以下是JavaScript语言的代码实现.

function _getScrollLeft(el) {
    var scrollLeft = el.scrollLeft;
    if (!scrollLeft) {
        scrollLeft = el.pageXOffset;
    }
    return scrollLeft;
}

function _getScrollTop(el) {
    var scrollTop = el.scrollTop;
    if (!scrollTop) {
        scrollTop = el.pageYOffset;
    }
    return scrollTop;
}

function _getClientRect(el) {
    var rect = el.getBoundingClientRect();
    return rect;
}

function _getScrollWidth(el) {
    var scrollWidth = el.scrollWidth;
    if (!scrollWidth) {
        scrollWidth = el.clientWidth;
    }
    return scrollWidth;
}

function _getScrollHeight(el) {
    var scrollHeight = el.scrollHeight;
    if (!scrollHeight) {
        scrollHeight = el.clientHeight;
    }
    return scrollHeight;
}

function _isScrolledPastEnd(el, endScrollLeft, endScrollTop, endScrollWidth, endScrollHeight) {
    if (el.scrollLeft >= endScrollLeft && el.scrollLeft < (endScrollLeft + endScrollWidth)) {
        return true;
    } else if (el.scrollTop >= endScrollTop && el.scrollTop < (endScrollTop + endScrollHeight)) {
        return true;
    } else {
        return false;
    }
}