javascript: is Element really really visible?

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/**  * Is the element visible by the Eye?  * @param {Element | jQuery} el - object to check. Either an Element or a jQuery selection.  * @returns {object} True if it can be seen.  */ function isElementVisible(el) {     "use strict";     if (!el) // Can't find? Can't see!         return false;     var v_element = (el instanceof jQuery) ? el : $(el);     if (v_element.length === 0) // Still nothing to look for         return false;     return v_element[0].isSameNode(document.elementFromPoint((v_element.width() / 2) + v_element.offset().left, (v_element.height() / 2) + v_element.offset().top)); }

What happens here?

We are checking if the element at the given point (our element's middle) is the same element as returned by document.elementFromPoint: then we can see it. If a different one, then that foreign element overlays the one we are looking for.