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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 dura-tion, duration,
       tion, 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 pur-poses purposes
       poses 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  Xkb-ForceBell. XkbForceBell.
       ForceBell.  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 XkbBell-Notify XkbBellNotify
       Notify events.


                                 Table 1 Predefined Bells
       -----------------------------------------------------------------------------Action ----------------------------------------------------------------------------Action
       Action                                                    Named Bell
       -----------------------------------------------------------------------------Indicator ----------------------------------------------------------------------------Indicator
       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 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 XkbChangeEnabledCon-trols. XkbChangeEnabledControls.
       trols.  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 XkbForceDeviceBell 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 --------------------------------------------------------------------------Function
       Function called      AudibleBell   Server sounds a bell   Server sends an
       XkbBellNotifyEvent
       ---------------------------------------------------------------------------XkbDeviceBell --------------------------------------------------------------------------XkbDeviceBell
       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 speci-fied specified
       fied  display  and percent, and returns False. Otherwise, XkbBell calls XkbDeviceBell with the speci-fied specified
       fied display, window, percent, and name, a device_spec of XkbUseCoreKbd, a bell_class  of  XkbDfltXI-Class, XkbDfltXIClass,
       Class, 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 XkbBellNotify event.

       You can call XkbBell without first initializing the keyboard extension.

RETURN VALUES
       FALSE          The XkbBell function returns FALSE if XlibDisplayNoXkb is set.

STRUCTURES
       Xkb generates XkbBellNotify events for all bells except for those resulting from calls to XkbForceDe-viceBell XkbForceDeviceBell
       viceBell  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.

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

       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 window ID in the XkbBellNotifyEvent, if present.


SEE ALSO
       XBell(3X11),  XkbBellNotify(3),  XkbChangeEnabledControls(3), XkbDeviceBell(3), XkbForceBell(3), Xkb-ForceDeviceBell(3), XkbForceDeviceBell(3),
       ForceDeviceBell(3), XkbUseCoreKbd(3)








X Version 11                                    libX11 1.2.1                                      XkbBell(3)