changed (
  GdkDevice* self,
  gpointer user_data

Description [src]

The ::changed signal is emitted either when the GdkDevice has changed the number of either axes or keys. For example In X this will normally happen when the slave device routing events through the master device changes (for example, user switches from the USB mouse to a tablet), in that case the master device will change to reflect the new slave device axes and keys.

Default handler:

The default handler is called after the handlers added via g_signal_connect().