Function getRect

src/utils.js:169–255

* Returns the "bounding client rect" of given element * @param {HTMLElement} el The element whose boundingClientRect is wanted * @param {[Boolean]} relativeToContainingBlock Whether the rect should be relative to the containing block of (including) the container * @param

(el, relativeToContainingBlock, relativeToNonStaticParent, undoScale, container)

 * @return {Object}                               The boundingClientRect of el, with specified adjustments
 */
function getRect(el, relativeToContainingBlock, relativeToNonStaticParent, undoScale, container) {
	if (!el.getBoundingClientRect && el !== window) return;

	let elRect,
		top,
		left,
		bottom,
		right,
		height,
		width;

	if (el !== window && el.parentNode && el !== getWindowScrollingElement()) {
		elRect = el.getBoundingClientRect();
		top = elRect.top;
		left = elRect.left;
		bottom = elRect.bottom;
		right = elRect.right;
		height = elRect.height;
		width = elRect.width;
	} else {
		top = 0;
		left = 0;
		bottom = window.innerHeight;
		right = window.innerWidth;
		height = window.innerHeight;
		width = window.innerWidth;
	}

	if ((relativeToContainingBlock || relativeToNonStaticParent) && el !== window) {
		// Adjust for translate()
		container = container || el.parentNode;

		// solves #1123 (see: https://stackoverflow.com/a/37953806/6088312)
		// Not needed on <= IE11
		if (!IE11OrLess) {
			do {
				if (
					container &&
					container.getBoundingClientRect &&
					(
						css(container, 'transform') !== 'none' ||
						relativeToNonStaticParent &&
						css(container, 'position') !== 'static'
					)
				) {
					let containerRect = container.getBoundingClientRect();

					// Set relative to edges of padding box of container
					top -= containerRect.top + parseInt(css(container, 'border-top-width'));
					left -= containerRect.left + parseInt(css(container, 'border-left-width'));
					bottom = top + elRect.height;
					right = left + elRect.width;

					break;
				}
				/* jshint boss:true */
			} while (container = container.parentNode);
		}