+def check_configuration_pre_save(configuration):
+ "Check that a configuration is safe for saving."
+ outputs = sorted(configuration.keys(), key=lambda x: configuration[x].sort_key)
+ for output in outputs:
+ if "off" not in configuration[output].options and not configuration[output].edid:
+ return ("`%(o)s' is not off (has a mode configured) but is disconnected (does not have an EDID).\n"
+ "This typically means that it has been recently unplugged and then not properly disabled\n"
+ "by the user. Please disable it (e.g. using `xrandr --output %(o)s --off`) and then rerun\n"
+ "this command.") % {"o": output}
+
+