flutter-sport/lib/widgets/dialog/search_device.dart

import 'dart:async';
import 'dart:io';
import 'dart:math';

import 'package:android_intent/android_intent.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_blue/flutter_blue.dart';
import 'package:provider/provider.dart';
import 'package:sport/pages/my/device_info_page.dart';
import 'package:sport/provider/bluetooth.dart';
import 'package:sport/widgets/button_cancel.dart';
import 'package:sport/widgets/button_primary.dart';
import 'package:sport/widgets/image.dart';
import 'package:sport/widgets/misc.dart';
import 'package:url_launcher/url_launcher.dart';

class SearchDeviceDialog extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => _SearchDeviceDialog();
}

class _SearchDeviceDialog extends State<SearchDeviceDialog> {
  @override
  void dispose() {
    super.dispose();
    FlutterBlue.instance.stopScan();
  }

  @override
  Widget build(BuildContext context) {
    return Dialog(
      elevation: 0,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
      child: Padding(
          padding: const EdgeInsets.all(8.0),
          child: ConstrainedBox(
            constraints: BoxConstraints(maxHeight: 350, minWidth: double.infinity),
            child: Column(
              children: <Widget>[
                Stack(
                  alignment: Alignment.center,
                  children: <Widget>[
                    Center(
                      child: Padding(
                        padding: const EdgeInsets.all(6.0),
                        child: Text("请选择鞋子", style: Theme.of(context).textTheme.headline3),
                      ),
                    ),
                    Positioned(
                      right: 0,
                      top: 0,
                      child: GestureDetector(
                        behavior: HitTestBehavior.opaque,
                        onTap: () => Navigator.pop(context),
                        child: Padding(
                          padding: const EdgeInsets.all(6.0),
                          child: Image.asset("lib/assets/img/btn_close_big.png"),
                        ),
                      ),
                    ),
                  ],
                ),
                Divider(),
                Expanded(
                  child: StreamBuilder<BluetoothState>(
                      stream: FlutterBlue.instance.state,
                      initialData: BluetoothState.unknown,
                      builder: (c, snapshot) {
                        final state = snapshot.data;
                        if (state == BluetoothState.on) {
                          return FindDevicesScreen();
                        }
                        return BluetoothOffScreen(state: state);
                      }),
                ),
              ],
            ),
          )),
    );
  }
}

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

  final BluetoothState state;

  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: <Widget>[
        SizedBox(
          height: 60,
        ),
        Image.asset("lib/assets/img/pop_image_close.png"),
        SizedBox(
          height: 20,
        ),
        Text(
          '搜索失败，请确认蓝牙是否打开',
          style: Theme.of(context).textTheme.bodyText2.copyWith(color: Color(0xff666666)),
        ),
        SizedBox(
          height: 10,
        ),
        GestureDetector(
          behavior: HitTestBehavior.opaque,
          onTap: () async {
            if (Platform.isAndroid) {
              AndroidIntent intent = AndroidIntent(action: "android.bluetooth.adapter.action.REQUEST_ENABLE");
              await intent.launch();
            } else if (Platform.isIOS) {
              launch("App-Prefs:root=Bluetooth ");
            }
          },
          child: Center(
            child: Row(
              mainAxisSize: MainAxisSize.min,
              children: <Widget>[
                Text(
                  '打开蓝牙设置',
                  style: Theme.of(context).textTheme.bodyText2.copyWith(color: Theme.of(context).accentColor),
                ),
                SizedBox(
                  width: 6,
                ),
                arrowRight6()
              ],
            ),
          ),
        ),
      ],
    );
  }
}

class FindDevicesScreen extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => _FindDevicesScreen();
}

class _FindDevicesScreen extends State<FindDevicesScreen> with SingleTickerProviderStateMixin {
  AnimationController _animationController;
  Animation _animation;
  bool _search = true;
  StreamSubscription streamSubscription;

