Added pylint and lots of bugfixes!

.pylintrc

@@ -0,0 +1,569 @@
+[MASTER]
+
+# A comma-separated list of package or module names from where C extensions may
+# be loaded. Extensions are loading into the active Python interpreter and may
+# run arbitrary code.
+extension-pkg-allow-list=
+
+# A comma-separated list of package or module names from where C extensions may
+# be loaded. Extensions are loading into the active Python interpreter and may
+# run arbitrary code. (This is an alternative name to extension-pkg-allow-list
+# for backward compatibility.)
+extension-pkg-whitelist=PyQt5
+
+# Return non-zero exit code if any of these messages/categories are detected,
+# even if score is above --fail-under value. Syntax same as enable. Messages
+# specified are enabled, while categories only check already-enabled messages.
+fail-on=
+
+# Specify a score threshold to be exceeded before program exits with error.
+fail-under=9
+
+# Files or directories to be skipped. They should be base names, not paths.
+ignore=CVS,resources
+
+# Add files or directories matching the regex patterns to the ignore-list. The
+# regex matches against paths and can be in Posix or Windows format.
+ignore-paths=
+
+# Files or directories matching the regex patterns are skipped. The regex
+# matches against base names, not paths.
+ignore-patterns=setup.py,resources.py
+
+# Python code to execute, usually for sys.path manipulation such as
+# pygtk.require().
+init-hook=import sys; sys.path.append('./src');
+
+# Use multiple processes to speed up Pylint. Specifying 0 will auto-detect the
+# number of processors available to use.
+jobs=1
+
+# Control the amount of potential inferred values when inferring a single
+# object. This can help the performance when dealing with large functions or
+# complex, nested conditions.
+limit-inference-results=100
+
+# List of plugins (as comma separated values of python module names) to load,
+# usually to register additional checkers.
+load-plugins=
+
+# Pickle collected data for later comparisons.
+persistent=yes
+
+# Minimum Python version to use for version dependent checks. Will default to
+# the version used to run pylint.
+py-version=3.8
+
+# When enabled, pylint would attempt to guess common misconfiguration and emit
+# user-friendly hints instead of false-positive error messages.
+suggestion-mode=yes
+
+# Allow loading of arbitrary C extensions. Extensions are imported into the
+# active Python interpreter and may run arbitrary code.
+unsafe-load-any-extension=no
+
+
+[MESSAGES CONTROL]
+
+# Only show warnings with the listed confidence levels. Leave empty to show
+# all. Valid levels: HIGH, INFERENCE, INFERENCE_FAILURE, UNDEFINED.
+confidence=
+
+# Disable the message, report, category or checker with the given id(s). You
+# can either give multiple identifiers separated by comma (,) or put this
+# option multiple times (only on the command line, not in the configuration
+# file where it should appear only once). You can also use "--disable=all" to
+# disable everything first and then reenable specific checks. For example, if
+# you want to run only the similarities checker, you can use "--disable=all
+# --enable=similarities". If you want to run only the classes checker, but have
+# no Warning level messages displayed, use "--disable=all --enable=classes
+# --disable=W".
+disable=raw-checker-failed,
+        bad-inline-option,
+        locally-disabled,
+        file-ignored,
+        suppressed-message,
+        useless-suppression,
+        deprecated-pragma,
+        use-symbolic-message-instead,
+        missing-module-docstring
+
+# Enable the message, report, category or checker with the given id(s). You can
+# either give multiple identifier separated by comma (,) or put this option
+# multiple time (only on the command line, not in the configuration file where
+# it should appear only once). See also the "--disable" option for examples.
+enable=c-extension-no-member
+
+
+[REPORTS]
+
+# Python expression which should return a score less than or equal to 10. You
+# have access to the variables 'error', 'warning', 'refactor', and 'convention'
+# which contain the number of messages in each category, as well as 'statement'
+# which is the total number of statements analyzed. This score is used by the
+# global evaluation report (RP0004).
+evaluation=10.0 - ((float(5 * error + warning + refactor + convention) / statement) * 10)
+
+# Template used to display messages. This is a python new-style format string
+# used to format the message information. See doc for all details.
+#msg-template=
+
+# Set the output format. Available formats are text, parseable, colorized, json
+# and msvs (visual studio). You can also give a reporter class, e.g.
+# mypackage.mymodule.MyReporterClass.
+output-format=text
+
+# Tells whether to display a full report or only the messages.
+reports=no
+
+# Activate the evaluation score.
+score=yes
+
+
+[REFACTORING]
+
+# Maximum number of nested blocks for function / method body
+max-nested-blocks=5
+
+# Complete name of functions that never returns. When checking for
+# inconsistent-return-statements if a never returning function is called then
+# it will be considered as an explicit return statement and no message will be
+# printed.
+never-returning-functions=sys.exit,argparse.parse_error
+
+
+[LOGGING]
+
+# The type of string formatting that logging methods do. `old` means using %
+# formatting, `new` is for `{}` formatting.
+logging-format-style=old
+
+# Logging modules to check that the string format arguments are in logging
+# function parameter format.
+logging-modules=logging
+
+
+[STRING]
+
+# This flag controls whether inconsistent-quotes generates a warning when the
+# character used as a quote delimiter is used inconsistently within a module.
+check-quote-consistency=no
+
+# This flag controls whether the implicit-str-concat should generate a warning
+# on implicit string concatenation in sequences defined over several lines.
+check-str-concat-over-line-jumps=no
+
+
+[SPELLING]
+
+# Limits count of emitted suggestions for spelling mistakes.
+max-spelling-suggestions=4
+
+# Spelling dictionary name. Available dictionaries: none. To make it work,
+# install the 'python-enchant' package.
+spelling-dict=
+
+# List of comma separated words that should be considered directives if they
+# appear and the beginning of a comment and should not be checked.
+spelling-ignore-comment-directives=fmt: on,fmt: off,noqa:,noqa,nosec,isort:skip,mypy:
+
+# List of comma separated words that should not be checked.
+spelling-ignore-words=
+
+# A path to a file that contains the private dictionary; one word per line.
+spelling-private-dict-file=
+
+# Tells whether to store unknown words to the private dictionary (see the
+# --spelling-private-dict-file option) instead of raising a message.
+spelling-store-unknown-words=no
+
+
+[FORMAT]
+
+# Expected format of line ending, e.g. empty (any line ending), LF or CRLF.
+expected-line-ending-format=
+
+# Regexp for a line that is allowed to be longer than the limit.
+ignore-long-lines=^\s*(# )?<?https?://\S+>?$
+
+# Number of spaces of indent required inside a hanging or continued line.
+indent-after-paren=4
+
+# String used as indentation unit. This is usually "    " (4 spaces) or "\t" (1
+# tab).
+indent-string='    '
+
+# Maximum number of characters on a single line.
+max-line-length=100
+
+# Maximum number of lines in a module.
+max-module-lines=1000
+
+# Allow the body of a class to be on the same line as the declaration if body
+# contains single statement.
+single-line-class-stmt=no
+
+# Allow the body of an if to be on the same line as the test if there is no
+# else.
+single-line-if-stmt=no
+
+
+[BASIC]
+
+# Naming style matching correct argument names.
+argument-naming-style=snake_case
+
+# Regular expression matching correct argument names. Overrides argument-
+# naming-style.
+#argument-rgx=
+
+# Naming style matching correct attribute names.
+attr-naming-style=snake_case
+
+# Regular expression matching correct attribute names. Overrides attr-naming-
+# style.
+#attr-rgx=
+
+# Bad variable names which should always be refused, separated by a comma.
+bad-names=foo,
+          bar,
+          baz,
+          toto,
+          tutu,
+          tata
+
+# Bad variable names regexes, separated by a comma. If names match any regex,
+# they will always be refused
+bad-names-rgxs=
+
+# Naming style matching correct class attribute names.
+class-attribute-naming-style=any
+
+# Regular expression matching correct class attribute names. Overrides class-
+# attribute-naming-style.
+#class-attribute-rgx=
+
+# Naming style matching correct class constant names.
+class-const-naming-style=UPPER_CASE
+
+# Regular expression matching correct class constant names. Overrides class-
+# const-naming-style.
+#class-const-rgx=
+
+# Naming style matching correct class names.
+class-naming-style=PascalCase
+
+# Regular expression matching correct class names. Overrides class-naming-
+# style.
+#class-rgx=
+
+# Naming style matching correct constant names.
+const-naming-style=UPPER_CASE
+
+# Regular expression matching correct constant names. Overrides const-naming-
+# style.
+#const-rgx=
+
+# Minimum line length for functions/classes that require docstrings, shorter
+# ones are exempt.
+docstring-min-length=-1
+
+# Naming style matching correct function names.
+function-naming-style=snake_case
+
