qa/qa_logging.py

#
#

# Copyright (C) 2014 Google Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

""" Handles the logging of messages with appropriate coloring.

"""

import sys


_INFO_SEQ = None
_WARNING_SEQ = None
_ERROR_SEQ = None
_RESET_SEQ = None


def _SetupColours():
  """Initializes the colour constants.

  """
  # pylint: disable=W0603
  # due to global usage
  global _INFO_SEQ, _WARNING_SEQ, _ERROR_SEQ, _RESET_SEQ

  # Don't use colours if stdout isn't a terminal
  if not sys.stdout.isatty():
    return

  try:
    import curses
  except ImportError:
    # Don't use colours if curses module can't be imported
    return

  curses.setupterm()

  _RESET_SEQ = curses.tigetstr("op")

  setaf = curses.tigetstr("setaf")
  _INFO_SEQ = curses.tparm(setaf, curses.COLOR_GREEN)
  _WARNING_SEQ = curses.tparm(setaf, curses.COLOR_YELLOW)
  _ERROR_SEQ = curses.tparm(setaf, curses.COLOR_RED)


_SetupColours()


def _FormatWithColor(text, seq):
  if not seq:
    return text
  return "%s%s%s" % (seq, text, _RESET_SEQ)


FormatWarning = lambda text: _FormatWithColor(text, _WARNING_SEQ)
FormatError = lambda text: _FormatWithColor(text, _ERROR_SEQ)
FormatInfo = lambda text: _FormatWithColor(text, _INFO_SEQ)