Tap tab bar to scroll to top of UITableViewController

Question

Tapping the tab bar icon for the current navigation controller already returns the user to the root view, but if they are scrolled way down, if they tap it again I want it t

Answer 1

Swift 5: no need for stored properties in the UITabBarController.

In MyTabBarController.swift, implement tabBarController(_:shouldSelect) to detect when the user re-selects the tab bar item:

protocol TabBarReselectHandling {
    func handleReselect()
}

class MyTabBarController: UITabBarController, UITabBarControllerDelegate {
    override func viewDidLoad() {
        super.viewDidLoad()
        delegate = self
    }

    func tabBarController(
        _ tabBarController: UITabBarController,
        shouldSelect viewController: UIViewController
    ) -> Bool {
        if tabBarController.selectedViewController === viewController,
            let handler = viewController as? TabBarReselectHandling {
            // NOTE: viewController in line above might be a UINavigationController,
            // in which case you need to access its contents
            handler.handleReselect()
        }

        return true
    }
}

In MyTableViewController.swift, handle the re-selection by scrolling the table view to the top:

class MyTableViewController: UITableViewController, TabBarReselectHandling {
    func handleReselect() {
        tableView?.setContentOffset(.zero, animated: true)
    }
}

Now you can easily extend this to other tabs by just implementing TabBarReselectHandling.