makeBytes method

@override Iterable<BarcodeElement> makeBytes(Uint8List data, { required double width, required double height, bool drawText = false, double? fontHeight, double? textPadding, })

Generate the barcode graphic description like make but takes a Uint8List data.

Implementation

@override
Iterable<BarcodeElement> makeBytes(
  Uint8List data, {
  required double width,
  required double height,
  bool drawText = false,
  double? fontHeight,
  double? textPadding,
}) sync* {
  assert(width > 0);
  assert(height > 0);
  assert(!drawText || fontHeight != null);
  fontHeight ??= 0;
  textPadding ??= Barcode1D.defaultTextPadding;

  final text = utf8.decoder.convert(data);
  final bars = convertHM(text).toList();

  if (bars.isEmpty) {
    return;
  }

  final top = marginTop(
    drawText,
    width,
    height,
    fontHeight,
    textPadding,
  );
  final left = marginLeft(
    drawText,
    width,
    height,
    fontHeight,
    textPadding,
  );
  final right = marginRight(
    drawText,
    width,
    height,
    fontHeight,
    textPadding,
  );
  final lineWidth = (width - left - right) / (bars.length * 2 - 1);
  var index = 0;

  final barHeight = height - (drawText ? fontHeight + textPadding : 0) - top;
  final tracker = barHeight * _tracker;

  for (final bar in bars) {
    switch (bar) {
      case BarcodeHMBar.tracker:
        yield BarcodeBar(
          left: left + (index * 2) * lineWidth,
          top: top + barHeight / 2 - tracker / 2,
          width: lineWidth,
          height: tracker,
          black: true,
        );
        break;
      case BarcodeHMBar.ascender:
        yield BarcodeBar(
          left: left + (index * 2) * lineWidth,
          top: top,
          width: lineWidth,
          height: barHeight / 2 + tracker / 2,
          black: true,
        );
        break;
      case BarcodeHMBar.descender:
        yield BarcodeBar(
          left: left + (index * 2) * lineWidth,
          top: top + barHeight / 2 - tracker / 2,
          width: lineWidth,
          height: barHeight / 2 + tracker / 2,
          black: true,
        );
        break;
      case BarcodeHMBar.full:
        yield BarcodeBar(
          left: left + (index * 2) * lineWidth,
          top: top,
          width: lineWidth,
          height: barHeight,
          black: true,
        );
        break;
    }

    index++;
  }

  if (drawText) {
    yield* makeText(text, width, height, fontHeight, textPadding, lineWidth);
  }
}