newpos_q_series

Flutter plugin for the internal thermal printer available on supported Newpos Q-series Android devices.

The plugin talks to the vendor IPOS printer service through Android AIDL and provides a Dart API for receipts, images, barcodes, QR codes, raw bytes, ESC/POS commands, and printer status events such as paper-out detection.

Features

• Bind to the Newpos/IPOS internal printer service.
• Print plain and formatted text.
• Print table-like column rows.
• Print bitmap images, including black-and-white artwork.
• Print QR codes and one-dimensional barcodes.
• Send raw bytes and ESC/POS commands.
• Feed paper and print blank lines.
• Listen for printer status events, including paperless alerts.

Platform Support

Platform	Status
Android	Supported
iOS	Not supported
Web/Desktop	Not supported

This package requires a Newpos firmware that includes the vendor service:

• Package: com.iposprinter.iposprinterservice
• Action: com.iposprinter.iposprinterservice.IPosPrintService

On regular Android devices or unsupported firmware, bind() returns false or print calls fail because the vendor printer service is not available.

Installation

Install the package from pub.dev:

flutter pub add newpos_q_series

Or add it manually to your pubspec.yaml:

dependencies:
  newpos_q_series: ^0.0.1

Then run:

flutter pub get

Basic Usage

import 'package:newpos_q_series/newpos_q_series.dart';

final printer = PrinterNewposQ();

final connected = await printer.bind();
if (!connected) {
  throw Exception('Newpos printer service not found');
}

await printer.printText(
  'Hello Newpos Q\n\n',
  fontSize: 24,
  alignment: NewposQAlignment.center,
);

Receipts

Use NewposQPrintJob for multi-step receipts.

final job = NewposQPrintJob()
  ..init()
  ..setDepth(6)
  ..formattedText(
    'MY STORE\n',
    fontSize: 32,
    alignment: NewposQAlignment.center,
  )
  ..formattedText('Order #123\n', fontSize: 24)
  ..columns(
    const [
      NewposQColumn(text: 'Item', width: 12),
      NewposQColumn(
        text: 'Qty',
        width: 6,
        alignment: NewposQAlignment.right,
      ),
      NewposQColumn(
        text: 'Total',
        width: 8,
        alignment: NewposQAlignment.right,
      ),
    ],
    continuous: true,
  )
  ..columns(
    const [
      NewposQColumn(text: 'Coffee', width: 12),
      NewposQColumn(
        text: '1',
        width: 6,
        alignment: NewposQAlignment.right,
      ),
      NewposQColumn(
        text: '5.00',
        width: 8,
        alignment: NewposQAlignment.right,
      ),
    ],
  )
  ..qrCode('https://www.setsistema.com.br/')
  ..performPrint(feedLines: 160);

await printer.execute(job);

Images

The printer is thermal, so output is monochrome. PNG/JPEG bytes can be sent to the plugin and are decoded as Android Bitmaps before being passed to the vendor service.

final data = await rootBundle.load('assets/logo.png');

final job = NewposQPrintJob()
  ..init()
  ..bitmap(
    data.buffer.asUint8List(),
    alignment: NewposQAlignment.center,
    size: 10,
  )
  ..performPrint(feedLines: 160);

await printer.execute(job);

Vendor SDK notes indicate a maximum image width of 384 px. For best results, prepare images at 384 px wide or less and use high-contrast black-and-white artwork.

Barcodes and QR Codes

final job = NewposQPrintJob()
  ..init()
  ..barcode(
    '7891234567895',
    symbology: NewposQBarcodeSymbology.ean13,
    height: 6,
    width: 12,
    textPosition: NewposQBarcodeTextPosition.below,
  )
  ..qrCode(
    'https://www.setsistema.com.br/',
    moduleSize: 8,
    errorCorrectionLevel: NewposQErrorCorrectionLevel.medium,
  )
  ..performPrint(feedLines: 160);

await printer.execute(job);

Printer Status Events

The plugin exposes printer status broadcasts as a Dart stream.

final subscription = printer.statusEvents.listen((event) {
  if (event.isPaperless) {
    // Show a dialog, banner, or retry prompt in your app.
  }
});

// Later:
await subscription.cancel();

Mapped statuses include:

• NewposQPrinterStatus.normal
• NewposQPrinterStatus.paperless
• NewposQPrinterStatus.thermalHeadHighTemperature
• NewposQPrinterStatus.motorHighTemperature
• NewposQPrinterStatus.busy
• NewposQPrinterStatus.unknownError

Example App

The example/ app includes a test panel for:

• connecting to the printer service;
• printing text, columns, images, QR codes, barcodes, raw data, and ESC/POS;
• changing density, font size, alignment, and feed lines;
• displaying paper-out events as an on-screen popup.

Run it on a supported Newpos Q device:

cd example
flutter pub get
flutter run

Troubleshooting

bind() returns false

The vendor printer service was not found. Confirm it exists on the device:

adb shell pm list packages | grep -i ipos
adb shell dumpsys package com.iposprinter.iposprinterservice

Print command succeeds but nothing prints

Check paper, printer temperature, and whether the device firmware is using the same IPOS service API. Use the example app's diagnostics and paper-out popup to confirm status broadcasts.

getPrinterStatus() is slow or unreliable

Some firmware versions may not respond consistently to synchronous status queries. Prefer statusEvents for real-time UI updates.

Notes

Only the AIDL interfaces required to compile the plugin are included in this repository. The original vendor SDK package and demo files are intentionally not included.

License

MIT License. See LICENSE.