barcode_widget 1.2.3

barcode_widget: ^1.2.3 copied to clipboard

example/lib/main.dart

import 'package:barcode_widget/barcode_widget.dart';
import 'package:flutter/material.dart';

import 'package:google_fonts/google_fonts.dart';

import 'settings.dart';

void main() => runApp(_MyApp());

const double _constraintWidth = 500;

Widget _barcodeError(String message) {
  return Container(
    margin: const EdgeInsets.symmetric(vertical: 20),
    alignment: Alignment.center,
    constraints: const BoxConstraints(maxWidth: _constraintWidth),
    child: Card(
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Text(
          message,
          style: const TextStyle(color: Colors.red),
        ),
      ),
    ),
  );
}

Widget _barcodeInfo(BarcodeConf conf) {
  final bc = Barcode.fromType(conf.type);

  final charset = StringBuffer();
  for (var c in bc.charSet) {
    if (c > 0x20) {
      charset.write(String.fromCharCode(c) + ' ');
    } else {
      charset.write('0x' + c.toRadixString(16) + ' ');
    }
  }

  var desc = '';
  switch (conf.type) {
    case BarcodeType.CodeITF14:
      desc =
          'ITF-14 is the GS1 implementation of an Interleaved 2 of 5 (ITF) bar code to encode a Global Trade Item Number. ITF-14 symbols are generally used on packaging levels of a product, such as a case box of 24 cans of soup. The ITF-14 will always encode 14 digits.';
      break;
    case BarcodeType.CodeEAN13:
      desc =
          'The International Article Number is a standard describing a barcode symbology and numbering system used in global trade to identify a specific retail product type, in a specific packaging configuration, from a specific manufacturer.';
      break;
    case BarcodeType.CodeEAN8:
      desc =
          'An EAN-8 is an EAN/UPC symbology barcode and is derived from the longer International Article Number code. It was introduced for use on small packages where an EAN-13 barcode would be too large; for example on cigarettes, pencils, and chewing gum packets. It is encoded identically to the 12 digits of the UPC-A barcode, except that it has 4 digits in each of the left and right halves.';
      break;
    case BarcodeType.CodeEAN5:
      desc =
          'The EAN-5 is a 5-digit European Article Number code, and is a supplement to the EAN-13 barcode used on books. It is used to give a suggestion for the price of the book.';
      break;
    case BarcodeType.CodeEAN2:
      desc =
          'The EAN-2 is a supplement to the EAN-13 and UPC-A barcodes. It is often used on magazines and periodicals to indicate an issue number.';
      break;
    case BarcodeType.CodeISBN:
      desc =
          'The International Standard Book Number is a numeric commercial book identifier which is intended to be unique. Publishers purchase ISBNs from an affiliate of the International ISBN Agency.';
      break;
    case BarcodeType.Code39:
      desc =
          'The Code 39 specification defines 43 characters, consisting of uppercase letters (A through Z), numeric digits (0 through 9) and a number of special characters (-, ., \$, /, +, %, and space). An additional character (denoted \'*\') is used for both start and stop delimiters.';
      break;
    case BarcodeType.Code93:
      desc =
          'Code 93 is a barcode symbology designed in 1982 by Intermec to provide a higher density and data security enhancement to Code 39. It is an alphanumeric, variable length symbology. Code 93 is used primarily by Canada Post to encode supplementary delivery information.';
      break;
    case BarcodeType.CodeUPCA:
      desc =
          'The Universal Product Code is a barcode symbology that is widely used in the United States, Canada, Europe, Australia, New Zealand, and other countries for tracking trade items in stores. UPC consists of 12 numeric digits that are uniquely assigned to each trade item.';
      break;
    case BarcodeType.CodeUPCE:
      desc =
          'The Universal Product Code is a barcode symbology that is widely used in the United States, Canada, Europe, Australia, New Zealand, and other countries for tracking trade items in stores. To allow the use of UPC barcodes on smaller packages, where a full 12-digit barcode may not fit, a zero-suppressed version of UPC was developed, called UPC-E, in which the number system digit, all trailing zeros in the manufacturer code, and all leading zeros in the product code, are suppressed';
      break;
    case BarcodeType.Code128:
      desc =
          'Code 128 is a high-density linear barcode symbology defined in ISO/IEC 15417:2007. It is used for alphanumeric or numeric-only barcodes. It can encode all 128 characters of ASCII and, by use of an extension symbol, the Latin-1 characters defined in ISO/IEC 8859-1.';
      break;
    case BarcodeType.GS128:
      desc =
          'The GS1-128 is an application standard of the GS1. It uses a series of Application Identifiers to include additional data such as best before dates, batch numbers, quantities, weights and many other attributes needed by the user.';
      break;
    case BarcodeType.Telepen:
      desc =
          'Telepen is a barcode designed in 1972 in the UK to express all 128 ASCII characters without using shift characters for code switching, and using only two different widths for bars and spaces.';
      break;
    case BarcodeType.QrCode:
      desc =
          'QR code (abbreviated from Quick Response code) is the trademark for a type of matrix barcode (or two-dimensional barcode) first designed in 1994 for the automotive industry in Japan.';
      break;
  }

