Closest thing you're going to get right now is the Render override on the Window I think , problem is its called at the beginning, so you'd need to catch the second invocation to know when a frame has been drawn
if we make changes to Avalonia, RenderQueueManager can be modified to do something on RenderFinished. Every Window is an IRenderRoot so it'd be really easy to know when a frame finished drawing
I just found this project and I would like to contribute. I'd like to make sure I'm setting this up correctly. I believe for debugging what I need is a sandbox Avalonia application using a package source pointing to my locally compiled source of a forked Avalonia build. Correct?
Once the screen API is built, I'd need someone with rendering experience to do the anti-clipping code for popups (where they can be pushed to the second screen if more than half would render off screen)