NSColor+CGColor.m

//
//  NSColor+CGColor.m
//
//  http://stackoverflow.com/questions/11950173/conditional-categories-in-mountain-lion
//

#import <objc/runtime.h>

static CGColorRef _NSColor_CGColor_(Class self, SEL cmd) {
  const NSInteger numberOfComponents = [(id)self numberOfComponents];
  CGFloat components[numberOfComponents];
  CGColorSpaceRef colorSpace = [[(id)self colorSpace] CGColorSpace];
  
  [(id)self getComponents:(CGFloat *)&components];
	
  return (CGColorRef)[(id)CGColorCreate(colorSpace, components) autorelease];
}

static NSColor* _NSColor_colorWithCGColor_(Class self, SEL cmd, CGColorRef CGColor) {
  if (CGColor == NULL) return nil;
  return [NSColor colorWithCIColor:[CIColor colorWithCGColor:CGColor]];
}

__attribute__((constructor))
static void initialize_NSColor_CGColorAdditions() {
  if (![[NSColor class] respondsToSelector:@selector(colorWithCGColor:)]) {
    class_addMethod(objc_getMetaClass("NSColor"), @selector(colorWithCGColor:), (IMP)_NSColor_colorWithCGColor_, "@@:@");
  }
  if (![[NSColor class] instancesRespondToSelector:@selector(CGColor)]) {
    class_addMethod(objc_getClass("NSColor"), @selector(CGColor), (IMP)_NSColor_CGColor_, "@@:");
  }
}