function Scrubber( values, { format = (value) => value, initial = 0, delay = null, autoplay = true, loop = true, loopDelay = null, alternate = false } = {} ) { values = Array.from(values); const form = html``; let frame = null; let timer = null; let interval = null; let direction = 1; function start() { form.b.textContent = "Pause"; if (delay === null) frame = requestAnimationFrame(tick); else interval = setInterval(tick, delay); } function stop() { form.b.textContent = "Play"; if (frame !== null) cancelAnimationFrame(frame), (frame = null); if (timer !== null) clearTimeout(timer), (timer = null); if (interval !== null) clearInterval(interval), (interval = null); } function running() { return frame !== null || timer !== null || interval !== null; } function tick() { if ( form.i.valueAsNumber === (direction > 0 ? values.length - 1 : direction < 0 ? 0 : NaN) ) { if (!loop) return stop(); if (alternate) direction = -direction; if (loopDelay !== null) { if (frame !== null) cancelAnimationFrame(frame), (frame = null); if (interval !== null) clearInterval(interval), (interval = null); timer = setTimeout(() => (step(), start()), loopDelay); return; } } if (delay === null) frame = requestAnimationFrame(tick); step(); } function step() { form.i.valueAsNumber = (form.i.valueAsNumber + direction + values.length) % values.length; form.i.dispatchEvent(new CustomEvent("input", { bubbles: true })); } form.i.oninput = (event) => { if (event && event.isTrusted && running()) stop(); form.value = values[form.i.valueAsNumber]; form.o.value = format(form.value, form.i.valueAsNumber, values); }; form.b.onclick = () => { if (running()) return stop(); direction = alternate && form.i.valueAsNumber === values.length - 1 ? -1 : 1; form.i.valueAsNumber = (form.i.valueAsNumber + direction) % values.length; form.i.dispatchEvent(new CustomEvent("input", { bubbles: true })); start(); }; form.i.oninput(); if (autoplay) start(); else stop(); Inputs.disposal(form).then(stop); return form; }