Popover's arrow to track an object in a scrollview

Question

I show a popover whenever a cell in my tableview is touched, with the arrow pointing to the cell, and always pointing left or right, not up or down.

The table view i

Answer 1

It turns out, you can use presentPopoverFromRect:InView: even when the popover has already been presented; this will cause the popover controller to recompute its arrow position.