ViewController with custom actions for showing/hiding the navigation bar and tab bar.

CustomNavBarDisplayViewController.swift

class CustomBarDisplayViewController: UIViewController {

    // MARK: - Enums

    enum NavBarDisplayAction {
        case show
        case hide
        case none
    }

    struct TabBarDisplayAction {
        enum ActionType {
            case show
            case hide
        }

        enum Trigger {
            case willAppear
            case didAppear
            case willDisappear
            case didDisappear
        }

        let type: ActionType
        let trigger: Trigger
        let isAnimated: Bool
    }

    // MARK: - Properties

    var navBarDisplayActionOnAppear = NavBarDisplayAction.none
    var navBarDisplayActionOnDisappear = NavBarDisplayAction.none

    private var tabBarDisplayActions = [TabBarDisplayAction]()
    
    // MARK: - Actions

    func addTabBarDisplayAction(_ type: TabBarDisplayAction.ActionType,
                                trigger: TabBarDisplayAction.Trigger,
                                isAnimated: Bool = false) {
        tabBarDisplayActions.append(TabBarDisplayAction(type: type, trigger: trigger, isAnimated: isAnimated))
    }

    // MARK: - Life-cycle

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        if let navigationController = navigationController {
            switch navBarDisplayActionOnAppear {
            case .show:
                guard navigationController.isNavigationBarHidden else { return }
                navigationController.setNavigationBarHidden(false, animated: animated)
            case .hide:
                guard !navigationController.isNavigationBarHidden else { return }
                navigationController.setNavigationBarHidden(true, animated: animated)
            case .none:
                break
            }
        }

        if let tabBarController = tabBarController,
            let action = tabBarDisplayActions.first(where: { $0.trigger == .willAppear }) {
            tabBarController.setTabBarHidden(action.type == .hide, animated: action.isAnimated)
        }
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        if let tabBarController = tabBarController,
            let action = tabBarDisplayActions.first(where: { $0.trigger == .didAppear }) {
            tabBarController.setTabBarHidden(action.type == .hide, animated: action.isAnimated)
        }
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)

        if let navigationController = navigationController {
            switch navBarDisplayActionOnDisappear {
            case .show:
                guard navigationController.isNavigationBarHidden else { return }
                navigationController.setNavigationBarHidden(false, animated: animated)
            case .hide:
                guard !navigationController.isNavigationBarHidden else { return }
                navigationController.setNavigationBarHidden(true, animated: animated)
            case .none:
                break
            }
        }

        if let tabBarController = tabBarController,
            let action = tabBarDisplayActions.first(where: { $0.trigger == .willDisappear }) {
            tabBarController.setTabBarHidden(action.type == .hide, animated: action.isAnimated)
        }
    }

    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)

        if let tabBarController = tabBarController,
            let action = tabBarDisplayActions.first(where: { $0.trigger == .didDisappear }) {
            tabBarController.setTabBarHidden(action.type == .hide, animated: action.isAnimated)
        }
    }
}