Is there a way to cut a transparent rectangle in the background of a wxFrame to see the desktop or other windows behind that rect?
Custom shape is not an option since I want to capture mouse events there too.
No, the only possibilities here are using a custom shape or SetTransparent() but the latter can only set the transparency uniformly.
SetTransparent() could probably be extended to be more flexible, but so far nobody has done it.
Transparent hole in wxFrame background