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.TH XkbBell __libmansuffix__ __xorgversion__ "XKB FUNCTIONS"
.SH NAME
XkbBell \- Rings the bell on the default keyboard
.SH SYNOPSIS
.HP
.B Bool XkbBell
.BI "(\^Display *" "display" "\^,"
.BI "Window " "window" "\^,"
.BI "int " "percent" "\^,"
.BI "Atom " "name" "\^);"
.if n .ti +5n
.if t .ti +.5i
.SH ARGUMENTS
.TP
.I display
connection to the X server
.TP
.I window
event window, or None
.TP
.I percent
relative volume, which can range from -100 to 100 inclusive
.TP
.I name
a bell name, or NULL
.SH DESCRIPTION
.LP
The core X protocol allows only applications to explicitly sound the system bell
with a
given duration, pitch, and volume. Xkb extends this capability by allowing
clients to
attach symbolic names to bells, disable audible bells, and receive an event
whenever the
keyboard bell is rung. For the purposes of this document, the
.I audible
bell is defined to be the system bell, or the default keyboard bell, as opposed
to any
other audible sound generated elsewhere in the system.
You can ask to receive XkbBellNotify events when any client rings any one of the
following:

.IP \(bu 5
The default bell
.IP \(bu 5
Any bell on an input device that can be specified by a bell_class and bell_id
pair
.IP \(bu 5
Any bell specified only by an arbitrary name. (This is, from the server's point
of view,
merely a name, and not connected with any physical sound-generating device. Some
client
application must generate the sound, or visual feedback, if any, that is
associated with
the name.)

.LP
You can also ask to receive XkbBellNotify events when the server rings the
default bell
or if any client has requested events only (without the bell sounding) for any
of the
bell types previously listed.

You can disable audible bells on a global basis. For example, a client that
replaces the
keyboard bell with some other audible cue might want to turn off the AudibleBell
control
to prevent the server from also generating a sound and avoid cacophony. If you
disable
audible bells and request to receive XkbBellNotify events, you can generate
feedback
different from the default bell.

You can, however, override the AudibleBell control by calling one of the
functions that
force the ringing of a bell in spite of the setting of the AudibleBell control -
.I XkbForceDeviceBell
or
.I XkbForceBell.
In this case the server does not generate a bell event.

Just as some keyboards can produce keyclicks to indicate when a key is pressed
or
repeating, Xkb can provide feedback for the controls by using special beep
codes. The
AccessXFeedback control is used to configure the specific types of operations
that
generate feedback.

Bell Names

You can associate a name to an act of ringing a bell by converting the name to
an Atom
and then using this name when you call the functions listed in this chapter. If
an event
is generated as a result, the name is then passed to all other clients
interested in
receiving XkbBellNotify events. Note that these are arbitrary names and that
there is no
binding to any sounds. Any sounds or other effects (such as visual bells on the
screen)
must be generated by a client application upon receipt of the bell event
containing the
name. There is no default name for the default keyboard bell. The server does
generate
some predefined bells for the AccessX controls. These named bells are shown in
Table 1 below; the name is included in any bell event sent to clients that have
requested to receive XkbBellNotify events.

.TS
c s
l l
lW(4I) l.
Table 1 Predefined Bells
_
Action	Named Bell
_
Indicator turned on	AX_IndicatorOn
Indicator turned off	AX_IndicatorOff
More than one indicator changed state	AX_IndicatorChange
Control turned on	AX_FeatureOn
Control turned off	AX_FeatureOff
More than one control changed state	AX_FeatureChange
SlowKeys and BounceKeys about to be turned on or off	AX_SlowKeysWarning
SlowKeys key pressed	AX_SlowKeyPress
SlowKeys key accepted	AX_SlowKeyAccept
SlowKeys key rejected	AX_SlowKeyReject
Accepted SlowKeys key released	AX_SlowKeyRelease
BounceKeys key rejected	AX_BounceKeyReject
StickyKeys key latched	AX_StickyLatch
StickyKeys key locked	AX_StickyLock
StickyKeys key unlocked	AX_StickyUnlock
.TE

Audible Bells

Using Xkb you can generate bell events that do not necessarily ring the system
bell. This
is useful if you need to use an audio server instead of the system beep. For
example,
when an audio client starts, it could disable the audible bell (the system bell)
and then
listen for XkbBellNotify events. When it receives a XkbBellNotify event, the
audio client
could then send a request to an audio server to play a sound.