  @override
  void initState() {
    _animationController = AnimationController(duration: Duration(seconds: 2), vsync: this);
    _animation = Tween(begin: .0, end: 1.0).animate(_animationController)
      ..addStatusListener((status) {
        if (status == AnimationStatus.completed) {
          _animationController.repeat();
        }
      });
    //开始动画
    _animationController.forward();
    super.initState();
    startScan();
    streamSubscription = Provider.of<Bluetooth>(context, listen: false).stateStream.listen((event) async {
      await Future.delayed(Duration(seconds: 2));
      Navigator.pop(context);
    });
  }

  startScan() async {
    setState(() {
      _search = true;
    });
    FlutterBlue.instance.startScan(timeout: Duration(seconds: 10)).whenComplete(() {
      if (mounted)
        setState(() {
          _search = false;
        });
    });
  }

  @override
  void dispose() {
    _animationController?.dispose();
    super.dispose();
    streamSubscription?.cancel();
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        Expanded(
          child: SingleChildScrollView(
            child: Column(
              children: <Widget>[
                // if (!_search)
                //   StreamBuilder<List<BluetoothDevice>>(
                //     stream: Stream.fromFuture(FlutterBlue.instance.connectedDevices),
                //     initialData: [],
                //     builder: (c, snapshot) => Column(
                //       children: snapshot.data
                //           .map((d) => Column(
                //                 children: <Widget>[
                //                   ListTile(
                //                     title: Column(
                //                       mainAxisAlignment: MainAxisAlignment.start,
                //                       crossAxisAlignment: CrossAxisAlignment.start,
                //                       children: <Widget>[
                //                         Text(
                //                           d.name,
                //                           overflow: TextOverflow.ellipsis,
                //                           style: Theme.of(context).textTheme.headline3,
                //                         ),
                //                         SizedBox(
                //                           height: 4,
                //                         ),
                //                         Text(
                //                           d.id.toString(),
                //                           style: Theme.of(context).textTheme.caption,
                //                         ),
                //                       ],
                //                     ),
                //                     trailing: StreamBuilder<BluetoothDeviceState>(
                //                       stream: d.state,
                //                       initialData: BluetoothDeviceState.disconnected,
                //                       builder: (c, snapshot) {
                //                         return GestureDetector(
                //                           onTap: () => Navigator.of(context).push(MaterialPageRoute(builder: (context) => DeviceInfoPage())),
                //                           child: Container(
                //                             width: 58,
                //                             height: 30,
                //                             alignment: Alignment.center,
                //                             decoration: BoxDecoration(
                //                                 shape: BoxShape.rectangle,
                //                                 borderRadius: BorderRadius.all(Radius.circular(100)),
                //                                 color: Theme.of(context).accentColor),
                //                             child: Text(
                //                               snapshot.data == BluetoothDeviceState.connected ? "已连接" : "未连接",
                //                               style: TextStyle(color: Colors.white, fontSize: 12),
                //                             ),
                //                           ),
                //                         );
                //                       },
                //                     ),
                //                   ),
                //                   Divider()
                //                 ],
                //               ))
                //           .toList(),
                //     ),
                //   ),
                // if (!_search)
                StreamBuilder<List<ScanResult>>(
                  stream: FlutterBlue.instance.scanResults,
                  initialData: [],
                  builder: (c, snapshot) {
                    var bluetooth = Provider.of<Bluetooth>(context, listen: false);
                    var list = snapshot.data.where((element) => element.device.name.isNotEmpty).toList();
                    list.sort((a, b) => bluetooth.device == a.device ? -1 : 1);
                    return Column(
                      children: list.isEmpty == true
                          ? [
                              _search
                                  ? Padding(
                                      padding: const EdgeInsets.symmetric(vertical: 30),
                                      child: Column(
                                        children: <Widget>[
                                          Stack(
                                            alignment: Alignment.center,
                                            children: <Widget>[
                                              RotationTransition(turns: _animation, child: Image.asset("lib/assets/img/pop_image_circle.png")),
                                              Image.asset("lib/assets/img/pop_image_shoes.png")
                                            ],
                                          ),
                                          SizedBox(
                                            height: 12,
                                          ),
                                          Text("搜索中...")
                                        ],
                                      ),
                                    )
                                  : Padding(
                                      padding: const EdgeInsets.symmetric(horizontal: 30.0,vertical: 65.0),
                                      child: Center(
                                        child: Column(
                                          children: <Widget>[
                                            Image.asset("lib/assets/img/pop_image_noequipment.png"),
                                            SizedBox(
                                              height: 10,
                                            ),
                                            Text("暂无设备")
                                          ],
                                        ),
                                      ))
                            ]
                          : list
                              .map(
                                (r) => Column(
                                  children: <Widget>[
                                    ScanResultTile(
                                      result: r,
                                      onTap: () async {
                                        await Provider.of<Bluetooth>(context, listen: false).saveDevice(r.device);
                                        setState(() {});
                                      },
                                    ),
                                    Divider()
                                  ],
                                ),
                              )
                              .toList(),
                    );
                  },
                ),
              ],
            ),
          ),
        ),
        Padding(
          padding: const EdgeInsets.all(8.0),
          child: StreamBuilder<bool>(
            stream: FlutterBlue.instance.isScanning,
            initialData: false,
            builder: (c, snapshot) {
              if (snapshot.data) {
                return CancelButton(
                  height: 35,
                  content: "搜索中...",
                  callback: () {
                    FlutterBlue.instance.stopScan();
                    setState(() {
                      _search = false;
                    });
                  },
                );
              } else {
                return PrimaryButton(height: 35, content: "重新搜索", callback: () => startScan());
              }
            },
          ),
        ),
      ],
    );
  }
}

