my flutter app.

//host_page.dart:

import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:flutter_moving_background/flutter_moving_background.dart';
import 'package:task_app_es/meeting_list_screen.dart';
import 'work_screen.dart';
import 'login_page.dart';
import 'meeting_list_screen.dart';
import 'package:qr_flutter/qr_flutter.dart';
import 'package:flutter_blue/flutter_blue.dart' as flutter_blue;

class HostPage extends StatefulWidget {
  final String id;
  final String username;
  final String esEmail;
  final String passCode;
  final String deviceID;
  final String jobs;
  final String meetingName;

  const HostPage(
      {super.key,
      required this.id,
      required this.username,
      required this.esEmail,
      required this.passCode,
      required this.deviceID,
      required this.meetingName,
      required this.jobs});

  @override
  _HostPageState createState() => _HostPageState();
}


class _HostPageState extends State<HostPage> {
  bool _fadeInCompleted = false;
  bool _attendMeetingActive = false;
   final TextEditingController _pinController = TextEditingController();
  bool _isSearching = false;
  String _message = '';

  @override
  void initState() {
    super.initState();
    print('ID: ${widget.id}');
    print('Username: ${widget.username}');
    print('ES_Email: ${widget.esEmail}');
    print('Passcode: ${widget.passCode}');
    print('Device ID passed over to HostPage: ${widget.deviceID}');
    Future.delayed(const Duration(milliseconds: 1000), () {
      _startFadeInAnimation();
       // Call the method to initialize NFC
    });
  }



  @override
  void dispose() {
    super.dispose();
  }

  void _loginback({required String deviceID}) {
    Navigator.push(
      context,
      MaterialPageRoute(
          builder: (context) => LoginPage(deviceID: widget.deviceID)),
    );
  }

  void _startFadeInAnimation() {
    Future.delayed(const Duration(milliseconds: 1000), () {
      setState(() {
        _fadeInCompleted = true;
      });
    });
  }

   void _searchForHost() async {
  setState(() {
    _isSearching = true;
  });

  flutter_blue.FlutterBlue flutterBlue = flutter_blue.FlutterBlue.instance;

  flutterBlue.scanResults.listen((results) {
    for (var result in results) {
      if (result.device.name == 'Your Host Device Name') {
        _connectToHost(result.device);
        break;
      }
    }
  });

  flutterBlue.startScan(timeout: Duration(seconds: 10));
}

void _connectToHost(flutter_blue.BluetoothDevice device) async {
  try {
    await device.connect();
    await _sendPayload(device);
  } catch (e) {
    print('Error connecting to host: $e');
  }
}

Future<void> _sendPayload(flutter_blue.BluetoothDevice device) async {
  final pin = await _promptPin();
  if (pin != null) {
    // Send payload in JSON format
    final userData = {
      'id': int.parse(widget.id),
      'username': widget.username,
      'esEmail': widget.esEmail,
    };
    final payload = jsonEncode(userData);

    try {
      // Connect to the device
      await device.connect();

      // Discover services
      List<flutter_blue.BluetoothService> services = await device.discoverServices();

      // Iterate through each service to find characteristics
      for (var service in services) {
        List<flutter_blue.BluetoothCharacteristic> characteristics = service.characteristics;

        // Iterate through each characteristic
        for (var characteristic in characteristics) {
          // Write the payload to the characteristic
          await characteristic.write(utf8.encode(payload));

          // Notify the user of successful connection
          setState(() {
            _message = 'You have joined the meeting.';
          });

          // Disconnect after sending payload
          await device.disconnect();

          return; // Exit the method after successful operation
        }
      }

      // If no characteristic was found
      print('No characteristic found.');
    } catch (e) {
      print('Error: $e');
    }
  } else {
    print('PIN entry cancelled.');
  }
}

Future<String?> _promptPin() async {
  String? pin;
  await showDialog(
    context: context,
    builder: (BuildContext context) {
      return AlertDialog(
        title: Text('Enter PIN'),
        content: TextField(
          controller: _pinController,
          keyboardType: TextInputType.number,
          decoration: InputDecoration(labelText: 'PIN'),
        ),
        actions: <Widget>[
          TextButton(
            child: Text('Cancel'),
            onPressed: () {
              Navigator.of(context).pop();
            },
          ),
          TextButton(
            child: Text('OK'),
            onPressed: () {
              pin = _pinController.text;
              Navigator.of(context).pop();
            },
          ),
        ],
      );
    },
  );
  return pin;
}


