THERMAL PRINTER FLUTTER

Flutter plugin for thermal printing with support for multiple platforms and connection types.

Support

Platform	USB	Bluetooth	Network
Android	❌	✅	✅
iOS	❌	✅	✅
macOS	❌	✅	✅
Windows	✅	🚧	✅
Linux	❌	❌	✅
Web	❌	❌	🚧

Project Setup

Android

1. Add the following permissions to the android/app/src/main/AndroidManifest.xml file:

<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
<uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

2. For Android 12 or higher, also add:

<uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE" />

iOS

1. Add the following keys to the ios/Runner/Info.plist file:

<key>NSBluetoothAlwaysUsageDescription</key>
<string>We need Bluetooth access to connect to thermal printers</string>
<key>NSBluetoothPeripheralUsageDescription</key>
<string>We need Bluetooth access to connect to thermal printers</string>

2. For iOS 13 or higher, also add:

<key>NSBluetoothAlwaysAndWhenInUseUsageDescription</key>
<string>We need Bluetooth access to connect to thermal printers</string>

macOS

1. Add the following keys to the macos/Runner/Info.plist file:

<key>NSBluetoothAlwaysUsageDescription</key>
<string>We need Bluetooth access to connect to thermal printers</string>
<key>NSBluetoothPeripheralUsageDescription</key>
<string>We need Bluetooth access to connect to thermal printers</string>

2. Add the following keys to the macos/Runner/DebugProfile.entitlements file:

<key>com.apple.security.device.bluetooth</key>
<true/>

3. Add the following keys to the macos/Runner/Release.entitlements file:

<key>com.apple.security.device.bluetooth</key>
<true/>

Windows

1. For USB printers, ensure the printer drivers are installed.
2. For Bluetooth printers, Windows must support Bluetooth LE (Bluetooth 4.0 or higher).

Linux

1. For network printers, ensure that the firewall allows connections on port 9100 (or the configured port).

Web

1. For network printers, ensure that the web server allows WebSocket connections.
2. Add the following script to the web/index.html file:

<script>
  if ("serviceWorker" in navigator) {
    window.addEventListener("flutter-first-frame", function () {
      navigator.serviceWorker.register("flutter_service_worker.js");
    });
  }
</script>

Usage

import 'package:thermal_printer_flutter/thermal_printer_flutter.dart';

// Create an instance of the plugin
final thermalPrinter = ThermalPrinterFlutter();
Printer? _selectedPrinter;

// Only Android, Ios, Macos
final bluetoothPrinters = await thermalPrinter.getPrinters(printerType: PrinterType.bluethoot);
// Only Windows
final usbPrinters = await thermalPrinter.getPrinters(printerType: PrinterType.usb);


// Connect to a printer only bluethoot
final connected = await thermalPrinter.connect(printer: selectedPrinter);


 Future<void> _printTest({required ThermalPrinterFlutter termalPrinter,  required Printer printer}) async {
    try {
      final generator = Generator(PaperSize.mm80, await CapabilityProfile.load());
      List<int> bytes = [];

      bytes += generator.text('Print Test',
          styles: const PosStyles(
            align: PosAlign.center,
            bold: true,
            height: PosTextSize.size2,
            width: PosTextSize.size2,
          ));
      bytes += generator.feed(2);
      bytes += generator.text('Date: ${DateTime.now()}');
      bytes += generator.feed(2);
      bytes += generator.text('This is a test print');
      bytes += generator.feed(2);
      bytes += generator.cut();

      await termalPrinter.printBytes(bytes: bytes, printer: printer);

    } catch (e) {
      print('Error printing: $e');
    }
  }

Dependency Compatibility

If you are using the packages below, we recommend using these specific versions for better compatibility:

dependencies:
  web: ^0.5.1
  image: ^4.5.4

Example

Check out the complete example at example/lib/main.dart for a sample implementation with a graphical interface.

Contribution

Contributions are welcome! Feel free to open issues or submit pull requests.

License

This project is licensed under the MIT License - see the LICENSE file for details.