Have you ever wondered how to detect if a macOS app you're building was launched as a login item, as opposed to being launched manually by the user? Well, here's how to do it in Swift:

private var launchedAsLogInItem: Bool {
	guard let event = NSAppleEventManager.shared().currentAppleEvent else { return false }
	return
		event.eventID == kAEOpenApplication &&
		event.paramDescriptor(forKeyword: keyAEPropData)?.enumCodeValue == keyAELaunchedAsLogInItem
}

There are probably a number of reasons you'd want to check for this. In my case, I wanted to prevent the main app window of my app CenterMouse from opening when the app was launched as a login item, but still open it if a user launches it manually.

You can see this code in context in CenterMouse's AppDelegate here: AppDelegate.swift.