XkbOpenDisplay (3)
Leading comments
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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