gdk-window-source-events (window source)

window -- a gdk-window object
source -- a gdk-input-source to define the source class
event-mask -- event mask of type gdk-event-mask for window

The function gdk-window-source-events returns the event mask for the window corresponding to the device class specified by source. The function (setf gdk-window-source-events) sets the event mask for any floating device, i.e. not attached to any visible pointer, that has source defined as source.

This event mask will be applied both to currently existing, newly added devices after this call, and devices being attached/detached.