How to get visible viewController from app delegate when using storyboard? - ios

Question

I have some viewControllers, and I don't use NavigationController.
How can I get visible view controller in app delegate methods (e.g. applicationWillResignActive)?
I know how to do it from NSNotification, but I think it's the wrong way.

Answer 1

This should do it for you:
- (void)applicationWillResignActive:(UIApplication *)application
{
UIViewController *vc = [self visibleViewController:[UIApplication sharedApplication].keyWindow.rootViewController];
}
- (UIViewController *)visibleViewController:(UIViewController *)rootViewController
{
if (rootViewController.presentedViewController == nil)
{
return rootViewController;
}
if ([rootViewController.presentedViewController isKindOfClass:[UINavigationController class]])
{
UINavigationController *navigationController = (UINavigationController *)rootViewController.presentedViewController;
UIViewController *lastViewController = [[navigationController viewControllers] lastObject];
return [self visibleViewController:lastViewController];
}
if ([rootViewController.presentedViewController isKindOfClass:[UITabBarController class]])
{
UITabBarController *tabBarController = (UITabBarController *)rootViewController.presentedViewController;
UIViewController *selectedViewController = tabBarController.selectedViewController;
return [self visibleViewController:selectedViewController];
}
UIViewController *presentedViewController = (UIViewController *)rootViewController.presentedViewController;
return [self visibleViewController:presentedViewController];
}

Answer 2

#aviatorken89's answer worked well for me. I had to translate it to Swift -
for anybody starting out with Swift:
Updated for Swift 3:
func getVisibleViewController(_ rootViewController: UIViewController?) -> UIViewController? {
var rootVC = rootViewController
if rootVC == nil {
rootVC = UIApplication.shared.keyWindow?.rootViewController
}
if rootVC?.presentedViewController == nil {
return rootVC
}
if let presented = rootVC?.presentedViewController {
if presented.isKind(of: UINavigationController.self) {
let navigationController = presented as! UINavigationController
return navigationController.viewControllers.last!
}
if presented.isKind(of: UITabBarController.self) {
let tabBarController = presented as! UITabBarController
return tabBarController.selectedViewController!
}
return getVisibleViewController(presented)
}
return nil
}
Old answer:
func applicationWillResignActive(application: UIApplication) {
let currentViewController = getVisibleViewController(nil)
}
func getVisibleViewController(var rootViewController: UIViewController?) -> UIViewController? {
if rootViewController == nil {
rootViewController = UIApplication.sharedApplication().keyWindow?.rootViewController
}
if rootViewController?.presentedViewController == nil {
return rootViewController
}
if let presented = rootViewController?.presentedViewController {
if presented.isKindOfClass(UINavigationController) {
let navigationController = presented as! UINavigationController
return navigationController.viewControllers.last!
}
if presented.isKindOfClass(UITabBarController) {
let tabBarController = presented as! UITabBarController
return tabBarController.selectedViewController!
}
return getVisibleViewController(presented)
}
return nil
}

Answer 3

We implemented it as an UIApplication extension:
import UIKit
extension UIApplication {
var visibleViewController: UIViewController? {
guard let rootViewController = keyWindow?.rootViewController else {
return nil
}
return getVisibleViewController(rootViewController)
}
private func getVisibleViewController(_ rootViewController: UIViewController) -> UIViewController? {
if let presentedViewController = rootViewController.presentedViewController {
return getVisibleViewController(presentedViewController)
}
if let navigationController = rootViewController as? UINavigationController {
return navigationController.visibleViewController
}
if let tabBarController = rootViewController as? UITabBarController {
return tabBarController.selectedViewController
}
return rootViewController
}
}

Answer 4

Here is an answer in Swift 4 that is very similar to the accepted answer but has a few improvements:
Iterative instead of recursive.
Goes all the way does the navigation stack.
More "swifty" syntax.
Static variable that can be put anywhere (not just in AppDelegate).
Won't crash in odd cases, i.e. when a tab bar controller has no selected view controller.
static var visibleViewController: UIViewController? {
var currentVc = UIApplication.shared.keyWindow?.rootViewController
while let presentedVc = currentVc?.presentedViewController {
if let navVc = (presentedVc as? UINavigationController)?.viewControllers.last {
currentVc = navVc
} else if let tabVc = (presentedVc as? UITabBarController)?.selectedViewController {
currentVc = tabVc
} else {
currentVc = presentedVc
}
}
return currentVc
}

