printData method

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

Implementation

Future<void> printData(
  Printer printer,
  List<int> bytes, {
  bool longData = false,
}) async {
  if (printer.connectionType == ConnectionType.USB) {
    try {
      await FlutterThermalPrinterPlatform.instance.printText(
        printer,
        Uint8List.fromList(bytes),
        path: printer.address,
      );
    } catch (e) {
      log("FlutterThermalPrinter: Unable to Print Data $e");
    }
  } else {
    try {
      final device = BluetoothDevice.fromId(printer.address!);
      if (!device.isConnected) {
        log('Device is not connected');
        return;
      }
      final services = (await device.discoverServices()).skipWhile((value) =>
          value.characteristics
              .where((element) => element.properties.write)
              .isEmpty);
      BluetoothCharacteristic? writecharacteristic;
      for (var service in services) {
        for (var characteristic in service.characteristics) {
          if (characteristic.properties.write) {
            writecharacteristic = characteristic;
            break;
          }
        }
      }
      if (writecharacteristic == null) {
        log('No write characteristic found');
        return;
      }
      if (longData) {
        int mtu = (await device.mtu.first) - 30;
        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 writecharacteristic.write(data);
        }
      } else {
        await writecharacteristic.write(bytes);
      }
      return;
    } catch (e) {
      log('Failed to print data to device $e');
    }
  }
}