embedding cursors.py example in a gui

[Todd Jennings]

I am trying to do something very similar to the cursors.py example, with
horizontal, vertical, or shaped marker lines that can be moved around, but
I want to embed it in a larger gui rather than as a standalone dialog. How
would I go about doing this?

I've tried reproducing the example using a CurveWidget, but I cannot click
on the marker lines. I've also tried setting the parent of the
CurveDialog, but nothing shows up at all. I've looked at the source code
of CurveWidget and CurveDialog but it is not obvious to me how mouse
interaction is enabled.