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X11R7.4 - man page for xkbbell (x11r4 section 3)

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 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 dif-
       ferent 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 - Xkb-
       ForceDeviceBell 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  repeat-
       ing,  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  gener-
       ate 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 receiv-
       ing 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 pre-
       defined 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 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  lis-
       ten  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 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 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, XkbBell calls XBell with
       the specified display and percent, and returns False. Otherwise, XkbBell calls  XkbDevice-
       Bell  with  the	specified  display,  window, percent, and name, a device_spec of XkbUseC-
       oreKbd, 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 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 parame-
       ters to XkbSelectEvents.

       The XkbBellNotify event has no event details. It is either selected or it  is  not.   How-
       ever,  you can call XkbSelectEventDetails using XkbBellNotify as the event_type and speci-
       fying 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),	XkbForce-
       Bell(3), XkbForceDeviceBell(3), XkbUseCoreKbd(3)

X Version 11				   libX11 1.2.1 			       XkbBell(3)


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