+# Regular expression matching correct function names. Overrides function-
+# naming-style.
+#function-rgx=
+
+# Good variable names which should always be accepted, separated by a comma.
+good-names=i,
+           j,
+           k,
+           ex,
+           Run,
+           _
+
+# Good variable names regexes, separated by a comma. If names match any regex,
+# they will always be accepted
+good-names-rgxs=
+
+# Include a hint for the correct naming format with invalid-name.
+include-naming-hint=no
+
+# Naming style matching correct inline iteration names.
+inlinevar-naming-style=any
+
+# Regular expression matching correct inline iteration names. Overrides
+# inlinevar-naming-style.
+#inlinevar-rgx=
+
+# Naming style matching correct method names.
+method-naming-style=snake_case
+
+# Regular expression matching correct method names. Overrides method-naming-
+# style.
+#method-rgx=
+
+# Naming style matching correct module names.
+module-naming-style=snake_case
+
+# Regular expression matching correct module names. Overrides module-naming-
+# style.
+#module-rgx=
+
+# Colon-delimited sets of names that determine each other's naming style when
+# the name regexes allow several styles.
+name-group=
+
+# Regular expression which should only match function or class names that do
+# not require a docstring.
+no-docstring-rgx=^_
+
+# List of decorators that produce properties, such as abc.abstractproperty. Add
+# to this list to register other decorators that produce valid properties.
+# These decorators are taken in consideration only for invalid-name.
+property-classes=abc.abstractproperty
+
+# Naming style matching correct variable names.
+variable-naming-style=snake_case
+
+# Regular expression matching correct variable names. Overrides variable-
+# naming-style.
+#variable-rgx=
+
+
+[VARIABLES]
+
+# List of additional names supposed to be defined in builtins. Remember that
+# you should avoid defining new builtins when possible.
+additional-builtins=
+
+# Tells whether unused global variables should be treated as a violation.
+allow-global-unused-variables=yes
+
+# List of names allowed to shadow builtins
+allowed-redefined-builtins=
+
+# List of strings which can identify a callback function by name. A callback
+# name must start or end with one of those strings.
+callbacks=cb_,
+          _cb
+
+# A regular expression matching the name of dummy variables (i.e. expected to
+# not be used).
+dummy-variables-rgx=_+$|(_[a-zA-Z0-9_]*[a-zA-Z0-9]+?$)|dummy|^ignored_|^unused_
+
+# Argument names that match this expression will be ignored. Default to name
+# with leading underscore.
+ignored-argument-names=_.*|^ignored_|^unused_
+
+# Tells whether we should check for unused import in __init__ files.
+init-import=no
+
+# List of qualified module names which can have objects that can redefine
+# builtins.
+redefining-builtins-modules=six.moves,past.builtins,future.builtins,builtins,io
+
+
+[SIMILARITIES]
+
+# Comments are removed from the similarity computation
+ignore-comments=yes
+
+# Docstrings are removed from the similarity computation
+ignore-docstrings=yes
+
+# Imports are removed from the similarity computation
+ignore-imports=no
+
+# Signatures are removed from the similarity computation
+ignore-signatures=no
+
+# Minimum lines number of a similarity.
+min-similarity-lines=4
+
+
+[MISCELLANEOUS]
+
+# List of note tags to take in consideration, separated by a comma.
+notes=FIXME,
+      XXX,
+      TODO
+
+# Regular expression of note tags to take in consideration.
+#notes-rgx=
+
+
+[TYPECHECK]
+
+# List of decorators that produce context managers, such as
+# contextlib.contextmanager. Add to this list to register other decorators that
+# produce valid context managers.
+contextmanager-decorators=contextlib.contextmanager
+
+# List of members which are set dynamically and missed by pylint inference
+# system, and so shouldn't trigger E1101 when accessed. Python regular
+# expressions are accepted.
+generated-members=
+
+# Tells whether missing members accessed in mixin class should be ignored. A
+# class is considered mixin if its name matches the mixin-class-rgx option.
+ignore-mixin-members=yes
+
+# Tells whether to warn about missing members when the owner of the attribute
+# is inferred to be None.
+ignore-none=yes
+
+# This flag controls whether pylint should warn about no-member and similar
+# checks whenever an opaque object is returned when inferring. The inference
+# can return multiple potential results while evaluating a Python object, but
+# some branches might not be evaluated, which results in partial inference. In
+# that case, it might be useful to still emit no-member and other checks for
+# the rest of the inferred objects.
+ignore-on-opaque-inference=yes
+
+# List of class names for which member attributes should not be checked (useful
+# for classes with dynamically set attributes). This supports the use of
+# qualified names.
+ignored-classes=optparse.Values,thread._local,_thread._local
+
+# List of module names for which member attributes should not be checked
+# (useful for modules/projects where namespaces are manipulated during runtime
+# and thus existing member attributes cannot be deduced by static analysis). It
+# supports qualified module names, as well as Unix pattern matching.
+ignored-modules=
+
+# Show a hint with possible names when a member name was not found. The aspect
+# of finding the hint is based on edit distance.
+missing-member-hint=yes
+
+# The minimum edit distance a name should have in order to be considered a
+# similar match for a missing member name.
+missing-member-hint-distance=1
+
+# The total number of similar names that should be taken in consideration when
+# showing a hint for a missing member.
+missing-member-max-choices=1
+
+# Regex pattern to define which classes are considered mixins ignore-mixin-
+# members is set to 'yes'
+mixin-class-rgx=.*[Mm]ixin
+
+# List of decorators that change the signature of a decorated function.
+signature-mutators=
+
+
+[CLASSES]
+
+# Warn about protected attribute access inside special methods
+check-protected-access-in-special-methods=no
+
+# List of method names used to declare (i.e. assign) instance attributes.
+defining-attr-methods=__init__,
+                      __new__,
+                      setUp,
+                      __post_init__
+
+# List of member names, which should be excluded from the protected access
+# warning.
+exclude-protected=_asdict,
+                  _fields,
+                  _replace,
+                  _source,
+                  _make
+
+# List of valid names for the first argument in a class method.
+valid-classmethod-first-arg=cls
+
+# List of valid names for the first argument in a metaclass class method.
+valid-metaclass-classmethod-first-arg=cls
+
+
+[IMPORTS]
+
+# List of modules that can be imported at any level, not just the top level
+# one.
+allow-any-import-level=
+
+# Allow wildcard imports from modules that define __all__.
+allow-wildcard-with-all=no
+
+# Analyse import fallback blocks. This can be used to support both Python 2 and
+# 3 compatible code, which means that the block might have code that exists
+# only in one or another interpreter, leading to false positives when analysed.
+analyse-fallback-blocks=no
+
+# Deprecated modules which should not be used, separated by a comma.
+deprecated-modules=
+
+# Output a graph (.gv or any supported image format) of external dependencies
+# to the given file (report RP0402 must not be disabled).
+ext-import-graph=
+
+# Output a graph (.gv or any supported image format) of all (i.e. internal and
+# external) dependencies to the given file (report RP0402 must not be
+# disabled).
+import-graph=
+
+# Output a graph (.gv or any supported image format) of internal dependencies
+# to the given file (report RP0402 must not be disabled).
+int-import-graph=
+
+# Force import order to recognize a module as part of the standard
+# compatibility libraries.
+known-standard-library=
+
+# Force import order to recognize a module as part of a third party library.
+known-third-party=enchant
+
+# Couples of modules and preferred modules, separated by a comma.
+preferred-modules=
+
+
+[DESIGN]
+
+# List of regular expressions of class ancestor names to ignore when counting
+# public methods (see R0903)
+exclude-too-few-public-methods=
+
+# List of qualified class names to ignore when counting class parents (see
+# R0901)
+ignored-parents=
+
+# Maximum number of arguments for function / method.
+max-args=5
+
+# Maximum number of attributes for a class (see R0902).
+max-attributes=7
+
+# Maximum number of boolean expressions in an if statement (see R0916).
+max-bool-expr=5
+
+# Maximum number of branch for function / method body.
+max-branches=12
+
+# Maximum number of locals for function / method body.
+max-locals=15
+
+# Maximum number of parents for a class (see R0901).
+max-parents=7
+
+# Maximum number of public methods for a class (see R0904).
+max-public-methods=20
+
+# Maximum number of return / yield for function / method body.
+max-returns=6
+
+# Maximum number of statements in function / method body.
+max-statements=50
+
+# Minimum number of public methods for a class (see R0903).
+min-public-methods=2
+
+
+[EXCEPTIONS]
+
+# Exceptions that will emit a warning when being caught. Defaults to
+# "BaseException, Exception".
+overgeneral-exceptions=BaseException,
+                       Exception

