modifier-only shortcuts

[Andriy Rysin]

Aaron J. Seigo wrote:
> how about ctrl+shift+tab ... where it would pop up a box just like the switch 
> window or switch desktop box and show the layouts available ...
>   
that's of one of the things on a whishlist for kxkb 
(https://bugs.kde.org/show_bug.cgi?id=66641), and may be implemented 
some day but I don't think it's reasonable default behaviour, especially 
if one does switch layouts a lot

Andriy