You can control the audible bells feature by passing the XkbAudibleBellMask to
.I XkbChangeEnabledControls.
If you set XkbAudibleBellMask on, the server rings the system bell when a bell
event
occurs. This is the default. If you set XkbAudibleBellMask off and a bell event
occurs,
the server does not ring the system bell unless you call
.I XkbForceDeviceBell
or
.I XkbForceBell.

Audible bells are also part of the per-client auto-reset controls.

Bell Functions

Use the functions described in this section to ring bells and to generate bell
events.

The input extension has two types of feedbacks that can generate bells - bell
feedback
and keyboard feedback. Some of the functions in this section have
.I bell_class
and
.I bell_id
parameters; set them as follows: Set
.I bell_class
to BellFeedbackClass or KbdFeedbackClass. A device can have more than one
feedback of
each type; set
.I bell_id
to the particular bell feedback of
.I bell_class
type.

Table 2 shows the conditions that cause a bell to sound or an XkbBellNotifyEvent
to be generated when a bell function is called.

.TS
c s s s
l l l l
l l l l.
Table 2 Bell Sounding and Bell Event Generating
_
Function called	AudibleBell	Server sounds a bell	Server sends an
XkbBellNotifyEvent
_
XkbDeviceBell	On	Yes	Yes
XkbDeviceBell	Off	No	Yes
XkbBell	On	Yes	Yes
XkbBell	Off	No	Yes
XkbDeviceBellEvent	On or Off	No	Yes
XkbBellEvent	On or Off	No	Yes
XkbDeviceForceBell	On or Off	Yes	No
XkbForceBell	On or Off	Yes	No
.TE

If a compatible keyboard extension isn't present in the X server,
.I XkbBell
calls
.I XBell
with the specified
.I display
and
.I percent,
and returns False. Otherwise,
.I XkbBell
calls
.I XkbDeviceBell
with the specified
.I display, window, percent,
and
.I name,
a
.I device_spec
of XkbUseCoreKbd, a
.I bell_class
of XkbDfltXIClass, and a
.I bell_id
of XkbDfltXIId, and returns True.

If you have disabled the audible bell, the server does not ring the system bell,
although it does generate a XkbBellNotify event.

You can call
.I XkbBell
without first initializing the keyboard extension.
.SH "RETURN VALUES"
.TP 15
FALSE
The XkbBell function returns FALSE if XlibDisplayNoXkb is set.
.SH STRUCTURES
.LP
Xkb generates XkbBellNotify events for all bells except for those resulting from
calls to
.I XkbForceDeviceBell
and
.I XkbForceBell.
To receive XkbBellNotify events under all possible conditions, pass
XkbBellNotifyMask in
both the
.I bits_to_change
and
.I values_for_bits
parameters to
.I XkbSelectEvents.

The XkbBellNotify event has no event details. It is either selected or it is
not.
However, you can call
.I XkbSelectEventDetails
using XkbBellNotify as the
.I event_type
and specifying XkbAllBellEventsMask in
.I bits_to_change
and
.I values_for_bits.
This has the same effect as a call to
.I XkbSelectEvents.

The structure for the XkbBellNotify event type contains:
.nf

   typedef struct _XkbBellNotify {
       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;    /\&* XkbBellNotify */
       unsigned int   device;      /\&* Xkb device ID, will not be XkbUseCoreKbd */
       int            percent;     /\&* requested volume as % of max */
       int            pitch;       /\&* requested pitch in Hz */
       int            duration;    /\&* requested duration in microseconds */
       unsigned int   bell_class;  /\&* X input extension feedback class */
       unsigned int   bell_id;     /\&* X input extension feedback ID */
       Atom           name;        /\&* "name" of requested bell */
       Window         window;      /\&* window associated with event */
       Bool           event_only;  /\&* False -> the server did not produce a beep */
   } XkbBellNotifyEvent;

.fi
If your application needs to generate visual bell feedback on the screen when it
receives
a bell event, use the window ID in the XkbBellNotifyEvent, if present.

.SH "SEE ALSO"
.BR XBell (__libmansuffix__),
.BR XkbBellNotify (__libmansuffix__),
.BR XkbChangeEnabledControls (__libmansuffix__),
.BR XkbDeviceBell (__libmansuffix__),
.BR XkbForceBell (__libmansuffix__),
.BR XkbForceDeviceBell (__libmansuffix__),
.BR XkbUseCoreKbd (__libmansuffix__)





