Source code for COT.ui_shared

#!/usr/bin/env python
#
# ui_shared.py - abstraction between CLI and GUI
#
# December 2014, Glenn F. Matthews
# Copyright (c) 2014-2015 the COT project developers.
# See the COPYRIGHT.txt file at the top-level directory of this distribution
# and at https://github.com/glennmatthews/cot/blob/master/COPYRIGHT.txt.
#
# This file is part of the Common OVF Tool (COT) project.
# It is subject to the license terms in the LICENSE.txt file found in the
# top-level directory of this distribution and at
# https://github.com/glennmatthews/cot/blob/master/LICENSE.txt. No part
# of COT, including this file, may be copied, modified, propagated, or
# distributed except according to the terms contained in the LICENSE.txt file.

"""Abstract user interface superclass."""

import logging
import sys

# VerboseLogger adds a log level 'verbose' between 'info' and 'debug'.
# This lets us be a bit more fine-grained in our logging verbosity.
from verboselogs import VerboseLogger
logging.setLoggerClass(VerboseLogger)
logger = logging.getLogger(__name__)


[docs]class UI(object): """Abstract user interface functionality. Can also be used in test code as a stub that autoconfirms everything. """ def __init__(self, force=False): """Constructor.""" self.force = force """Whether to automatically select the default value in all cases. (As opposed to interactively prompting the user.) """ self.default_confirm_response = True """Knob for API testing, sets the default response to confirm().""" self._terminal_width = 80 import COT.helpers.helper COT.helpers.helper.confirm = self.confirm @property def terminal_width(self): """Get the width of the terminal in columns.""" return self._terminal_width
[docs] def fill_usage(self, subcommand, usage_list): """Pretty-print a list of usage strings. :param str subcommand: Subcommand name/keyword :param list usage_list: List of usage strings for this subcommand. :returns: String containing all usage strings, each appropriately wrapped to the :attr:`terminal_width` value. """ return "\n".join(["{0} {1}".format(subcommand, usage) for usage in usage_list])
[docs] def fill_examples(self, example_list): """Pretty-print a set of usage examples. :param list example_list: List of (example, description) tuples. :raise NotImplementedError: Must be implemented by a subclass. """ raise NotImplementedError("No implementation for fill_examples()")
[docs] def confirm(self, prompt): """Prompt user to confirm the requested operation. Auto-accepts if :attr:`force` is set to ``True``. .. warning:: This stub implementation does not actually interact with the user, but instead returns :attr:`default_confirm_response`. Subclasses should override this method. :param str prompt: Message to prompt the user with :return: ``True`` (user confirms acceptance) or ``False`` (user declines) """ if self.force: logger.warning("Automatically agreeing to '{0}'".format(prompt)) return True return self.default_confirm_response
[docs] def confirm_or_die(self, prompt): """If the user doesn't agree, abort the program. A simple wrapper for :meth:`confirm` that calls :func:`sys.exit` if :meth:`confirm` returns ``False``. """ if not self.confirm(prompt): sys.exit("Aborting.")
[docs] def choose_from_list(self, footer, option_list, default_value, header="", info_list=[]): """Prompt the user to choose from a list. :param footer: Prompt string to display following the list :param option_list: List of strings to choose amongst :param default_value: Default value to select if user declines :param header: String to display prior to the list :param info_list: Verbose strings to display instead of option_list """ if not info_list: info_list = option_list prompt_list = [header] + ["""{0:2}) {1}""".format(i, inf.strip()) for i, inf in enumerate(info_list, start=1)] prompt_list.append(footer) prompt = "\n".join(prompt_list) while True: result = self.get_input(prompt, default_value) # Exact match or user declined to choose if result == default_value or result in option_list: return result # Unique prefix match match = [opt for opt in option_list if opt.startswith(result)] if len(match) == 1: return match[0] # Did user enter a list index? try: i = int(result) return option_list[i-1] except (ValueError, IndexError): pass logger.error("Invalid input. Please try again.")
[docs] def get_input(self, prompt, default_value): """Prompt the user to enter a string. Auto-inputs the :attr:`default_value` if :attr:`force` is set to ``True``. .. warning:: This stub implementation does not actually interact with the user, but instead always returns :attr:`default_value`. Subclasses should override this method. :param str prompt: Message to prompt the user with :param str default_value: Default value to input if the user simply hits Enter without entering a value, or if :attr:`force`. :return: Input value :rtype: str """ if self.force: logger.warning("Automatically entering {0} in response to '{1}'" .format(default_value, prompt)) return default_value return default_value
[docs] def get_password(self, username, host): """Get password string from the user. .. warning:: This stub implementation does not actually interact with the user, but instead always returns ``"passwd"``. Subclasses should override this method. :param str username: Username the password is associated with :param str host: Host the password is associated with """ return "passwd"