QML window translucent for mouse events except rectangle

[Jens van koolwijk]

I have a window with multiple buttons. I would like that my window is transparent to mouse events except for the button. I don't want to use multiple windows. How can I do this(event filter)?Platform is windows 10. The application is a fullscreen overlay always on top.I want the window to be translucent for mouse event except for the parts where I put a button or image

[GPBeta]

I think it's not easy to be done on Windows system.
You might have to update the window's region every frame get rendered, and this operation would be somehow overhead.