Provided by: libx11-doc_1.6.9-2ubuntu1_all bug


       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  XkbSelectEvents  and  pass
       XkbControlsNotifyMask in both bits_to_change and values_for_bits.

       To    receive    XkbControlsNotify    events    only   under   certain   conditions,   use
       XkbSelectEventDetails using XkbControlsNotify as the event_type and specifying the desired
       state changes in bits_to_change and values_for_bits using 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.

                              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_ctrls field 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_ctrls column.

       The  controls  currently enabled in the server are reported in the enabled_ctrls field. If
       any controls were just enabled or disabled (that is, the  contents  of  the  enabled_ctrls
       field  changed),  they  are  flagged in the enabled_ctrl_changes field. The valid bits for
       these fields are the masks listed in Table 10.7 with "ok" in the enabled_ctrls column. The
       num_groups  field  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 keycode and event_type fields are
       set  to  zero  and  the req_major and req_minor fields identify the request. The req_major
       value is the same as the major extension opcode. Otherwise, event_type is set to the  type
       of   event   that   caused  the  change  (one  of  KeyPress,  KeyRelease,  DeviceKeyPress,
       DeviceKeyRelease,  ButtonPress  or  ButtonRelease),  and  req_major  and   req_minor   are
       undefined. If event_type is KeyPress, KeyRelease, DeviceKeyPress, or DeviceKeyRelease, the
       keycode field is set to the key that caused the change. If event_type  is  ButtonPress  or
       ButtonRelease, keycode contains the button number.

       When  a  client  receives an XkbControlsNotify event, it can note the changes in a changes
       structure using XkbNoteControlsChanges.

       XkbGetControlsChanges examines the changes parameter, queries the server for the necessary
       information, and copies the results into the xkb->ctrls keyboard description. If the ctrls
       field of xkb is NULL, XkbGetControlsChanges allocates and  initializes  it.  To  free  the
       ctrls field, use XkbFreeControls.

       XkbGetControlsChanges   returns   Success   if   successful  and  can  generate  BadAlloc,
       BadImplementation, and BadMatch errors.


       Success        The XkbGetControlsChanges function 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;


       BadAlloc       Unable to allocate storage

                      Invalid reply from server

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


       XkbFreeControls(3),          XkbNoteControlsChanges(3),          XkbSelectEventDetails(3),