Index of Section 3 Manual Pages
| Interix / SUA | XkbBell.3 | Interix / SUA |
XkbBell(3) XKB FUNCTIONS XkbBell(3)
NAME
XkbBell - Rings the bell on the default keyboard
SYNOPSIS
Bool XkbBell ( display, window, percent, name )
Display *display;
Window window;
int percent;
Atom name;
ARGUMENTS
- display
connection to the X server
- window
event window, or None
- percent
relative volume, which can range from -100 to 100
inclusive
- name a bell name, or NULL
DESCRIPTION
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 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:
o The default bell
o Any bell on an input device that can be specified by
a bell_class and bell_id pair
o 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.)
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 exam-
ple, 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 -
XkbForceDeviceBell or 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 feed-
back 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 con-
taining 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.
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
T{ SlowKeys and BounceKeys about to be turned on or off
T} 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
Audible Bells
Using Xkb you can generate bell events that do not neces-
sarily ring the system bell. This is useful if you need to
use an audio server instead of the system beep. For exam-
ple, 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 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 Xkb-
ForceDeviceBell or 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 bell_class and
bell_id parameters; set them as follows: Set bell_class to
BellFeedbackClass or KbdFeedbackClass. A device can have
more than one feedback of each type; set bell_id to the
particular bell feedback of 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.
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
If a compatible keyboard extension isn't present in the X
server, XkbBell calls XBell with the specified display and
percent, and returns False. Otherwise, XkbBell calls Xkb-
DeviceBell with the specified display, window, percent,
and name, a device_spec of XkbUseCoreKbd, a bell_class of
XkbDfltXIClass, and a 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 XkbBell-
Notify event.
You can call XkbBell without first initializing the key-
board extension.
RETURN VALUES
FALSE The XkbBell function returns FALSE if Xlib-
DisplayNoXkb is set.
STRUCTURES
Xkb generates XkbBellNotify events for all bells except
for those resulting from calls to XkbForceDeviceBell and
XkbForceBell. To receive XkbBellNotify events under all
possible conditions, pass XkbBellNotifyMask in both the
bits_to_change and values_for_bits parameters to XkbSe-
lectEvents.
The XkbBellNotify event has no event details. It is either
selected or it is not. However, you can call XkbSe-
lectEventDetails using XkbBellNotify as the event_type and
specifying XkbAllBellNotifyMask in bits_to_change and val-
ues_for_bits. This has the same effect as a call to XkbS-
electEvents.
The structure for the XkbBellNotify event type contains:
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;
If your application needs to generate visual bell feedback
on the screen when it receives a bell event, use the win-
dow ID in the XkbBellNotifyEvent, if present.
SEE ALSO
XBell(3X11), XkbBellNotify(3), XkbChangeEnabledCon-
trols(3), XkbDeviceBell(3), XkbForceBell(3), XkbForceDe-
viceBell(3), XkbUseCoreKbd(3)
X Version 11 libX11 1.1.5 XkbBell(3)