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:
- •
- If Shift and Lock are both set, the default ALPHABETIC type yields level
one.
- •
- If Shift alone is set, it yields level two.
- •
- 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.
- •
- 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:
- •
- If Shift and NumLock are both set, the default KEYPAD type yields level
one.
- •
- If Shift alone is set, it yields level two.
- •
- If NumLock alone is set, it yields level two.
- •
- 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.