Path: utzoo!attcan!uunet!lll-winken!ames!ucsd!rutgers!mailrus!caen.engin.umich.edu!mystone
From: mystone@caen.engin.umich.edu (Dean Yu)
Newsgroups: comp.sys.mac.programmer
Subject: Problem getting disk icons with PBControl
Message-ID: <42a89bde.bfbf@shank.engin.umich.edu>
Date: 16 Apr 89 03:30:00 GMT
Reply-To: mystone@caen.engin.umich.edu (Dean Yu)
Organization: Univ. of Michigan College of Engineering, Ann Arbor, MI
Lines: 57


  I'm trying to get drive icons via a call to PBControl with csCode
21.  This works fine for hard drive icons, but I get garbage for
floppies.  IM V says this has been extended to work with all drives,
so I assume I'm doing something wrong.
  The relevant code:

procedure GetDriveIcon(theVolume : infoPtr);

var pBlock : ParmBlkPtr
    iconErr : OSErr;

begin
   pBlock:=ParmBlkPtr(NewPtr(SizeOf(ParamBLockRec)));
   with pBlock^ do
      begin
         csCode:=21;
         ioCompletion:=nil;
         iovRefNum:=theVolume^.vInf.driveNum;     { Logical drive number }
         ioRefNum:=theVolume^.vInf.drvRefNum;     { Driver reference number }
      end;

   iconErr:=PBControl(pBlock, false);             { Synchronous control call }
   if iconErr = noErr then
      begin
         theVolume^.icon.baseAddr:=pointer(pBlock^.csParam[0]*65536+
                                           pBlock^.csParam[1]);
         theVolume^.icon.rowBytes:=4;
         SetRect(theVolume^.icon.bounds,0,0,32,64);
      end;
   DisposPtr(ptr(pBlock));
end;


  The code does the same thing with and without Facade.
  If it's just a case of PBControl not returning a pointer to the icon
for a floppy (which I doubt, since Facade works with floppies), how can
I tell when I'm trying to get an icon for a floppy?  csParam isn't NIL
for a bad icon, so it's not that simple.  And PBControl still returns
noErr.
  As a side note, what's the difference between sending csCode 21 and 22
besides the fact that 21 returns a string for the Get Info box?
  Thanks in advance!

______________________________________________________________________________
Dean Yu                            |  E-mail:    mystone@caen.engin.umich.edu
University of Michigan             |  Real-mail: Dean Yu
Computer Aided Engineering Network |             2413 Kelsey House
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"These are MY opinions." (My       |             Ann Arbor, MI 48109
 employer doesn't want them.       |==========================================
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 Duderstadt does...)               | 
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