NAME
XkbDeviceBell - Rings the bell on an X input extension device or the default keyboardSYNOPSIS
Bool
XkbDeviceBell (Display *display, Window
window, unsigned int device_spec,
unsigned int bell_class, unsigned int
bell_id, int percent, Atom
name);
ARGUMENTS
- display
- connection to the X server
- window
- window for which the bell is generated, or None
- device_spec
- device ID, or XkbUseCoreKbd
- bell_class
- X input extension bell class of the bell to be rung
- bell_id
- X input extension bell ID of the bell to be rung
- percent
- bell volume, from -100 to 100 inclusive
- name
- a name for the bell, 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:- •
- The default bell
- •
- Any bell on an input device that can be specified by a bell_class and bell_id pair
- •
- 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 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 - 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 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 the Table 1 ; 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 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 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
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 XkbSelectEvents.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 window ID in the XkbBellNotifyEvent, if present.
SEE ALSO
XBell(3), XkbBellNotify(3), XkbChangeEnabledControls(3), , XkbForceBell(3), XkbForceDeviceBell(3), XGetFeedbackControl(3), XkbSelectEvents(3)libX11 1.8.4 | X Version 11 |