smart_bluetooth_pos_printer 1.0.1

A flutter plugin that prints esc commands to printers in different platforms such as android, ios, windows and different interfaces Bluetooth and BLE

example/lib/main.dart

import 'dart:async';
import 'dart:developer';
import 'dart:io';
import 'package:esc_pos_utils/esc_pos_utils.dart';
import 'package:flutter/material.dart';
import 'package:smart_bluetooth_pos_printer/smart_bluetooth_pos_printer.dart';

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

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

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

class _MyAppState extends State<MyApp> {
  var _isBle = false;
  var _reconnect = false;
  var _isConnected = false;
  var printerManager = PrinterManager.instance;
  var devices = <BluetoothPrinter>[];
  StreamSubscription<List<PrinterDevice>>? _subscription;
  StreamSubscription<BTStatus>? _subscriptionBtStatus;
  BTStatus _currentStatus = BTStatus.none;
  // _currentUsbStatus is only supports on Android
  // ignore: unused_field
  List<int>? pendingTask;
  BluetoothPrinter? selectedPrinter;

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

    _scan();

    // subscription to listen change status of bluetooth connection
    _subscriptionBtStatus =
        PrinterManager.instance.stateBluetooth.listen((status) {
      log(' ----------------- status bt $status ------------------ ');
      _currentStatus = status;
      if (status == BTStatus.connected) {
        setState(() {
          _isConnected = true;
        });
      }
      if (status == BTStatus.none) {
        setState(() {
          _isConnected = false;
        });
      }
      if (status == BTStatus.connected && pendingTask != null) {
        if (Platform.isAndroid) {
          Future.delayed(const Duration(milliseconds: 1000), () {
            PrinterManager.instance.send(bytes: pendingTask!);
            pendingTask = null;
          });
        } else if (Platform.isIOS) {
          PrinterManager.instance.send(bytes: pendingTask!);
          pendingTask = null;
        }
      }
    });
  }

  @override
  void dispose() {
    _subscription?.cancel();
    _subscriptionBtStatus?.cancel();

    super.dispose();
  }

  // method to scan devices according PrinterType
  void _scan() {
    printerManager.startScan(timeout: const Duration(seconds: 4), isBle: true);
    _subscription = printerManager.scanResults().listen((results) {
      devices.clear();
      for (PrinterDevice r in results) {
        devices.add(BluetoothPrinter(
          deviceName: r.name,
          address: r.address,
          isBle: _isBle,
        ));
      }
      print(devices.length);
      setState(() {});
    });
  }

  void selectDevice(BluetoothPrinter device) async {
    if (selectedPrinter != null) {
      if (device.address != selectedPrinter!.address) {
        await PrinterManager.instance.disconnect();
      }
    }

    selectedPrinter = device;
    setState(() {});
  }

  Future _printReceiveTest() async {
    List<int> bytes = [];

    // Xprinter XP-N160I
    final profile = await CapabilityProfile.load(name: 'XP-N160I');
    // PaperSize.mm80 or PaperSize.mm58
    final generator = Generator(PaperSize.mm80, profile);
    bytes += generator.setGlobalCodeTable('CP1252');
    bytes += generator.text('Test Print',
        styles: const PosStyles(align: PosAlign.center));
    bytes += generator.text('Product 1');
    bytes += generator.text('Product 2');

    _printEscPos(bytes, generator);
  }

  /// print ticket
  void _printEscPos(List<int> bytes, Generator generator) async {
    if (selectedPrinter == null) return;
    var bluetoothPrinter = selectedPrinter!;

    bytes += generator.cut();
    await printerManager.connect(
        model: BluetoothPrinterInput(
            name: bluetoothPrinter.deviceName,
            address: bluetoothPrinter.address!,
            isBle: bluetoothPrinter.isBle ?? false,
            autoConnect: _reconnect));
    pendingTask = null;
    if (Platform.isAndroid) pendingTask = bytes;

    if (Platform.isAndroid) {
      if (_currentStatus == BTStatus.connected) {
        printerManager.send(bytes: bytes);
        pendingTask = null;
      }
    } else {
      printerManager.send(bytes: bytes);
    }
  }

