XInput2 raw events only for root window

[Will Song]

Hey all. I am writing a small-ish application and when grabbing for keyboard
events I noticed that it was not possible to select for raw key press/releasee
events on the client window I created, and must be done on the screen root. Is
this an intentional design in the xorg server or is it possible to do this
generally in a non-root window? Thanks.

-- 
Will Song