16).padLeft(2, '0')).join(', ')}]'
        .toUpperCase();
  }

  String getNiceManufacturerData(Map<int, List<int>> data) {
    if (data.isEmpty) {
      return 'N/A';
    }
    List<String> res = [];
    data.forEach((id, bytes) {
      res.add(
          '${id.toRadixString(16).toUpperCase()}: ${getNiceHexArray(bytes)}');
    });
    return res.join(', ');
  }

  String getNiceServiceData(Map<String, List<int>> data) {
    if (data.isEmpty) {
      return 'N/A';
    }
    List<String> res = [];
    data.forEach((id, bytes) {
      res.add('${id.toUpperCase()}: ${getNiceHexArray(bytes)}');
    });
    return res.join(', ');
  }

  @override
  Widget build(BuildContext context) {
    return ExpansionTile(
      title: _buildTitle(context),
      leading: Text(result.rssi.toString()),
      trailing: RaisedButton(
        child: const Text('LED'),
        color: Colors.black,
        textColor: Colors.white,
        onPressed: (result.advertisementData.connectable) ? onTap : null,
      ),
      children: <Widget>[
        _buildAdvRow(
            context, 'Complete Local Name', result.advertisementData.localName),
        _buildAdvRow(context, 'Tx Power Level',
            '${result.advertisementData.txPowerLevel ?? 'N/A'}'),
        _buildAdvRow(context, 'Manufacturer Data',
            getNiceManufacturerData(result.advertisementData.manufacturerData)),
        _buildAdvRow(
            context,
            'Service UUIDs',
            (result.advertisementData.serviceUuids.isNotEmpty)
                ? result.advertisementData.serviceUuids.join(', ').toUpperCase()
                : 'N/A'),
        _buildAdvRow(context, 'Service Data',
            getNiceServiceData(result.advertisementData.serviceData)),
      ],
    );
  }
}

class BluetoothOffScreen extends StatelessWidget {
  const BluetoothOffScreen({Key? key, this.state}) : super(key: key);

  final BluetoothState? state;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.lightBlue,
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: <Widget>[
            const Icon(
              Icons.bluetooth_disabled,
              size: 200.0,
              color: Colors.white54,
            ),
            Text(
              'Bluetooth Adapter is ${state != null ? state.toString().substring(15) : 'not available'}.',
              style: Theme.of(context)
                  .primaryTextTheme
                  .subtitle1
                  ?.copyWith(color: Colors.white),
            ),
          ],
        ),
      ),
    );
  }
}