Pedro Vieira Pedro Vieira - 2 months ago 11
Objective-C Question

How to automatically choose between NSColor and UIColor for the correct build system? (Using a #define, or something)

I'm trying to make a

NSObject
subclass that will have a lot of methods that return colors, so I wanna return
UIColor
if I'm building for iOS or
NSColor
if I'm building for OS X.

This is kind of a pseudo-code of what the expected behaviour should be:


#define COLOR #if TARGET_OS_IPHONE UIColor #elif TARGET_OS_MAC NSColor #endif

+ (COLOR *)makeMeColorful;


Is it possible to do something like this instead of making 2 methods for each of my object's method (one for iOS and another for OS X)?

Answer

This is absolutely doable. SKColor from SpriteKit for example, is defined like:

#if TARGET_OS_IPHONE
#define SKColor UIColor
#else
#define SKColor NSColor
#endif

And then utilized like this:

SKColor *color = [SKColor colorWithHue:0.5 saturation:1.0 brightness:1.0 alpha:1.0];

This simply takes advantage of the fact that UIColor and NSColor share some of their class methods.