Cocoa Programming for OS X: The Big Nerd Ranch Guide

Improving Controller Design

Currently, in AppDelegate.swift, you create a window controller and pass in a string – "MainWindowController". The string is the name of a NIB file. When the project is launched, the window controller is created and the objects in the named NIB file are unarchived along with their connections.

import Cocoa

@NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {

    var mainWindowController: MainWindowController?

    func applicationDidFinishLaunching(aNotification: NSNotification) {

        // Create a window controller with a XIB file of the same name
        let mainWindowController = MainWindowController(windowNibName:
                                                            "MainWindowController") // Put the window of the window controller on screen mainWindowController.showWindow(self) ...