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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  *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, 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;	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
       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 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, XkbForceDeviceBell imme-
       diately	returns  False. Otherwise, XkbForceDeviceBell 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  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(3),  XkbBell(3),  XkbBellNotify(3),  XkbChangeEnabledControls(3),	XkbDeviceBell(3),
       XkbForceBell(3), XkbForceDeviceBell(3), XkbSelectEventDetails(3), XkbSelectEvents(3)

X Version 11				   libX11 1.6.0 		    XkbForceDeviceBell(3)
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