Function measureLine

tools/pythonauto/static/codemirrorepl/codemirrorepl.js:1779–1794

(line, ch)

        var tempId = "CodeMirror-temp-" + Math.floor(Math.random() * 0xffffff).toString(16);
        function measureLine(line, ch) {
            if (ch == 0) return {top: 0, left: 0};
            var wbr = options.lineWrapping && ch < line.text.length &&
                spanAffectsWrapping.test(line.text.slice(ch - 1, ch + 1));
            measure.innerHTML = "<pre>" + line.getHTML(makeTab, ch, tempId, wbr) + "</pre>";
            var elt = document.getElementById(tempId);
            var top = elt.offsetTop, left = elt.offsetLeft;
            // Older IEs report zero offsets for spans directly after a wrap
            if (ie && top == 0 && left == 0) {
                var backup = document.createElement("span");
                backup.innerHTML = "x";
                elt.parentNode.insertBefore(backup, elt.nextSibling);
                top = backup.offsetTop;
            }
            return {top: top, left: left};
        }
        function localCoords(pos, inLineWrap) {
            var x, lh = textHeight(), y = lh * (heightAtLine(doc, pos.line) - (inLineWrap ? displayOffset : 0));
            if (pos.ch == 0) x = 0;