原生JS判断一个元素是否在可视区域

参考链接http://www.tuicool.com/articles/3aABJr

   function getElementTopLeft(obj) {
        var top = 0;
        var left = 0;

        while(obj){
            top += obj.offsetTop;
            left += obj.offsetLeft;

            obj = obj.offsetParent;
        }

        return {top:top,left:left};
    }

if (getElementTopLeft(element).top + element.clientHeight > window.pageYOffset && window.pageYOffset + window.innerHeight > getElementTopLeft(element).top) {
            console.log('可见')
        } else {
            console.log('不可见')
        }