decentralized-video-chat/public/js/scroll-reveal.js
2020-03-30 14:16:08 -04:00

77 lines
2.0 KiB
JavaScript
Executable File

(function () {
"use strict";
const revealEl = document.querySelectorAll("[class*=reveal-]");
let viewportHeight = window.innerHeight;
function throttle(delay, fn) {
var lastCall = 0;
return function () {
var now = new Date().getTime();
if (now - lastCall < delay) {
return;
}
lastCall = now;
return fn.apply(void 0, arguments);
};
}
function elementIsVisible(el, offset) {
return el.getBoundingClientRect().top <= viewportHeight - offset;
}
function revealElements() {
for (let i = 0; i < revealEl.length; i++) {
let el = revealEl[i];
let revealDelay = el.getAttribute("data-reveal-delay");
let revealOffset = el.getAttribute("data-reveal-offset")
? el.getAttribute("data-reveal-offset")
: "200";
let listenedEl = el.getAttribute("data-reveal-container")
? el.closest(el.getAttribute("data-reveal-container"))
: el;
if (
elementIsVisible(listenedEl, revealOffset) &&
!el.classList.contains("is-revealed")
) {
if (revealDelay && revealDelay !== 0) {
setTimeout(function () {
el.classList.add("is-revealed");
}, revealDelay);
} else {
el.classList.add("is-revealed");
}
}
}
revealDone();
}
function revealScroll() {
throttle(30, revealElements());
}
function revealResize() {
viewportHeight = window.innerHeight;
throttle(30, revealElements());
}
function revealDone() {
if (
revealEl.length >
document.querySelectorAll("[class*=reveal-].is-revealed").length
)
return;
window.removeEventListener("load", revealElements);
window.removeEventListener("scroll", revealScroll);
window.removeEventListener("resize", revealResize);
}
if (
revealEl.length > 0 &&
document.body.classList.contains("has-animations")
) {
window.addEventListener("load", revealElements);
window.addEventListener("scroll", revealScroll);
window.addEventListener("resize", revealResize);
}
})();