class DomHelper { static isVisible(element) { return element.offsetParent !== null; } static openNewTab(url) { let win = window.open(""); win.opener = null; win.location = url; win.focus(); } static scrollPageTo(element, evenIfOnScreen) { let windowScrollPosition = window.pageYOffset; let windowHeight = document.documentElement.clientHeight; let viewportPosition = windowScrollPosition + windowHeight; let itemBottomPosition = element.offsetTop + element.offsetHeight; if (evenIfOnScreen || viewportPosition - itemBottomPosition < 0 || viewportPosition - element.offsetTop > windowHeight) { window.scrollTo(0, element.offsetTop - 10); } } static getVisibleElements(selector) { let elements = document.querySelectorAll(selector); let result = []; for (let i = 0; i < elements.length; i++) { if (this.isVisible(elements[i])) { result.push(elements[i]); } } return result; } static findParent(element, selector) { for (; element && element !== document; element = element.parentNode) { if (element.classList.contains(selector)) { return element; } } return null; } static hasPassiveEventListenerOption() { var passiveSupported = false; try { var options = Object.defineProperty({}, "passive", { get: function() { passiveSupported = true; } }); window.addEventListener("test", options, options); window.removeEventListener("test", options, options); } catch(err) { passiveSupported = false; } return passiveSupported; } }