FIX: ensures the element is on the page before scroll with lockon (#8458)

This commit is contained in:
Joffrey JAFFEUX
2019-12-04 14:12:50 +01:00
committed by GitHub
parent be1510b09d
commit b74679f231

View File

@@ -35,7 +35,7 @@ export default class LockOn {
elementTop() {
const $selected = $(this.selector);
if ($selected && $selected.offset && $selected.offset()) {
if ($selected.length && $selected.offset && $selected.offset()) {
return $selected.offset().top - minimumOffset();
}
}
@@ -49,22 +49,25 @@ export default class LockOn {
}
lock() {
let previousTop = this.elementTop();
const startedAt = new Date().getTime();
$(window).scrollTop(previousTop);
let previousTop = this.elementTop();
const interval = setInterval(() => {
const top = Math.max(0, this.elementTop());
const scrollTop = $(window).scrollTop();
if (!previousTop) {
previousTop = this.elementTop();
previousTop && $(window).scrollTop(previousTop);
} else {
const top = Math.max(0, this.elementTop());
const scrollTop = $(window).scrollTop();
if (typeof top === "undefined" || isNaN(top)) {
return this.clearLock(interval);
}
if (typeof top === "undefined" || isNaN(top)) {
return this.clearLock(interval);
}
if (!within(4, top, previousTop) || !within(4, scrollTop, top)) {
$(window).scrollTop(top);
previousTop = top;
if (!within(4, top, previousTop) || !within(4, scrollTop, top)) {
$(window).scrollTop(top);
previousTop = top;
}
}
// Commit suicide after a little while