AtAddCallback(3X) — Series 700 Only

NAME

AtAddCallback − add callback procedure for audio toolkit

SYNOPSIS

#include <audio/Alib.h>

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       AuNerror              AuNdataNeeded
AuNstopped       AuNmonitor            AuNloopStarted
AuNpaused        AuNpreempted          AuNloopStopped
AuNresumed       AuNdataAvailable      AuNbrokenConnection
AuNcompleted

Note: AuNBrokenConnection indicates that the connection to the server has been severed. A callback for this event should arrange for the application to exit gracefully.

proc Name of the callback procedure.

client_data Data that the client wants to use; can 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.

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