py/test/pytests/brightness/brightness.py

# Copyright 2016 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""This is a factory test to check the brightness of LCD backlight or LEDs."""

import time
import unittest

import factory_common  # pylint: disable=unused-import
from cros.factory.device import device_utils
from cros.factory.test.i18n import arg_utils as i18n_arg_utils
from cros.factory.test.i18n import test_ui as i18n_test_ui
from cros.factory.test import test_ui
from cros.factory.test import ui_templates
from cros.factory.utils.arg_utils import Arg
from cros.factory.utils import process_utils


_MSG_CSS_CLASS = 'brightness-test-info'
_MSG_PASS_FAIL_PROMPT = i18n_test_ui.MakeI18nLabelWithClass(
    '<br>Press ENTER to pass, or ESC to fail.', _MSG_CSS_CLASS)
_MSG_TIME_REMAINING = lambda time: i18n_test_ui.MakeI18nLabelWithClass(
    'Time remaining: {time}', _MSG_CSS_CLASS, time=time)

_ID_PROMPT = 'brightness-test-prompt'
_ID_COUNTDOWN_TIMER = 'brightness-test-timer'

_HTML_BRIGHTNESS_TEST = '<div id="%s"></div>\n<div id="%s"></div>\n' % (
    _ID_PROMPT, _ID_COUNTDOWN_TIMER)
_BRIGHTNESS_TEST_DEFAULT_CSS = '.brightness-test-info { font-size: 2em; }'


class BrightnessTest(unittest.TestCase):
  ARGS = i18n_arg_utils.BackwardCompatibleI18nArgs('msg', 'Message HTML') + [
      Arg('timeout_secs', int, 'Timeout value for the test in seconds.',
          default=10),
      Arg('levels', (tuple, list), 'A sequence of brightness levels.'),
      Arg('interval_secs', (int, float),
          'Time for each brightness level in seconds.')]

  def setUp(self):
    i18n_arg_utils.ParseArg(self, 'msg')
    self.dut = device_utils.CreateDUTInterface()
    self.ui = test_ui.UI()
    self.template = ui_templates.OneSection(self.ui)
    self.ui.AppendCSS(_BRIGHTNESS_TEST_DEFAULT_CSS)
    self.ui.BindStandardKeys()
    self.template.SetState(_HTML_BRIGHTNESS_TEST)
    self.ui.SetHTML(i18n_test_ui.MakeI18nLabelWithClass(
        self.args.msg, _MSG_CSS_CLASS), id=_ID_PROMPT)
    self.ui.SetHTML(_MSG_PASS_FAIL_PROMPT, append=True, id=_ID_PROMPT)
    process_utils.StartDaemonThread(target=self._BrightnessChangeLoop)
    process_utils.StartDaemonThread(target=self._CountdownTimer)

  def runTest(self):
    self.ui.Run()

  def tearDown(self):
    raise NotImplementedError

  def _SetBrightnessLevel(self, level):
    raise NotImplementedError

  def _BrightnessChangeLoop(self):
    """Starts an infinite loop to change brightness."""
    while True:
      for level in self.args.levels:
        self._SetBrightnessLevel(level)
        time.sleep(self.args.interval_secs)

  def _CountdownTimer(self):
    """Starts a countdown timer and fails the test if timer reaches zero."""
    time_remaining = self.args.timeout_secs
    while time_remaining > 0:
      label = _MSG_TIME_REMAINING(time_remaining)
      self.ui.SetHTML(label, id=_ID_COUNTDOWN_TIMER)
      time.sleep(1)
      time_remaining -= 1
    self.ui.Fail('Brightness test failed due to timeout.')