Loading a Shape during onviewchanged

I am trying to code a navigation plugin like the one used by 360cities. So far so good. But I would like to display a wedge at the top displaying the current hlookat and fov. In order to synchronize panning and zooming I have used the onviewchanged event - works like a charm. But a call in my onViewChanged event to a function drawing the wedge shape results in a deadlock (have added a progress bar in the xml file).
I suspect it has to do with a change in the view.
Looking for tips on how to get over this hurdle.