  @override
  Widget build(BuildContext context) {
    return AnimatedOpacity(
      opacity: _fadeInCompleted ? 1.0 : 0.0,
      duration: const Duration(milliseconds: 1500),
      child: Stack(
        children: [
          SizedBox(
            width: MediaQuery.of(context).size.width,
            height: MediaQuery.of(context).size.height,
            child: const MovingBackground(
              backgroundColor: Colors.transparent,
              circles: [
                MovingCircle(
                    color: Color.fromARGB(149, 39, 2, 102), blurSigma: 100),
                MovingCircle(
                    color: Color.fromARGB(118, 217, 0, 255), blurSigma: 170),
                MovingCircle(
                    color: Color.fromARGB(123, 150, 2, 214), blurSigma: 80),
                MovingCircle(
                    color: Color.fromARGB(115, 84, 10, 105), blurSigma: 120),
                MovingCircle(
                    color: Color.fromARGB(129, 213, 128, 255), blurSigma: 60),
                MovingCircle(
                    color: Color.fromARGB(99, 255, 255, 255), blurSigma: 100),
              ],
            ),
          ),
          Center(
            child: Container(
              width: MediaQuery.of(context).size.width * 0.95,
              height: MediaQuery.of(context).size.height * 0.95,
              child: Column(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: [
                  Container(
                    height: MediaQuery.of(context).size.height * 0.7,
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        ElevatedButton(
                          onPressed: () {
                            Navigator.pushReplacement(
                              context,
                              MaterialPageRoute(
                                builder: (context) => WorkScreen(
                                  id: widget.id,
                                  username: widget.username,
                                  esEmail: widget.esEmail,
                                  passCode: widget.passCode,
                                  deviceID: widget.deviceID,
                                  meetingName: '',
                                  jobs: '',
                                ),
                              ),
                            );
                          },
                          style: ElevatedButton.styleFrom(
                            backgroundColor: const Color.fromARGB(118, 101, 31, 170),
                            minimumSize: Size(
                              double.infinity,
                              MediaQuery.of(context).size.height * 0.35,
                            ),
                            shape: const RoundedRectangleBorder(
                              borderRadius: BorderRadius.only(
                                topLeft: Radius.circular(20),
                                topRight: Radius.circular(20),
                              ),
                              side: BorderSide(
                                color: Color.fromARGB(194, 132, 0, 255),
                                width: 5.0,
                              ),
                            ),
                          ),
                          child: Column(
                            children: [
                              Icon(
                                Icons.perm_identity,
                                color: const Color.fromARGB(194, 132, 0, 255),
                                size: MediaQuery.of(context).size.width * 0.4,
                              ),
                              const SizedBox(height: 5),
                              Text(
                                'Host a meeting',
                                style: TextStyle(
                                  color: const Color.fromARGB(255, 132, 0, 255),
                                  fontSize:
                                      MediaQuery.of(context).size.width * 0.08,
                                ),
                              ),
                            ],
                          ),
                        ),
                        const SizedBox(height: 5),
                        ElevatedButton(
                          onPressed: () {
                            setState(() {
                              _attendMeetingActive = !_attendMeetingActive;
                              // Additional logic can be added here
                            });
                          },
                          style: ElevatedButton.styleFrom(
                            backgroundColor: _attendMeetingActive
                                ? const Color.fromARGB(169, 172, 89, 255)
                                : const Color.fromARGB(118, 101, 31, 170),
                            minimumSize: Size(
                              double.infinity,
                              MediaQuery.of(context).size.height * 0.335,
                            ),
                            shape: RoundedRectangleBorder(
                              borderRadius: BorderRadius.circular(0),
                              side: const BorderSide(
                                color: Color.fromARGB(194, 132, 0, 255),
                                width: 5.0,
                              ),
                            ),
                          ),
                          child: Stack(
                            children: [
                              Align(
                                alignment: Alignment.center,
                                child: Column(
                                  children: [
                                    Icon(
                                      Icons.group_add_rounded,
                                      color: _attendMeetingActive
                                          ? const Color.fromARGB(193, 255, 255, 255)
                                          : const Color.fromARGB(194, 132, 0, 255),
                                      size: MediaQuery.of(context).size.width *
                                          0.339,
                                    ),
                                    SizedBox(
                                        height: _attendMeetingActive ? 15 : 5),
                                    Text(
                                      _attendMeetingActive
                                          ? ''
                                          : 'Attend a meeting',
                                      style: TextStyle(
                                        color: _attendMeetingActive
                                            ? const Color.fromARGB(193, 255, 255, 255)
                                            : const Color.fromARGB(194, 132, 0, 255),
                                        fontSize:
                                            MediaQuery.of(context).size.width *
                                                0.08,
                                      ),
                                    ),
                                  ],
                                ),
                              ),
                              Positioned.fill(
                                child: Visibility(
                                  visible: _attendMeetingActive,
                                  child: Row(
                                    mainAxisAlignment:
                                        MainAxisAlignment.spaceBetween,
                                    crossAxisAlignment: CrossAxisAlignment.end,
                                    children: [
                                      ElevatedButton(
                                        onPressed: () {
                                          // Create a Map with the desired key-value pairs
                                          Map<String, dynamic> userData = {
                                            'id': int.parse(widget.id),
                                            'username': widget.username,
                                            'esEmail': widget.esEmail,
                                          };

