XkbBellEvent(3) 						   XKB FUNCTIONS						   XkbBellEvent(3)

NAME

       XkbBellEvent - Provides a function that initiates a bell event for the keyboard without ringing the bell

SYNOPSIS

       Bool XkbBellEvent ( display, window, percent, name )
	     Display * display ;
	     Window  window ;
	     int  percent ;
	     Atom  name ;

ARGUMENTS

       - display
	      connection to the X server

       - window
	      the 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 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 Table 1; the name is included in any bell event sent to clients that have requested to receive XkbBell-
	    Notify 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   AX_SlowKeysWarning
	    turned on or off
	    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 XkbChangeEnabledControls.  If you  set  XkbAudibleBell-
	    Mask  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 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, XkbBellEvent  immediately  returns  False.  Otherwise,  XkbBellEvent
	    calls  XkbDeviceBellEvent with the specified display, window, percent, and name, a device_spec of XkbUseCoreKbd, a bell_class of XkbD-
	    fltXIClass, and a bell_id of XkbDfltXIId, and returns what XkbDeviceBellEvent returns.

	    XkbBellEvent generates a XkbBellNotify event.

	    You can call XkbBellEvent without first initializing the keyboard extension.

RETURN VALUES

       False	      The XkbBellEvent immediately returns False, if a compatible keyboard extension isn't present in the X server.

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.

       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 XkbBellNo-
       tifyEvent, if present.

SEE ALSO

       XkbChangeEnabledControls(3), XkbDeviceBellEvent(3), XkbForceBell(3), XkbForceDeviceBell(3), XkbSelectEventDetails(3), XkbSelectEvents(3)

X Version 11							   libX11 1.2.1 						   XkbBellEvent(3)