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)
