How to add Tabs in a non-document-based app under macOS?

Question

I like to build an app in Swift 3 with Xcode 8 and it should enable the Apple tab bar. It is not document-based. I learned here, that the tabs can be enabled if I override t

Answer 1

Ok here are new files,

Appdelegate

import Cocoa

@NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {

func applicationDidFinishLaunching(_ aNotification: Notification) {
    // Insert code here to initialize your application
}

func applicationWillTerminate(_ aNotification: Notification) {
    // Insert code here to tear down your application
}

func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
    return true
}

@IBAction func newWindowForTab(_ sender: Any?){
} // without this the + button doesn't show from start

}

ViewController

import Cocoa

class ViewController: NSViewController {

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
}

override var representedObject: Any? {
    didSet {
    // Update the view, if already loaded.
    }
}
}

and WindowController

import Cocoa

class WindowController: NSWindowController {

var subview: WindowController?

override func windowDidLoad() {
    super.windowDidLoad()
    // Implement this method to handle any initialization after your window controller's window has been loaded from its nib file.
}

@IBAction override func newWindowForTab(_ sender: Any?) {

    let story = self.storyboard
    let windowVC: WindowController = story?.instantiateInitialController() as! WindowController

    self.window?.addTabbedWindow(windowVC.window!, ordered: .above)
    self.subview = windowVC

    windowVC.window?.orderFront(self.window)
    windowVC.window?.makeKey()
}

}

you have to add menu item and connect it to FirstResponder in menu view to newWindowForTab: action, assign key, say cmd+t to work, this example as is just adds tab from + button and window menu options work, "move tab to new window" and "merge all windows". You can drag tab out and drop back , move tabs horizontally. Look like it works.

done with Xcode Version 8.2 beta (8C30a)