/* animation  对象要发生的动画 数组*/
/* option     对象 */
/* targetele  动画发生的目标对象 dom对象或其集合 */
/* funcall    回调函数   执行动画后将要执行的操作有一个参数为 触发动画的对象 */
/* threshold    元素在视口中所占的比例 */



const scrl = (
    arg = {
        option: null,
        targetele: null,
        animation: null,
        funcall: null
    }
) => {
    if (arg.animation == null) {
        throw error("error in effect parameter");
    }
    else if (arg.targetele == null) {
        throw error("the target object was passed in incorrectly");
    }
    else {
        if (window.intersectionobserver) {

            var callback = (en) => {
                en.foreach(element => {
                    if (element.isintersecting) {
                        var ele = element.target;
                        ele.style.animation = arg.animation;
                        observer.unobserve(ele);
                        if (arg.funcall)
                            arg.funcall(ele);
                    }
                });
            }

            const observer = new intersectionobserver(callback, arg.option);
            observer.observe(arg.targetele);
        }
        else {
            throw error("intersectionobserver are not compatible");
        }
    }
    
}






const scan = (
    arg = {
        option: null,
        targetele: null,
        animation: null,
        funcall: null
    }
) => {
    if (arg.animation == null) {
        throw error("error in effect parameter");
    }
    else if (arg.targetele == null) {
        throw error("the target object was passed in incorrectly");
    }
    else {
        if (window.intersectionobserver) {
            opt = {
                threshold: [arg.option]
            }
            var callback = (en) => {
                en.foreach(element => {
                    if (element.isintersecting) {
                        var ele = element.target;
                        ele.style.animation = arg.animation;
                        observer.unobserve(ele);
                        if (arg.funcall)
                            arg.funcall(ele);
                    }
                });
            }
            const observer = new intersectionobserver(callback, opt);
            observer.observe(arg.targetele);
        }
        else {
            /* arg.targetele.style.opacity = "1"; */
            throw error("intersectionobserver are not compatible");
        }
    }
    
}