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XkbBell(3)			 XKB FUNCTIONS			    XkbBell(3)

NAME
       XkbBell - Rings the bell	on the default keyboard

SYNOPSIS
       Bool XkbBell (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, 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 us-
       ing special beep	codes. The AccessXFeedback control is used to  config-
       ure 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 re-
       ceipt 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 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 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.

		    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 XkbDeviceBell with the	specified dis-
       play, 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	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  re-
       sulting	from calls to XkbForceDeviceBell and XkbForceBell.  To receive
       XkbBellNotify events under all possible conditions, pass	XkbBellNotify-
       Mask in both the	bits_to_change and values_for_bits parameters to XkbS-
       electEvents.

       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(3),  XkbBellNotify(3),  XkbChangeEnabledControls(3),   XkbDevice-
       Bell(3),	XkbForceBell(3), XkbForceDeviceBell(3),	XkbUseCoreKbd(3)

X Version 11			 libX11	1.6.5			    XkbBell(3)

NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | RETURN VALUES | STRUCTURES | SEE ALSO

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