Simple example of using Builder pattern in Objective-C

ThemeBuilder

//header file

typedef void (^ColorThemeBuilder)(id<ColorThemeProtocol> colorTheme);

@interface ThemeBuilder : NSObject <ColorThemeProtocol>
- (instancetype)initColorTheme:(ColorThemeBuilder)builder;
@end

//Implementation

@implementation ThemeBuilder

@synthesize backgroundColor;
@synthesize textColor;
@synthesize hudTextColor;
@synthesize hudBackgroundColor;
@synthesize tintColor;
@synthesize title;
@synthesize details;

- (instancetype)initColorTheme:(ColorThemeBuilder)builder {
    self = [super init];
    if (self) {
        builder(self);
    }
    return self;
}
@end