src/__main__.py

@@ -26,14 +26,16 @@
 #  along with Web Greeter; If not, see <http://www.gnu.org/licenses/>.
 
 # Standard lib
-import sys, argparse, os
+import sys
+import argparse
+import os
 from typing import List
 
 # 3rd-Party Libs
-import globals
 import config
 
 def list_themes() -> List[str]:
+    """List available themes"""
     themes_dir = config.web_greeter_config["app"]["theme_dir"]
     themes_dir = themes_dir if os.path.exists(themes_dir) else "/usr/share/web-greeter/themes"
     filenames = os.listdir(themes_dir)
@@ -46,18 +48,21 @@ def list_themes() -> List[str]:
     return dirlist
 
 def print_themes():
+    """Print available themes"""
     themes_dir = config.web_greeter_config["app"]["theme_dir"]
     themes_dir = themes_dir if os.path.exists(themes_dir) else "/usr/share/web-greeter/themes"
     themes = list_themes()
-    print("Themes are located in {themes_dir}\n".format(themes_dir = themes_dir))
+    print(f"Themes are located in {themes_dir}\n")
     for theme in themes:
         print("-", theme)
 
 
 def set_theme(theme: str):
+    """Sets the theme"""
     config.web_greeter_config["config"]["greeter"]["theme"] = theme
 
 def set_debug(value: bool):
+    """Sets debug mode"""
     conf = config.web_greeter_config["config"]
     app = config.web_greeter_config["app"]
     conf["greeter"]["debug_mode"] = value
@@ -65,16 +70,23 @@ def set_debug(value: bool):
     app["fullscreen"] = not value
 
 def parse(argv):
+    """Parse command arguments"""
     version = config.web_greeter_config["app"]["version"]["full"]
-    parser = argparse.ArgumentParser(prog="web-greeter", add_help=False)
-    parser.add_argument("-h", "--help", action="help", help="Show this help message and exit")
-    parser.add_argument("-v", "--version", action="version", version=version, help="Show version number")
-
-    parser.add_argument("--debug", action="store_true", help="Run the greeter in debug mode", dest="debug", default=None)
-    parser.add_argument("--normal", action="store_false", help="Run in non-debug mode", dest="debug")
-    parser.add_argument("--list", action="store_true", help="List available themes")
-    parser.add_argument("--theme", help="Set the theme to use", metavar="[name]")
-    parser.add_argument("--no-sandbox", action="store_true", help=argparse.SUPPRESS)
+    parser = argparse.ArgumentParser(prog="web-greeter", add_help = False)
+    parser.add_argument("-h", "--help", action = "help",
+                        help = "Show this help message and exit")
+    parser.add_argument("-v", "--version", action = "version",
+                        version = version, help = "Show version number")
+
+    parser.add_argument("--debug", action = "store_true",
+                        help = "Run the greeter in debug mode",
+                        dest = "debug", default = None)
+    parser.add_argument("--normal", action = "store_false",
+                        help = "Run in non-debug mode", dest = "debug")
+    parser.add_argument("--list", action = "store_true",
+                        help = "List available themes")
+    parser.add_argument("--theme", help = "Set the theme to use", metavar = "[name]")
+    parser.add_argument("--no-sandbox", action = "store_true", help = argparse.SUPPRESS)
 
     args: argparse.Namespace
 
@@ -85,20 +97,21 @@ def parse(argv):
 
     # print(args)
 
-    if (args.list):
+    if args.list:
         print_themes()
         sys.exit()
-    if (args.theme):
+    if args.theme:
         set_theme(args.theme)
-    if (args.debug != None):
+    if args.debug is not None:
         set_debug(args.debug)
 
 if __name__ == '__main__':
     parse(sys.argv[1:])
 
+    import globales
     from browser.browser import Browser
 
-    globals.greeter = Browser()
-    greeter = globals.greeter
+    globales.greeter = Browser()
+    greeter = globales.greeter
     greeter.show()
     greeter.run()

src/bridge/Config.py

@@ -26,27 +26,32 @@
 #  You should have received a copy of the GNU General Public License
 #  along with Web Greeter; If not, see <http://www.gnu.org/licenses/>.
 
