Function index

src/utils.js:373–388

* Returns the index of an element within its parent for a selected set of * elements * @param {HTMLElement} el * @param {selector} selector * @return {number}

(el, selector)

 * @return {number}
 */
function index(el, selector) {
	let index = 0;

	if (!el || !el.parentNode) {
		return -1;
	}

	/* jshint boss:true */
	while (el = el.previousElementSibling) {
		if ((el.nodeName.toUpperCase() !== 'TEMPLATE') && el !== Sortable.clone && (!selector || matches(el, selector))) {
			index++;
		}
	}

	return index;
}

/**
 * Returns the scroll offset of the given element, added with all the scroll offsets of parent elements.