NAME¶
XkbQueryExtension - Determines the compatibility of a library at runtime.
SYNOPSIS¶
Bool
XkbQueryExtension (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 version
out
DESCRIPTION¶
Call
XkbQueryExtension to check for the presence and compatibility of the
extension in the server and to initialize the extension. Because of potential
version mismatches, 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, XkbLibraryVersion, 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 compatible version of
the X Keyboard Extension is present in the server. If a compatible extension
is present,
XkbQueryExtension returns True; otherwise, it returns
False.
If a compatible version of Xkb is present,
XkbQueryExtension 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),
XkbOpenDisplay(3)