[Development] old-style, consistent fullscreen behaviour on Mac

[René J.V. Bertin]

Hi,

Can anyone comment on the feasibility of the following idea, please?

OS X 10.7 introduced an optional separation in Mission Control between "spaces" (virtual desktops) and physical screens and coupled that with a fullscreen window inconsistency. By default each monitor has its own virtual desktop and in that case windows that go fullscreen do not affect the other displays (monitors).
But when each virtual destop spans all connected screens (so that you can swap spaces on all screens with the keyboard shortcuts) putting a window in fullscreen has an annoying side-effect. The window content is still shown on only the monitor it occupied but the other monitors are all blacked out.

Sadly this Mission Control option is not one that can be toggled easily; one has to log off and back in to see the effect.

As a laptop user I usually use the laptop's own screen as a secondary monitor when I have my large-screen monitor connected, and thus find it more productive to have virtual desktops that span both screens. I'd love to see an option in Qt like the one provided by VLC, allowing fullscreen windows that leave the other monitor(s) untouched regardless of how Mission Control is configured w.r.t. Spaces. VLC is a good example where this is useful: it allows to watch fullscreen videos and keep an eye on apps running on the secondary screen, for instance to monitor incoming email.

How feasible would it be (for a mere mortal like myself) to implement the old-style fullscreen behaviour? I guess that would have to be done in the Cocoa platform plugin? It's been a long time since I looked at how pre-10.7 applications achieved fullscreen mode but I recall it was rather complicated, involving managing different NSWindows for each NSView that could be shown in fullscreen mode.

Thanks,
René