Function updateExternalMeasurement

src/codemirror.js:2579–2588

(cm, line)

  // Render a line into the hidden node display.externalMeasured. Used
  // when measurement is needed for a line that's not in the viewport.
  function updateExternalMeasurement(cm, line) {
    line = visualLine(line);
    var lineN = lineNo(line);
    var view = cm.display.externalMeasured = new LineView(cm.doc, line, lineN);
    view.lineN = lineN;
    var built = view.built = buildLineContent(cm, view);
    view.text = built.pre;
    removeChildrenAndAdd(cm.display.lineMeasure, built.pre);
    return view;
  }

  // Get a {top, bottom, left, right} box (in line-local coordinates)
  // for a given character.