-# 3rd-Party Libs
-from browser.bridge import Bridge, BridgeObject
-from PyQt5.QtCore import QVariant
+# pylint: disable=wrong-import-position
 
+# Standard Lib
+from typing import List
+
+# 3rd-Party Libs
 import gi
 gi.require_version('LightDM', '1')
 from gi.repository import LightDM
 
-from typing import List
+from PyQt5.QtCore import QVariant
+
+# This application
+from browser.bridge import Bridge, BridgeObject
 from config import web_greeter_config
 
-from . import (
-    layout_to_dict
-)
+from . import layout_to_dict
 
 def get_layouts(config_layouts: List[str]):
+    """Get layouts from web-greeter's config"""
     layouts = LightDM.get_layouts()
     final_layouts: list[LightDM.Layout] = []
     for ldm_lay in layouts:
         for conf_lay in config_layouts:
-            if type(conf_lay) != str: return
+            if not isinstance(conf_lay, str):
+                return []
             conf_lay = conf_lay.replace(" ", "\t")
             if ldm_lay.get_name() == conf_lay:
                 final_layouts.append(layout_to_dict(ldm_lay))
@@ -54,17 +59,19 @@ def get_layouts(config_layouts: List[str]):
 
 
 class Config(BridgeObject):
+    # pylint: disable=no-self-use,missing-function-docstring,too-many-public-methods,invalid-name
+    """Config bridge class, known as `greeter_config` in javascript"""
 
     noop_signal = Bridge.signal()
 
     def __init__(self, *args, **kwargs):
         super().__init__(name='Config', *args, **kwargs)
 
-        config = web_greeter_config["config"]
-        self._branding = config["branding"]
-        self._greeter = config["greeter"]
-        self._features = config["features"]
-        self._layouts = get_layouts(config["layouts"])
+        _config = web_greeter_config["config"]
+        self._branding = _config["branding"]
+        self._greeter = _config["greeter"]
+        self._features = _config["features"]
+        self._layouts = get_layouts(_config["layouts"])
 
     @Bridge.prop(QVariant, notify=noop_signal)
     def branding(self):
@@ -81,3 +88,5 @@ class Config(BridgeObject):
     @Bridge.prop(QVariant, notify=noop_signal)
     def layouts(self):
         return self._layouts
+
+config = Config()

src/bridge/Greeter.py

@@ -26,33 +26,32 @@
 #  You should have received a copy of the GNU General Public License
 #  along with Web Greeter; If not, see <http://www.gnu.org/licenses/>.
 
-# Standard Lib
-from browser.error_prompt import Dialog
-import subprocess
-import threading
+# pylint: disable=wrong-import-position
 
 # 3rd-Party Libs
 import gi
 gi.require_version('LightDM', '1')
 from gi.repository import LightDM
+from gi.repository.GLib import GError
+
+from PyQt5.QtCore import QVariant
 
+# This Application
+from logger import logger
+from browser.error_prompt import Dialog
 from browser.bridge import Bridge, BridgeObject
-from PyQt5.QtCore import QFileSystemWatcher, QVariant, QTimer
 
 from config import web_greeter_config
 from utils.battery import Battery
-from utils.screensaver import reset_screensaver
+from utils.screensaver import screensaver
 from utils.brightness import BrightnessController
-import globals
 
-# This Application
 from . import (
     language_to_dict,
     layout_to_dict,
     session_to_dict,
     user_to_dict,
-    battery_to_dict,
-    logger
+    battery_to_dict
 )
 
 # import utils.battery as battery
@@ -60,18 +59,9 @@ from . import (
 LightDMGreeter = LightDM.Greeter()
 LightDMUsers = LightDM.UserList()
 
-def getBrightness(self):
-    if self._config["features"]["backlight"]["enabled"] != True:
-        return -1
-    try:
-        level = subprocess.run(["xbacklight", "-get"], stdout=subprocess.PIPE,
-                               stderr=subprocess.PIPE, text=True, check=True)
-        return int(level.stdout)
-    except Exception as err:
-        logger.error("Brightness: {}".format(err))
-        return -1
-
 class Greeter(BridgeObject):
+    # pylint: disable=no-self-use,missing-function-docstring,too-many-public-methods,invalid-name
+    """Greeter bridge class, known as `lightdm` in javascript"""
 
     # LightDM.Greeter Signals
     authentication_complete = Bridge.signal()
@@ -103,14 +93,18 @@ class Greeter(BridgeObject):
 
         try:
             LightDMGreeter.connect_to_daemon_sync()
-        except Exception as err:
+        except GError as err:
             logger.error(err)
-            dia = Dialog(title="An error ocurred",
-                         message="Detected a problem that could interfere with the system login process",
-                         detail="LightDM: {0}\nYou can continue without major problems, but you won't be able to log in".format(err),
-                         buttons=["Okay"])
+            dia = Dialog(
+                title = "An error ocurred",
+                message = "Detected a problem that could interfere" \
+                    " with the system login process",
+                detail = f"LightDM: {err}\n" \
+                    "You can continue without major problems, " \
+                    "but you won't be able to log in",
+                buttons = ["Okay"]
+            )
             dia.exec()
-            pass
 
         self._connect_signals()
         self._determine_shared_data_directory_path()
@@ -119,35 +113,32 @@ class Greeter(BridgeObject):
     def _determine_shared_data_directory_path(self):
         user = LightDMUsers.get_users()[0]
         user_data_dir = LightDMGreeter.ensure_shared_data_dir_sync(user.get_name())
-        if user_data_dir == None:
+        if user_data_dir is None:
             return
         self._shared_data_directory = user_data_dir.rpartition('/')[0]
 
     def _connect_signals(self):
         LightDMGreeter.connect(
             'authentication-complete',
-            lambda greeter: self._emit_signal(self.authentication_complete)
+            lambda _: self._emit_signal(self.authentication_complete)
         )
         LightDMGreeter.connect(
             'autologin-timer-expired',
-            lambda greeter: self._emit_signal(self.autologin_timer_expired)
+            lambda _: self._emit_signal(self.autologin_timer_expired)
         )
 
-        LightDMGreeter.connect('idle', lambda greeter: self._emit_signal(self.idle))
-        LightDMGreeter.connect('reset', lambda greeter: self._emit_signal(self.reset))
+        LightDMGreeter.connect('idle', lambda _: self._emit_signal(self.idle))
+        LightDMGreeter.connect('reset', lambda _: self._emit_signal(self.reset))
 
