I will be needing to implement 2 cursors (markers) in my graph. One should be able to grab
and move each of the 2 cursors with a deltaX, deltaY being displayed somewhere that
shows the difference between cursor1 and cursor 2.

This seems like functionality that someone would have already done, so before I start to reinvent the wheel, are there any examples of similar functionality out there?

If not any suggestions on how to best approach it?

Thank you.

Mark