public class EventProximity : Event
Proximity events are generated when using GDK’s wrapper for the XInput extension.
The XInput extension is an add-on for standard X that allows you to use nonstandard devices such as graphics tablets. A proximity event indicates that the stylus has moved in or out of contact with the tablet, or perhaps that the user’s finger has moved in or out of contact with a touch screen.
This event type will be used pretty rarely. It only is important for XInput aware programs that are drawing their own cursor.