Entry.setActivatesDefault

If setting is true, pressing Enter in the entry will activate the default widget for the window containing the entry. This usually means that the dialog box containing the entry will be closed, since the default widget is usually one of the dialog buttons.

(For experts: if setting is true, the entry calls [gtk.window.Window.activateDefault] on the window containing the entry, in the default handler for the #GtkEntry::activate signal.)