NAME
XkbOpenDisplay - Checks for a compatible version of the Xkb extension
in both the library and the server, and initializes the extension for
use.
SYNOPSIS
Display XkbOpenDisplay (char *display_name, int *event_rtrn, int
*error_rtrn, int *major_in_out, int *minor_in_out, int
*reason_rtrn);
ARGUMENTS
display_name
hardware display name, which determines the display and
communications domain to be used
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 version out
reason_rtrn
backfilled with a status code
DESCRIPTION
As a convenience, you can use the function XkbOpenDisplay to perform
these three tasks at once: open a connection to an X server, check for
a compatible version of the Xkb extension in both the library and the
server, and initialize the extension for use.
XkbOpenDisplay is a convenience function that opens an X display
connection and initializes the X keyboard extension. In all cases, upon
return reason_rtrn contains a status value indicating success or the
type of failure. If major_in_out and minor_in_out are not NULL,
XkbOpenDisplay first calls XkbLibraryVersion to determine whether the
client library is compatible, passing it the values pointed to by
major_in_out and minor_in_out. If the library is incompatible,
XkbOpenDisplay backfills major_in_out and minor_in_out with the major
and minor extension versions of the library being used and returns
NULL. If the library is compatible, XkbOpenDisplay next calls
XOpenDisplay with the display_name. If this fails, the function
returns NULL. If successful, XkbOpenDisplay calls XkbQueryExtension and
backfills the major and minor Xkb server extension version numbers in
major_in_out and minor_in_out. If the server extension version is not
compatible with the library extension version or if the server
extension is not present, XkbOpenDisplay closes the display and returns
NULL. When successful, the function returns the display connection.
The possible values for reason_rtrn are:
· XkbOD_BadLibraryVersion indicates XkbLibraryVersion returned
False.
· XkbOD_ConnectionRefused indicates the display could not be opened.
· XkbOD_BadServerVersion indicates the library and the server have
incompatible extension versions.
· XkbOD_NonXkbServer indicates the extension is not present in the X
server.
· XkbOD_Success indicates that the function succeeded.
RETURN VALUES
NULL The XkbOpenDisplay function returns NULL if the library
is incompatible.
The XkbOpenDisplay function returns NULL if the call to
XOpenDisplay with the display_name fails.
The XkbOpenDisplay function returns NULL and closes the
display if the server extension version is not compatible
with the library extension version or if the server
extension is not present.
DIAGNOSTICS
BadAccess The Xkb extension has not been properly initialized
SEE ALSO
XkbLibraryVersion(3), XkbQueryExtension(3), XOpenDisplay(3)