The Preview Resource Item Structure(IM: QC)

Inside Macintosh: QuickTime Components /

Chapter 12 - Preview Components / Preview Components Reference

The Preview Resource Item Structure
The preview resource item structure is an array that allows you to store an unlimited number of additional pieces of file information. Each piece of data contains a reference to its information using the structure defined by the pnotResItem data type, which is shown in Listing 12-4.
Listing 12-4 The preview resource item structure
typedef struct pnotResItem {
   unsigned long  modDate; /* last modification date of item */
   OSType         useType; /* what type of data */
   OSType         resType; /* resource type containing item */
   short          resID;   /* resource ID containing this item */
   short          rgnCode; /* region code */
   long           reserved;/* set to 0 */
} pnotResItem; *pnotResItemPtr;
Field descriptions

modDate
Contains the modification time (in standard Macintosh seconds since midnight, January 1, 1904) of this item. This parameter allows you to find out if the item is out of date with the rest of the items in the array.
useType
Indicates the meaning of the data pointed to by this item. Two values are currently defined for this field.
KeyW
Indicates that this item points to a list of keywords, typically stored in an'STR#' resource.
Desc
Indicates that the item points to a brief text description of the file, typically stored in a 'TEXT' resource.

Developers are encouraged to expand the list of types to include additional relevant kinds of information.
resType
Contains the type of a resource used as a preview cache for the file associated with the given item. The type of the resource determines which preview component should be used to display the preview.
resID
Contains the identification number of a resource used as a preview cache for the specified file.
rgnCode
Contains the region code for this item.
reserved
Reserved for use by Apple. Set this field to 0.