public static unowned Display? open_default_libgtk_only ()
Warning: open_default_libgtk_only is deprecated since 3.16.
Opens the default display specified by command line arguments or environment variables, sets it as the default display, and returns it.
This symbol was never meant to be used outside of GTK+
parse_args must have been called first. If the default display has previously been set, simply returns that. An internal function that should not be used by applications.
the default display, if it could be opened, otherwise null.