如何检查交叉路口节点是否可见节点

Question

给定IntersectionObserver像这样：

const observeVisibility = intersectionMargin => {
    const observer = new IntersectionObserver(
        nodes => {
            if (nodes[0].isIntersecting) {
                /* is really in viewport? */
                this.observer.disconnect();
            }
        },
        { rootMargin: intersectionMargin }
    );

    observer.observe(...);
};

如何检查节点本身实际上是在视口中还是只是导致观察者被调用的intersectionMargin？

Answer 1