XkbSelectEvents - Selects and / or deselects for delivery of one or
more Xkb events and has them delivered under all conditions
Bool XkbSelectEvents (Display *display, unsigned int device_spec,
unsigned long int bits_to_change, unsigned long int
connection to the X server
device ID, or XkbUseCoreKbd
determines events to be selected / deselected
1=>select, 0->deselect; for events in bits_to_change
Xkb events are selected using an event mask, much the same as normal
core X events are selected. However, unlike selecting core X events,
where you must specify the selection status (on or off) for all
possible event types whenever you wish to change the selection criteria
for any one event, Xkb allows you to restrict the specification to only
the event types you wish to change. This means that you do not need to
remember the event selection values for all possible types each time
you want to change one of them.
Many Xkb event types are generated under several different
circumstances. When selecting to receive an Xkb event, you may specify
either that you want it delivered under all circumstances, or that you
want it delivered only for a subset of the possible circumstances.
You can also deselect an event type that was previously selected for,
using the same granularity.
Xkb provides two functions to select and deselect delivery of Xkb
events. XkbSelectEvents allows you to select or deselect delivery of
more than one Xkb event type at once. Events selected using
XkbSelectEvents are delivered to your program under all circumstances
that generate the events. To restrict delivery of an event to a subset
of the conditions under which it occurs, use XkbSelectEventDetails.
XkbSelectEventDetails only allows you to change the selection
conditions for a single event at a time, but it provides a means of
fine-tuning the conditions under which the event is delivered.
This request changes the Xkb event selection mask for the keyboard
specified by device_spec.
Each Xkb event that can be selected is represented by a bit in the
bits_to_change and values_for_bits masks. Only the event selection bits
specified by the bits_to_change parameter are affected; any unspecified
bits are left unchanged. To turn on event selection for an event, set
the bit for the event in the bits_to_change parameter and set the
corresponding bit in the values_for_bits parameter. To turn off event
selection for an event, set the bit for the event in the bits_to_change
parameter and do not set the corresponding bit in the values_for_bits
parameter. The valid values for both of these parameters are an
inclusive bitwise OR of the masks shown in Table 1. There is no
interface to return your client's current event selection mask. Clients
cannot set other clients' event selection masks.
The X server reports the events defined by Xkb to your client
application only if you have requested them via a call to
XkbSelectEvents or XkbSelectEventDetails. Specify the event types in
which you are interested in a mask.
Table 1 lists the event mask constants that can be specified with the
XkbSelectEvents request and the circumstances in which the mask should
Table 1 XkbSelectEvents Mask Constants
Event Mask Value Notification Wanted
XkbNewKeyboardNotifyMask (1L<<0) Keyboard geometry change
XkbMapNotifyMask (1L<<1) Keyboard mapping change
XkbStateNotifyMask (1L<<2) Keyboard state change
XkbControlsNotifyMask (1L<<3) Keyboard control change
XkbIndicatorStateNotifyMask (1L<<4) Keyboard indicator state change
XkbIndicatorMapNotifyMask (1L<<5) Keyboard indicator map change
XkbNamesNotifyMask (1L<<6) Keyboard name change
XkbCompatMapNotifyMask (1L<<7) Keyboard compat map change
XkbBellNotifyMask (1L<<8) Bell
XkbActionMessageMask (1L<<9) Action message
XkbAccessXNotifyMask (1L<<10) AccessX features
XkbExtensionDeviceNotifyMask (1L<<11) Extension device
XkbAllEventsMask (0xFFF) All Xkb events
If a bit is not set in the bits_to_change parameter, but the
corresponding bit is set in the values_for_bits parameter, a BadMatch
protocol error results. If an undefined bit is set in either the
bits_to_change or the values_for_bits parameter, a BadValue protocol
All event selection bits are initially zero for clients using the Xkb
extension. Once you set some bits, they remain set for your client
until you clear them via another call to XkbSelectEvents.
XkbSelectEvents returns False if the Xkb extension has not been
initilialized and True otherwise.
True The XkbSelectEvents function returns True if the Xkb
extension has been initilialized.
False The XkbSelectEvents function returns False if the Xkb
extension has not been initilialized.