XkbKeyTypesForCoreSymbols - Man Page

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

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

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.

IsCursorKey(3).