https://www.morrisseycentral.com/static/theme_api/vendor/scrollDel…df2ac0e991ffe130f23a3b1943b7ee57fe861ea0.js

1jQuery.event.special.scrolldelta = {
2    delegateType: "scroll",
3    bindType: "scroll",
4    handle: function (event) {
5        var handleObj = event.handleObj;
6        var targetData = jQuery.data(event.target);
7        var ret = null;
8        var elem = event.target;
9        var isDoc = elem === document;
10        var oldTop = targetData.top || 0;
11        var oldLeft = targetData.left || 0;
12        targetData.top = isDoc ? elem.documentElement.scrollTop + elem.body.scrollTop : elem.scrollTop;
13        targetData.left = isDoc ? elem.documentElement.scrollLeft + elem.body.scrollLeft : elem.scrollLeft;
14        event.scrollTopDelta = targetData.top - oldTop;
15        event.scrollTop = targetData.top;
16        event.scrollLeftDelta = targetData.left - oldLeft;
17        event.scrollLeft = targetData.left;
18        event.type = handleObj.origType;
19        ret = handleObj.handler.apply(this, arguments);
20        event.type = handleObj.type;
21        return ret;
22    }
23};