XkbCopyKeyType - Man Page

Status XkbCopyKeyType (XkbKeyTypePtr from, XkbKeyTypePtr into);

from

pointer to XkbKeyTypeRec to be copied

into

pointer to XkbKeyTypeRec to be changed

XkbCopyKeyType copies the key type specified by from to the key type specified by into. Both must point to legal XkbKeyTypeRec structures. Xkb assumes from and into point to different places. As a result, overlaps can be fatal. XkbCopyKeyType frees any existing map, preserve, and level_names in into prior to copying. If any allocation errors occur while copying from to into, XkbCopyKeyType returns BadAlloc. Otherwise, XkbCopyKeyType copies from to into and returns Success.

Key types are used to determine the shift level of a key given the current state of the  keyboard. The set of all possible key types for the Xkb keyboard description are held in the types field of the client map, whose total size is stored in size_types, and whose total number of valid entries is stored in num_types. Key types are defined using the following structure:

typedef struct {                   /* Key Type */
    XkbModsRec        mods;        /* modifiers used to compute shift level */
    unsigned char     num_levels;  /* total # shift levels, do not modify directly */
    unsigned char     map_count;   /* # entries in map, preserve (if non-NULL) */
    XkbKTMapEntryPtr  map;         /* vector of modifiers for each shift level */
    XkbModsPtr        preserve;    /* mods to preserve for corresponding map entry */
    Atom              name;        /* name of key type */
    Atom *            level_names; /* array of names of each shift level */
} XkbKeyTypeRec, *XkbKeyTypePtr;

BadAlloc

Unable to allocate storage

XkbCopyKeyTypes(3), XkbGetMap(3), XkbGetUpdatedMap(3), XkbSetMap(3).