XkbGetControlsChanges - Updates a local copy of a keyboard description with the changes previously noted by one or more calls to XkbNoteControlsChanges


XkbGetControlsChanges (Display * dpy , XkbDescPtr xkb , XkbNameChangesPtr changes );


  • - dpy
        connection to X server
  • - xkb
        xkb->ctrls will be updated
  • - changes
        indicates which parts of xkb->ctrls to update


Whenever a field in the controls structure changes in the server's keyboard description, the server sends an XkbControlsNotify event to all interested clients.To receive XkbControlsNotify events under all possible conditions, use XkbSelectEventsand pass XkbControlsNotifyMask in both bits_to_changeand values_for_bits. To receive XkbControlsNotify events only under certain conditions, use XkbSelectEventDetailsusing XkbControlsNotify as the event_typeand specifying the desired state changes in bits_to_changeand values_for_bitsusing mask bits from Table 1. Table 1 shows the actual values for the individual mask bits used to select controls for modification and to enable and disable the control. Note that the same mask bit is used to specify general modifications to the parameters used to configure the control (which), and to enable and disable the control (enabled_ctrls). The anomalies in the table (no "ok" in column) are for controls that have no configurable attributes; and for controls that are not boolean controls and therefore cannot be enabled or disabled.

c s s s
l l l l
l l l l
Table 1 Controls Mask Bits
Mask Bit which or enabled Value
changed_ctrls _ctrls
XkbRepeatKeysMask ok ok (1L<<0)
XkbSlowKeysMask ok ok (1L<<1)
XkbBounceKeysMask ok ok (1L<<2)
XkbStickyKeysMask ok ok (1L<<3)
XkbMouseKeysMask ok ok (1L<<4)
XkbMouseKeysAccelMask ok ok (1L<<5)
XkbAccessXKeysMask ok ok (1L<<6)
XkbAccessXTimeoutMask ok ok (1L<<7)
XkbAccessXFeedbackMask ok ok (1L<<8)
XkbAudibleBellMask ok (1L<<9)
XkbOverlay1Mask ok (1L<<10)
XkbOverlay2Mask ok (1L<<11)
XkbIgnoreGroupLockMask ok (1L<<12)
XkbGroupsWrapMask ok (1L<<27)
XkbInternalModsMask ok (1L<<28)
XkbIgnoreLockModsMask ok (1L<<29)
XkbPerKeyRepeatMask ok (1L<<30)
XkbControlsEnabledMask ok (1L<<31)
XkbAccessXOptionsMask ok ok (XkbStickyKeysMask |
XkbAllBooleanCtrlsMask ok (0x00001FFF)
XkbAllControlsMask ok (0xF8001FFF)

The changed_ctrlsfield specifies the controls components that have changed and consists of bits taken from the masks defined in Table 10.7 with "ok" in the changed_ctrlscolumn. The controls currently enabled in the server are reported in the enabled_ctrlsfield. If any controls were just enabled or disabled (that is, the contents of the enabled_ctrlsfield changed), they are flagged in the enabled_ctrl_changesfield. The valid bits for these fields are the masks listed in Table 10.7 with "ok" in the enabled_ctrlscolumn. The num_groupsfield reports the number of groups bound to the key belonging to the most number of groups and is automatically updated when the keyboard mapping changes. If the change was caused by a request from a client, the keycodeand event_typefields are set to zero and the req_majorand req_minorfields identify the request. The req_major value is the same as the major extension opcode. Otherwise,event_typeis set to the type of event that caused the change (one of KeyPress, KeyRelease, DeviceKeyPress, DeviceKeyRelease, ButtonPress or ButtonRelease), and req_majorand req_minorare undefined. If event_typeis KeyPress, KeyRelease, DeviceKeyPress, or DeviceKeyRelease, the keycodefield is set to the key that caused the change. If event_typeis ButtonPress or ButtonRelease, keycodecontains the button number. When a client receives an XkbControlsNotify event, it can note the changes in a changes structure using XkbNoteControlsChanges. XkbGetControlsChangesexamines the changesparameter, queries the server for the necessary information, and copies the results into the xkb->ctrlskeyboard description. If the ctrlsfield of xkbis NULL, XkbGetControlsChangesallocates and initializes it. To free the ctrlsfield, use XkbFreeControls. XkbGetControlsChangesreturns Success if successful and can generate BadAlloc, BadImplementation, and BadMatch errors.


  • Success
                   The XkbGetControlsChangesfunction returns Success if the query of the server was successful.


The structure for the XkbControlsNotify event is defined as follows:
typedef struct {
    int           type;          /(** Xkb extension base event code */
    unsigned long serial;        /(** X server serial number for event */
    Bool          send_event;    /(** True => synthetically generated */
    Display *     display;       /(** server connection where event generated */
    Time          time;          /(** server time when event generated */
    int           xkb_type;      /(** XkbCompatMapNotify */
    int           device;        /(** Xkb device ID, will not be XkbUseCoreKbd */
    unsigned int  changed_ctrls; /(** bits indicating which controls data have
    unsigned int  enabled_ctrls; /(** controls currently enabled in server */
    unsigned int  enabled_ctrl_changes; /(** bits indicating enabled/disabled
controls */
    int           num_groups;    /(** current number of keyboard groups */
    KeyCode       keycode;       /(** != 0 => keycode of key causing change */
    char          event_type;    /(** Type of event causing change */
    char          req_major;     /(** major event code of event causing change */
    char          req_minor;     /(** minor event code of event causing change */
} XkbControlsNotifyEvent;



               Unable to allocate storage


               Invalid reply from server


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


R XkbFreeControls (3),

R XkbNoteControlsChanges (3),

R XkbSelectEventDetails (3),

R XkbSelectEvents (3)