Hi Bernhard,

re:
> That why I thought this mechanism might be suitable to determine which view has the focus
> for the mouse-wheel zoom.

I see. But that particular mechanism is part of the operating system - the way Windows is set up a mouse move message is sent to the window the mouse cursor is over (unless the mouse has been captured) while a mouse wheel message is sent to the window that has keyboard focus.

But it should not be difficult for me to cook up something similar.

- Michael