Question

I have this macro in my header file:

#define UIColorFromRGB(rgbValue) \
        [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 \
                        green:((float)((rgbValue & 0xFF00) >> 8))/255.0 \
                         blue:((float)(rgbValue & 0xFF))/255.0 \
                        alpha:1.0]

And I am using this as something like this in my .m file:

cell.textColor = UIColorFromRGB(0x663333);

So I want to ask everyone is this better or should I use this approach:

cell.textColor = [UIColor colorWithRed:66/255.0
                                 green:33/255.0
                                  blue:33/255.0
                                 alpha:1.0];

Which one is the better approach?

Answer 1

A middle ground might be your best option. You could define either a regular C or objective-C function to do what your macro is doing now:

// As a C function:
UIColor* UIColorFromRGB(NSInteger rgbValue) {
    return [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0
                           green:((float)((rgbValue & 0xFF00) >> 8))/255.0
                            blue:((float)(rgbValue & 0xFF))/255.0
                           alpha:1.0];
}

// As an Objective-C function:
- (UIColor *)UIColorFromRGB:(NSInteger)rgbValue {
return [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0
                       green:((float)((rgbValue & 0xFF00) >> 8))/255.0
                        blue:((float)(rgbValue & 0xFF))/255.0
                       alpha:1.0];
}

If you decide to stick with the macro, though, you should put parentheses around rgbValue wherever it appears. If I decide to call your macro with:

UIColorFromRGB(0xFF0000 + 0x00CC00 + 0x000099);

you may run into trouble.

The last bit of code is certainly the most readable, but probably the least portable – you can’t call it simply from anywhere in your program.

All in all, I’d suggest refactoring your macro into a function and leaving it at that.