usb_thermal_printer_web_pro 0.1.2

Connect to a thermal printer via USB in Flutter Web and print.

This package allows you to connect to a thermal printer via USB in Flutter Web and print.

It forks from usb_printer_thermal_web and improves upon it and provides more configuration options.

Features

printFlex: This function accepts a list of string, a list of flex sizes as int and a list of alignments. Using this, you can print any data in tabular form. It takes care of wrapping any long text that does not fit within its flex size.

printText: It allows you to print any text. Configuration options include making the text bold, change alignment or double its size (make it a title).

printEmptyLine: It prints an empty line to create add a space between two printed statements

printDottedLine: It prints a dotted line or you can use it as a divider

printKeyValue: It takes two inputs and prints them as separate columns within a row.

printBarcode: It prints the barcode and prints the given barcode String beneath the barcode.

Getting started

You should have a web project as this package only supports Flutter Web for now. Before starting the printing, you need to call the pairDevice() function. You can optionally provide the vendorId, productId, interfaceNumber and endpointNumber. If you do not pass these variables, you can still select a device from the list of all connected USB devices and it will automatically try to determine these variables.

Usage

The function below prints a sample receipt. A fully functional example is present in the example directory. Simply clone the package, cd into the example directory and run flutter run -d chrome to test locally.

//Create an instance of printer
WebThermalPrinter _printer = WebThermalPrinter();

printReceipt() async {
  await _printer.pairDevice();

  await _printer.printText('Sebastien Brocard',
      bold: true, align: 'center', title: true);
  await _printer.printEmptyLine();

  await _printer.printKeyValue("Products", "Sale");
  await _printer.printEmptyLine();

  for (int i = 0; i < 2; i++) {
    await _printer.printKeyValue(
        'A big title very big title ${i + 1}', '${(i + 1) * 510}.00 AED');
    await _printer.printEmptyLine();
  }

  await _printer.printFlex(
      ['Chocolate Truffle Cake Small', '1', '550.85', '550.85'],
      [4, 1, 2, 2],
      ['left', 'right', 'right', 'right']);

  await _printer.printFlex(
      ['Chocolate Truffle Cake Small', '1', '550.85', '550.85'],
      [4, 1, 2, 2],
      ['left', 'right', 'right', 'right']);

  await _printer.printFlex(
      ['Chocolate Truffle Cake Small', '1', '550.85', '550.85'],
      [4, 1, 2, 2],
      ['left', 'right', 'right', 'right']);

  await _printer.printDottedLine();

  await _printer.printBarcode('123456');

  await _printer.printEmptyLine();
  await _printer.closePrinter();
}