Function drawForLine

static/js/codemirror/codemirror.js:775–798

(line, fromArg, toArg, retTop)

    }

    function drawForLine(line, fromArg, toArg, retTop) {
      var lineObj = getLine(doc, line);
      var lineLen = lineObj.text.length, rVal = retTop ? Infinity : -Infinity;
      function coords(ch) {
        return charCoords(cm, Pos(line, ch), "div", lineObj);
      }

      iterateBidiSections(getOrder(lineObj), fromArg || 0, toArg == null ? lineLen : toArg, function(from, to, dir) {
        var leftPos = coords(dir == "rtl" ? to - 1 : from);
        var rightPos = coords(dir == "rtl" ? from : to - 1);
        var left = leftPos.left, right = rightPos.right;
        if (rightPos.top - leftPos.top > 3) { // Different lines, draw top part
          add(left, leftPos.top, null, leftPos.bottom);
          left = pl;
          if (leftPos.bottom < rightPos.top) add(left, leftPos.bottom, null, rightPos.top);
        }
        if (toArg == null && to == lineLen) right = clientWidth;
        if (fromArg == null && from == 0) left = pl;
        rVal = retTop ? Math.min(rightPos.top, rVal) : Math.max(rightPos.bottom, rVal);
        if (left < pl + 1) left = pl;
        add(left, rightPos.top, right - left, rightPos.bottom);
      });
      return rVal;
    }

    if (sel.from.line == sel.to.line) {
      drawForLine(sel.from.line, sel.from.ch, sel.to.ch);