[SOLVED] How to get the 'com.apple.icns' data of a file for filling the pasteboard?

How to get the 'com.apple.icns' data of a file for filling the pasteboard?

When one copies a file in Finder, the pasteboard contains a 'icns' type with the various icon descriptions of the copied item(s).

I need to accomplish the same effect in my code, i.e. generate the data I can put into the pasteboard for the com.apple.icns type.

How do I collect the data for this type? All I can find in AppKit are functions for getting an NSImage for a file, but nothing that gives me the icns resource.

Solution

Here's code, using deprecated functions (but there's no modern alternative, apparently):

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"

NSData* icnsOfFileAtPath (NSString *path)
{
    // based on https://github.com/sveinbjornt/IconFamily
    CFURLRef urlRef = CFURLCreateWithFileSystemPath (kCFAllocatorDefault, (CFStringRef)path, kCFURLPOSIXPathStyle, false);
    if (!urlRef) {
        return nil;
    }
    FSRef fsRef;
    bool ok = CFURLGetFSRef (urlRef, &fsRef);
    CFRelease (urlRef);
    if (!ok) {
        return nil;
    }
    IconRef iconRef;
    SInt16  label;
    OSStatus res = GetIconRefFromFileInfo (&fsRef, 0, NULL, kFSCatInfoNone, NULL, kIconServicesNormalUsageFlag, &iconRef, &label);
    if (res) {
        return nil;
    }
    IconFamilyHandle ifh;
    res = IconRefToIconFamily (iconRef, kSelectorAllAvailableData, &ifh);
    ReleaseIconRef (iconRef);
    NSData *icns = [NSData dataWithBytes:*ifh length:GetHandleSize((Handle)ifh)];
    DisposeHandle ((Handle)ifh);
    return icns;
}

#pragma clang diagnostic pop