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XkbKeyNumActions(3)		 XKB FUNCTIONS		   XkbKeyNumActions(3)

NAME
       XkbKeyNumActions	 -  Computes the number	of actions associated with the
       key corresponding to keycode

SYNOPSIS
       int XkbKeyNumActions (XkbDescPtr	xkb, KeyCode keycode);

ARGUMENTS
       - xkb  Xkb description of interest

       - keycode
	      keycode of interest

DESCRIPTION
       A key action defines the	effect key presses and releases	 have  on  the
       internal	 state of the server. For example, the expected	key action as-
       sociated	with pressing the Shift	key is	to  set	 the  Shift  modifier.
       There  is  zero	or one key action associated with each keysym bound to
       each key.

       Just as the entire list of key symbols for the keyboard mapping is held
       in the syms field of the	client map, the	entire list of key actions for
       the keyboard mapping is held in the acts	array of the server  map.  The
       total size of acts is specified by size_acts, and the number of entries
       is specified by num_acts.

       The key_acts array, indexed by keycode, describes the  actions  associ-
       ated  with a key. The key_acts array has	min_key_code unused entries at
       the start to allow direct indexing using	a keycode. If a	key_acts entry
       is zero,	it means the key does not have any actions associated with it.
       If an entry is not zero,	the entry represents an	index  into  the  acts
       field  of  the  server  map, much as the	offset field of	a KeySymMapRec
       structure is an index into the syms field of the	client map.

       The reason the acts field is a linear list of XkbActions	is  to	reduce
       the memory consumption associated with a	keymap.	Because	Xkb allows in-
       dividual	keys to	have multiple shift levels and a different  number  of
       groups  per key,	a single two-dimensional array of KeySyms would	poten-
       tially be very large and	sparse.	Instead, Xkb provides a	small  two-di-
       mensional array of XkbActions for each key. To store all	of these indi-
       vidual arrays, Xkb concatenates each array together in the  acts	 field
       of the server map.

       The  key	 action	 structures consist only of fields of type char	or un-
       signed char. This is done to optimize data  transfer  when  the	server
       sends  bytes  over  the wire. If	the fields are anything	but bytes, the
       server has to sift through all of the  actions  and  swap  any  nonbyte
       fields.	Because	 they  consist	of nothing but bytes, it can just copy
       them out.

       XkbKeyNumActions	computes the number of actions associated with the key
       corresponding  to keycode.  This	should be the same value as the	result
       of XkbKeyNumSyms.

STRUCTURES
       The KeySymMapRec	structure is defined as	follows:

	   #define XkbNumKbdGroups	       4
	   #define XkbMaxKbdGroup	       (XkbNumKbdGroups-1)

	   typedef struct {		       /* map to keysyms for a single keycode */
	       unsigned	char	   kt_index[XkbNumKbdGroups];  /* key type index for each group	*/
	       unsigned	char	   group_info; /* # of groups and out of range group handling */
	       unsigned	char	   width;      /* max #	of shift levels	for key	*/
	       unsigned	short	   offset;     /* index	to keysym table	in syms	array */
       } XkbSymMapRec, *XkbSymMapPtr;

SEE ALSO
       XkbKeyNumSyms(3)

X Version 11			 libX11	1.6.5		   XkbKeyNumActions(3)

NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | STRUCTURES | SEE ALSO

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