Plotting icons into NSImage

FROM : Daniel Dalquen
DATE : Mon Apr 30 18:55:52 2007

Hello everybody!

I am running into problems when plotting an IconRef into an NSImage. 
Here is the piece of code I am using:

         IconRef ref;
         err = GetIconRefFromFileInfo (&fsref, fname.length, fname.unicode,
               kIconServicesCatalogInfoMask, &catinfo, 
kIconServicesNormalUsageFlag, &ref, &label);
                  
         if (err == noErr)
         {
             CGRect myRect = CGRectMake(0,0,128,128);
             NSImage* image = [[NSImage alloc] initWithSize:NSMakeSize
(128,128)];
             [image lockFocus];
             PlotIconRefInContext((CGContextRef)[[NSGraphicsContext 
currentContext]
                   
graphicsPort],&myRect,kAlignNone,kTransformNone,NULL,kPlotIconRefNormalF
lags,ref);
             [image unlockFocus];
             NSData * imageData = [image TIFFRepresentation];
           
             [imageData writeToFile:@"/Users/daniel/Desktop/myicon.tif" 
atomically:YES];

When I open myicon.tif in Preview, the icon is on top of a black 
background. I thought it might be the alpha channel, but then Preview 
should be able to deal with transparency... What is it that goes wrong?

Cheers,
Daniel