Unfortunately I'm not sure of a reactor noticing when something like a scroll zoom / pan happened. Otherwise you could have simply redrawn the grdraw.
Actually my code does detect zoom and pan actions. That is not the issue. The problem is that there is an automatic redraw after the call-back.
The sequence seems to be:
- Zoom/scroll action is detected by the reactor.
- The call-back recreates the temp graphics.
- The CAD-program redraws the current view destroying the temp graphics.