class DeviceScreen extends StatelessWidget {
  const DeviceScreen({Key key, this.device}) : super(key: key);

  final BluetoothDevice device;

  List<int> _getRandomBytes() {
    final math = Random();
    return [math.nextInt(255), math.nextInt(255), math.nextInt(255), math.nextInt(255)];
  }

  List<Widget> _buildServiceTiles(List<BluetoothService> services) {
    return services
        .map(
          (s) => ServiceTile(
            service: s,
            characteristicTiles: s.characteristics
                .map(
                  (c) => CharacteristicTile(
                    characteristic: c,
                    onReadPressed: () => c.read(),
                    onWritePressed: () async {
                      await c.write(_getRandomBytes(), withoutResponse: true);
                      await c.read();
                    },
                    onNotificationPressed: () async {
                      await c.setNotifyValue(!c.isNotifying);
                      c.value.listen((value) {
                        print(value.length);
                      });
                    },
                    descriptorTiles: c.descriptors
                        .map(
                          (d) => DescriptorTile(
                            descriptor: d,
                            onReadPressed: () => d.read(),
                            onWritePressed: () => d.write(_getRandomBytes()),
                          ),
                        )
                        .toList(),
                  ),
                )
                .toList(),
          ),
        )
        .toList();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(device.name),
        actions: <Widget>[
          StreamBuilder<BluetoothDeviceState>(
            stream: device.state,
            initialData: BluetoothDeviceState.connecting,
            builder: (c, snapshot) {
              VoidCallback onPressed;
              String text;
              switch (snapshot.data) {
                case BluetoothDeviceState.connected:
                  onPressed = () => device.disconnect();
                  text = 'DISCONNECT';
                  break;
                case BluetoothDeviceState.disconnected:
                  onPressed = () => device.connect();
                  text = 'CONNECT';
                  break;
                default:
                  onPressed = null;
                  text = snapshot.data.toString().substring(21).toUpperCase();
                  break;
              }
              return FlatButton(
                  onPressed: onPressed,
                  child: Text(
                    text,
                    style: Theme.of(context).primaryTextTheme.button.copyWith(color: Colors.white),
                  ));
            },
          )
        ],
      ),
      body: SingleChildScrollView(
        child: Column(
          children: <Widget>[
            StreamBuilder<BluetoothDeviceState>(
              stream: device.state,
              initialData: BluetoothDeviceState.connecting,
              builder: (c, snapshot) => ListTile(
                leading: (snapshot.data == BluetoothDeviceState.connected) ? Icon(Icons.bluetooth_connected) : Icon(Icons.bluetooth_disabled),
                title: Text('Device is ${snapshot.data.toString().split('.')[1]}.'),
                subtitle: Text('${device.id}'),
                trailing: StreamBuilder<bool>(
                  stream: device.isDiscoveringServices,
                  initialData: false,
                  builder: (c, snapshot) => IndexedStack(
                    index: snapshot.data ? 1 : 0,
                    children: <Widget>[
                      IconButton(
                        icon: Icon(Icons.refresh),
                        onPressed: () => device.discoverServices(),
                      ),
                      IconButton(
                        icon: SizedBox(
