title: Detecting if an external mouse is connected in Swift?
body: <p>For an app I am making on macOS I want different behaviour for the trackpad vs. a mouse. Is there any way to check if an external mouse is connected (e.g via usb or bluetooth) to the mac in Swift? I.e the assumption will be that if an external mouse is connected then the user will be using that rather than the trackpad. If they have an external mouse connected but would like to use the trackpad as as a pointer then they can change this in a settings menu.</p>