ninjinkun/NJKScrollFullScreen — pull request #29 by jcavar (2014-12-06 15:53:38+00:00)
Title: Fixed wrong calculation of bottomBoundary

If you try to log isOverBottomBoundary you can see that it is always false. It looks like bottomBoundary logic was wrong.
The condition we actually need is scrollView.height - scrollViewContent.height + offset > 0. When this condition is true scroll view is over bottom boundary. I just translated this into variables and conditions in your code.

Also, I can't see reason why _downThresholdY is not 0 by default?