Get the current active view controller on iOS screen

UIViewController+Utils.m

//
//  UIViewController+Utils.m
//  Novel
//
//  Created by Axel Kee on 07/12/2016.
//  Copyright © 2016 Javed. All rights reserved.
//

#import "UIViewController+Utils.h"

@interface UIViewController (Utils)

@end

@implementation UIViewController (Utils)

/*
 
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

*/

+(UIViewController*) findBestViewController:(UIViewController*)vc {
    
    if (vc.presentedViewController) {
        
        // Return presented view controller
        return [UIViewController findBestViewController:vc.presentedViewController];
        
    } else if ([vc isKindOfClass:[UISplitViewController class]]) {
        
        // Return right hand side
        UISplitViewController* svc = (UISplitViewController*) vc;
        if (svc.viewControllers.count > 0)
            return [UIViewController findBestViewController:svc.viewControllers.lastObject];
        else
            return vc;
        
    } else if ([vc isKindOfClass:[UINavigationController class]]) {
        
        // Return top view
        UINavigationController* svc = (UINavigationController*) vc;
        if (svc.viewControllers.count > 0)
            return [UIViewController findBestViewController:svc.topViewController];
        else
            return vc;
        
    } else if ([vc isKindOfClass:[UITabBarController class]]) {
        
        // Return visible view
        UITabBarController* svc = (UITabBarController*) vc;
        if (svc.viewControllers.count > 0)
            return [UIViewController findBestViewController:svc.selectedViewController];
        else
            return vc;
        
    } else {
        
        // Unknown view controller type, return last child view controller
        return vc;
        
    }
    
}

+(UIViewController*) currentViewController {
    
    // Find best view controller
    UIViewController* viewController = [UIApplication sharedApplication].keyWindow.rootViewController;
    return [UIViewController findBestViewController:viewController];
    
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

@end