XkbKeyTypesForCoreSymbols(3) XKB FUNCTIONS XkbKeyTypesForCoreSymbols(3)

NAME

XkbKeyTypesForCoreSymbols - Determine the Xkb key types appropriate
for the symbols bound to a key in a core keyboard mapping

SYNOPSIS

int XkbKeyTypesForCoreSymbols (XkbDescPtr xkb, int map_width, KeySym
*core_syms, unsigned int protected, int *types_inout, KeySym
*xkb_syms_rtrn);

ARGUMENTS

xkb keyboard description in which to place symbols

map_width
width of core protocol keymap in xkb_syms_rtrn

core_syms
core protocol format array of KeySyms

protected
explicit key types

types_inout
backfilled with the canonical types bound to groups one and
two for the key

xkb_syms_rtrn
backfilled with symbols bound to the key in the Xkb mapping

DESCRIPTION

XkbKeyTypesForCoreSymbols expands the symbols in core_syms and types
in types_inout, then chooses canonical key types (canonical key types
are defined The Canonical Key Types) for groups 1 and 2 using the
rules specified by the Xkb protocol and places them in xkb_syms_rtrn,
which will be non-NULL.

The Canonical Key Types

Xkb allows up to XkbMaxKeyTypes (255) key types to be defined, but
requires at least XkbNumRequiredTypes (4) predefined types to be in a
key map. These predefined key types are referred to as the canonical
key types and describe the types of keys available on most keyboards.
The definitions for the canonical key types are held in the first
XkbNumRequiredTypes entries of the types field of the client map and
are indexed using the following constants:

XkbOneLevelIndex
XkbTwoLevelIndex
XkbAlphabeticIndex
XkbKeypadIndex


ONE_LEVEL

The ONE_LEVEL key type describes groups that have only one symbol.
The default ONE_LEVEL key type has no map entries and does not pay
attention to any modifiers. A symbolic representation of this key
type could look like the following:

type "ONE_LEVEL" {
modifiers = None;
map[None]= Level1;
level_name[Level1]= "Any";
};

The description of the ONE_LEVEL key type is stored in the
types[XkbOneLevelIndex] entry of the client key map.

TWO_LEVEL

The TWO_LEVEL key type describes groups that consist of two symbols
but are neither alphabetic nor numeric keypad keys. The default
TWO_LEVEL type uses only the Shift modifier. It returns shift level
two if Shift is set, and level one if it is not. A symbolic
representation of this key type could look like the following:

type "TWO_LEVEL" {
modifiers = Shift;
map[Shift]= Level2;
level_name[Level1]= "Base";
level_name[Level2]= "Shift";
};


The description of the TWO_LEVEL key type is stored in the
types[XkbTwoLevelIndex] entry of the client key map.

ALPHABETIC

The ALPHABETIC key type describes groups consisting of two symbols:
the lowercase form of a symbol followed by the uppercase form of the
same symbol. The default ALPHABETIC type implements locale-sensitive
"Shift cancels CapsLock" behavior using both the Shift and Lock
modifiers as follows:


+o If Shift and Lock are both set, the default ALPHABETIC type
yields level one.

+o If Shift alone is set, it yields level two.

+o If Lock alone is set, it yields level one, but preserves the
Lock modifier so Xlib notices and applies the appropriate
capitalization rules. The Xlib functions are locale-sensitive
and apply different capitalization rules for different locales.

+o If neither Shift nor Lock is set, it yields level one.

A symbolic representation of this key type could look like the
following:

type "ALPHABETIC" {
modifiers = Shift+Lock;
map[Shift]= Level2;
preserve[Lock]= Lock;
level_name[Level1]= "Base";
level_name[Level2]= "Caps";
};

The description of the ALPHABETIC key type is stored in the
types[XkbAlphabeticIndex] entry of the client key map.

KEYPAD

The KEYPAD key type describes groups that consist of two
symbols, at least one of which is a numeric keypad symbol. The
numeric keypad symbol is assumed to reside at level two. The
default KEYPAD key type implements "Shift cancels NumLock"
behavior using the Shift modifier and the real modifier bound to
the virtual modifier named "NumLock," known as the NumLock
modifier, as follows:


+o If Shift and NumLock are both set, the default KEYPAD type
yields level one.

+o If Shift alone is set, it yields level two.

+o If NumLock alone is set, it yields level two.

+o If neither Shift nor NumLock is set, it yields level one.

A symbolic representation of this key type could look like the
following:

type "KEYPAD" {
modifiers = Shift+NumLock;
map[None]= Level1;
map[Shift]= Level2;
map[NumLock]= Level2;
map[Shift+NumLock]= Level1;
level_name[Level1]= "Base";
level_name[Level2]= "Caps";
};

The description of the KEYPAD key type is stored in the
types[XkbKeypadIndex] entry of the client key map.

A core keymap is a two-dimensional array of keysyms. It has
map_width columns and max_key_code rows.
XkbKeyTypesForCoreSymbols takes a single row from a core keymap,
determines the number of groups associated with it, the type of
each group, and the symbols bound to each group. The return
value is the number of groups, types_inout has the types for
each group, and xkb_syms_rtrn has the symbols in Xkb order (that
is, groups are contiguous, regardless of size).

protected contains the explicitly protected key types. There is
one explicit override control associated with each of the four
possible groups for each Xkb key, ExplicitKeyType1 through
ExplicitKeyType4; protected is an inclusive OR of these
controls. map_width is the width of the core keymap and is not
dependent on any Xkb definitions. types_inout is an array of
four type indices. On input, types_inout contains the indices of
any types already assigned to the key, in case they are
explicitly protected from change.

Upon return, types_inout contains any automatically selected
(that is, canonical) types plus any protected types. Canonical
types are assigned to all four groups if there are enough
symbols to do so. The four entries in types_inout correspond to
the four groups for the key in question.

X Version 11 libX11 1.8.10 XkbKeyTypesForCoreSymbols(3)