Returns False if user has cancelled a "save as" operation, otherwise True.

def __generic_save(self):
        """Returns False if user has cancelled a "save as" operation, otherwise True."""
        page = self._get_page()
        f = page.editor.f
        if not f:
            return True
        if not page.editor.flag_valid:
            a99.show_error("Cannot save, {0!s} has error(s)!".format(f.description))
            return True
        if f.filename:
            f.save_as()

            self.add_log("Saved '{}'".format(f.filename))
            page.flag_changed = False
            self._update_gui_text_tabs()

            if hasattr(page.editor, "update_gui_label_fn"):
                page.editor.update_gui_label_fn()  # duck typing
            return True
        else:
            return self.__generic_save_as()