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XkbForceDeviceBell(3)            XKB FUNCTIONS           XkbForceDeviceBell(3)



NAME
       XkbForceDeviceBell  -  Rings  the bell on any keyboard, overriding user
       preference settings for audible bells

SYNOPSIS
       Bool XkbForceDeviceBell (  display,  window,  device_spec,  bell_class,
       bell_id, percent )
             Display * display ;
             Window  window ;
             unsigned int  device_spec ;
             unsigned int  bell_class ;
             unsigned int  bell_id ;
             int  percent ;

ARGUMENTS
       - display
              connection to the X server

       - window
              event window, or None

       - device_spec
              device ID, or XkbUseCoreKbd

       - bell_class
              input extension class of the bell to be rung

       - bell_id
              input extension ID of the bell to be rung

       - percent
              relative volume, which can range from -100 to 100 inclusive

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, dis-
       able 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  fol-
       lowing:


       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 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  con-
       figure 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  XkbBellNo-
       tify  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;
       the  name  is  included  in  any  bell  event sent to clients that have
       requested to receive XkbBellNotify events.


       c s l l lW(4i) l.  Table 1 Predefined Bells _  Action    Named  Bell  _
       Indicator turned on    AX_IndicatorOn Indicator turned off     AX_Indi-
       catorOff 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_Stick-
       yUnlock

       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 XkbBell-
       Notify 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  XkbAudible-
       BellMask  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  XkbForceDe-
       viceBell 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 gener-
       ate 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 XkbBell-
       NotifyEvent to be generated when a bell function is called.


       c s s s l l l l l l l l.  Table 2 Bell Sounding and Bell Event Generat-
       ing    _    Function    called     AudibleBell    Server    sounds    a
       bell     Server    sends    an    XkbBellNotifyEvent    _    XkbDevice-
       Bell  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  XkbDeviceForce-
       Bell  On or Off    Yes  No XkbForceBell   On or Off Yes  No


       If a compatible keyboard extension isn't present in the X server,  Xkb-
       ForceDeviceBell  immediately  returns False. Otherwise, XkbForceDevice-
       Bell rings the bell as specified for the display  and  keyboard  device
       and  returns  True.  Set  percent to be the volume relative to the base
       volume for the keyboard as described for XBell.

       There is no name parameter because XkbForceDeviceBell does not cause an
       XkbBellNotify event.

       You can call XkbBell without first initializing the keyboard extension.

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 param-
       eters to XkbSelectEvents.

       The  XkbBellNotify event has no event details. It is either selected or
       it is not.  However, you can call XkbSelectEventDetails using  XkbBell-
       Notify   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 XkbBell-
       NotifyEvent, if present.

SEE ALSO
       XBell(3X11), XkbBell(3), XkbBellNotify(3), XkbChangeEnabledControls(3),
       XkbDeviceBell(3),   XkbForceBell(3),   XkbForceDeviceBell(3),    XkbSe-
       lectEventDetails(3), XkbSelectEvents(3)







X Version 11                     libX11 1.1.5            XkbForceDeviceBell(3)