Apple-style onboarding for applications

onboarding.swift

func showOnboarding() {
  let window = NSWindow(
    contentRect: NSRect(x: 0, y: 0, width: 640, height: 600),
    styleMask: [.fullSizeContentView, .nonactivatingPanel],
    backing: .buffered,
    defer: false
  )

  // Replace your own view here
  let onboardingWindow = NSHostingView(rootView: EmptyView())

  if let screen = NSScreen.main {
    window.setFrameOrigin(NSPoint(
      x: (screen.frame.width - window.frame.width) / 2,
      y: (screen.frame.height - window.frame.height) / 2
    ))
  }

  window.animationBehavior = .documentWindow
  window.backgroundColor = .clear
  window.isReleasedWhenClosed = true
  window.level = .floating
  window.contentView = onboardingWindow
  window.makeKeyAndOrderFront(true)

  onboardingWindow.wantsLayer = true
  onboardingWindow.layer!.cornerRadius = 10

  window.invalidateShadow()
}