var lastId = null; var lastBg = null;
function highlight(id) {
var el = document.getElementById(id); if (el) { if (lastId) unhighlight(lastId, lastBg); lastId = id; lastBg = el.style.backgroundColor; el.style.backgroundColor = 'yellow'; }
}
function unhighlight(id, bg) {
var el = document.getElementById(id); if (el) { el.style.backgroundColor = bg; }
}
document.addEventListener('DOMContentLoaded', function() {
var toc = document.getElementsByClassName('toc'); var lis = document.getElementsByClassName('listing'); if (toc.length != 1 || lis.length != 1) return; window.onscroll = function() { if (lis[0].getBoundingClientRect().y <= 0) { toc[0].classList.add('toc-fixed'); lis[0].classList.add('listing-fixed'); } else { toc[0].classList.remove('toc-fixed'); lis[0].classList.remove('listing-fixed'); } }
});