flutter_sewoo_usb_printer 0.0.1 
flutter_sewoo_usb_printer: ^0.0.1 copied to clipboard
Flutter plugin for Sewoo USB POS printers using serial connection
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_sewoo_usb_printer/flutter_sewoo_usb_printer.dart';
import 'dart:async';
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> {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Sewoo USB Printer Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
useMaterial3: true,
),
home: const PrinterHomePage(),
);
}
}
class PrinterHomePage extends StatefulWidget {
const PrinterHomePage({Key? key}) : super(key: key);
@override
State<PrinterHomePage> createState() => _PrinterHomePageState();
}
class _PrinterHomePageState extends State<PrinterHomePage> {
List<String> _availablePorts = [];
String? _selectedPort;
int _selectedBaudRate = 9600;
bool _isConnected = false;
bool _isLoading = false;
PrinterStatus? _currentStatus;
StreamSubscription<PrinterStatus>? _statusSubscription;
bool _asbModeEnabled = false;
final List<int> _baudRates = [9600, 19200, 38400, 57600, 115200];
@override
void initState() {
super.initState();
_loadAvailablePorts();
}
@override
void dispose() {
_statusSubscription?.cancel();
super.dispose();
}
Future<void> _loadAvailablePorts() async {
try {
final ports = await SewooUsbPrinter.getAvailablePorts();
setState(() {
_availablePorts = ports;
if (ports.isNotEmpty && _selectedPort == null) {
_selectedPort = ports.first;
}
});
} catch (e) {
_showError('Failed to load ports: $e');
}
}
Future<void> _connect() async {
if (_selectedPort == null) return;
setState(() => _isLoading = true);
try {
final connected = await SewooUsbPrinter.connect(
_selectedPort!,
baudRate: _selectedBaudRate,
);
setState(() {
_isConnected = connected;
_isLoading = false;
});
if (connected) {
_showMessage('Connected successfully');
_checkStatus();
}
} catch (e) {
setState(() => _isLoading = false);
_showError('Connection failed: $e');
}
}
Future<void> _disconnect() async {
setState(() => _isLoading = true);
try {
await SewooUsbPrinter.disconnect();
setState(() {
_isConnected = false;
_isLoading = false;
_currentStatus = null;
});
_showMessage('Disconnected');
} catch (e) {
setState(() => _isLoading = false);
_showError('Disconnect failed: $e');
}
}
Future<void> _checkStatus() async {
try {
final status = await SewooUsbPrinter.checkPrinterStatus();
setState(() => _currentStatus = status);
} catch (e) {
_showError('Status check failed: $e');
}
}
Future<void> _toggleASBMode() async {
try {
await SewooUsbPrinter.enableASBMode(!_asbModeEnabled);
if (!_asbModeEnabled) {
_statusSubscription = SewooUsbPrinter.getStatusStream().listen(
(status) {
setState(() => _currentStatus = status);
},
onError: (error) {
_showError('Status stream error: $error');
},
);
} else {
_statusSubscription?.cancel();
_statusSubscription = null;
}
setState(() => _asbModeEnabled = !_asbModeEnabled);
_showMessage('ASB mode ${_asbModeEnabled ? "enabled" : "disabled"}');
} catch (e) {
_showError('Failed to toggle ASB mode: $e');
}
}
Future<void> _printSampleReceipt() async {
try {
await SewooUsbPrinter.printText(
'SAMPLE RECEIPT',
alignment: SewooUsbPrinter.ALIGN_CENTER,
fontType: SewooUsbPrinter.FONT_BOLD,
textSize: SewooUsbPrinter.TEXT_SIZE_2X,
);
await SewooUsbPrinter.lineFeed(lines: 2);
await SewooUsbPrinter.printText(
'Date: ${DateTime.now().toString().substring(0, 19)}',
alignment: SewooUsbPrinter.ALIGN_LEFT,
);
await SewooUsbPrinter.lineFeed();
await SewooUsbPrinter.printText('Items:',
fontType: SewooUsbPrinter.FONT_BOLD);
