Checks whether a document-relative position is currently within the visible viewport. Used to detect when a popover anchor has scrolled out of view.
The document-relative position to check
Optional
Extra margin outside the viewport to tolerate (default 50px)
True if the position is within the viewport (plus margin)
Checks whether a document-relative position is currently within the visible viewport. Used to detect when a popover anchor has scrolled out of view.