Answer 5

The top recommendations here will work ok in many scenarios to get the 'best guess' solution but with a few minor adjustments, we can get a more complete solution that doesn't rely on your app's view hierarchy implementation.
1) Cocoa Touch's view hierarchy allows for multiple children to be present and visible at one time so we need to instead ask for the current visible view controllers (plural) and handle the results accordingly
2) UINavigationControllers and UITabBarControllers are commonly used in iOS applications, but they are not the only kind of container view controllers. UIKit also supplies the UIPageViewController, UISplitViewController, and allows you to write your own custom container view controllers.
3) We probably want to ignore popover modals and specific types of view controllers such UIAlertControllers or a custom embedded child-viewcontroller.
private func visibleViewControllers() -> [UIViewController] {
guard let root = window?.rootViewController else { return [] }
return visibleLeaves(from: root, excluding: [UIAlertController.self])
}
private func visibleLeaves(from parent: UIViewController, excluding excludedTypes: [UIViewController.Type] = []) -> [UIViewController] {
let isExcluded: (UIViewController) -> Bool = { vc in
excludedTypes.contains(where: { vc.isKind(of: $0) }) || vc.modalPresentationStyle == .popover
}
if let presented = parent.presentedViewController, !isExcluded(presented) {
return self.visibleLeaves(from: presented, excluding: excludedTypes)
}
let visibleChildren = parent.childViewControllers.filter {
$0.isViewLoaded && $0.view.window != nil
}
let visibleLeaves = visibleChildren.flatMap {
return self.visibleLeaves(from: $0, excluding: excludedTypes)
}
if visibleLeaves.count > 0 {
return visibleLeaves
} else if !isExcluded(parent) {
return [parent]
} else {
return []
}
}

Answer 6

This is an improved version of #ProgrammierTier's answer. If you have a navbar nested in a tabbar, you will get back UINavigationController using #ProgrammierTier's answer. Also, there is less force unwrapping. This should address the issue #Harendra-Tiwari is facing.
Swift 4.2:
func getVisibleViewController(_ rootViewController: UIViewController?) -> UIViewController? {
var rootVC = rootViewController
if rootVC == nil {
rootVC = UIApplication.shared.keyWindow?.rootViewController
}
var presented = rootVC?.presentedViewController
if rootVC?.presentedViewController == nil {
if let isTab = rootVC?.isKind(of: UITabBarController.self), let isNav = rootVC?.isKind(of: UINavigationController.self) {
if !isTab && !isNav {
return rootVC
}
presented = rootVC
} else {
return rootVC
}
}
if let presented = presented {
if presented.isKind(of: UINavigationController.self) {
if let navigationController = presented as? UINavigationController {
return navigationController.viewControllers.last!
}
}
if presented.isKind(of: UITabBarController.self) {
if let tabBarController = presented as? UITabBarController {
if let navigationController = tabBarController.selectedViewController! as? UINavigationController {
return navigationController.viewControllers.last!
} else {
return tabBarController.selectedViewController!
}
}
}
return getVisibleViewController(presented)
}
return nil
}

Answer 7

Here is a recursive, protocol-oriented approach in Swift. Can be extended to custom types but any kind of UIViewController subclass should work with the code below.
public protocol ViewControllerContainer {
var topMostViewController: UIViewController? { get }
}
extension UIViewController: ViewControllerContainer {
public var topMostViewController: UIViewController? {
if let presentedView = presentedViewController {
return recurseViewController(presentedView)
}
return childViewControllers.last.map(recurseViewController)
}
}
extension UITabBarController {
public override var topMostViewController: UIViewController? {
return selectedViewController.map(recurseViewController)
}
}
extension UINavigationController {
public override var topMostViewController: UIViewController? {
return viewControllers.last.map(recurseViewController)
}
}
extension UIWindow: ViewControllerContainer {
public var topMostViewController: UIViewController? {
return rootViewController.map(recurseViewController)
}
}
func recurseViewController(viewController: UIViewController) -> UIViewController {
return viewController.topMostViewController.map(recurseViewController) ?? viewController
}

Answer 8

If you are using IQKeyboardManager they have an extension in there
(UIViewController*)currentViewController;
so you can do
application.keyWindow?.currentViewController? // <- there you go
so add this to your pod file
pod 'IQKeyboardManager'
then pod update and you are away!
hope this helps

Answer 9

If your app's root view controller is a UINavigationController than you can use this:
UIViewController *currentControllerName = ((UINavigationController*)appDelegate.window.rootViewController).visibleViewController;
and if you are using UITabBarController than you can use this:
UIViewController *currentControllerName = ((UITabBarController*)appDelegate.window.rootViewController).selectedViewController;

