ClockStartStopChanged(IM: QC)

Inside Macintosh: QuickTime Components /

Chapter 11 - Clock Components / Clock Components Reference

Clock Component Functions / Managing the Time

ClockStartStopChanged
The Movie Toolbox calls your component's ClockStartStopChanged function whenever the start or stop time of the callback's time base changes. The Movie
Toolbox calls this function only if the qtcbNeedsStartStop flag is set to 1 in the callBackFlags field of the callback header structure in the QTCallBackHeader structure allocated by your clock component (see "Data Type" beginning on page 11-5 for more information about the callback header structure).
pascal ComponentResult ClockStartStopChanged 
                        (ComponentInstance aClock, QTCallBack cb,
                         Boolean startChanged, 
                         Boolean stopChanged);
aClock
Specifies the clock for the operation. Applications obtain this identifier from the Component Manager's OpenComponent function.
cb
Specifies the callback for the operation. The Movie Toolbox obtains this value from your component's ClockNewCallBack function (described on page 11-9).
startChanged
Indicates that the start time of the time base associated with the clock component instance has changed.
stopChanged
Indicates that the stop time of the time base associated with the clock component instance has changed.

DESCRIPTION
The Movie Toolbox calls this function once for each qualified callback function associated with the time base. Note that the Movie Toolbox calls this function only for callback events that are currently scheduled.