await SewooUsbPrinter.printText('Hamburger \$10.00');
await SewooUsbPrinter.printText('French Fries \$5.00');
await SewooUsbPrinter.printText('Soft Drink \$3.00');
await SewooUsbPrinter.printText(
'------------------------------------',
alignment: SewooUsbPrinter.ALIGN_CENTER,
);
await SewooUsbPrinter.printText(
'Total: \$18.00',
alignment: SewooUsbPrinter.ALIGN_RIGHT,
fontType: SewooUsbPrinter.FONT_BOLD,
textSize: SewooUsbPrinter.TEXT_SIZE_2X,
);
await SewooUsbPrinter.lineFeed(lines: 2);
await SewooUsbPrinter.printText(
'Thank you for your purchase!',
alignment: SewooUsbPrinter.ALIGN_CENTER,
);
await SewooUsbPrinter.lineFeed(lines: 4);
await SewooUsbPrinter.cutPaper();
_showMessage('Receipt printed successfully');
} catch (e) {
_showError('Print failed: $e');
}
}
Future<void> _printBarcode() async {
try {
await SewooUsbPrinter.printText(
'Barcode Example',
alignment: SewooUsbPrinter.ALIGN_CENTER,
fontType: SewooUsbPrinter.FONT_BOLD,
);
await SewooUsbPrinter.lineFeed(lines: 2);
await SewooUsbPrinter.printBarcode(
'1234567890',
barcodeType: SewooUsbPrinter.BARCODE_CODE128,
height: 100,
width: 2,
alignment: SewooUsbPrinter.ALIGN_CENTER,
hriPosition: SewooUsbPrinter.HRI_TEXT_BELOW,
);
await SewooUsbPrinter.lineFeed(lines: 4);
await SewooUsbPrinter.cutPaper();
_showMessage('Barcode printed successfully');
} catch (e) {
_showError('Barcode print failed: $e');
}
}
Future<void> _printQRCode() async {
try {
await SewooUsbPrinter.printText(
'QR Code Example',
alignment: SewooUsbPrinter.ALIGN_CENTER,
fontType: SewooUsbPrinter.FONT_BOLD,
);
await SewooUsbPrinter.lineFeed(lines: 2);
await SewooUsbPrinter.printQRCode(
'https://github.com',
moduleSize: 6,
errorLevel: SewooUsbPrinter.QR_ERROR_LEVEL_M,
);
await SewooUsbPrinter.lineFeed(lines: 4);
await SewooUsbPrinter.cutPaper();
_showMessage('QR Code printed successfully');
} catch (e) {
_showError('QR Code print failed: $e');
}
}
Future<void> _openCashDrawer() async {
try {
await SewooUsbPrinter.openCashDrawer();
_showMessage('Cash drawer opened');
} catch (e) {
_showError('Failed to open cash drawer: $e');
}
}
void _showMessage(String message) {
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text(message), backgroundColor: Colors.green),
);
}
void _showError(String error) {
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text(error), backgroundColor: Colors.red),
);
}
Widget _buildStatusIndicator() {
if (_currentStatus == null) {
return const Text('Status: Unknown');
}
return Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
'Printer Status:',
style: Theme.of(context).textTheme.titleMedium,
),
const SizedBox(height: 8),
_buildStatusRow('Normal', _currentStatus!.isNormal, Colors.green),
_buildStatusRow(
'Paper Empty', _currentStatus!.isPaperEmpty, Colors.red),
_buildStatusRow(
'Paper Near End', _currentStatus!.isPaperNearEnd, Colors.orange),
_buildStatusRow('Cover Open', _currentStatus!.isCoverOpen, Colors.red),
_buildStatusRow('Error', _currentStatus!.isError, Colors.red),
if (_currentStatus!.errorMessage != null)
Padding(
padding: const EdgeInsets.only(top: 4),
child: Text(
'Error: ${_currentStatus!.errorMessage}',
style: const TextStyle(color: Colors.red),
),
),
],
);
}
Widget _buildStatusRow(String label, bool active, Color activeColor) {
return Padding(
padding: const EdgeInsets.symmetric(vertical: 2),
child: Row(
children: [
Icon(
active ? Icons.circle : Icons.circle_outlined,
size: 12,
color: active ? activeColor : Colors.grey,
),
const SizedBox(width: 8),
Text(label),
],
),
);
