def tabnanny(self, filename):
        f = open(filename, 'r')
        try:
            tabnanny.process_tokens(tokenize.generate_tokens(f.readline))
        except tokenize.TokenError, msg:
            msgtxt, (lineno, start) = msg
            self.editwin.gotoline(lineno)
            self.errorbox("Tabnanny Tokenizing Error",
                          "Token Error: %s" % msgtxt)
            return False
        except tabnanny.NannyNag, nag:
            # The error messages from tabnanny are too confusing...
            self.editwin.gotoline(nag.get_lineno())
            self.errorbox("Tab/space error", indent_message)
            return False
        return True