private void addQueryRule(T anchor, boolean afterwards, int pageSize, AVQuery<T> query) {
// set page size
query.limit(pageSize);
// before or after
String queryOrder = query.getOrder();
if ((anchor != null) && (queryOrder != null)) {
boolean isDescending = queryOrder.startsWith("-");
String field = isDescending ? queryOrder.substring(1) : queryOrder;
if ((isDescending && afterwards) || (!isDescending && !afterwards)) {
query.whereLessThan(field, anchor.get(field));
} else {
query.whereGreaterThan(field, anchor.get(field));
}
}
}
