Inside Macintosh: Sound /

Chapter 2 - Sound Manager / Sound Manager Reference

Sound Manager Routines / Playing From Disk

SndStopFilePlay

You can use SndStopFilePlay to stop an asynchronous play from disk.

FUNCTION SndStopFilePlay (chan: SndChannelPtr; 
                           quietNow: Boolean): OSErr;

chan

A pointer to a valid sound channel currently processing a play from disk initiated by a call to the SndStartFilePlay function.

quietNow

A Boolean value that indicates whether the play from disk should be stopped immediately (TRUE) or when it completes execution (FALSE).

DESCRIPTION

The SndStopFilePlay function either can stop an asynchronous play from disk immediately or can take control of the CPU until a play from disk finishes. The SndStopFilePlay function does not return until all asynchronous file I/O calls have completed and any internally allocated memory has been released. If async is FALSE, then SndStopFilePlay lets the sound complete normally and returns only after the sound has completed, all asynchronous file I/O calls have completed, and any internal allocated memory has been released.

For example, you might use the function to stop the playing of a sound file if the user selects an option that turns off sound output while the file is already playing. In that case, you would pass TRUE to quietNow. Alternatively, you might have started a sound playing asynchronously so that you could perform other tasks while the sound plays. But you might then finish those other tasks and want to convert the play from disk into a synchronous play. By passing FALSE to quietNow, you effectively achieve that.

SPECIAL CONSIDERATIONS

Because the SndStopFilePlay function might move memory, you should not call it at interrupt time.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the SndStopFilePlay function are

Trap macro	Selector
_SoundDispatch	$03080008

RESULT CODES

noErr	0	No error
badChannel	-205	Channel is corrupt or unusable