CODEWITHSUNDEEP
iosswiftuitabbarcontrolleruitabbaruitabbaritem
Matt Bart
Matt Bart

Reputation: 939

How to tell if TabBarItem is already Selected

So I have a viewController with a tableView that is being presented from a tabBarController. If the user taps the tabBarItem for the view that is already being shown, I want the tableView to scroll to the top. I have set the UITabBarControllerDelegate to be the viewController and then added the following method:

func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
    if tabBarController.selectedIndex == 0 {
        //scroll to the top!
    }
}

The problem is that the tableView scrolls to the top regardless of the current view. So I tried to add a second condition that makes sure that the currently displayed view is the correct one but nothing seemed to be correct.

TL;DR

How can I tell that the user is tapping on the tabBarItem that is already selected?

Upvotes: 2

Views: 349

Answers (1)

ukim
ukim

Reputation: 2465

You can use self.view.window != nil to determine if the view of the vc is already displayed. Use shouldSelect delegate method, which is called before the selection.

func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {



    if viewController === self && self.isViewLoaded {

    // Please use viewController === self.navigationController
    // if self is a child of a UINavigationController. We should
    // compare the viewController with a direct child of the 
    // UITabController

        if self.view.window != nil {
            print("scroll to top")
        } else {
            print("Don't scroll to top")
        }
    }
    return true
}

Upvotes: 3

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