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('Sewoo USB Printer'),
backgroundColor: Theme.of(context).colorScheme.inversePrimary,
),
body: Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
Card(
child: Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
'Connection Settings',
style: Theme.of(context).textTheme.titleLarge,
),
const SizedBox(height: 16),
Row(
children: [
Expanded(
child: DropdownButtonFormField<String>(
decoration: const InputDecoration(
labelText: 'Port',
border: OutlineInputBorder(),
),
value: _selectedPort,
items: _availablePorts.map((port) {
return DropdownMenuItem(
value: port,
child: Text(port),
);
}).toList(),
onChanged: _isConnected
? null
: (value) {
setState(() => _selectedPort = value);
},
),
),
const SizedBox(width: 8),
IconButton(
icon: const Icon(Icons.refresh),
onPressed: _isConnected ? null : _loadAvailablePorts,
),
],
),
const SizedBox(height: 16),
DropdownButtonFormField<int>(
decoration: const InputDecoration(
labelText: 'Baud Rate',
border: OutlineInputBorder(),
),
value: _selectedBaudRate,
items: _baudRates.map((rate) {
return DropdownMenuItem(
value: rate,
child: Text(rate.toString()),
);
}).toList(),
onChanged: _isConnected
? null
: (value) {
if (value != null) {
setState(() => _selectedBaudRate = value);
}
},
),
const SizedBox(height: 16),
Row(
children: [
Expanded(
child: ElevatedButton.icon(
onPressed: _isLoading
? null
: (_isConnected ? _disconnect : _connect),
icon: Icon(
_isConnected ? Icons.link_off : Icons.link),
label:
Text(_isConnected ? 'Disconnect' : 'Connect'),
style: ElevatedButton.styleFrom(
backgroundColor:
_isConnected ? Colors.red : Colors.green,
foregroundColor: Colors.white,
),
),
),
const SizedBox(width: 8),
ElevatedButton(
onPressed: _isConnected ? _checkStatus : null,
child: const Text('Check Status'),
),
],
),
const SizedBox(height: 8),
CheckboxListTile(
title: const Text('ASB Mode (Auto Status)'),
value: _asbModeEnabled,
onChanged: _isConnected ? (_) => _toggleASBMode() : null,
),
],
),
),
),
const SizedBox(height: 16),
if (_isConnected) ...[
Card(
child: Padding(
padding: const EdgeInsets.all(16.0),
child: _buildStatusIndicator(),
),
),
const SizedBox(height: 16),
Expanded(
child: GridView.count(
crossAxisCount: 2,
childAspectRatio: 2.5,
mainAxisSpacing: 8,
crossAxisSpacing: 8,
children: [
_buildActionButton(
'Sample Receipt',
Icons.receipt,
_printSampleReceipt,
),
_buildActionButton(
'Barcode',
Icons.barcode_reader,
_printBarcode,
),
_buildActionButton(
'QR Code',
Icons.qr_code,
_printQRCode,
),
_buildActionButton(
'Cash Drawer',
Icons.money,
_openCashDrawer,
),
_buildActionButton(
'Line Feed',
Icons.format_line_spacing,
() => SewooUsbPrinter.lineFeed(lines: 3),
),
_buildActionButton(
'Cut Paper',
Icons.cut,
SewooUsbPrinter.cutPaper,
),
],
),
),
],
if (_isLoading)
const Center(
child: CircularProgressIndicator(),
),
],
),
),
);
}
Widget _buildActionButton(
String label, IconData icon, VoidCallback onPressed) {
return ElevatedButton(
onPressed: _isConnected ? onPressed : null,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Icon(icon, size: 24),
const SizedBox(height: 4),
Text(
label,
textAlign: TextAlign.center,
style: const TextStyle(fontSize: 12),
),
],
),
);
}
}Metadata
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Metadata
Flutter plugin for Sewoo USB POS printers using serial connection
Repository (GitHub)
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Documentation
License
MIT (license)
Dependencies
flutter, plugin_platform_interface
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