         LightDMGreeter.connect(
             'show-message',
-            lambda greeter, msg, mtype: self._emit_signal(self.show_message, msg, mtype.real)
+            lambda _, msg, mtype: self._emit_signal(self.show_message, msg, mtype.real)
         )
         LightDMGreeter.connect(
             'show-prompt',
-            lambda greeter, msg, mtype: self._emit_signal(self.show_prompt, msg, mtype.real)
+            lambda _, msg, mtype: self._emit_signal(self.show_prompt, msg, mtype.real)
         )
 
-        if self._battery:
-            self._battery.connect(lambda: self.battery_update.emit())
-
     def _emit_signal(self, _signal, *args):
         self.property_changed.emit()
         _signal.emit(*args)
@@ -173,6 +164,10 @@ class Greeter(BridgeObject):
     def batteryData(self):
         return battery_to_dict(self._battery)
 
+    @Bridge.prop(QVariant, notify=battery_update)
+    def battery_data(self):
+        return battery_to_dict(self._battery)
+
     @Bridge.prop(int, notify=brightness_update)
     def brightness(self):
         return self._brightness_controller.brightness
@@ -243,7 +238,7 @@ class Greeter(BridgeObject):
 
     @layout.setter
     def layout(self, layout):
-        if type(layout) != dict:
+        if not isinstance(layout, dict):
             return False
         lay = dict(
             name = layout.get("name") or "",
@@ -310,14 +305,26 @@ class Greeter(BridgeObject):
     def brightnessSet(self, quantity):
         self._brightness_controller.set_brightness(quantity)
 
+    @Bridge.method(int)
+    def brightness_set(self, quantity):
+        self._brightness_controller.inc_brightness(quantity)
+
     @Bridge.method(int)
     def brightnessIncrease(self, quantity):
         self._brightness_controller.inc_brightness(quantity)
 
+    @Bridge.method(int)
+    def brightness_increase(self, quantity):
+        self._brightness_controller.inc_brightness(quantity)
+
     @Bridge.method(int)
     def brightnessDecrease(self, quantity):
         self._brightness_controller.dec_brightness(quantity)
 
+    @Bridge.method(int)
+    def brightness_decrease(self, quantity):
+        self._brightness_controller.inc_brightness(quantity)
+
     @Bridge.method()
     def cancel_authentication(self):
         LightDMGreeter.cancel_authentication()
@@ -343,7 +350,7 @@ class Greeter(BridgeObject):
 
     @Bridge.method(str)
     def set_language(self, lang):
-        if self.is_authenticated:
+        if self.is_authenticated is True:
             LightDMGreeter.set_language(lang)
             self.property_changed.emit()
 
@@ -354,13 +361,15 @@ class Greeter(BridgeObject):
     @Bridge.method(str, result=bool)
     def start_session(self, session):
         if not session.strip():
-            return
-        started = LightDMGreeter.start_session_sync(session)
+            return False
+        started: bool = LightDMGreeter.start_session_sync(session)
         if started or self.is_authenticated:
-            logger.debug("Session \"" + session + "\" started")
-            reset_screensaver()
+            logger.debug("Session \"%s\" started", session)
+            screensaver.reset_screensaver()
         return started
 
     @Bridge.method(result=bool)
     def suspend(self):
         return LightDM.suspend()
+
+greeter = Greeter()

src/bridge/ThemeUtils.py

@@ -26,25 +26,32 @@
 #  You should have received a copy of the GNU General Public License
 #  along with Web Greeter; If not, see <http://www.gnu.org/licenses/>.
 
+# pylint: disable=wrong-import-position
+
 # Standard Lib
 import os
 import re
 import tempfile
 
 # 3rd-Party Libs
-from browser.bridge import Bridge, BridgeObject
 from PyQt5.QtCore import QVariant
 
+# This application
+from browser.bridge import Bridge, BridgeObject
+
 from config import web_greeter_config
 from logger import logger
+from bridge.Greeter import greeter
 
 class ThemeUtils(BridgeObject):
+    # pylint: disable=no-self-use,missing-function-docstring,too-many-public-methods,invalid-name
+    """ThemeUtils bridge class, known as `theem_utils` in javascript"""
 
-    def __init__(self, greeter, *args, **kwargs):
+    def __init__(self, greeter_object, *args, **kwargs):
         super().__init__(name='ThemeUtils', *args, **kwargs)
 
         self._config = web_greeter_config
-        self._greeter = greeter
+        self._greeter = greeter_object
 
         self._allowed_dirs = (
             os.path.dirname(
@@ -61,8 +68,11 @@ class ThemeUtils(BridgeObject):
         if not dir_path or not isinstance(dir_path, str) or '/' == dir_path:
             return []
 
-        if (dir_path.startswith("./")):
-            dir_path = os.path.join(os.path.dirname(self._config["config"]["greeter"]["theme"]), dir_path)
+        if dir_path.startswith("./"):
+            dir_path = os.path.join(
+                os.path.dirname(self._config["config"]["greeter"]["theme"]),
+                dir_path
+            )
 
         dir_path = os.path.realpath(os.path.normpath(dir_path))
 
@@ -77,7 +87,7 @@ class ThemeUtils(BridgeObject):
                 break
 
         if not allowed:
-            logger.error("Path \"" + dir_path + "\" is not allowed");
+            logger.error("Path \"%s\" is not allowed", dir_path)
             return []
 
         result = []
@@ -91,3 +101,5 @@ class ThemeUtils(BridgeObject):
 
         result.sort()
         return result
+
+theme_utils = ThemeUtils(greeter)

src/bridge/__init__.py

@@ -26,90 +26,70 @@
 #  You should have received a copy of the GNU General Public License
 #  along with Web Greeter; If not, see <http://www.gnu.org/licenses/>.
 
-import re
-import threading, time
-
-from logging import (
-    getLogger,
-    DEBUG,
-    ERROR,
-    Formatter,
-    StreamHandler,
-)
-
-log_format = ''.join([
-    '%(asctime)s [ %(levelname)s ] %(filename)s %(',
-    'lineno)d : %(funcName)s | %(message)s'
-])
-formatter = Formatter(fmt=log_format, datefmt="%Y-%m-%d %H:%M:%S")
-logger = getLogger("greeter")
-logger.propagate = False
-stream_handler = StreamHandler()
-stream_handler.setLevel(DEBUG)
-stream_handler.setFormatter(formatter)
-logger.setLevel(DEBUG)
-logger.addHandler(stream_handler)
-
 def language_to_dict(lang):
-    if (not lang):
-        return dict()
-    return dict(code=lang.get_code(), name=lang.get_name(), territory=lang.get_territory())
+    """Returns a dict from LightDMLanguage object"""
+    if not lang:
+        return {}
+    return {
+        "code": lang.get_code(),
+        "name": lang.get_name(),
+        "territory": lang.get_territory()
+    }
 
