Function autoGrowTextArea

app/utils.ts:197–218

(dom: HTMLTextAreaElement)

}

export function autoGrowTextArea(dom: HTMLTextAreaElement) {
  const measureDom = getOrCreateMeasureDom("__measure");
  const singleLineDom = getOrCreateMeasureDom("__single_measure", (dom) => {
    dom.innerText = "TEXT_FOR_MEASURE";
  });

  const width = getDomContentWidth(dom);
  measureDom.style.width = width + "px";
  measureDom.innerText = dom.value !== "" ? dom.value : "1";
  measureDom.style.fontSize = dom.style.fontSize;
  measureDom.style.fontFamily = dom.style.fontFamily;
  const endWithEmptyLine = dom.value.endsWith("\n");
  const height = parseFloat(window.getComputedStyle(measureDom).height);
  const singleLineHeight = parseFloat(
    window.getComputedStyle(singleLineDom).height,
  );

  const rows =
    Math.round(height / singleLineHeight) + (endWithEmptyLine ? 1 : 0);

  return rows;
}

export function getCSSVar(varName: string) {
  return getComputedStyle(document.body).getPropertyValue(varName).trim();