[xmonad] Smart Decorations?

[Steffen Schuldenzucker]

Hi!

I've been experimenting with window decorations (specifically noFrillsDeco).
Since I also have the window title in xmobar, it'd be cool to have 
decorations not shown if there is only one window, similarly to what 
'smartBorders' does for borders.

Has anyone implemented this already? What would be a good place to start?

Thanks,
Best, Steffen