CentOS 7.0 - man page for xkballoccompatmap (centos section 3)

XkbAllocCompatMap(3)			  XKB FUNCTIONS 		     XkbAllocCompatMap(3)

NAME
       XkbAllocCompatMap - Allocate a new compatibility map if you do not already have one avail-
       able

SYNOPSIS
       Status XkbAllocCompatMap (XkbDescPtr xkb, unsigned int which, unsigned int num_si);

ARGUMENTS
       - xkb  keyboard description in which to allocate compat map

       - which
	      mask of compatibility map components to allocate

       - num_si
	      number of symbol interpretations to allocate

DESCRIPTION
       xkb specifies the keyboard description for which compatibility maps are to  be  allocated.
       The compatibility map is the compat field in this structure.

       which  specifies  the  compatibility map components to be allocated (see XkbGetCompatMap).
       which is an inclusive OR of the bits shown in Table 1.

		 Table 1 Compatibility Map Component Masks
       ---------------------------------------------------------------
       Mask		    Value    Affecting
       ---------------------------------------------------------------
       XkbSymInterpMask     (1<<0)   Symbol interpretations
       XkbGroupCompatMask   (1<<1)   Group maps
       XkbAllCompatMask     (0x3)    All compatibility map components

       num_si specifies the total number of entries to allocate in the symbol interpretation vec-
       tor (xkb.compat.sym_interpret).

       XkbAllocCompatMap  returns  Success if successful, BadMatch if xkb is NULL, or BadAlloc if
       errors are encountered when attempting to allocate storage.

STRUCTURES
	   typedef struct {
	       KeySym		 sym;	       /* keysym of interest or NULL */
	       unsigned char	 flags;        /* XkbSI_AutoRepeat, XkbSI_LockingKey */
	       unsigned char	 match;        /* specifies how mods is interpreted */
	       unsigned char	 mods;	       /* modifier bits, correspond to eight real modifiers */
	       unsigned char	 virtual_mod;  /* 1 modifier to add to key virtual mod map */
	       XkbAnyAction	 act;	       /* action to bind to symbol position on key */
	   } XkbSymInterpretRec,*XkbSymInterpretPtr;

DIAGNOSTICS
       BadAlloc       Unable to allocate storage

       BadMatch       A compatible version of Xkb was not available in the server or an  argument
		      has correct type and range, but is otherwise invalid

SEE ALSO
       XkbGetCompatMap(3)

NOTES
       Note  that symbol interpretations in a compatibility map (the sym_interpret vector of Xkb-
       SymInterpretRec structures) are also allocated using this same function.  To  ensure  that
       there is sufficient space in the symbol interpretation vector for entries to be added, use
       XkbAllocCompatMap specifying which as XkbSymInterpretMask and the number  of  free  symbol
       interpretations needed in num_si.

X Version 11				   libX11 1.6.0 		     XkbAllocCompatMap(3)