flutter_bixolon_printer 0.0.1

A Flutter plugin for connecting to and printing with Bixolon thermal printers. Supports device discovery, connection management, text/image/barcode printing, and international character sets.

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:flutter_bixolon_printer/flutter_bixolon_printer.dart';
import 'package:permission_handler/permission_handler.dart';
import 'dart:async';

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

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

  @override
  State<PrinterExampleApp> createState() => _PrinterExampleAppState();
}

class _PrinterExampleAppState extends State<PrinterExampleApp> {
  bool _isConnected = false;
  List<PrinterDevice> _devices = [];
  PrinterDevice? _selectedDevice;
  String _status = "Ready";
  bool _isLoading = false;

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

  Future<void> _requestPermissions() async {
    if (Theme.of(context).platform == TargetPlatform.android) {
      await [
        Permission.bluetooth,
        Permission.bluetoothConnect,
        Permission.bluetoothScan,
        Permission.location,
        Permission.storage,
      ].request();
    }
  }

  Future<void> _scanPrinters() async {
    setState(() {
      _isLoading = true;
      _status = "Scanning for printers...";
      _devices = [];
    });

    try {
      // Scan for Bluetooth printers
      final bluetoothPrinters =
          await FlutterBixolonPrinter.scanBluetoothPrinters();

      // Scan for network printers
      final networkPrinters = await FlutterBixolonPrinter.scanNetworkPrinters();

      setState(() {
        _devices = [...bluetoothPrinters, ...networkPrinters];
        _status = "Found ${_devices.length} printers";
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _status = "Error scanning: $e";
        _isLoading = false;
      });
    }
  }

  Future<void> _connectPrinter() async {
    if (_selectedDevice == null) {
      setState(() {
        _status = "No printer selected";
      });
      return;
    }

    setState(() {
      _isLoading = true;
      _status = "Connecting to ${_selectedDevice!.name}...";
    });

    try {
      // Initialize the printer
      final initialized = await FlutterBixolonPrinter.initialize(
        deviceName: _selectedDevice!.name,
        address: _selectedDevice!.address,
        connectionType: _selectedDevice!.connectionType,
        model: _getModelFromName(_selectedDevice!.name),
      );

      if (!initialized) {
        setState(() {
          _status = "Failed to initialize printer";
          _isLoading = false;
        });
        return;
      }

      // Connect to the printer
      final connected = await FlutterBixolonPrinter.connect(timeout: 5000);

      setState(() {
        _isConnected = connected;
        _status = connected
            ? "Connected to ${_selectedDevice!.name}"
            : "Failed to connect";
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _status = "Connection error: $e";
        _isLoading = false;
      });
    }
  }

  Future<void> _disconnectPrinter() async {
    setState(() {
      _isLoading = true;
      _status = "Disconnecting...";
    });

    try {
      final disconnected = await FlutterBixolonPrinter.disconnect();

      setState(() {
        _isConnected = !disconnected;
        _status = disconnected ? "Disconnected" : "Failed to disconnect";
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _status = "Disconnection error: $e";
        _isLoading = false;
      });
    }
  }

  Future<void> _printTextSample() async {
    if (!_isConnected) {
      _showNotConnectedMessage();
      return;
    }

    setState(() {
      _isLoading = true;
      _status = "Printing text sample...";
    });

    try {
      await FlutterBixolonPrinter.printCenteredText(
        text: "TEXT PRINTING SAMPLE",
        fontSize: 28,
        fontWeight: FontWeight.bold,
      );

      await FlutterBixolonPrinter.printBlankLines(1);

      await FlutterBixolonPrinter.printText("Regular text printing\n");
      await FlutterBixolonPrinter.printText("More regular text\n");

      await FlutterBixolonPrinter.printBlankLines(1);

      await FlutterBixolonPrinter.printCenteredText(
        text: "Centered Text Example",
        fontSize: 22,
      );

      await FlutterBixolonPrinter.printBlankLines(1);

      await FlutterBixolonPrinter.printFormattedText(
        columns: [
          const TextColumn(text: 'Left', x: 0),
          const TextColumn(text: 'Center', x: 288, align: TextAlign.center),
          const TextColumn(text: 'Right', x: 576, align: TextAlign.right),
        ],
      );

      await FlutterBixolonPrinter.cutPaper();

      setState(() {
        _status = "Text sample printed";
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _status = "Printing error: $e";
        _isLoading = false;
      });
    }
  }

