Emitting events to a non-visible widget

[Zan Dobersek <zandobersek gmail com>]

Is there any way to emit events to a non-visible GtkWidget? By 
non-visible, I'm thinking of a GtkWidget that never gets shown, i.e. 
gtk_widget_show_all or similar never gets called on this widget.

Just to clarify on the events - I'd like to emit button, emotion and key 
events.
As far as I've tried, I saw that the problem occurs because no useful 
x_root or y_root can actually be set to event, when specifically talking 
about a GdkEventButton event. I also fairly doubt about widget's window 
validity when that widget is not visible, since a window needs to be set 
in a GdkEvent.

Can anyone suggest a solution or an effective bypass? I thank you sincerely.