                                          // Encode the map to JSON format
                                          String jsonData =
                                              jsonEncode(userData);

                                              print(jsonData);

                                          showDialog(
                                            context: context,
                                            builder: (BuildContext context) {
                                              return AlertDialog(
                                                backgroundColor: const Color.fromARGB(
                                                    248, 0, 0, 0),
                                                contentPadding: EdgeInsets.zero,
                                                content: Container(
                                                  width: MediaQuery.of(context)
                                                          .size
                                                          .width *
                                                      0.99, // 80% of screen width
                                                  height: MediaQuery.of(context)
                                                          .size
                                                          .height *
                                                      0.4, // 90% of screen height
                                                  child: Column(
                                                    mainAxisAlignment:
                                                        MainAxisAlignment
                                                            .center,
                                                    mainAxisSize:
                                                        MainAxisSize.min,
                                                    children: [
                                                      Text(
                                                        'SHOW TO HOST',
                                                        style: TextStyle(
                                                          fontSize: MediaQuery.of(
                                                                      context)
                                                                  .size
                                                                  .width *
                                                              0.055, // Adjust title size
                                                          color: const Color.fromARGB(
                                                              255,
                                                              213,
                                                              181,
                                                              255),
                                                        ),
                                                      ),
                                                      const SizedBox(height: 10),
                                                      Container(
                                                        width: 200,
                                                        height: 200,
                                                        child: QrImageView(
                                                          data:
                                                              jsonData, // Pass the JSON encoded data
                                                          version:
                                                              QrVersions.auto,
                                                          gapless: true,
                                                          eyeStyle: const QrEyeStyle(
                                                              eyeShape:
                                                                  QrEyeShape
                                                                      .square,
                                                              color: Color.fromARGB(255, 0, 0, 0)),
                                                          dataModuleStyle:
                                                              const QrDataModuleStyle(
                                                                  color: Color.fromARGB(255, 0, 0, 0)),
                                                          backgroundColor:
                                                              Color.fromARGB(255, 255, 255, 255),
                                                        ),
                                                      ),
                                                    ],
                                                  ),
                                                ),
                                                actions: [
                                                  Center(
                                                    child: TextButton(
                                                      onPressed: () {
                                                        Navigator.of(context)
                                                            .pop();
                                                      },
                                                      child: Text(
                                                        'CLOSE',
                                                        style: TextStyle(
                                                          color: const Color.fromARGB(
                                                              255,
                                                              213,
                                                              181,
                                                              255),
                                                          fontSize: MediaQuery.of(
                                                                      context)
                                                                  .size
                                                                  .width *
                                                              0.045,
                                                        ),
                                                      ),
                                                    ),
                                                  ),
                                                ],
                                              );
                                            },
                                          );
                                        },
                                        style: ElevatedButton.styleFrom(
                                          backgroundColor:
                                              const Color.fromARGB(118, 101, 31, 170),
                                          minimumSize: Size(
                                            MediaQuery.of(context).size.width *
                                                0.4,
                                            MediaQuery.of(context).size.height *
                                                0.04,
                                          ),
                                          shape: const RoundedRectangleBorder(
                                            borderRadius: BorderRadius.only(
                                                topLeft: Radius.circular(20)),
                                          ),
                                          side: const BorderSide(
                                            color: Color.fromARGB(
                                                194, 132, 0, 255),
                                            width: 3.0,
                                          ),
                                        ),
                                        child: const Text(
                                          'QR Code',
                                          style: TextStyle(
                                              fontSize: 18,
                                              color: Color.fromARGB(
                                                  194, 255, 255, 255)),
                                        ),
                                      ),
                                      ElevatedButton(
                                        onPressed: () {
                                        _searchForHost();
                                        },
                                        style: ElevatedButton.styleFrom(
                                          backgroundColor:
                                              const Color.fromARGB(118, 101, 31, 170),
                                          minimumSize: Size(
                                            MediaQuery.of(context).size.width *
                                                0.4,
                                            MediaQuery.of(context).size.height *
                                                0.04,
                                          ),
                                          shape: const RoundedRectangleBorder(
                                            borderRadius: BorderRadius.only(
                                                bottomRight:
                                                    Radius.circular(20)),
