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 Xkb-
       NumRequiredTypes 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	atten-
       tion 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[XkbT-
       woLevelIndex] 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  capitaliza-
	    tion rules. The Xlib functions are locale-sensitive and apply dif-
	    ferent 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 key-
	    pad 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.	XkbKeyTypesForCoreSym-
	    bols takes a single row from a core keymap, determines the	number
	    of groups associated with it, the type of each group, and the sym-
	    bols 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 Explic-
	    itKeyType4; 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 1.6.0	  XkbKeyTypesForCoreSymbols(3)