printData method

Future<void> printData(Printer device, List<int> bytes, { bool longData = false, })

Implementation

Future<void> printData(
  Printer device,
  List<int> bytes, {
  bool longData = false,
}) async {
  if (device.connectionType == ConnectionType.USB) {
    using((Arena alloc) {
      final printer = RawPrinter(device.name!, alloc);
      printer.printbytes(bytes);
    });
    return;
  }
  if (!isInitialized) {
    throw Exception('WindowBluetoothManager is not initialized');
  }
  final services = await WinBle.discoverServices(device.address!);
  final service = services.first;
  final characteristics = await WinBle.discoverCharacteristics(
    address: device.address!,
    serviceId: service,
  );
  final characteristic = characteristics
      .firstWhere((element) => element.properties.write ?? false)
      .uuid;
  final mtusize = await WinBle.getMaxMtuSize(device.address!);
  if (longData) {
    int mtu = mtusize - 50;
    if (mtu.isNegative) {
      mtu = 20;
    }
    final numberOfTimes = bytes.length / mtu;
    final numberOfTimesInt = numberOfTimes.toInt();
    int timestoPrint = 0;
    if (numberOfTimes > numberOfTimesInt) {
      timestoPrint = numberOfTimesInt + 1;
    } else {
      timestoPrint = numberOfTimesInt;
    }
    for (var i = 0; i < timestoPrint; i++) {
      final data = bytes.sublist(i * mtu,
          ((i + 1) * mtu) > bytes.length ? bytes.length : ((i + 1) * mtu));
      await WinBle.write(
        address: device.address!,
        service: service,
        characteristic: characteristic,
        data: Uint8List.fromList(data),
        writeWithResponse: false,
      );
    }
  } else {
    await WinBle.write(
      address: device.address!,
      service: service,
      characteristic: characteristic,
      data: Uint8List.fromList(bytes),
      writeWithResponse: false,
    );
  }
}