 
 def layout_to_dict(layout):
-    if (not layout):
-        return dict()
-    return dict(
-        description=layout.get_description(),
-        name=layout.get_name(),
-        short_description=layout.get_short_description()
-    )
+    """Returns a dict from LightDMLayout object"""
+    if not layout:
+        return {}
+    return {
+        "description": layout.get_description(),
+        "name": layout.get_name(),
+        "short_description": layout.get_short_description()
+    }
 
 
 def session_to_dict(session):
-    if (not session):
-        return dict()
-    return dict(
-        comment=session.get_comment(),
-        key=session.get_key(),
-        name=session.get_name(),
-        type=session.get_session_type(),
-    )
+    """Returns a dict from LightDMSession object"""
+    if not session:
+        return {}
+    return {
+        "comment": session.get_comment(),
+        "key": session.get_key(),
+        "name": session.get_name(),
+        "type": session.get_session_type(),
+    }
 
 
 def user_to_dict(user):
-    if (not user):
-        return dict()
-    return dict(
-        background=user.get_background(),
-        display_name=user.get_display_name(),
-        home_directory=user.get_home_directory(),
-        image=user.get_image(),
-        language=user.get_language(),
-        layout=user.get_layout(),
-        layouts=user.get_layouts(),
-        logged_in=user.get_logged_in(),
-        session=user.get_session(),
-        username=user.get_name(),
-    )
+    """Returns a dict from LightDMUser object"""
+    if not user:
+        return {}
+    return {
+        "background": user.get_background(),
+        "display_name": user.get_display_name(),
+        "home_directory": user.get_home_directory(),
+        "image": user.get_image(),
+        "language": user.get_language(),
+        "layout": user.get_layout(),
+        "layouts": user.get_layouts(),
+        "logged_in": user.get_logged_in(),
+        "session": user.get_session(),
+        "username": user.get_name(),
+    }
 
 
 def battery_to_dict(battery):
-    if (not battery):
-        return dict()
-    if (len(battery._batteries) == 0):
-        return dict()
-    return dict(
-        name = battery.get_name(),
-        level = battery.get_level(),
-        status = battery.get_status(),
-        ac_status = battery.get_ac_status(),
-        capacity = battery.get_capacity(),
-        time = battery.get_time(),
-        watt = battery.get_watt()
-    )
-
-
-from .Greeter import Greeter
-from .Config import Config
-from .ThemeUtils import ThemeUtils
+    """Returns a dict from Battery object"""
+    if not battery:
+        return {}
+    if len(battery.batteries) == 0:
+        return {}
+    return {
+        "name": battery.get_name(),
+        "level": battery.get_level(),
+        "status": battery.get_status(),
+        "ac_status": battery.get_ac_status(),
+        "capacity": battery.get_capacity(),
+        "time": battery.get_time(),
+        "watt": battery.get_watt()
+    }

src/browser/bridge.py

@@ -28,19 +28,24 @@
 from PyQt5.QtCore import QObject, pyqtSignal, pyqtSlot, pyqtProperty
 
 class Bridge:
+    """Bridge class"""
     @staticmethod
     def method(*args, **kwargs):
+        """Declare a method"""
         return pyqtSlot(*args, **kwargs)
 
     @staticmethod
     def prop(*args, **kwargs):
+        """Declare a property"""
         return pyqtProperty(*args, **kwargs)
 
     @staticmethod
     def signal(*args, **kwargs):
+        """Declare a signal"""
         return pyqtSignal(*args, **kwargs)
 
 class BridgeObject(QObject):
+    """BridgeObject class"""
     def __init__(self, name: str):
         super().__init__(parent=None)
         self._name = name

src/browser/browser.py

@@ -30,7 +30,6 @@
 
 import re
 import sys
-from browser.window import MainWindow
 import os
 from typing import (
     Dict,
@@ -39,26 +38,38 @@ from typing import (
 )
 
 # 3rd-Party Libs
-from PyQt5.QtCore import QRect, QUrl, Qt, QCoreApplication, QFile, QSize
-from PyQt5.QtWidgets import QAction, QApplication, QDesktopWidget, QDockWidget, QMainWindow, QLayout, qApp, QWidget
+from PyQt5.QtCore import QUrl, Qt, QCoreApplication, QFile, QSize
 from PyQt5.QtWebEngineCore import QWebEngineUrlScheme
-from PyQt5.QtWebEngineWidgets import QWebEngineScript, QWebEngineProfile, QWebEngineSettings, QWebEngineView, QWebEnginePage
+from PyQt5.QtWidgets import (
+    QAction, QApplication, QDesktopWidget,
+    QDockWidget, QMainWindow, QLayout, qApp, QWidget
+)
+from PyQt5.QtWebEngineWidgets import (
+    QWebEngineScript, QWebEngineProfile,
+    QWebEngineSettings, QWebEngineView, QWebEnginePage
+)
 from PyQt5.QtGui import QColor, QIcon
 from PyQt5.QtWebChannel import QWebChannel
 
 from browser.error_prompt import WebPage
 from browser.url_scheme import QtUrlSchemeHandler
 from browser.interceptor import QtUrlRequestInterceptor
+from browser.window import MainWindow
 
 from logger import logger
 from config import web_greeter_config
-from bridge import Greeter, Config, ThemeUtils
-from utils.screensaver import reset_screensaver, set_screensaver, init_display
+from bridge.Greeter import greeter
+from bridge.Config import config
+from bridge.ThemeUtils import theme_utils
+from utils.screensaver import screensaver
+
+# pylint: disable-next=unused-import
+# Do not ever remove this import
 import resources
 
 # Typing Helpers
-BridgeObjects = Tuple['BridgeObject']
-Url = TypeVar('Url', str, QUrl)
+BridgeObjects = Tuple["BridgeObject"]
+Url = TypeVar("Url", str, QUrl)
 
 os.environ["QT_DEVICE_PIXEL_RATIO"] = "0"
 os.environ["QT_AUTO_SCREEN_SCALE_FACTOR"] = "1"
@@ -66,10 +77,10 @@ os.environ["QT_SCREEN_SCALE_FACTORS"] = "1"
 os.environ["QT_SCALE_FACTOR"] = "1"
 
 WINDOW_STATES = {
-    'NORMAL': Qt.WindowState.WindowNoState,
-    'MINIMIZED': Qt.WindowState.WindowMinimized,
-    'MAXIMIZED': Qt.WindowState.WindowMaximized,
-    'FULLSCREEN': Qt.WindowState.WindowFullScreen,
+    'NORMAL': Qt.WindowNoState,
+    'MINIMIZED': Qt.WindowMinimized,
+    'MAXIMIZED': Qt.WindowMaximized,
+    'FULLSCREEN': Qt.WindowFullScreen,
 }  # type: Dict[str, Qt.WindowState]
 
 DISABLED_SETTINGS = [
@@ -85,14 +96,15 @@ ENABLED_SETTINGS = [
     'FocusOnNavigationEnabled',      # Qt 5.11+
 ]
 