                          child: CircularProgressIndicator(
                            valueColor: AlwaysStoppedAnimation(Colors.grey),
                          ),
                          width: 18.0,
                          height: 18.0,
                        ),
                        onPressed: null,
                      )
                    ],
                  ),
                ),
              ),
            ),
            StreamBuilder<int>(
              stream: device.mtu,
              initialData: 0,
              builder: (c, snapshot) => ListTile(
                title: Text('MTU Size'),
                subtitle: Text('${snapshot.data} bytes'),
                trailing: IconButton(
                  icon: Icon(Icons.edit),
                  onPressed: () => device.requestMtu(223),
                ),
              ),
            ),
            StreamBuilder<List<BluetoothService>>(
              stream: device.services,
              initialData: [],
              builder: (c, snapshot) {
                return Column(
                  children: _buildServiceTiles(snapshot.data),
                );
              },
            ),
            RaisedButton(
              onPressed: () {
                Provider.of<Bluetooth>(context, listen: false).queryDeviceStep();
              },
              child: Text("同步步数"),
            ),
            RaisedButton(
              onPressed: () {
                Provider.of<Bluetooth>(context, listen: false).resetData();
              },
              child: Text("清零"),
            ),
            RaisedButton(
              onPressed: () {
                Provider.of<Bluetooth>(context, listen: false).setupGameMode(true);
              },
              child: Text("游戏模式开"),
            ),
            RaisedButton(
              onPressed: () {
                Provider.of<Bluetooth>(context, listen: false).setupGameMode(false);
              },
              child: Text("游戏模式关"),
            ),
            RaisedButton(
              onPressed: () {
                Provider.of<Bluetooth>(context, listen: false).vibrate(Provider.of<Bluetooth>(context, listen: false).vibrateNotifier.value);
              },
              child: Text("发送震动"),
            ),
            ValueListenableBuilder(
              valueListenable: Provider.of<Bluetooth>(context, listen: false).vibrateNotifier,
              builder: (BuildContext context, int v, Widget child) => Row(
                children: <Widget>[
                  Slider(
                    divisions: 9,
                    value: v.toDouble(),
                    min: 100,
                    max: 1000,
                    onChanged: (double value) {
                      Provider.of<Bluetooth>(context, listen: false).vibrateNotifier.value = value.toInt();
                    },
                  ),
                  Text("$v")
                ],
              ),
            ),
            ValueListenableBuilder(
              valueListenable: Provider.of<Bluetooth>(context, listen: false).actionNotifier,
              builder: (BuildContext context, int value, Widget child) => Text("当前动作: $value"),
            ),
            ValueListenableBuilder(
              valueListenable: Provider.of<Bluetooth>(context, listen: false).stepTotalNotifier,
              builder: (BuildContext context, int value, Widget child) => Text("同步步数: $value"),
            ),
            ValueListenableBuilder(
              valueListenable: Provider.of<Bluetooth>(context, listen: false).stepNotifier,
              builder: (BuildContext context, int value, Widget child) => Text("相对步数: $value"),
            ),
            ValueListenableBuilder(
              valueListenable: Provider.of<Bluetooth>(context, listen: false).byteNotifier,
              builder: (BuildContext context, List<int> value, Widget child) => Text("接收: $value"),
            ),
          ],
        ),
      ),
    );
  }
}