                                          ),
                                          side: const BorderSide(
                                            color: Color.fromARGB(
                                                194, 132, 0, 255),
                                            width: 3.0,
                                          ),
                                        ),
                                        child: const Text(
                                          'Bluetooth',
                                          style: TextStyle(
                                              fontSize: 18,
                                              color: Color.fromARGB(
                                                  194, 255, 255, 255)),
                                        ),
                                      ),
                                    ],
                                  ),
                                ),
                              ),
                            ],
                          ),
                        ),
                      ],
                    ),
                  ),
                  Container(
                    height: MediaQuery.of(context).size.height * 0.15,
                    width: MediaQuery.of(context).size.width * 0.95,
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: [
                        ElevatedButton(
                          onPressed: () {
                            Navigator.pushReplacement(
                              context,
                              MaterialPageRoute(
                                builder: (context) => MeetingListScreen(
                                  id: widget.id,
                                  username: widget.username,
                                  esEmail: widget.esEmail,
                                  passCode: widget.passCode,
                                  deviceID: widget.deviceID,
                                  meetingName: '',
                                  jobs: '',
                                ),
                              ),
                            );
                          },
                          style: ElevatedButton.styleFrom(
                            backgroundColor: const Color.fromARGB(118, 101, 31, 170),
                            minimumSize: Size(
                              MediaQuery.of(context).size.width * 0.313,
                              double.infinity,
                            ),
                            padding: EdgeInsets.symmetric(
                                vertical:
                                    MediaQuery.of(context).size.width * 0.04),
                            shape: RoundedRectangleBorder(
                              borderRadius: BorderRadius.circular(0),
                              side: const BorderSide(
                                color: Color.fromARGB(194, 132, 0, 255),
                                width: 5.0,
                              ),
                            ),
                          ),
                          child: Column(
                            children: [
                              Icon(
                                Icons.app_shortcut_rounded,
                                color: const Color.fromARGB(194, 132, 0, 255),
                                size: MediaQuery.of(context).size.width * 0.12,
                              ),
                              const SizedBox(height: 5),
                              Text(
                                'My Meetings',
                                style: TextStyle(
                                  color: const Color.fromARGB(255, 132, 0, 255),
                                  fontSize:
                                      MediaQuery.of(context).size.width * 0.03,
                                ),
                              ),
                            ],
                          ),
                        ),
                        ElevatedButton(
                          onPressed: () {
                            // Handle 'Collaborators' button press
                          },
                          style: ElevatedButton.styleFrom(
                            backgroundColor: const Color.fromARGB(118, 101, 31, 170),
                            minimumSize: Size(
                              MediaQuery.of(context).size.width * 0.313,
                              double.infinity,
                            ),
                            padding: EdgeInsets.symmetric(
                                vertical:
                                    MediaQuery.of(context).size.width * 0.04),
                            shape: RoundedRectangleBorder(
                              borderRadius: BorderRadius.circular(0),
                              side: const BorderSide(
                                color: Color.fromARGB(194, 132, 0, 255),
                                width: 5.0,
                              ),
                            ),
                          ),
                          child: Column(
                            children: [
                              Icon(
                                Icons.group_rounded,
                                color: const Color.fromARGB(194, 132, 0, 255),
                                size: MediaQuery.of(context).size.width * 0.12,
                              ),
                              const SizedBox(height: 5),
                              Text(
                                'Collaborators',
                                style: TextStyle(
                                  color: const Color.fromARGB(255, 132, 0, 255),
                                  fontSize:
                                      MediaQuery.of(context).size.width * 0.03,
                                ),
                              ),
                            ],
                          ),
                        ),
                        ElevatedButton(
                          onPressed: () {
                            // Handle 'Options' button press
                          },
                          style: ElevatedButton.styleFrom(
                            backgroundColor: const Color.fromARGB(118, 101, 31, 170),
                            minimumSize: Size(
                              MediaQuery.of(context).size.width * 0.313,
                              double.infinity,
                            ),
                            padding: EdgeInsets.symmetric(
                                vertical:
                                    MediaQuery.of(context).size.width * 0.04),
                            shape: RoundedRectangleBorder(
                              borderRadius: BorderRadius.circular(0),
                              side: const BorderSide(
                                color: Color.fromARGB(194, 132, 0, 255),
                                width: 5.0,
                              ),
                            ),
                          ),
                          child: Column(
                            children: [
                              Icon(
                                Icons.settings,
                                color: const Color.fromARGB(194, 132, 0, 255),
                                size: MediaQuery.of(context).size.width * 0.12,
                              ),
                              const SizedBox(height: 5),
                              Text(
                                'Options',
                                style: TextStyle(
                                  color: const Color.fromARGB(255, 132, 0, 255),
                                  fontSize:
                                      MediaQuery.of(context).size.width * 0.03,
                                ),
                              ),
                            ],
                          ),
                        ),
                      ],
                    ),
                  ),
                  Container(
                    child: ElevatedButton(
                      onPressed: () {
                        _loginback(deviceID: widget.deviceID);
                      },
                      style: ElevatedButton.styleFrom(
                        backgroundColor: const Color.fromARGB(45, 255, 0, 21),
                        minimumSize: Size(
                          double.infinity,
                          MediaQuery.of(context).size.height * 0.05,
                        ),
                        shape: const RoundedRectangleBorder(
                          borderRadius: BorderRadius.only(
                            bottomLeft: Radius.circular(20),
                            bottomRight: Radius.circular(20),
                          ),
                        ),
                        side: const BorderSide(
                          color: Color.fromARGB(194, 132, 0, 255),
                          width: 5.0,
                        ),
                      ),
                      child: Text(
                        'LOG OUT',
                        style: TextStyle(
                          color: const Color.fromARGB(115, 255, 58, 58),
                          fontSize: MediaQuery.of(context).size.width * 0.06,
                        ),
                      ),
                    ),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}