-def getDefaultCursor():
+def get_default_cursor():
+    """Gets the default cursor theme"""
+    default_theme = "/usr/share/icons/default/index.theme"
     cursor_theme = ""
     matched = None
     try:
-        file = open("/usr/share/icons/default/index.theme")
+        with open(default_theme, "r", encoding = "utf-8") as file:
             matched = re.search(r"Inherits=.*", file.read())
-        file.close()
-    except Exception:
+    except IOError:
         return ""
     if not matched:
         logger.error("Default cursor couldn't be get")
@@ -101,31 +113,34 @@ def getDefaultCursor():
     return cursor_theme
 
 class Application:
+    """Main application"""
     app: QApplication
     desktop: QDesktopWidget
     window: QMainWindow
     states = WINDOW_STATES
 
     def __init__(self):
-        QCoreApplication.setAttribute(Qt.ApplicationAttribute.AA_EnableHighDpiScaling)
-        QApplication.setAttribute(Qt.ApplicationAttribute.AA_EnableHighDpiScaling)
+        QCoreApplication.setAttribute(Qt.AA_EnableHighDpiScaling)
+        QApplication.setAttribute(Qt.AA_EnableHighDpiScaling)
 
         self.app = QApplication(sys.argv)
         self.window = MainWindow()
         self.desktop = self.app.desktop()
 
-        self.window.setAttribute(Qt.WidgetAttribute.WA_DeleteOnClose)
+        self.window.setAttribute(Qt.WA_DeleteOnClose)
         self.window.setWindowTitle("Web Greeter")
 
 
         self.window.setWindowFlags(
-            self.window.windowFlags() | Qt.WindowType.MaximizeUsingFullscreenGeometryHint
+            self.window.windowFlags() | Qt.MaximizeUsingFullscreenGeometryHint
         )
 
         if web_greeter_config["app"]["frame"]:
             self._init_menu_bar()
         else:
-            self.window.setWindowFlags(self.window.windowFlags() | Qt.WindowType.FramelessWindowHint)
+            self.window.setWindowFlags(
+                self.window.windowFlags() | Qt.FramelessWindowHint
+            )
 
         screen_size = self.desktop.availableGeometry().size()
 
@@ -138,29 +153,34 @@ class Application:
 
         try:
             self.window.windowHandle().setWindowState(state)
-        except Exception:
+        except (AttributeError, TypeError):
             self.window.setWindowState(state)
 
-        self.window.setCursor(Qt.CursorShape.ArrowCursor)
-
-        init_display()
+        self.window.setCursor(Qt.ArrowCursor)
 
         timeout = web_greeter_config["config"]["greeter"]["screensaver_timeout"]
-        set_screensaver(timeout or 300)
+        screensaver.set_screensaver(timeout or 300)
 
         cursor_theme = web_greeter_config["config"]["greeter"]["icon_theme"]
-        os.environ["XCURSOR_THEME"] = cursor_theme if cursor_theme != None else getDefaultCursor()
+        if cursor_theme is not None:
+            os.environ["XCURSOR_THEME"] = cursor_theme
+        else:
+            os.environ["XCURSOR_THEME"] = get_default_cursor()
 
         self.app.aboutToQuit.connect(self._before_exit)
 
-    def _before_exit(self):
-        reset_screensaver()
+    @classmethod
+    def _before_exit(cls):
+        """Runs before exit"""
+        screensaver.reset_screensaver()
 
     def show(self):
+        """Show window"""
         self.window.show()
         logger.debug("Window is ready")
 
     def run(self) -> int:
+        """Runs the application"""
         logger.debug("Web Greeter started")
         return self.app.exec_()
 
@@ -185,23 +205,33 @@ class Application:
         about_menu.addAction(exit_action)
 
 class NoneLayout(QLayout):
-    def __init__(self):
-        super().__init__()
-
-    def count(self) -> int:
+    """Layout that shows nothing"""
+    @classmethod
+    def count(cls) -> int:
+        # pylint: disable=missing-function-docstring
         return 0
 
-    def sizeHint(self) -> QSize:
+    @classmethod
+    def sizeHint(cls) -> QSize:
+        # pylint: disable=invalid-name,missing-function-docstring
         size = QSize(0, 0)
         return size
 
-    def minimumSizeHint(self) -> QSize:
+    @classmethod
+    def minimumSizeHint(cls) -> QSize:
+        # pylint: disable=invalid-name,missing-function-docstring
         size = QSize(0, 0)
         return size
 
 
 class Browser(Application):
+    # pylint: disable=too-many-instance-attributes
+    """The main browser"""
     url_scheme: QWebEngineUrlScheme
+    bridge_initialized: bool
+    dev_view: QWebEngineView
+    dev_page: WebPage
+    qdock: QDockWidget
 
     def __init__(self):
         super().__init__()
@@ -209,6 +239,7 @@ class Browser(Application):
         self.load()
 
     def init(self):
+        """Initialize browser"""
         logger.debug("Initializing Browser Window")
 
         if web_greeter_config["config"]["greeter"]["debug_mode"]:
@@ -216,10 +247,10 @@ class Browser(Application):
 
         url_scheme = "web-greeter"
         self.url_scheme = QWebEngineUrlScheme(url_scheme.encode())
-        self.url_scheme.setDefaultPort(QWebEngineUrlScheme.SpecialPort.PortUnspecified)
-        self.url_scheme.setFlags(QWebEngineUrlScheme.Flag.SecureScheme or
-                                 QWebEngineUrlScheme.Flag.LocalScheme or
-                                 QWebEngineUrlScheme.Flag.LocalAccessAllowed)
+        self.url_scheme.setDefaultPort(QWebEngineUrlScheme.PortUnspecified)
+        self.url_scheme.setFlags(QWebEngineUrlScheme.SecureScheme or
+                                 QWebEngineUrlScheme.LocalScheme or
+                                 QWebEngineUrlScheme.LocalAccessAllowed)
         QWebEngineUrlScheme.registerScheme(self.url_scheme)
 
         self.profile = QWebEngineProfile.defaultProfile()
@@ -243,7 +274,7 @@ class Browser(Application):
             self.view.setContextMenuPolicy(Qt.PreventContextMenu)
 
         if web_greeter_config["config"]["greeter"]["secure_mode"]:
-            if (hasattr(QWebEngineProfile, "setUrlRequestInterceptor")):
+            if hasattr(QWebEngineProfile, "setUrlRequestInterceptor"):
                 self.profile.setUrlRequestInterceptor(self.interceptor)
             else: # Older Qt5 versions
                 self.profile.setRequestInterceptor(self.interceptor)
@@ -258,10 +289,11 @@ class Browser(Application):
         logger.debug("Browser Window created")
 
     def load(self):
+        """Load theme and initialize bridge"""
         self.load_theme()
-        self.greeter = Greeter()
-        self.greeter_config = Config()
-        self.theme_utils = ThemeUtils(self.greeter)
+        self.greeter = greeter
+        self.greeter_config = config
+        self.theme_utils = theme_utils
 
         self.bridge_objects = (self.greeter, self.greeter_config, self.theme_utils)
         self.initialize_bridge_objects()
@@ -280,11 +312,12 @@ class Browser(Application):
         titlebar.setLayout(layout)
         self.qdock.setTitleBarWidget(titlebar)
 
