Find the active responder by going through the responder chain

UIResponder+CMAdditions.h

//
//  UIResponder+CMAdditions.h
//  ProtoSketch
//
//  Created by Robert Dimitrov on 5/23/16.
//  Copyright © 2016 Codemotion Ltd. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIResponder (CMAdditions)

- (instancetype)cm_activeResponder;

@end

UIResponder+CMAdditions.m

//
//  UIResponder+CMAdditions.m
//  ProtoSketch
//
//  Created by Robert Dimitrov on 5/23/16.
//  Copyright © 2016 Codemotion Ltd. All rights reserved.
//

#import "UIResponder+CMAdditions.h"

@implementation UIResponder (CMAdditions)

- (instancetype)cm_activeResponder {
    UIResponder *activeResponder = nil;
    
    if (self.isFirstResponder) {
        activeResponder = self;
    } else if ([self isKindOfClass:[UIViewController class]]) {
        if ([(UIViewController *)self parentViewController]) {
            activeResponder = [[(UIViewController *)self parentViewController] cm_activeResponder];
        }
        
        if (!activeResponder) {
            activeResponder = [[(UIViewController *)self view] cm_activeResponder];
        }
    } else if ([self isKindOfClass:[UIView class]]) {
        for (UIView *subview in [(UIView *)self subviews]) {
            activeResponder = [subview cm_activeResponder];
            if (activeResponder) break;
        }
    }
    
    return activeResponder;
}

@end