flutter_thermal_printer 0.0.17

Plugin for Flutter to print on thermal printers via ESC/POS commands.

example/lib/main.dart

// ignore_for_file: depend_on_referenced_packages

import 'dart:async';
import 'dart:developer';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_thermal_printer/flutter_thermal_printer.dart';
import 'package:flutter_thermal_printer/utils/printer.dart';

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

class MyApp extends StatefulWidget {
  const MyApp({super.key});

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

class _MyAppState extends State<MyApp> {
  final _flutterThermalPrinterPlugin = FlutterThermalPrinter.instance;

  List<Printer> printers = [];

  StreamSubscription<List<Printer>>? _devicesStreamSubscription;

  // Get Printer List
  void startScan() async {
    _devicesStreamSubscription?.cancel();
    await _flutterThermalPrinterPlugin.getPrinters(connectionTypes: [
      ConnectionType.USB,
    ]);
    _devicesStreamSubscription = _flutterThermalPrinterPlugin.devicesStream
        .listen((List<Printer> event) {
      log(event.map((e) => e.name).toList().toString());
      setState(() {
        printers = event;
        printers
            .removeWhere((element) => element.name == null || element.name == ''
                //  ||
                // !element.name!.toLowerCase().contains('print')
                );
      });
    });
  }

  // @override
  // void initState() {
  //   super.initState();
  //   _devicesStreamSubscription = _flutterThermalPrinterPlugin.devicesStream
  //       .listen((List<Printer> event) {
  //     log(event.map((e) => e.name).toList().toString());
  //     setState(() {
  //       printers = event;
  //       printers.removeWhere((element) =>
  //           element.name == null ||
  //           element.name == '' ||
  //           !element.name!.toLowerCase().contains('print'));
  //     });
  //   });
  // }

  stopScan() {
    _devicesStreamSubscription?.cancel();
    _flutterThermalPrinterPlugin.stopScan();
  }

  void getUsbDevices() async {
    await _flutterThermalPrinterPlugin.getUsbDevices();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Plugin example app'),
          systemOverlayStyle: const SystemUiOverlayStyle(
            statusBarColor: Colors.transparent,
          ),
        ),
        body: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            ElevatedButton(
              onPressed: () {
                // startScan();
                startScan();
              },
              child: const Text('Get Printers'),
            ),
            ElevatedButton(
              onPressed: () {
                // startScan();
                stopScan();
              },
              child: const Text('Stop Scan'),
            ),
            Expanded(
              child: ListView.builder(
                itemCount: printers.length,
                itemBuilder: (context, index) {
                  return ListTile(
                    onTap: () async {
                      if (printers[index].isConnected ?? false) {
                        await _flutterThermalPrinterPlugin
                            .disconnect(printers[index]);
                      } else {
                        final isConnected = await _flutterThermalPrinterPlugin
                            .connect(printers[index]);
                        log("Devices: $isConnected");
                      }
                    },
                    title: Text(printers[index].name ?? 'No Name'),
                    subtitle: Text("Connected: ${printers[index].isConnected}"),
                    trailing: IconButton(
                      icon: const Icon(Icons.connect_without_contact),
                      onPressed: () async {
                        final profile = await CapabilityProfile.load();
                        final generator = Generator(PaperSize.mm80, profile);
                        List<int> bytes = [];
                        bytes += generator.text(
                          "Sunil Kumar",
                          styles: const PosStyles(
                            bold: true,
                            height: PosTextSize.size3,
                            width: PosTextSize.size3,
                          ),
                        );
                        bytes += generator.cut();
                        await _flutterThermalPrinterPlugin.printData(
                          printers[index],
                          bytes,
                          longData: true,
                        );
                      },
                    ),
                  );
                },
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget receiptWidget() {
    return Container(
        padding: const EdgeInsets.all(8),
        color: Colors.white,
        width: 300,
        height: 300,
        child: const Center(
          child: Column(
            children: [
              Text(
                "FLUTTER THERMAL PRINTER",
                style: TextStyle(
                  fontSize: 20,
                  fontWeight: FontWeight.bold,
                  color: Colors.black,
                ),
              ),
              SizedBox(height: 10),
              Text(
                "Hello World",
                style: TextStyle(
                  fontSize: 16,
                  fontWeight: FontWeight.bold,
                  color: Colors.black,
                ),
              ),
              SizedBox(height: 10),
              Text(
                "This is a test receipt",
                style: TextStyle(
                  fontSize: 16,
                  fontWeight: FontWeight.bold,
                  color: Colors.black,
                ),
              ),
            ],
          ),
        ));
  }
}