Schnelldruck

Quick Print

A comprehensive Flutter package for handling PDF printing across different platforms and devices. This package provides a unified interface for printing PDFs using various printer types, including ESC/POS, Sunmi, Bluetooth, USB, and system printers.

Features

• 🖨️ Multi-printer Support
  • Sunmi printer support for Android devices
  • Bluetooth printer integration (including BLE)
  • USB printer compatibility
  • Desktop system printer support
  • Mobile device printing
• 🖼️ Image Printing Support
  • Print images (Uint8List) directly to any supported printer
• 📄 Paper Size Options
  • 80mm paper width (POS printers)
  • 58mm paper width (Thermal printers)
  • A4 paper size
• 🎯 Platform Support
  • Android
  • iOS
  • Windows
  • Linux
  • macOS
• 🔍 Printer Discovery
  • Discover Bluetooth, BLE, USB, and desktop printers
  • Unified API for managing discovered printers
• 🛠️ Error Handling
  • Custom exceptions for invalid files, unconnected devices, and unsupported operations

Getting Started

Add this to your package's pubspec.yaml file:

dependencies:
  quick_print: <LASTEST_VERSION>

Then run:

flutter pub get

Usage

Basic Usage

import 'package:quick_print/quick_print.dart';

// Create a printer instance
final printer = QuickPrint(PrinterDeviceType.mobile);

// Print a PDF file
await printer.instance.print(
  path: 'assets/document.pdf',
  paperSize: PaperSize.a4,
);

// Print an image (as Uint8List)
final imageBytes = await File('assets/image.png').readAsBytes();
await printer.instance.printImage(
  bytes: imageBytes,
  paperSize: PaperSize.a4,
);

Printer Discovery

The PrinterDiscoveryService class allows you to discover printers on various platforms.

import 'package:quick_print/quick_print.dart';

final discoveryService = PrinterDiscoveryService();

// Initialize the service (required for BLE on Windows)
await discoveryService.initialize();

// Discover printers
await discoveryService.discoverDevices();

// List discovered printers
final printers = discoveryService.printerDevicesList;
printers.forEach((printer) {
  print('Discovered printer: ${printer.name}');
});

// Dispose of the service when done
discoveryService.dispose();

Bluetooth Printer

import 'package:quick_print/quick_print.dart';

// Create a Bluetooth printer model
final bluetoothModel = BluetoothPrinterModel(
  name: 'Thermal Printer',
  address: '00:11:22:33:44:55',
  isBle: false,
);

// Create a printer instance
final printer = QuickPrint(PrinterDeviceType.bluetooth);

// Print with the Bluetooth printer
await printer.instance.print(
  path: 'assets/receipt.pdf',
  paperSize: PaperSize.mm80,
  model: bluetoothModel,
);

USB Printer

import 'package:quick_print/quick_print.dart';

// Create a USB printer model
final usbModel = UsbPrinterModel(
  name: 'POS-58',
  productId: '0x0483',
  vendorId: '0x5740',
);

// Create a printer instance
final printer = QuickPrint(PrinterDeviceType.usb);

// Print with the USB printer
await printer.instance.print(
  path: 'assets/receipt.pdf',
  paperSize: PaperSize.mm58,
  model: usbModel,
);

Platform-specific Setup

Android

Add the following permissions to your AndroidManifest.xml:

<!-- For Bluetooth printers -->
<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"/>

<!-- For USB printers -->
<uses-feature android:name="android.hardware.usb.host"/>

iOS

Add the following to your Info.plist:

<key>UISupportedExternalAccessoryProtocols</key>
<array>
    <string>com.printer.protocol</string>
</array>

<!-- For Bluetooth printers -->
<key>NSBluetoothAlwaysUsageDescription</key>
<string>Need BT access for printing</string>
<key>NSBluetoothPeripheralUsageDescription</key>
<string>Need BT access for printing</string>

macOS

Add the following entitlements to your app:

com.apple.security.print
com.apple.security.device.usb
com.apple.security.device.bluetooth

Error Handling

The package uses custom exceptions for error handling:

• PrinterException: General printer errors
• InvalidFileException: Errors related to invalid files
• InvalidTypeException: Errors for invalid printer models
• UnConnectedDeviceException: Errors for unconnected devices

Example:

try {
  await printer.instance.print(
    path: 'assets/document.pdf',
    paperSize: PaperSize.a4,
  );
} on PrinterException catch (e) {
  print('Printing failed: ${e.message}');
  if (e.cause != null) {
    print('Cause: ${e.cause}');
  }
}

Additional Information

• Documentation: Full API documentation is available here.
• Examples: Check the example directory for more detailed examples.
• Issues: File issues, bugs, or feature requests here.
• Contributing: See CONTRIBUTING.md for guidelines.

License

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

Support

For support and questions, please:

1. Check the FAQ section
2. Search for existing issues
3. Create a new issue if needed

Acknowledgments

• Thanks to all contributors who have helped make this package better
• Special thanks to the Flutter and Dart teams for their amazing work

/// Printer implementation for USB-connected printers. class UsbPrinter extends IConnectionPrinter { }