Question

My application uses the following code:

#if MAC_OS_X_VERSION_10_5 < MAC_OS_X_VERSION_MAX_ALLOWED
    NSArray *globalPreferencePanes = 
        NSSearchPathForDirectoriesInDomains(NSPreferencePanesDirectory,
            NSAllDomainsMask, YES);        
#else
    NSArray *globalPreferencePanes = 
        [NSArray arrayWithObjects:@"/Library/PreferencePanes", 
            [@"~/Library/PreferencePanes" stringByExpandingTildeInPath], nil];
#endif
return globalPreferencePanes;

The project under which I’m compiling this is aimed at the 10.5 Mac OSX SDK, where NSPreferencePanesDirectory does not exist (it only exists in 10.6+). Because of this, I have the #if and #else in order to check what version of Mac OSX we’re running under, so I know whether I should use the NSPreferencePanesDirectory or just manually give the location of the preference pane directories.

What should I change in order to stop getting this “use of undeclared identifier” error?

Thanks.

Answer 1

#if is evaluated at compile time, not run time. What you probably want to do is use the current SDK (10.7), and do something like this:

NSArray *globalPreferencePanes;

if (NSAppKitVersionNumber >= NSAppKitVersionNumber10_6)
    globalPreferencePanes = NSSearchPathForDirectoriesInDomains(NSPreferencePanesDirectory, NSAllDomainsMask, YES);        
else
    globalPreferencePanes = [NSArray arrayWithObjects:@"/Library/PreferencePanes", [@"~/Library/PreferencePanes" stringByExpandingTildeInPath], nil];

    return globalPreferencePanes;

Making sure to set your target OS version to 10.5 so the symbol is weak linked. Otherwise, you could drop down and use CoreServices’ FSFindFolder():

NSMutableArray *globalPreferencePanes = [NSMutableArray array];
FSRef foundRef;

OSErr err = FSFindFolder(kLocalDomain, kPreferencePanesFolderType, false, &foundRef);

if (err != noErr) {
    CFURLRef url = CFURLCreateFromFSRef(NULL, &fsRef);
    CFStringRef path = CFURLCopyPath(url);
    [globalPreferencePanes addObject:(id)path];
    CFRelease(path);
    CFRelease(url);
}

OSErr err = FSFindFolder(kUserDomain, kPreferencePanesFolderType, false, &foundRef);

if (err != noErr) {
    CFURLRef url = CFURLCreateFromFSRef(NULL, &fsRef);
    CFStringRef path = CFURLCopyPath(url);
    [globalPreferencePanes addObject:(id)path];
    CFRelease(path);
    CFRelease(url);
}

return globalPreferencePanes;

(Not tested)