XFilterEvent - filter X events for an input method

event     Specifies the event to filter.

       w         Specifies the window for which the filter is to be applied.

       If  the  window  argument  is None, XFilterEvent applies the filter to the window specified in the XEvent
       structure.  The window argument is provided so that layers above  Xlib  that  do  event  redirection  can
       indicate to which window an event has been redirected.

       If  XFilterEvent  returns  True,  then  some  input  method has filtered the event, and the client should
       discard the event.  If XFilterEvent returns False, then the client should continue processing the event.

       If a grab has occurred in the client  and  XFilterEvent  returns  True,  the  client  should  ungrab  the
       keyboard.

       XFilterEvent - filter X events for an input method

XNextEvent(3)
       Xlib-CLanguageXInterface

X Version 11                                      libX11 1.8.12                                  XFilterEvent(3)

       Bool XFilterEvent(XEvent *event, Window w);