class ScanResultTile extends StatelessWidget {
  const ScanResultTile({Key key, 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,
            style: Theme.of(context).textTheme.headline3,
          ),
          SizedBox(
            height: 4,
          ),
          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: EdgeInsets.symmetric(horizontal: 16.0, vertical: 4.0),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Text(title, style: Theme.of(context).textTheme.caption),
          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 null;
    }
    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 null;
    }
    List<String> res = [];
    data.forEach((id, bytes) {
      res.add('${id.toUpperCase()}: ${getNiceHexArray(bytes)}');
    });
    return res.join(', ');
  }

  @override
  Widget build(BuildContext context) {
    return ListTile(
      contentPadding: EdgeInsets.symmetric(horizontal: 12),
      title: _buildTitle(context),
      // leading: Text(result.rssi.toString()),
      trailing: StreamBuilder<BluetoothDeviceState>(
        stream: result.device.state,
        initialData: BluetoothDeviceState.connecting,
        builder: (c, snapshot) {
          if (snapshot.data == BluetoothDeviceState.connected) {
            return Row(
              mainAxisSize: MainAxisSize.min,
              children: <Widget>[
                Image.asset(
                  "lib/assets/img/pop_icon_conneted.png",
                  width: 14.0,
                ),
                SizedBox(
                  width: 4,
                ),
                Text(
                  "已连接",
                  style: TextStyle(
                    color: Theme.of(context).accentColor,
                    fontSize: 12,
                  ),
                  strutStyle: fixedLine,
                )
              ],
            );
          }
          int status = Provider.of<Bluetooth>(context, listen: false).device == result.device
              ? 1
              : snapshot.data == BluetoothDeviceState.disconnected
                  ? 0
                  : snapshot.data == BluetoothDeviceState.connecting ? 1 : snapshot.data == BluetoothDeviceState.connected ? 2 : 3;
          return status == 1
              ? Padding(
                  padding: const EdgeInsets.symmetric(horizontal: 4.0),
                  child: Text(
                    "正在连接...",
                    style: TextStyle(
                      color: Theme.of(context).accentColor,
                      fontSize: 12,
                    ),
                    strutStyle: fixedLine,
                  ),
                )
              : GestureDetector(
                  onTap: onTap,
                  child: Container(
                    width: 64,
                    height: 30,
                    alignment: Alignment.center,
                    decoration: BoxDecoration(
                        borderRadius: BorderRadius.all(Radius.circular(100)),
                        border: Border.all(
                          color: Theme.of(context).accentColor,
                        )),
                    child: Center(
                      child: Row(
                        mainAxisSize: MainAxisSize.min,
                        children: <Widget>[
                          Text(
                            status == 1 ? "连接中" : status == 0 ? "连接" : "已连接",
                            style: TextStyle(
                              color: Theme.of(context).accentColor,
                              fontSize: 12,
                            ),
                            strutStyle: fixedLine,
                          )
                        ],
                      ),
                    ),
                  ),
                );
        },
      ),
//      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) ?? 'N/A'),
//        _buildAdvRow(context, 'Service UUIDs',
//            (result.advertisementData.serviceUuids.isNotEmpty) ? result.advertisementData.serviceUuids.join(', ').toUpperCase() : 'N/A'),
//        _buildAdvRow(context, 'Service Data', getNiceServiceData(result.advertisementData.serviceData) ?? 'N/A'),
//      ],
    );
  }
}

class ServiceTile extends StatelessWidget {
  final BluetoothService service;
  final List<CharacteristicTile> characteristicTiles;

  const ServiceTile({Key key, this.service, this.characteristicTiles}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    if (characteristicTiles.length > 0) {
      return ExpansionTile(
        title: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Text('Service'),
            Text('0x${service.uuid.toString().toUpperCase().substring(4, 8)}',
                style: Theme.of(context).textTheme.body1.copyWith(color: Theme.of(context).textTheme.caption.color))
          ],
        ),
        children: characteristicTiles,
      );
    } else {
      return ListTile(
        title: Text('Service'),
        subtitle: Text('0x${service.uuid.toString().toUpperCase().substring(4, 8)}'),
      );
    }
  }
}

