XkbQueryExtension(3)      XKB FUNCTIONS      XkbQueryExtension(3)



NAME
       XkbQueryExtension  -   Determines  the  compatibility of a
       library at runtime.

SYNOPSIS
       Bool XkbQueryExtension  (  dpy,  opcode_rtrn,  event_rtrn,
       error_rtrn, major_in_out, minor_in_out )
             Display *dpy;
             int opcode_rtrn;
             int event_rtrn;
             int *error_rtrn;
             int major_in_out;
             int minor_in_out;

ARGUMENTS
       dpy    connection to the X server

       opcode_rtrn
              backfilled with the major extension opcode

       event_rtrn
              backfilled with the extension base event code

       error_rtrn
              backfilled with the extension base error code

       major_in_out
              compile  time  lib  major  version in, server major
              version out

       minor_in_out
              compile time lib min version in, server minor  ver-
              sion out

DESCRIPTION
       Call  XkbQueryExtension to check for the presence and com-
       patibility of the extension in the server and to  initial-
       ize  the  extension.  Because  of  potential  version mis-
       matches, you cannot use the  generic  extension  mechanism
       functions  (  XQueryExtension  and  XInitExtension  )  for
       checking for the presence of,  and  initializing  the  Xkb
       extension.

       You  must  call XkbQueryExtension or XkbOpenDisplay before
       using any other Xkb library interfaces, unless such  usage
       is explicitly allowed in the interface description in this
       document. The exceptions are:  XkbIgnoreExtension,  XkbLi-
       braryVersion, and a handful of audible-bell functions. You
       should not use any other Xkb functions if the extension is
       not  present or is uninitialized. In general, calls to Xkb
       library functions  made  prior  to  initializing  the  Xkb
       extension cause BadAccess protocol errors.

       XkbQueryExtension both determines whether a compatible Xkb
       extension is present in the X server and  initializes  the
       extension when it is present.

       The  XkbQueryExtension  function determines whether a com-
       patible version of the X Keyboard Extension is present  in
       the  server.  If  a  compatible extension is present, Xkb-
       QueryExtension returns True; otherwise, it returns  False.

       If  a compatible version of Xkb is present, XkbQueryExten-
       sion initializes the extension.  It  backfills  the  major
       opcode for the keyboard extension in opcode_rtrn, the base
       event  code  in  event_rtrn,  the  base  error   code   in
       error_rtrn, and the major and minor version numbers of the
       extension in major_in_out  and  minor_in_out.   The  major
       opcode  is  reported  in  the req_major fields of some Xkb
       events. For a discussion of the base event code.

RETURN VALUES
       True           The XkbQueryExtension function returns True
                      if  it  determines  a compatible version of
                      the X Keyboard Extension is present in  the
                      server.

       False          The   XkbQueryExtension   function  returns
                      False if it determines a compatible version
                      of  the X Keyboard Extension is not present
                      in the server.

SEE ALSO
       XkbIgnoreExtension(3),  XkbLibraryVersion(3),  XkbOpenDis-
       play(3)



X Version 11               libX11 1.1.5      XkbQueryExtension(3)