Programmatically create NSWindow

Question

I want to programmatically create a new NSWindow, but I can't find a way to succeed. This simple code doesn't display a new window. What's wrong with it?

@NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {

    @IBOutlet weak var window: NSWindow!

    func applicationDidFinishLaunching(aNotification: NSNotification) {
        let win = NSWindow(contentRect: NSMakeRect(100, 100, 600, 200),
            styleMask: NSResizableWindowMask,
            backing: NSBackingStoreType.Buffered, defer: true)

        let controller = NSWindowController(window: win)

        controller.showWindow(self)
        win.makeKeyAndOrderFront(win)
    }
}

Answer 1

Xcode 11 • Swift 5.1

import Cocoa

@NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {
    @IBOutlet weak var window: NSWindow!
    let newWindow = NSWindow(contentRect: .init(origin: .zero,
                                                size: .init(width: NSScreen.main!.frame.midX,
                                                            height: NSScreen.main!.frame.midY)),
                             styleMask: [.closable],
                             backing: .buffered,
                             defer: false)
    func createNewWindow() {
        newWindow.title = "New Window"
        newWindow.isOpaque = false
        newWindow.center()
        newWindow.isMovableByWindowBackground = true
        newWindow.backgroundColor = NSColor(calibratedHue: 0, saturation: 1.0, brightness: 0, alpha: 0.7)
        newWindow.makeKeyAndOrderFront(nil)
    }
    func applicationDidFinishLaunching(_ aNotification: Notification) {
        createNewWindow()
    }
    func applicationWillTerminate(_ aNotification: Notification) {
        // Insert code here to tear down your application
    }
}

Window Style Mask

Sample project