NAME

AtAddCallback − add callback procedure for audio toolkit

SYNOPSIS

void
AtAddCallback (

Widget widget,

char ∗  event,

XtCallbackProc proc,

XtPointer client_data);

DESCRIPTION

AtAddCallback() adds a callback for the audio toolkit to use.  When the toolkit receives an event, it checks to see if a callback procedure has been entered for the event; if a procedure has been entered, the toolkit calls it. 

Note that a callback for AuNdataAvailable must be added for a record stream widget operation to work, and a callback for AuNdataNeeded must be added for a play stream widget operation to work. 

widget Name of the widget

event Event type of the callback.  Acceptable values are:

AuNstarted AuNstopped

AuNpaused AuNresumed

AuNcompleted AuNerror

AuNmonitor AuNpreempted

AuNdataAvailable AuNdataNeeded

AuNloopStarted AuNloopStopped

proc Name of the callback procedure. 

client_data Data that the client wants to use; may be NULL. 

ERRORS

AtAddCallback() does not return an error status. 

DEPENDENCIES

This function belongs to the Audio Application Program Interface toolkit.  The audio server must run on a system equipped with audio hardware.  To find out whether or not your system has audio hardware, refer to the hardware manual provided with your system. 

AUTHOR

AtAddCallback() was developed by HP. 

SEE ALSO

AtInitialize(), AuCreatePlay(), AuCreateRecord(), AuInvokePlay(), AuInvokeRecord().

Using the Audio Application Program Interface.

Hewlett-Packard Company  —  HP-UX Release 8.07: November 1991