Inside Macintosh: QuickTime Components /

Chapter 12 - Preview Components / Preview Components Reference

Functions / Creating Previews

PreviewMakePreviewReference

Instead of creating a handle to data that is to be added to the file, the PreviewMakePreviewReference function returns the type and identification number of a resource within the file to be used as the preview for the file.

pascal ComponentResult PreviewMakePreviewReference 
                        (pnotComponent p, OSType *previewType,
                         short *resID, const FSSpec *sourceFile);

p

Specifies your preview component. You obtain this identifier from
the Component Manager's OpenComponent function. See the chapter "Component Manager" in Inside Macintosh: More Macintosh Toolbox for details.

previewType

Contains a pointer to the type of preview component that should be used to display the preview.

resID

Contains a pointer to the identification number of a resource within the file to be used as the preview for the file.

sourceFile

Contains a pointer to a reference to the file for which the preview is created.

DESCRIPTION

If your preview component creates previews by reference, you must also implement the PreviewMakePreview function, described in the previous section. However, you should return an error from it. PreviewMakePreview is always called first. If it fails, PreviewMakePreviewReference is tried next.

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