Present View Controller Over current tabBarController with NavigationController

Question

When presenting or dismissing VC, I do not want to keep hiding and showing tabBar because it creates a poor user experience. Instead, I want present the next VC straight over the tab bar such that when I dismiss the nextVC by dragging slowly from left to right, I can see the tabBar hidden behind the view (As shown in image below)

Note, my app has two tabs with two VCs(VCA,VCB) associated to it. Both VC also have navigation bar embedded. VCA segues to VCA1 and VCB segues to VCB1. At the moment, inside VCA and VCB I am calling the following function to segue with some hiding and unhiding done when viewWillappear (Code below).

self.navigationController?.showViewController(vc, sender: self)

  // Inside ViewWillAppear Only reappear the tab bar if we successfully enter Discover VC (To prevent drag back half way causing tab bar to cause comment entry to be floating). This code check if we have successfully enters DiscoverVC
    if let tc = transitionCoordinator() {
        if tc.initiallyInteractive() == true {
            tc.notifyWhenInteractionEndsUsingBlock({(context: UIViewControllerTransitionCoordinatorContext) -> Void in
                if context.isCancelled() {
                    // do nothing!
                }
                else {
                    // not cancelled, do it
                    self.tabbarController.tabBar.hidden = false
                }
            })
        } else {
            // not interactive, do it
            self.tabbarController.tabBar.hidden = false
        }
    } else {
        // not interactive, do it
        self.tabbarController.tabBar.hidden = false
    }

----------Working solution from GOKUL-----------

Gokul's answer is close to spot on. I have played with his solution and came up with the following improvement to eliminate the need to have a redundant VC and also eliminate the initial VC being shown for a brief second before tabVC appears. But without Gokul, I would never ever come up with this!!

Additionally, Gokul's method would create a bug for me because even though I do have a initial "normal" VC as LoginVC before tabVC is shown. This loginVC is ONLY the rootVC if the user needs to login. So by setting the rootVC to tabVC in most cases, the navVC will never be registered.

The solution is to embed navigation controller and tabBar controller to one VC. But it ONLY works if the navVC is before the TabBarVC. I am not sure why but the only way that allowed me to have navVC-> tabVC-> VC1/VC2 is to embed VC1 with a navVC first than click on VC1 again to embed tabVC (It wouldn't allow me to insert one before tabVC and I also had to click the VC1 again after embedding the NavVC).

Answer 1

For your requirement we need to make some small changes in your given view hierarchy

• Let me explain step by step,

  1. To meet your requirement we have to add a UIViewController(let's say InitialVC) embedded with a UINavigationController and make it as initial viewcontroller.

  2. Then add a UITabbarController with 2 VC (VCA,VCB) // IMPORTANT: Without any navigationcontroller embedded.

  3. Add a segue between InitalVC and TabbarController with an unique identifier(ex: Initial)

  4. In viewWillAppear of InitalVC perform segue as below (InitialVC is unnecessary to our design we are using this just to bridge navigationController and tabbarController).

         self.performSegueWithIdentifier("Initial", sender: nil)
     

  5. In TabbarControllerclass hide your back button, this ensures that InitialVC is unreachable.

         override func viewDidLoad() {
            super.viewDidLoad()
            self.navigationItem.hidesBackButton = true
         }
     

  6. Now add a segue from a button between VCA and VCA1, thats it build and run you will see VCA1 presenting over VCA's tabbar.

• What we have changed?

  1. Instead of adding UINavigationController inside UITabbarController we have done vice versa. We can't directly add Tabbar inside navigation to do that we are using InitialVC between them.

Result: