XkbKeyNumGroups - Man Page

int XkbKeyNumGroups (XkbDescPtr xkb, KeyCode keycode);

xkb

Xkb description of interest

keycode

keycode of interest

The group_info field of an XkbSymMapRec is an encoded value containing the number of groups of  symbols bound to the  key as well as the specification of the treatment of out-of-range groups. It is  legal for a key to  have zero groups, in which case it also has zero symbols and all events from  that key yield NoSymbol.  To obtain the number of groups of symbols bound to the key, use XkbKeyNumGroups. To change the number of groups bound to a key, use XkbChangeTypesOfKey. To obtain a mask that determines the treatment of out-of-range groups, use XkbKeyGroupInfo and XkbOutOfRangeGroupInfo.

The keyboard controls contain a groups_wrap field specifying the handling of illegal groups on a global basis. That is, when  the user performs an  action causing the effective group to go out of the legal range, the groups_wrap field specifies how to normalize the effective keyboard group to a group that is  legal for the  keyboard as a whole, but there is no guarantee that the normalized group will be  within the range of  legal groups for any individual key. The per-key group_info field specifies how a key treats a legal effective group if the key does not  have a type specified for  the group of concern. For example, the Enter key usually has just one group  defined. If the user  performs an action causing the global keyboard group to change to Group2, the group_info field for the Enter key describes how to handle this situation.

Out-of-range groups for individual keys are mapped to a legal group using the  same options as are used  for the overall keyboard group. The particular type of mapping used is  controlled by the bits set in  the group_info flag, as shown in Table 1.

The Xkb extension is composed of two parts: a server extension, and a  client-side X library extension.  This chapter discusses functions used to modify controls effecting the behavior  of the server portion  of the Xkb extension. X Library Controls discusses functions used to modify  controls that affect only  the behavior of the client portion of the extension; those controls are known as  Library Controls.

Xkb contains control features that affect the entire keyboard, known as global  keyboard controls. Some  of the controls may be selectively enabled and disabled; these controls are  known as the Boolean Controls. Boolean Controls can be turned on or off under program control and can also be  automatically set to an  on or off condition when a client program exits. The remaining controls, known  as the Non-Boolean Controls, are always active. The XkbControlsRec structure describes the current state of  most of the global  controls and the attributes effecting the behavior of each of these Xkb  features. This chapter  describes the Xkb controls and how to manipulate them.

There are two possible components for each of the Boolean Controls: attributes  describing how the  control should work, and a state describing whether the behavior as a whole is  enabled or disabled.  The attributes and state for most of these controls are held in the  XkbControlsRec structure.

You can manipulate the Xkb controls individually, via convenience functions, or  as a whole. To treat  them as a group, modify an XkbControlsRec structure to describe all of the  changes to be made, and  then pass that structure and appropriate flags to an Xkb library function, or  use a  XkbControlsChangesRec to reduce network traffic. When using a convenience  function to manipulate one  control individually, you do not use an XkbControlsRec structure directly.

The Xkb controls are grouped as shown in Table 2.

The individual categories and controls are described first, together with  functions for manipulating  them.

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;

The XkbControlsRec structure is defined as follows:

    #define XkbMaxLegalKeyCode     255
    #define XkbPerKeyBitArraySize  ((XkbMaxLegalKeyCode+1)/8)
    
    
    typedef struct {
        unsigned char   mk_dflt_btn;      /* default button for keyboard driven mouse */
        unsigned char   num_groups;       /* number of keyboard groups */
        unsigned char   groups_wrap;      /* how to wrap out-of-bounds groups */
        XkbModsRec      internal;         /* defines server internal modifiers */
        XkbModsRec      ignore_lock;      /* modifiers to ignore when checking for grab */
        unsigned int    enabled_ctrls;    /* 1 bit => corresponding boolean control enabled */
        unsigned short  repeat_delay;     /* ms delay until first repeat */
        unsigned short  repeat_interval;  /* ms delay between repeats */
        unsigned short  slow_keys_delay;  /* ms minimum time key must be down to be ok */
        unsigned short  debounce_delay;   /* ms delay before key reactivated */
        unsigned short  mk_delay;         /* ms delay to second mouse motion event */
        unsigned short  mk_interval;      /* ms delay between repeat mouse events */
        unsigned short  mk_time_to_max;   /* # intervals until constant mouse move */
        unsigned short  mk_max_speed;     /* multiplier for maximum mouse speed */
        short           mk_curve;         /* determines mouse move curve type */
        unsigned short  ax_options;       /* 1 bit => Access X option enabled */
        unsigned short  ax_timeout;       /* seconds until Access X disabled */
        unsigned short  axt_opts_mask;    /* 1 bit => options to reset on Access X timeout */
        unsigned short  axt_opts_values;  /* 1 bit => turn option on, 0=> off */
        unsigned int    axt_ctrls_mask;   /* which bits in enabled_ctrls to modify */
        unsigned int    axt_ctrls_values; /* values for new bits in enabled_ctrls */
        unsigned char   per_key_repeat[XkbPerKeyBitArraySize];  /* per key auto repeat */
     } XkbControlsRec, *XkbControlsPtr;

The XkbControlsRec structure is defined as follows:

    #define XkbMaxLegalKeyCode     255
    #define XkbPerKeyBitArraySize  ((XkbMaxLegalKeyCode+1)/8)
    
    typedef struct {
        unsigned char   mk_dflt_btn;      /* default button for keyboard driven mouse */
        unsigned char   num_groups;       /* number of keyboard groups */
        unsigned char   groups_wrap;      /* how to wrap out-of-bounds groups */
        XkbModsRec      internal;         /* defines server internal modifiers */
        XkbModsRec      ignore_lock;      /* modifiers to ignore when checking for grab */
        unsigned int    enabled_ctrls;    /* 1 bit => corresponding booleancontrol enabled */
        unsigned short  repeat_delay;     /* ms delay until first repeat */
        unsigned short  repeat_interval;  /* ms delay between repeats */
        unsigned short  slow_keys_delay;  /* ms minimum time key must be down to be ok */
        unsigned short  debounce_delay;   /* ms delay before key reactivated */
        unsigned short  mk_delay;         /* ms delay to second mouse motion event */
        unsigned short  mk_interval;      /* ms delay between repeat mouse events */
        unsigned short  mk_time_to_max;   /* # intervals until constant mouse move */
        unsigned short  mk_max_speed;     /* multiplier for maximum mouse speed */
        short           mk_curve;         /* determines mouse move curve type */
        unsigned short  ax_options;       /* 1 bit => Access X option enabled */
        unsigned short  ax_timeout;       /* seconds until Access X disabled */
        unsigned short  axt_opts_mask;    /* 1 bit => options to reset on Access X timeout */
        unsigned short  axt_opts_values;  /* 1 bit => turn option on, 0=> off */
        unsigned int    axt_ctrls_mask;   /* which bits in enabled_ctrls to modify */
        unsigned int    axt_ctrls_values; /* values for new bits in enabled_ctrls */
        unsigned char   per_key_repeat[XkbPerKeyBitArraySize];  /* per key auto repeat */
     } XkbControlsRec, *XkbControlsPtr;

XkbChangeTypesOfKey(3), XkbKeyGroupInfo(3), XkbOutOfRangeGroupInfo.(3)