(function(d) {
let p = d.body; // container of slides; assume for now
const s1 = ':scope > hr:not([class])', s2 = ':scope > h2';
// find a container that has at least n "slides"
function findContainer(s, n = 1) {
if (p.querySelectorAll(s).length >= n) return true;
// if body doesn't contain headings or
s, look into children
for (let i = 0; i < p.children.length; i++) {
if (p.children[i].querySelectorAll(s).length >= n) {
p = p.children[i]; break;
}
}
return false;
}
function newEl(tag, cls) {
const el = d.createElement(tag);
if (cls) el.className = cls;
return el;
}
if (!findContainer(s1, 3)) {
// if not enough
s found in children; look for instead
if (p.tagName === 'BODY') {
// not enough h2 found, this page is not appropriate for slides
if (!findContainer(s2) && p.tagName === 'BODY') return;
p.querySelectorAll(s2).forEach(h2 => h2.before(newEl('hr')));
}
}
p.classList.add('slide-container');
// add 'slide' class to the frontmatter div and toc
['.frontmatter', '#TOC'].forEach(s => {
d.body.querySelector(s)?.classList.add('slide');
});
function newSlide(s) {
return (s?.innerText === '') ? s : newEl('div', 'slide');
}
function isSep(el) {
return el.tagName === 'HR' && el.attributes.length === 0;
}
let el = p.firstElementChild; if (isSep(el)) el.remove();
el = p.firstElementChild; if (!el) return;
let s = newSlide(); el.before(s);
while (true) {
let el = s.nextSibling;
if (!el) break;
// remove slide separators (
) and create new slide
if (isSep(el)) {
s = newSlide(s);
el.before(s); el.remove();
} else if (el.classList?.contains('slide')) {
s = newSlide(s);
el.after(s);
} else {
s.append(el);
}
}
function setAttr(el, attr) {
const m = newEl('div');
m.innerHTML = `
`;
const attrs = m.firstElementChild.attributes;
for (let i = 0; i < attrs.length; i++) {
let a = attrs[i];
el.setAttribute(a.name, a.value);
}
m.remove();
}
const slides = d.querySelectorAll('div.slide'), N = slides.length,
tm = d.querySelector('span.timer'), fn = d.querySelector('.footnotes');
slides.forEach((s, i) => {
// append footnotes
if (fn) s.querySelectorAll('.footnote-ref > a[href^="#fn"]').forEach(a => {
const li = fn.querySelector('li' + a.getAttribute('href'));
if (!li) return;
let f = s.querySelector('section.footnotes');
if (!f) {
f = newEl('section', 'footnotes'); s.append(f);
}
f.append(li);
li.firstElementChild?.insertAdjacentHTML('afterbegin', `[${a.innerHTML}] `);
li.outerHTML = li.innerHTML;
});
// add a timer
s.append(tm ? tm.cloneNode() : newEl('span', 'timer'));
// add page numbers
const n = newEl('span', 'page-number');
n.innerText = i + 1 + '/' + N;
n.onclick = e => location.hash = i + 1;
s.append(n);
// apply slide attributes in
for (let k in s.childNodes) {
const node = s.childNodes[k];
if (node.nodeType !== Node.COMMENT_NODE) continue;
let t = node.textContent;
if (!/^#/.test(t)) continue;
t = t.replace(/^#/, '');
const r = /[\s\n]class="([^"]+)"/, m = t.match(r);
if (m) {
t = t.replace(r, '').trim();
s.className += ' ' + m[1];
}
if (t) setAttr(s, t);
break;
}
s.classList.contains('extend') && s.append(newEl('div', 'spacer fade'));
location.hash === ('#' + (i + 1)) && s.scrollIntoView();
s.addEventListener('click', e => {
if (!e.altKey) return;
d.body.classList.toggle('overview');
setTimeout(() => e.target.scrollIntoView(), 100);
});
});
[...d.querySelectorAll('a.footnote-backref'), fn, tm].forEach(el => el?.remove());
const tms = d.querySelectorAll('span.timer'), t1 = 1000 * tms[0].dataset.total;
let t0;
function startTimers() {
t0 = new Date();
setInterval(setTimers, 1000);
}
function setTimers() {
let t = (new Date() - t0);
if (t1) t = t1 - t;
const t2 = new Date(Math.abs(t)).toISOString().substr(11, 8).replace(/^00:/, '');
tms.forEach(el => {
el.innerText = t2;
if (t < 0) el.style.display = el.style.display === 'none' ? '' : 'none';
});
}
// press f for fullscreen mode
d.addEventListener('keyup', (e) => {
if (e.target !== d.body) return;
e.key === 'f' && d.documentElement.requestFullscreen();
e.key === 'o' && d.body.classList.toggle('overview');
e.key === 'm' && d.body.classList.toggle('mirrored');
sessionStorage.setItem('body-class', d.body.className);
});
// start timer on fullscreen
d.onfullscreenchange = (e) => d.fullscreenElement && !t0 && startTimers();
tms.forEach(el => el.addEventListener('click', e => startTimers()));
// restore previously saved body class
const bc = sessionStorage.getItem('body-class');
if (bc) d.body.className += ' ' + bc;
})(document);