Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Functions for Editing Movies / Undo for Tracks

UseTrackEditState

Your application can use the UseTrackEditState function to return a track to its condition according to an edit state you created previously.

pascal OSErr UseTrackEditState (Track theTrack, 
                                 TrackEditState state); 

theTrack

Specifies the track for this operation. Your application obtains this track identifier from such Movie Toolbox functions as NewMovieTrack and GetMovieTrack (described on page 2-136 and page 2-188, respectively).

state

Specifies the edit state for this operation. Your application obtains this edit state identifier when you create the edit state by calling the NewTrackEditState function, which is described in the previous section.

DESCRIPTION

The UseTrackEditState function uses the information stored in the edit state to update the track's contents. This may change the contents of some of the track. Consequently, the time characteristics of the movie that contains the track, especially the duration, may change as a result of restoring the saved edit state. Your application creates an edit state by calling the NewTrackEditState function.

SPECIAL CONSIDERATIONS

You can use the UseTrackEditState function only with tracks that currently belong to a movie. A track may be detached from its movie as a result of edit processing--you cannot use this function with such a track.

ERROR CODES

invalidTrack	-2009	This track is corrupted or invalid
invalidEditState	-2023	This edit state is invalid
nonMatchingEditState	-2024	This edit state is not valid for this movie