Answer 10

Here's a Swift 2.3 implementation of #ProgrammierTier's answer as an extension to a UIViewController
extension UIViewController {
var visibleViewController: UIViewController? {
if presentedViewController == nil {
return self
}
if let presented = presentedViewController {
if presented.isKindOfClass(UINavigationController) {
let navigationController = presented as! UINavigationController
return navigationController.viewControllers.last
}
if presented.isKindOfClass(UITabBarController) {
let tabBarController = presented as! UITabBarController
return tabBarController.selectedViewController
}
return presented.visibleViewController
}
return nil
}
}
To get it from applicationWillResignActive
func applicationWillResignActive(application: UIApplication) {
let visibleVC = application.keyWindow?.rootViewController?.visibleViewController
}

Answer 11

Here's just a quick fix inspired from #krcjr89's answer. The accepted answer doesn't go all the way down the navigation. For instance, if you have a navigation controller embedded in tab bar controller, you won't get to the visible view controller but the navigation controller.
I made it an extension of UIApplication like #Christian, as this makes the most sense.
extension UIApplication {
var visibleViewController: UIViewController? {
return getVisibleViewController(nil)
}
private func getVisibleViewController(_ rootViewController: UIViewController?) -> UIViewController? {
let rootVC = rootViewController ?? UIApplication.shared.keyWindow?.rootViewController
if rootVC!.isKind(of: UINavigationController.self) {
let navigationController = rootVC as! UINavigationController
return getVisibleViewController(navigationController.viewControllers.last!)
}
if rootVC!.isKind(of: UITabBarController.self) {
let tabBarController = rootVC as! UITabBarController
return getVisibleViewController(tabBarController.selectedViewController!)
}
if let presentedVC = rootVC?.presentedViewController {
return getVisibleViewController(presentedVC)
}
return rootVC
}
}

Answer 12

A modified version of a previous answer using UIViewController category in ObjC:
UIViewController+VisibleViewController.h
#import <UIKit/UIKit.h>
#interface UIViewController (VisibleViewController)
- (UIViewController *)visibleViewController;
#end
UIViewController+VisibleViewController.m
#import "UIViewController+VisibleViewController.h"
#implementation UIViewController (VisibleViewController)
- (UIViewController *)visibleViewController {
if (self.presentedViewController == nil) {
return self;
}
if ([self.presentedViewController isKindOfClass:[UINavigationController class]]) {
UINavigationController *navigationController = (UINavigationController *)self.presentedViewController;
UIViewController *lastViewController = [[navigationController viewControllers] lastObject];
return [lastViewController visibleViewController];
}
if ([self.presentedViewController isKindOfClass:[UITabBarController class]]) {
UITabBarController *tabBarController = (UITabBarController *)self.presentedViewController;
UIViewController *selectedViewController = tabBarController.selectedViewController;
return [selectedViewController visibleViewController];
}
UIViewController *presentedViewController = (UIViewController *)self.presentedViewController;
return [presentedViewController visibleViewController];
}
#end
AppDelegate.m
#import "UIViewController+VisibleViewController.h"
- (UIViewController *) applicationVisibleViewController {
return [self.window.rootViewController visibleViewController];
}

Answer 13

In my case i have Tabbar controller and then Navigation controller for each Tab hope it helps someone
UIViewController *loginViewController = self.window.rootViewController;
UITabBarController *controller = loginViewController.tabBarController;
UIViewController *currentController = controller.selectedViewController.childViewControllers.lastObject;

Answer 14

modified from troop231
+ (UIViewController *)visibleViewController:(UIViewController *)rootViewController
{
if ([rootViewController isKindOfClass:[UINavigationController class]])
{
UINavigationController *navigationController = (UINavigationController *)rootViewController;
UIViewController *lastViewController = [[navigationController viewControllers] lastObject];
return [self visibleViewController:lastViewController];
}
if ([rootViewController isKindOfClass:[UITabBarController class]])
{
UITabBarController *tabBarController = (UITabBarController *)rootViewController;
UIViewController *selectedViewController = tabBarController.selectedViewController;
return [self visibleViewController:selectedViewController];
}
if (rootViewController.presentedViewController != nil)
{
UIViewController *presentedViewController = (UIViewController *)rootViewController.presentedViewController;
return [self visibleViewController:presentedViewController];
}
return rootViewController;
}