Ultimate Catalyst Guide

How do I display a segmented control in the toolbar?

released Fri, 05 Jul 2019
Swift Version 5.1

A segmented control is a convenient replacement for the iOS tabbar, as it also groups related segments and only allows one of them to be active. It is basically just another type of NSToolbarItem. Thus, the process is very similar to how you set up a toolbar with elements before.

  1. Define a identifier
  2. Return the identifiers
  3. For the new identifier, return a segmented control
  4. Set up an action and target for the segmented control

As a bonus point, you can tell the toolbar that the segmented control should be the centered item in the toolbar (much like with a tabbar).

In this example, we also have a UITabBar that we're hiding, so that the switching of the visible view controller is still handled by the hidden tabbar.

Here is the necessary code:

class SceneDelegate: UIResponder, UIWindowSceneDelegate, NSToolbarDelegate {

     // We need a toolbar identifier

     static let SegmentedItemToolbarIdentifier = NSToolbarItem.Identifier(rawValue: \"PrimaryGroup\")

     func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {

         #if targetEnvironment(UIKitForMac)

         if let windowScene = scene as? UIWindowScene {

             if let titlebar = windowScene.titlebar {

                 let toolbar = NSToolbar(identifier: \"NerauToolbar\")

                 let rootViewController = window?.rootViewController as? UITabBarController

			// Hide the tabbasr

                 rootViewController?.tabBar.isHidden = true

                 toolbar.delegate = self

			// Our segmented control should be centered

                 toolbar.centeredItemIdentifier = SceneDelegate.SegmentedItemToolbarIdentifier

                 titlebar.titleVisibility = .hidden

                 titlebar.toolbar = toolbar





     func toolbar(_ toolbar: NSToolbar, itemForItemIdentifier itemIdentifier: NSToolbarItem.Identifier, willBeInsertedIntoToolbar flag: Bool) -> NSToolbarItem? {

             if (itemIdentifier == SceneDelegate.SegmentedItemToolbarIdentifier) {

		        // Create a new group item that hosts two buttons

                 let group = NSToolbarItemGroup(itemIdentifier: SceneDelegate.SegmentedItemToolbarIdentifier,

                                                titles: [\"Startpage\", \"Categories\"],

                                                selectionMode: .selectOne,

                                                labels: [\"section1\", \"section2\"],

                                                target: self,

                                                action: #selector(toolbarGroupSelectionChanged))

			// Set the initial selection

                 group.setSelected(true, at: 0)

                 return group


     	return nil


     @objc func toolbarGroupSelectionChanged(sender: NSToolbarItemGroup) {

         // This is called when the user changes the selection

		// Notice how we get the tab bar controller and change the selection there

         let rootViewController = window?.rootViewController as? UITabBarController

         rootViewController?.selectedIndex = sender.selectedIndex


     func toolbarDefaultItemIdentifiers(_ toolbar: NSToolbar) -> [NSToolbarItem.Identifier] {

         return [SceneDelegate.SegmentedItemToolbarIdentifier,



     func toolbarAllowedItemIdentifiers(_ toolbar: NSToolbar) -> [NSToolbarItem.Identifier] {

         return self.toolbarDefaultItemIdentifiers(toolbar)