  // conectar dispositivo
  _connectDevice() async {
    _isConnected = false;
    if (selectedPrinter == null) return;
    await printerManager.connect(
        model: BluetoothPrinterInput(
            name: selectedPrinter!.deviceName,
            address: selectedPrinter!.address!,
            isBle: selectedPrinter!.isBle ?? false,
            autoConnect: _reconnect));

    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Flutter Pos Plugin Platform example app'),
        ),
        body: Center(
          child: Container(
            height: double.infinity,
            constraints: const BoxConstraints(maxWidth: 400),
            child: SingleChildScrollView(
              padding: EdgeInsets.zero,
              child: Column(
                children: [
                  Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: Row(
                      children: [
                        Expanded(
                          child: ElevatedButton(
                            onPressed: selectedPrinter == null || _isConnected
                                ? null
                                : () {
                                    _connectDevice();
                                  },
                            child: const Text("Connect",
                                textAlign: TextAlign.center),
                          ),
                        ),
                        const SizedBox(width: 8),
                        Expanded(
                          child: ElevatedButton(
                            onPressed: selectedPrinter == null || !_isConnected
                                ? null
                                : () {
                                    if (selectedPrinter != null) {
                                      printerManager.disconnect();
                                      setState(() {
                                        _isConnected = false;
                                      });
                                    }
                                  },
                            child: const Text("Disconnect",
                                textAlign: TextAlign.center),
                          ),
                        ),
                      ],
                    ),
                  ),
                  Visibility(
                    visible: Platform.isAndroid,
                    child: SwitchListTile.adaptive(
                      contentPadding:
                          const EdgeInsets.only(bottom: 20.0, left: 20),
                      title: const Text(
                        "This device supports ble (low energy)",
                        textAlign: TextAlign.start,
                        style: TextStyle(fontSize: 19.0),
                      ),
                      value: _isBle,
                      onChanged: (bool? value) {
                        setState(() {
                          _isBle = value ?? false;
                          _isConnected = false;
                          selectedPrinter = null;
                          _scan();
                        });
                      },
                    ),
                  ),
                  Visibility(
                    visible: Platform.isAndroid,
                    child: SwitchListTile.adaptive(
                      contentPadding:
                          const EdgeInsets.only(bottom: 20.0, left: 20),
                      title: const Text(
                        "reconnect",
                        textAlign: TextAlign.start,
                        style: TextStyle(fontSize: 19.0),
                      ),
                      value: _reconnect,
                      onChanged: (bool? value) {
                        setState(() {
                          _reconnect = value ?? false;
                        });
                      },
                    ),
                  ),
                  Column(
                      children: devices
                          .map(
                            (device) => ListTile(
                              title: Text('${device.deviceName}'),
                              onTap: () {
                                // do something
                                selectDevice(device);
                              },
                              leading: selectedPrinter != null &&
                                      ((device.address != null &&
                                          selectedPrinter!.address ==
                                              device.address))
                                  ? const Icon(
                                      Icons.check,
                                      color: Colors.green,
                                    )
                                  : null,
                              trailing: OutlinedButton(
                                onPressed: selectedPrinter == null ||
                                        device.deviceName !=
                                            selectedPrinter?.deviceName
                                    ? null
                                    : () async {
                                        _printReceiveTest();
                                      },
                                child: const Padding(
                                  padding: EdgeInsets.symmetric(
                                      vertical: 2, horizontal: 20),
                                  child: Text("Print test ticket",
                                      textAlign: TextAlign.center),
                                ),
                              ),
                            ),
                          )
                          .toList()),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}

class BluetoothPrinter {
  int? id;
  String? deviceName;
  String? address;
  bool? isBle;

  bool? state;

  BluetoothPrinter(
      {this.deviceName, this.address, this.state, this.isBle = false});
}