class CharacteristicTile extends StatelessWidget {
  final BluetoothCharacteristic characteristic;
  final List<DescriptorTile> descriptorTiles;
  final VoidCallback onReadPressed;
  final VoidCallback onWritePressed;
  final VoidCallback onNotificationPressed;

  const CharacteristicTile({Key key, this.characteristic, this.descriptorTiles, this.onReadPressed, this.onWritePressed, this.onNotificationPressed})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<List<int>>(
      stream: characteristic.value,
      initialData: characteristic.lastValue,
      builder: (c, snapshot) {
        final value = snapshot.data;
        return ExpansionTile(
          title: ListTile(
            title: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: <Widget>[
                Text('Characteristic'),
                Text('0x${characteristic.uuid.toString().toUpperCase().substring(4, 8)}',
                    style: Theme.of(context).textTheme.body1.copyWith(color: Theme.of(context).textTheme.caption.color))
              ],
            ),
            subtitle: Text(value.toString()),
            contentPadding: EdgeInsets.all(0.0),
          ),
          trailing: Row(
            mainAxisSize: MainAxisSize.min,
            children: <Widget>[
              IconButton(
                icon: Icon(
                  Icons.file_download,
                  color: Theme.of(context).iconTheme.color.withOpacity(0.5),
                ),
                onPressed: onReadPressed,
              ),
              IconButton(
                icon: Icon(Icons.file_upload, color: Theme.of(context).iconTheme.color.withOpacity(0.5)),
                onPressed: onWritePressed,
              ),
              IconButton(
                icon: Icon(characteristic.isNotifying ? Icons.sync_disabled : Icons.sync, color: Theme.of(context).iconTheme.color.withOpacity(0.5)),
                onPressed: onNotificationPressed,
              )
            ],
          ),
          children: descriptorTiles,
        );
      },
    );
  }
}

class DescriptorTile extends StatelessWidget {
  final BluetoothDescriptor descriptor;
  final VoidCallback onReadPressed;
  final VoidCallback onWritePressed;

  const DescriptorTile({Key key, this.descriptor, this.onReadPressed, this.onWritePressed}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return ListTile(
      title: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Text('Descriptor'),
          Text('0x${descriptor.uuid.toString().toUpperCase().substring(4, 8)}',
              style: Theme.of(context).textTheme.body1.copyWith(color: Theme.of(context).textTheme.caption.color))
        ],
      ),
      subtitle: StreamBuilder<List<int>>(
        stream: descriptor.value,
        initialData: descriptor.lastValue,
        builder: (c, snapshot) => Text(snapshot.data.toString()),
      ),
      trailing: Row(
        mainAxisSize: MainAxisSize.min,
        children: <Widget>[
          IconButton(
            icon: Icon(
              Icons.file_download,
              color: Theme.of(context).iconTheme.color.withOpacity(0.5),
            ),
            onPressed: onReadPressed,
          ),
          IconButton(
            icon: Icon(
              Icons.file_upload,
              color: Theme.of(context).iconTheme.color.withOpacity(0.5),
            ),
            onPressed: onWritePressed,
          )
        ],
      ),
    );
  }
}

class AdapterStateTile extends StatelessWidget {
  const AdapterStateTile({Key key, @required this.state}) : super(key: key);

  final BluetoothState state;

  @override
  Widget build(BuildContext context) {
    return Container(
      color: Colors.redAccent,
      child: ListTile(
        title: Text(
          'Bluetooth adapter is ${state.toString().substring(15)}',
          style: Theme.of(context).primaryTextTheme.subhead,
        ),
        trailing: Icon(
          Icons.error,
          color: Theme.of(context).primaryTextTheme.subhead.color,
        ),
      ),
    );
  }
}