UIColor-LKNSDictionaryCoding.swift

extension UIColor : LKNSDictionaryCoding {
    
    static func lk_dictEncode(object: AnyObject?)->NSMutableDictionary {
        let color = object as? UIColor
        var red: CGFloat = 0, 
          green: CGFloat = 0, 
           blue: CGFloat = 0, 
          alpha: CGFloat = 0
        if color?.getRed(&red, 
                        green: &green, 
                         blue: &blue, 
                        alpha: &alpha) == false {
            
            _ = color?.getWhite(&red, alpha:&alpha)
            green = red
            blue = red
        }
        let result = NSMutableDictionary(sharedKeySet: 
                                         NSMutableDictionary.sharedKeySet(forKeys:  [ 
                                             NSString("r"), 
                                             NSString("g"), 
                                             NSString("b"), 
                                             NSString("a")
                                         ]))
        result["r"] = red
        result["g"] = green
        result["b"] = blue
        result["a"] = alpha
        return result
    }
    
    static func lk_dictDecode(dictionaryRepresentation dictionary: NSDictionary?)->Self {
        var red : CGFloat = 0, green : CGFloat = 0, blue : CGFloat = 0, alpha: CGFloat = 0
        if let redValue = dictionary?["r"] as? CGFloat {
            red = redValue
        }
        if let greenValue = dictionary?["g"] as? CGFloat {
            green = greenValue
        }
        if let blueValue = dictionary?["b"] as? CGFloat {
            blue = blueValue
        }
        if let alphaValue = dictionary?["a"] as? CGFloat {
            alpha = alphaValue
        }
        return Self(red: red, green: green, blue: blue, alpha: alpha)
    }
}