  return Center(
    child: ConstrainedBox(
      constraints: const BoxConstraints(maxWidth: _constraintWidth),
      child: Card(
        child: Padding(
          padding: const EdgeInsets.all(20),
          child: Text.rich(
            TextSpan(
              children: [
                TextSpan(
                  text: '${bc.name}\n',
                  style: const TextStyle(
                      fontWeight: FontWeight.bold, fontSize: 30),
                ),
                const TextSpan(
                  text: '\nDescription:\n',
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 20),
                ),
                TextSpan(
                  text: '$desc\n',
                ),
                const TextSpan(
                  text: '\nAccepted data:\n',
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 20),
                ),
                TextSpan(
                  text: '$charset\n\n',
                ),
                TextSpan(
                  text: 'Minimum length: ${bc.minLength}\n',
                  style: const TextStyle(fontWeight: FontWeight.bold),
                ),
                // if (bc.maxLength < Barcode.infiniteMaxLength)
                TextSpan(
                  text: 'Maximum length: ${bc.maxLength}\n',
                  style: const TextStyle(fontWeight: FontWeight.bold),
                ),
              ],
            ),
            // textAlign: TextAlign.center,
          ),
        ),
      ),
    ),
  );
}

Widget _barcode(BarcodeConf conf) {
  try {
    Barcode.fromType(conf.type).verify(conf.data);
  } on BarcodeException catch (error) {
    return _barcodeError(error.message);
  }

  return Padding(
    padding: const EdgeInsets.symmetric(vertical: 20),
    child: Center(
      child: Card(
        child: BarcodeWidget(
          barcode: Barcode.fromType(conf.type),
          data: conf.data,
          width: conf.width,
          height: conf.height,
          style: GoogleFonts.sourceCodePro(
            textStyle: TextStyle(
              fontSize: conf.fontSize,
            ),
          ),
          margin: EdgeInsets.symmetric(
              horizontal: (_constraintWidth - conf.width) / 2, vertical: 20),
          padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 5),
          decoration: BoxDecoration(
            border: Border.all(
              color: Colors.blue,
            ),
          ),
        ),
      ),
    ),
  );
}

class _MyApp extends StatelessWidget {
  final BarcodeConf conf = BarcodeConf();

  @override
  Widget build(BuildContext context) {
    const title = 'Barcode Demo';

    return const MaterialApp(
      title: title,
      home: _Home(title),
    );
  }
}

class _Home extends StatefulWidget {
  const _Home(this.title);

  final String title;

  @override
  _HomeState createState() => _HomeState();
}

class _HomeState extends State<_Home> {
  final BarcodeConf conf = BarcodeConf();

  @override
  void initState() {
    conf.addListener(confListener);
    super.initState();
  }

  @override
  void dispose() {
    conf.removeListener(confListener);
    super.dispose();
  }

  void confListener() {
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    final width = MediaQuery.of(context).size.width;

    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Scrollbar(
        child: width < 800
            ? ListView(
                children: <Widget>[
                  Settings(conf),
                  _barcode(conf),
                  _barcodeInfo(conf),
                ],
              )
            : Row(
                children: [
                  SizedBox(width: 400, child: Settings(conf)),
                  Flexible(
                    child: ListView(
                      children: <Widget>[
                        _barcode(conf),
                        _barcodeInfo(conf),
                      ],
                    ),
                  ),
                ],
              ),
      ),
    );
  }
}