we need to load more messages when user scrolled to top (or if it is already at the top), but there are no events/hooks that can be used to trigger page-loading method.

There are no events or attachable actions, and the only class ScrollMediator's members are fully consealed by internal directive and cannot be overriden/inherited/created either.

1. How to detect scroll position at the top/bottom?
2. How to initially scroll to certain message (aka unread one) instead of straight to bottom?