Tribblix: manual page: XkbListComponents.3

XkbListComponents(3) XKB FUNCTIONS XkbListComponents(3)

NAME

XkbListComponents - List of components for one or more component
types

SYNOPSIS

XkbComponentListPtr XkbListComponents (Display *dpy, unsigned int
device_spec, XkbComponentNamesPtr ptrns, int *max_inout);

ARGUMENTS

dpy connection to X server

device_spec
device ID, or XkbUseCoreKbd

ptrns namelist for components of interest

max_inout
max # returned names, # left over

DESCRIPTION

You may ask the server for a list of components for one or more
component types. The request takes the form of a set of patterns, one
pattern for each of the component types, including a pattern for the
complete keyboard description. To obtain this list, use
XkbListComponents.

XkbListComponents queries the server for a list of component names
matching the patterns specified in ptrns. It waits for a reply and
returns the matching component names in an XkbComponentListRec
structure. When you are done using the structure, you should free it
using XkbFreeComponentList. device_spec indicates a particular device
in which the caller is interested. A server is allowed (but not
required) to restrict its reply to portions of the database that are
relevant for that particular device.

ptrns is a pointer to an XkbComponentNamesRec. Each of the fields in
ptrns contains a pattern naming the components of interest. Each of
the patterns is composed of characters from the ISO Latin1 encoding,
but can contain only parentheses, the wildcard characters `?' and
`*', and characters permitted in a component class or member name. A
pattern may be NULL, in which case no components for that type is
returned. Pattern matches with component names are case sensitive.
The `?' wildcard matches any single character, except a left or right
parenthesis; the `*' wildcard matches any number of characters,
except a left or right parenthesis. If an implementation allows
additional characters in a component class or member name other than
those required by the Xkb extension, the result of comparing one of
the additional characters to either of the wildcard characters is
implementation-dependent.

If a pattern contains illegal characters, the illegal characters are
ignored. The matching process is carried out as if the illegal
characters were omitted from the pattern.

max_inout is used to throttle the amount of data passed to and from
the server. On input, it specifies the maximum number of names to be
returned (the total number of names in all component categories).
Upon return from XkbListComponents, max_inout contains the number of
names that matched the request but were not returned because of the
limit.

Component Names

Component names have the form class(member) where class describes a
subset of the available components for a particular type and the
optional member identifies a specific component from that subset. For
example, the name "atlantis(acme)" for a symbols component might
specify the symbols used for the atlantis national keyboard layout by
the vendor "acme." Each class has an optional default member -
references that specify a class but not a member refer to the default
member of the class, if one exists. Xkb places no constraints on the
interpretation of the class and member names used in component names.

The class and member names are both specified using characters from
the Latin-1 character set. Xkb implementations must accept all
alphanumeric characters, minus (`-') and underscore (`_') in class or
member names, and must not accept parentheses, plus, vertical bar,
percent sign, asterisk, question mark, or white space. The use of
other characters is implementation-dependent.

STRUCTURES

The component name patterns used to describe the request are passed
to XkbListComponents using an XkbComponentNamesRec structure. This
structure has no special allocation constraints or interrelationships
with other structures; allocate and free this structure using
standard malloc and free calls or their equivalent:

typedef struct _XkbComponentNames {
char * keymap; /* keymap names */
char * keycodes; /* keycode names */
char * types; /* type names */
char * compat; /* compatibility map names */
char * symbols; /* symbol names */
char * geometry; /* geometry names */
} XkbComponentNamesRec, *XkbComponentNamesPtr;

XkbListComponents returns a pointer to an XkbComponentListRec:

typedef struct _XkbComponentList {
int num_keymaps; /* number of entries in keymap */
int num_keycodes; /* number of entries in keycodes */
int num_types; /* number of entries in types */
int num_compat; /* number of entries in compat */
int num_symbols; /* number of entries in symbols */
int num_geometry; /* number of entries in geometry;
XkbComponentNamePtr keymap; /* keymap names */
XkbComponentNamePtr keycodes; /* keycode names */
XkbComponentNamePtr types; /* type names */
XkbComponentNamePtr compat; /* compatibility map names */
XkbComponentNamePtr symbols; /* symbol names */
XkbComponentNamePtr geometry; /* geometry names */
} XkbComponentListRec, *XkbComponentListPtr;

typedef struct _XkbComponentName {
unsigned short flags; /* hints regarding component name */
char * name; /* name of component */
} XkbComponentNameRec, *XkbComponentNamePtr;

NOTES