gdk:screen-setting (screen name gtype)

screen -- a gdk:screen object where the setting is located
name -- a string with the name of the setting
gtype -- a string with the g:type-t type ID of the setting

The value of the setting, or nil if the setting does not exist.

Retrieves a desktop wide setting such as double-click time for the screen. See the gtk:settings class for the available settings.

(let ((screen (gdk:display-default-screen (gdk:display-default))))
  (gdk:screen-setting screen "gtk-double-click-time" "gint"))
=> 400