----------------------------------------------

//qr_scanner.dart:

import 'dart:async';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter/widgets.dart';
import 'dart:math';
import 'package:flutter_barcode_scanner/flutter_barcode_scanner.dart' as barcode_scanner;
import 'package:flutter_blue/flutter_blue.dart' as flutter_blue;

class BarcodeScannerWidget extends StatefulWidget {
  @override
  _BarcodeScannerWidgetState createState() => _BarcodeScannerWidgetState();
}

class _BarcodeScannerWidgetState extends State<BarcodeScannerWidget> with WidgetsBindingObserver {
  List<Map<String, dynamic>> _scannedDataList = [];
  bool _acceptBluetooth = false;
  String _randomPin = '';
  bool _isScanningBluetooth = false;
  flutter_blue.FlutterBlue flutterBlue = flutter_blue.FlutterBlue.instance;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance!.addObserver(this);
    _generateRandomPin();
  }

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

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (state == AppLifecycleState.paused) {
      // Save data or perform other tasks when app is paused
    }
  }

  Future<void> scanQR() async {
    try {
      final qrScanRes = await barcode_scanner.FlutterBarcodeScanner.scanBarcode(
        '#ff6666',
        'Cancel',
        true,
        barcode_scanner.ScanMode.QR,
      );
      if (qrScanRes != '-1') {
        final data = parseQRData(qrScanRes);
        setState(() {
          _scannedDataList.add(data);
        });
      }
    } catch (e) {
      print('Error scanning QR code: $e');
    }
  }

  Map<String, dynamic> parseQRData(String qrData) {
    try {
      return jsonDecode(qrData);
    } catch (e) {
      print('Error parsing QR data: $e');
      return {};
    }
  }

  Color generateRandomColor(List<Color> previousColors) {
    final random = Random();
    Color color;
    do {
      final r = 180 + random.nextInt(76);
      final g = 180 + random.nextInt(76);
      final b = 180 + random.nextInt(76);
      color = Color.fromRGBO(r, g, b, 0.7);
    } while (previousColors.contains(color));
    return color;
  }

  void _generateRandomPin() {
    final random = Random();
    _randomPin = '${random.nextInt(10)}${random.nextInt(10)}${random.nextInt(10)}${random.nextInt(10)}';
  }

  void simulateScan() {
    final random = Random();
    final id = random.nextInt(1000);
    final username = 'Lewis.Whitehead';
    final email = 'Lewis.whitehead@epilepsysociety.org.uk';
    final data = {
      'id': id,
      'username': username,
      'esEmail': email,
    };
    setState(() {
      _scannedDataList.insert(0, data);
    });
  }

