Function adjustPaddingFlat

src/components/TextInput/helpers.tsx:164–246

({
  pad,
  scale,
  multiline,
  label,
  height,
  offset,
  dense,
  fontSize,
  isAndroid,
  styles,
}: AdjProps)

};

export const adjustPaddingFlat = ({
  pad,
  scale,
  multiline,
  label,
  height,
  offset,
  dense,
  fontSize,
  isAndroid,
  styles,
}: AdjProps): Padding => {
  let result = pad;
  let topResult = result;
  let bottomResult = result;
  const { paddingTop, paddingBottom } = styles;
  const refFontSize = scale * fontSize;

  if (!multiline) {
    // do not modify padding if input is not multiline
    if (label) {
      // return const style for flat input with label
      return { paddingTop, paddingBottom };
    }
    // return pad for flat input without label
    return { paddingTop: result, paddingBottom: result };
  }

  if (label) {
    // add paddings passed from styles
    topResult = paddingTop;
    bottomResult = paddingBottom;

    // adjust top padding for iOS
    if (!isAndroid) {
      if (dense) {
        topResult +=
          scale < 1
            ? Math.min(result, refFontSize * scale) - result / 2
            : Math.min(result, refFontSize * scale) - result / 2;
      }
      if (!dense) {
        topResult +=
          scale < 1
            ? Math.min(offset / 2, refFontSize * scale)
            : Math.min(result, refFontSize * scale) - offset / 2;
      }
    }
    topResult = Math.floor(topResult);
  } else {
    if (height) {
      // center text when height is passed
      return {
        paddingTop: Math.max(0, (height - fontSize) / 2),
        paddingBottom: Math.max(0, (height - fontSize) / 2),
      };
    }
    // adjust paddings for iOS if no label