3775e09 timed-revealer: listen to the "grab-notify" signal

Authored and Committed by fidencio 7 years ago
    timed-revealer: listen to the "grab-notify" signal
    
    The "grab-notify" signal lets us know when our widget becomes
    shadowed by a Gtk+ grab on another widget, or when it becomes unshadowed
    due to a grab being removed.
    
    That's exactly the case we face when dealing with "usb-redirection" and
    "close" items of the fullscreen toolbar. And, currently, when these
    widgets get closed the timed-revealer stays there forever. From now on
    let's take advantage of the "grab-notify" signal and schedule a timeout
    for the revealer when these widgets' windows get closed.
    
    Signed-off-by: Fabiano FidĂȘncio <fidencio@redhat.com>
    Acked-by: Christophe Fergeau <cfergeau@redhat.com>
    Acked-by: Eduardo Lima (Etrunko) <etrunko@redhat.com>