  void _startBluetoothScan() {
    _isScanningBluetooth = true;
    flutterBlue.scanResults.listen((results) {
      for (var result in results) {
        _connectToDevice(result.device);
      }
    });
    flutterBlue.startScan(timeout: Duration(seconds: 10));
  }

  void _stopBluetoothScan() {
    _isScanningBluetooth = false;
    flutterBlue.stopScan();
  }

  void _connectToDevice(flutter_blue.BluetoothDevice device) async {
    try {
      await device.connect();
      List<flutter_blue.BluetoothService> services = await device.discoverServices();
      services.forEach((service) async {
        List<flutter_blue.BluetoothCharacteristic> characteristics = service.characteristics;
        for (var characteristic in characteristics) {
          if (characteristic.uuid.toString() == 'Your PIN Characteristic UUID') {
            List<int> pin = await characteristic.read();
            if (utf8.decode(pin) == _randomPin) {
              // Send payload if PIN is correct
              await _sendData(characteristic);
              break;
            } else {
              print('Incorrect PIN');
            }
          }
        }
      });
    } catch (e) {
      print('Error connecting to device: $e');
    } finally {
      await device.disconnect();
    }
  }

  Future<void> _sendData(flutter_blue.BluetoothCharacteristic characteristic) async {
    try {
      // Write payload data to the characteristic
      await characteristic.write(utf8.encode('Your Payload Data'));
    } catch (e) {
      print('Error sending data: $e');
    }
  }

  @override
  Widget build(BuildContext context) {
    List<Color> previousColors = [];
    return MaterialApp(
      home: WillPopScope(
        onWillPop: () async {
          return true;
        },
        child: Scaffold(
          appBar: AppBar(
            title: const Text('Add Attendees by Scanning.'),
            actions: [
              IconButton(
                icon: Icon(Icons.add),
                onPressed: simulateScan,
              ),
            ],
          ),
          body: Column(
            children: [
              Row(
                children: [
                  Expanded(
                    child: ElevatedButton(
                      onPressed: scanQR,
                      child: Text('Scan QR', maxLines: 1,),
                    ),
                  ),
                  Spacer(),
                  Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      Text('Accept Bluetooth Connections?'),
                      Switch(
                        value: _acceptBluetooth,
                        onChanged: (bool value) {
                          setState(() {
                            _acceptBluetooth = value;
                            if (_acceptBluetooth) {
                              _startBluetoothScan();
                            } else {
                              _stopBluetoothScan();
                              _randomPin = '';
                            }
                          });
                        },
                      ),
                      if (_acceptBluetooth) Text('Random PIN: $_randomPin'),
                      if (_isScanningBluetooth) CircularProgressIndicator(),
                    ],
                  ),
                ],
              ),
              Expanded(
                child: ListView.builder(
                  itemCount: _scannedDataList.length,
                  itemBuilder: (context, index) {
                    final data = _scannedDataList[index];
                    final color = generateRandomColor(previousColors);
                    previousColors.add(color);
                    if (previousColors.length > 5) {
                      previousColors.removeAt(0);
                    }
                    return Dismissible(
                      key: Key(data['id'].toString()),
                      onDismissed: (direction) {
                        setState(() {
                          _scannedDataList.removeAt(index);
                        });
                      },
                      background: Container(
                        color: Colors.red,
                        child: Icon(Icons.delete),
                        alignment: Alignment.centerRight,
                        padding: EdgeInsets.only(right: 16.0),
                      ),
                      child: Card(
                        color: color,
                        child: ListTile(
                          title: Text('Name: ${data['username'] ?? ''}'),
                          subtitle: Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              Text('Email: ${data['esEmail'] ?? ''}'),
                              Text('ID: ${data['id']}'),
                            ],
                          ),
                        ),
                      ),
                    );
                  },
                ),
              ),
              Container(
                height: MediaQuery.of(context).size.height * 0.09,
                padding: const EdgeInsets.all(8.0),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    ElevatedButton(
                      onPressed: () {
                        Navigator.pop(context);
                      },
                      child: Text('Cancel'),
                    ),
                    if (_scannedDataList.isNotEmpty)
                      ElevatedButton(
                        onPressed: () {
                          Navigator.pop(context, _scannedDataList);
                        },
                        child: Text('Add Attendees'),
                      ),
                  ],
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}