@shinyformica, thanks. I will include the weakref version.

I was also wondering if you had some globals-clearing code somewhere. Remembering some previous threads where the goal was to make Pythonista act like a fresh interpreter starting every time you run a script.

Clearly I need to explore the API modules more :)

@dgelessus , super cool. The problem was the set_needs_display().works as expected now, have to say, it's pretty nice. I know what you mean about the zero base. Things started going wrong so I started adjusting things. But just happy it's working. Will go and look at your other ideas. I also have another mistake with scaling the rects for the ovals also. It's just top,left based. But now the basics are working I can get excited again 😱👍

Edit : I also meant to say thank you.

Right. Forgot about that one.

@TutorialDoctor, you ask what it could be used for. I think is just nice ui control, same as a slider. I think a nice step fwd would be to be able to provide a ui.view. Then not just images anymore. Also the cover controller doesn't care, just providing a series of frames with all the correct math and animations and touch events.