bluetooth_pos_printer_utils 1.0.1

This package is a fork of flutter_esc_pos_utils customized for bluetooth_pos_printer.

bluetooth_pos_printer_utils

Base Flutter/Dart classes for ESC/POS printing. Generator class generates ESC/POS commands that can be sent to a thermal printer.

This is the "base" library that used for:

• Flutter WiFi/Ethernet printing: esc_pos_printer
• Flutter Bluetooth printing: esc_pos_bluetooth

Main Features

• Connect to Wi-Fi / Ethernet printers
• Simple text printing using text method
• Tables printing using row method
• Text styling:
  • size, align, bold, reverse, underline, different fonts, turn 90°
• Print images
• Print barcodes
  • UPC-A, UPC-E, JAN13 (EAN13), JAN8 (EAN8), CODE39, ITF (Interleaved 2 of 5), CODABAR (NW-7), CODE128
• Paper cut (partial, full)
• Beeping (with different duration)
• Paper feed, reverse feed

Note: Your printer may not support some of the presented features (some styles, partial/full paper cutting, reverse feed, barcodes...).

Generate a Ticket

🌟 NEW: Print as Image (ImageGenerator) 🌟

The most reliable way to print complex layouts, international characters (like €), and rich formatting on thermal printers is to render the ticket as a single image. We introduced ImageGenerator to build your ticket using Flutter Widgets and automatically print them via a high-performance background isolate!

import 'package:bluetooth_pos_printer_utils/bluetooth_pos_printer_utils.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

Future<List<int>> generateTicketAsImage() async {
  final profile = await CapabilityProfile.load();
  final generator = ImageGenerator(PaperSize.mm58, profile);

  // 1. Build your ticket using simple generator methods:
  generator.text('SUPERMARKET', styles: const PosStyles(bold: true, align: PosAlign.center));
  
  // Render tables
  generator.row([
    PosColumn(text: 'Item 1', width: 6),
    PosColumn(text: '€ 10.00', width: 6, styles: const PosStyles(align: PosAlign.right)),
  ]);

  // Insert standard Flutter widgets directly!
  generator.widget(
    Container(
      padding: const EdgeInsets.all(8),
      color: Colors.black,
      child: const Text('CUSTOM FLUTTER WIDGET', style: TextStyle(color: Colors.white)),
    )
  );
  
  // Add Barcodes and QR Codes seamlessly
  generator.barcode(Barcode.code128('123456789'));
  generator.qrcode('https://example.com');

  // Add images from assets (will be processed with Halftone/Dithering automatically and cached for performance)
  final data = await rootBundle.load('assets/logo.png');
  generator.image(data.buffer.asUint8List(), width: 200, halftone: true);

  // 2. Build the final ESC/POS byte array (Uses Isolates & GS v 0 algorithm for ultra-fast processing)
  final bytes = await generator.buildImageBytes();
  return bytes;
}

---

Simple ticket with bytes (Traditional Method):

List<int> testTicket() {
  final List<int> bytes = [];
  // Using default profile
  final profile = await CapabilityProfile.load();
  final generator = Generator(PaperSize.mm80, profile);
  List<int> bytes = [];

  bytes += generator.text(
      'Regular: aA bB cC dD eE fF gG hH iI jJ kK lL mM nN oO pP qQ rR sS tT uU vV wW xX yY zZ');
  bytes += generator.text('Special 1: àÀ èÈ éÉ ûÛ üÜ çÇ ôÔ',
      styles: PosStyles(codeTable: PosCodeTable.westEur));
  bytes += generator.text('Special 2: blåbærgrød',
      styles: PosStyles(codeTable: PosCodeTable.westEur));

  bytes += generator.text('Bold text', styles: PosStyles(bold: true));
  bytes += generator.text('Reverse text', styles: PosStyles(reverse: true));
  bytes += generator.text('Underlined text',
      styles: PosStyles(underline: true), linesAfter: 1);
  bytes += generator.text('Align left', styles: PosStyles(align: PosAlign.left));
  bytes += generator.text('Align center', styles: PosStyles(align: PosAlign.center));
  bytes += generator.text('Align right',
      styles: PosStyles(align: PosAlign.right), linesAfter: 1);

  bytes += generator.text('Text size 200%',
      styles: PosStyles(
        height: PosTextSize.size2,
        width: PosTextSize.size2,
      ));

  bytes += generator.feed(2);
  bytes += generator.cut();
  return bytes;
}

Print a table row:

generator.row([
    PosColumn(
      text: 'col3',
      width: 3,
      styles: PosStyles(align: PosAlign.center, underline: true),
    ),
    PosColumn(
      text: 'col6',
      width: 6,
      styles: PosStyles(align: PosAlign.center, underline: true),
    ),
    PosColumn(
      text: 'col3',
      width: 3,
      styles: PosStyles(align: PosAlign.center, underline: true),
    ),
  ]);

Print an image:

This package implements 3 ESC/POS functions:

• ESC * - print in column format
• GS v 0 - print in bit raster format (obsolete)
• GS ( L - print in bit raster format

Note that your printer may support only some of the above functions.

import 'dart:io';
import 'package:image/image.dart';

final ByteData data = await rootBundle.load('assets/logo.png');
final Uint8List bytes = data.buffer.asUint8List();
final Image image = decodeImage(bytes);
// Using `ESC *`
generator.image(image);
// Using `GS v 0` (obsolete)
generator.imageRaster(image);
// Using `GS ( L`
generator.imageRaster(image, imageFn: PosImageFn.graphics);

Print a Barcode:

final List<int> barData = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 4];
generator.barcode(Barcode.upcA(barData));

Print a QR Code:

Using native ESC/POS commands:

generator.qrcode('example.com');

To print a QR Code as an image (if your printer doesn't support native commands), add qr_flutter and path_provider as a dependency in your pubspec.yaml file.

String qrData = "google.com";
const double qrSize = 200;
try {
  final uiImg = await QrPainter(
    data: qrData,
    version: QrVersions.auto,
    gapless: false,
  ).toImageData(qrSize);
  final dir = await getTemporaryDirectory();
  final pathName = '${dir.path}/qr_tmp.png';
  final qrFile = File(pathName);
  final imgFile = await qrFile.writeAsBytes(uiImg.buffer.asUint8List());
  final img = decodeImage(imgFile.readAsBytesSync());

  generator.image(img);
} catch (e) {
  print(e);
}

Using Code Tables

Different printers support different sets of code tables. Some printer models are defined in CapabilityProfile class. So, if you want to change the default code table, it's important to choose the right profile:

// Xprinter XP-N160I
final profile = await CapabilityProfile.load('XP-N160I');
final generator = Generator(PaperSize.mm80, profile);
bytes += generator.setGlobalCodeTable('CP1252');

All available profiles can be retrieved by calling :

final profiles = await CapabilityProfile.getAvailableProfiles();

How to Help

• Add a CapabilityProfile to support your printer's model. A new profile should be added to lib/resources/capabilities.json file
• Test and report bugs
• Share your ideas about what could be improved (code optimization, new features...)