  Future<void> _printBarcodeSample() async {
    if (!_isConnected) {
      _showNotConnectedMessage();
      return;
    }

    setState(() {
      _isLoading = true;
      _status = "Printing barcode sample...";
    });

    try {
      await FlutterBixolonPrinter.printCenteredText(
        text: "BARCODE SAMPLES",
        fontSize: 28,
        fontWeight: FontWeight.bold,
      );

      await FlutterBixolonPrinter.printBlankLines(1);

      // Print Code 128 barcode
      await FlutterBixolonPrinter.printCenteredText(
        text: "CODE 128",
        fontSize: 22,
      );

      await FlutterBixolonPrinter.printBarcode(
        "1234567890",
        BarcodeType.code128,
        height: 100,
        width: 2,
        alignment: Alignment.center,
        textPosition: BarcodeTextPosition.below,
      );

      await FlutterBixolonPrinter.printBlankLines(1);

      // Print QR Code
      await FlutterBixolonPrinter.printCenteredText(
        text: "QR CODE",
        fontSize: 22,
      );

      await FlutterBixolonPrinter.printQRCode(
        "https://pub.dev/packages/flutter_bixolon_printer",
        size: 200,
        alignment: Alignment.center,
      );

      await FlutterBixolonPrinter.cutPaper();

      setState(() {
        _status = "Barcode sample printed";
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _status = "Printing error: $e";
        _isLoading = false;
      });
    }
  }

  Future<void> _printReceiptSample() async {
    if (!_isConnected) {
      _showNotConnectedMessage();
      return;
    }

    setState(() {
      _isLoading = true;
      _status = "Printing receipt sample...";
    });

    try {
      // Sample receipt data
      final items = [
        {'product': 'Coffee', 'qty': '1', 'price': '\$3.50'},
        {'product': 'Sandwich', 'qty': '1', 'price': '\$5.75'},
        {'product': 'Cookie', 'qty': '2', 'price': '\$2.00'},
      ];

      await FlutterBixolonPrinter.printReceipt(
        header: 'SAMPLE RECEIPT',
        items: items,
        footer: 'Thank you for your business!',
      );

      setState(() {
        _status = "Receipt sample printed";
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _status = "Printing error: $e";
        _isLoading = false;
      });
    }
  }

  void _showNotConnectedMessage() {
    setState(() {
      _status = "Not connected to a printer";
    });

    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(
        content: Text('Please connect to a printer first'),
        backgroundColor: Colors.red,
      ),
    );
  }

  // Helper method to guess model name from device name
  String _getModelFromName(String name) {
    if (name.contains('R200')) return 'SPP-R200III';
    if (name.contains('R210')) return 'SPP-R210';
    if (name.contains('R310')) return 'SPP-R310';
    if (name.contains('R400')) return 'SPP-R400';

    // Default to R310 if model can't be determined
    return 'SPP-R310';
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        primarySwatch: Colors.blue,
        useMaterial3: true,
      ),
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Bixolon Printer Example'),
        ),
        body: _isLoading
            ? const Center(child: CircularProgressIndicator())
            : SingleChildScrollView(
                padding: const EdgeInsets.all(16.0),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    // Status display
                    Container(
                      padding: const EdgeInsets.all(12.0),
                      decoration: BoxDecoration(
                        color:
                            _isConnected ? Colors.green[100] : Colors.grey[200],
                        borderRadius: BorderRadius.circular(8),
                      ),
                      child: Row(
                        children: [
                          Icon(
                            _isConnected ? Icons.check_circle : Icons.info,
                            color: _isConnected ? Colors.green : Colors.grey,
                          ),
                          const SizedBox(width: 8),
                          Expanded(
                            child: Text(
                              _status,
                              style: TextStyle(
                                fontWeight: FontWeight.bold,
                                color: _isConnected
                                    ? Colors.green[800]
                                    : Colors.black87,
                              ),
                            ),
                          ),
                        ],
                      ),
                    ),

