gdk:device-active-layout-index (object)

object -- a gdk:device object
index -- an integer for the layout index of the active layout, or -1.

The accessor for the active-layout-index slot of the gdk:device class retrieves the index of the active layout of the keyboard. If there is no valid active layout for the device, this function will return -1. This is only relevant for keyboard devices.

Since 4.18