[PATCH] xwayland: Handle the wl_keyboard modifiers event

[Bill Spitzak]

Are "latched modifiers" things like the Compose Key and dead-key accent 
prefixes?

I think this is usually dropped when the focus changes.

It also seems like these should be handled by the input method. I don't 
like the fact that clients can figure out European composed characters 
without correctly using the input method api, since it means that use of 
the input method will be, in effect, optional.

Rui Matos wrote:
> This allows us to keep track of latched and locked modifiers as well
> as the XKB group while the keyboard focus is on another wayland
> client. Note that we don't need to track depressed modifiers since
> wayland guarantees that we'll get them as key press events whenever
> we get the keyboard focus.