                    const SizedBox(height: 24),

                    // Printer discovery section
                    const Text(
                      'Printer Discovery',
                      style: TextStyle(
                        fontSize: 18,
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                    const SizedBox(height: 12),
                    ElevatedButton.icon(
                      onPressed: _scanPrinters,
                      icon: const Icon(Icons.search),
                      label: const Text('Scan for Printers'),
                      style: ElevatedButton.styleFrom(
                        padding: const EdgeInsets.symmetric(vertical: 12),
                      ),
                    ),

                    const SizedBox(height: 12),

                    // Printer selection dropdown
                    if (_devices.isNotEmpty) ...[
                      DropdownButtonFormField<PrinterDevice>(
                        decoration: const InputDecoration(
                          labelText: 'Select a printer',
                          border: OutlineInputBorder(),
                        ),
                        value: _selectedDevice,
                        onChanged: (PrinterDevice? device) {
                          setState(() {
                            _selectedDevice = device;
                          });
                        },
                        items: _devices.map((printer) {
                          return DropdownMenuItem<PrinterDevice>(
                            value: printer,
                            child: Text(
                              '${printer.name} (${printer.connectionType.toString().split('.').last})',
                              overflow: TextOverflow.ellipsis,
                            ),
                          );
                        }).toList(),
                      ),
                    ] else if (_devices.isEmpty &&
                        _status.contains('Found')) ...[
                      const Padding(
                        padding: EdgeInsets.all(8.0),
                        child: Text(
                          'No printers found. Make sure your printer is turned on and discoverable.',
                          style: TextStyle(fontStyle: FontStyle.italic),
                        ),
                      ),
                    ],

                    const SizedBox(height: 24),

                    // Connection controls
                    const Text(
                      'Connection',
                      style: TextStyle(
                        fontSize: 18,
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                    const SizedBox(height: 12),
                    Row(
                      children: [
                        Expanded(
                          child: ElevatedButton.icon(
                            onPressed: _isConnected ? null : _connectPrinter,
                            icon: const Icon(Icons.bluetooth_connected),
                            label: const Text('Connect'),
                            style: ElevatedButton.styleFrom(
                              padding: const EdgeInsets.symmetric(vertical: 12),
                            ),
                          ),
                        ),
                        const SizedBox(width: 12),
                        Expanded(
                          child: ElevatedButton.icon(
                            onPressed: _isConnected ? _disconnectPrinter : null,
                            icon: const Icon(Icons.bluetooth_disabled),
                            label: const Text('Disconnect'),
                            style: ElevatedButton.styleFrom(
                              backgroundColor: Colors.red,
                              foregroundColor: Colors.white,
                              padding: const EdgeInsets.symmetric(vertical: 12),
                            ),
                          ),
                        ),
                      ],
                    ),

                    const SizedBox(height: 24),

                    // Printing examples
                    const Text(
                      'Printing Examples',
                      style: TextStyle(
                        fontSize: 18,
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                    const SizedBox(height: 12),

                    _buildPrintButton(
                      'Print Text Sample',
                      Icons.text_fields,
                      _printTextSample,
                    ),

                    const SizedBox(height: 8),

                    _buildPrintButton(
                      'Print Barcode Sample',
                      Icons.qr_code,
                      _printBarcodeSample,
                    ),

                    const SizedBox(height: 8),

                    _buildPrintButton(
                      'Print Receipt Sample',
                      Icons.receipt_long,
                      _printReceiptSample,
                    ),
                  ],
                ),
              ),
      ),
    );
  }

  Widget _buildPrintButton(String text, IconData icon, VoidCallback onPressed) {
    return ElevatedButton.icon(
      onPressed: _isConnected ? onPressed : null,
      icon: Icon(icon),
      label: Text(text),
      style: ElevatedButton.styleFrom(
        padding: const EdgeInsets.symmetric(vertical: 12),
      ),
    );
  }
}