makeText method

@override Iterable<BarcodeElement> makeText(String data, double width, double height, double fontHeight, double textPadding, double lineWidth,)

Stream the text operations required to draw the barcode texts. This is automatically called by make

Implementation

@override
Iterable<BarcodeElement> makeText(
  String data,
  double width,
  double height,
  double fontHeight,
  double textPadding,
  double lineWidth,
) sync* {
  if (data.length <= 8) {
    // Try to convert UPC-E to UPC-A
    data = upceToUpca(data);
  }

  data = checkLength(data, maxLength);
  final first = data.substring(0, 1);
  final last = data.substring(11, 12);

  try {
    data = upcaToUpce(data);
  } on BarcodeException {
    if (fallback) {
      yield* const BarcodeUpcA().makeText(
        data,
        width,
        height,
        fontHeight,
        textPadding,
        lineWidth,
      );
      return;
    }
    rethrow;
  }

  final w = lineWidth * 7;
  final left = marginLeft(true, width, height, fontHeight, textPadding);
  final right = marginRight(true, width, height, fontHeight, textPadding);

  yield BarcodeText(
    left: 0,
    top: height - fontHeight,
    width: left - lineWidth,
    height: fontHeight,
    text: first,
    align: BarcodeTextAlign.right,
  );

  var offset = left + lineWidth * 3;

  for (var i = 0; i < data.length; i++) {
    yield BarcodeText(
      left: offset,
      top: height - fontHeight,
      width: w,
      height: fontHeight,
      text: data[i],
      align: BarcodeTextAlign.center,
    );

    offset += w;
  }

  yield BarcodeText(
    left: width - right + lineWidth,
    top: height - fontHeight,
    width: right - lineWidth,
    height: fontHeight,
    text: last,
    align: BarcodeTextAlign.left,
  );
}