Technical Q&As

FL 04 - Standard File Package (1-May-95)

Q Where does the Standard File Package get its icons?

A The Standard File Package uses PBDTGetIcon to get icon data from the desktop database. You can observe this by entering the following command in MacsBug to place a break point on the call:

atb _HFSDispatch d0=23

The sample code calls PBDTGetIcon.

static OSErr GetIconHandle(Handle h)
{
   OSErr err;
   short DTrefNum;
   Rect srcRect;
   Str255 volName = "\pMacintosh HD";
   short i;
   IcnInfo ic;

   pb.ioCompletion = NULL;
   pb.ioVRefNum = 0;
   pb.ioNamePtr = volName;
   err= PBDTGetPath(&pb);

   if( err ) return err;

   DTrefNum = pb.ioDTRefNum;

   HLock(h);
   b.ioCompletion = NULL;
   b.ioDTRefNum = DTrefNum;
   b.ioTagInfo = 0L;
   b.ioDTBuffer = *h;
   b.ioDTReqCount = kLarge8BitIconSize; /* ask for the largest */
   b.ioFileCreator = 'ttxt';       /* hard wiring these values */
   b.ioFileType = 'APPL';
   err = PBDTGetIcon(&b,0);

   HUnlock(h);
   return(err);
}

Disclaimer: This code has not been fully tested, so it is provided on an as- is basis only. You are responsible for all testing, if you decide to include it in any of your own code.

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