-        self.window.addDockWidget(Qt.DockWidgetArea.RightDockWidgetArea, self.qdock)
+        self.window.addDockWidget(Qt.RightDockWidgetArea, self.qdock)
         self.qdock.hide()
         logger.debug("DevTools initialized")
 
     def toggle_devtools(self):
+        """Toggle devtools"""
         if not web_greeter_config["config"]["greeter"]["debug_mode"]:
             return
         win_size = self.window.size()
@@ -322,26 +355,28 @@ class Browser(Application):
         self.page.setView(self.view)
 
     def load_theme(self):
+        """Load theme"""
         theme = web_greeter_config["config"]["greeter"]["theme"]
-        dir = "/usr/share/web-greeter/themes/"
-        path_to_theme = os.path.join(dir, theme, "index.html")
+        dir_t = "/usr/share/web-greeter/themes/"
+        path_to_theme = os.path.join(dir_t, theme, "index.html")
         def_theme = "gruvbox"
 
-        if (theme.startswith("/")): path_to_theme = theme
-        elif (theme.__contains__(".") or theme.__contains__("/")):
+        if theme.startswith("/"):
+            path_to_theme = theme
+        elif theme.__contains__(".") or theme.__contains__("/"):
             path_to_theme = os.path.join(os.getcwd(), theme)
             path_to_theme = os.path.realpath(path_to_theme)
 
-        if (not path_to_theme.endswith(".html")):
+        if not path_to_theme.endswith(".html"):
             path_to_theme = os.path.join(path_to_theme, "index.html")
 
-        if (not os.path.exists(path_to_theme)):
+        if not os.path.exists(path_to_theme):
             print("Path does not exists", path_to_theme)
-            path_to_theme = os.path.join(dir, def_theme, "index.html")
+            path_to_theme = os.path.join(dir_t, def_theme, "index.html")
 
         web_greeter_config["config"]["greeter"]["theme"] = path_to_theme
 
-        url = QUrl("web-greeter://app/{0}".format(path_to_theme))
+        url = QUrl(f"web-greeter://app/{path_to_theme}")
         self.page.load(url)
 
         logger.debug("Theme loaded")
@@ -353,7 +388,7 @@ class Browser(Application):
 
         # print(script_file, path)
 
-        if script_file.open(QFile.OpenModeFlag.ReadOnly):
+        if script_file.open(QFile.ReadOnly):
             script_string = str(script_file.readAll(), 'utf-8')
 
             script.setInjectionPoint(QWebEngineScript.DocumentCreation)
@@ -372,19 +407,21 @@ class Browser(Application):
         self.bridge_initialized = True
 
     def initialize_bridge_objects(self) -> None:
+        """Initialize bridge objects :D"""
         if not self.bridge_initialized:
             self._init_bridge_channel()
         registered_objects = self.channel.registeredObjects()
 
         for obj in self.bridge_objects:
             if obj not in registered_objects:
+                # pylint: disable=protected-access
                 self.channel.registerObject(obj._name, obj)
                 # print("Registered", obj._name)
 
     def load_script(self, path: Url, name: str):
+        """Loads a script in page"""
         qt_api = self._get_channel_api_script()
         qt_api_source = qt_api.sourceCode()
         script = self._create_webengine_script(path, name)
         script.setSourceCode(qt_api_source + "\n" + script.sourceCode())
         self.page.scripts().insert(script)
-

src/browser/error_prompt.py

@@ -29,23 +29,30 @@
 
 # 3rd-Party Libs
 from typing import List
-from PyQt5.QtWebEngineWidgets import QWebEnginePage
-from PyQt5.QtWidgets import QAbstractButton, QDialogButtonBox, QDialog, QVBoxLayout, QLabel, QPushButton
-from config import web_greeter_config
-
-import globals
 from logging import (
     getLogger,
     DEBUG,
     Formatter,
     StreamHandler,
 )
+from PyQt5.QtWebEngineWidgets import QWebEnginePage
+from PyQt5.QtWidgets import (
+    QAbstractButton,
+    QDialogButtonBox,
+    QDialog,
+    QVBoxLayout,
+    QLabel,
+    QPushButton
+)
+from config import web_greeter_config
 
-log_format = ''.join([
+import globales
+
+LOG_FORMAT = ''.join([
     '%(asctime)s [ %(levelname)s ] %(filename)s %(',
     'lineno)d: %(message)s'
 ])
-formatter = Formatter(fmt=log_format, datefmt="%Y-%m-%d %H:%M:%S")
+formatter = Formatter(fmt=LOG_FORMAT, datefmt="%Y-%m-%d %H:%M:%S")
 logger = getLogger("javascript")
 logger.propagate = False
 stream_handler = StreamHandler()
@@ -55,66 +62,79 @@ logger.setLevel(DEBUG)
 logger.addHandler(stream_handler)
 
 class WebPage(QWebEnginePage):
-
-    def javaScriptConsoleMessage(self, level: QWebEnginePage.JavaScriptConsoleMessageLevel, message: str, lineNumber: int, sourceID: str):
-        if sourceID == "":
-            sourceID = "console"
-
-        logLevel = 0
-        if level == WebPage.JavaScriptConsoleMessageLevel.ErrorMessageLevel:
-            logLevel = 40
-        elif level == WebPage.JavaScriptConsoleMessageLevel.WarningMessageLevel:
-            logLevel = 30
-        elif level == WebPage.JavaScriptConsoleMessageLevel.InfoMessageLevel:
+    """web-greeter's webpage class"""
+
+    def javaScriptConsoleMessage(
+            self, level: QWebEnginePage.JavaScriptConsoleMessageLevel,
+            message: str, line_number: int, source_id: str
+        ):
+        # pylint: disable = no-self-use,missing-function-docstring,invalid-name
+        if source_id == "":
+            source_id = "console"
+
+        log_level = 0
+        if level == WebPage.ErrorMessageLevel:
+            log_level = 40
+        elif level == WebPage.WarningMessageLevel:
+            log_level = 30
+        elif level == WebPage.InfoMessageLevel:
             return
         else:
             return
 
         record = logger.makeRecord(
             name="javascript",
-            level=logLevel,
+            level=log_level,
             fn="",
-            lno=lineNumber,
+            lno=line_number,
             msg=message,
             args=(),
             exc_info=None
         )
-        record.filename = sourceID
+        record.filename = source_id
         logger.handle(record)
 
-        if logLevel == 40:
-            errorMessage = "{source} {line}: {msg}".format(
-                source=sourceID, line=lineNumber, msg=message)
-            errorPrompt(errorMessage)
+        if log_level == 40:
+            errorMessage = f"{source_id} {line_number}: {message}"
+            error_prompt(errorMessage)
 
 class Dialog(QDialog):
-    def __init__(self, parent=None, title:str = "Dialog", message:str = "Message", detail:str = "", buttons: List[str] = []):
+    """Popup dialog class"""
+
+    def __init__(
+            self, parent = None, title: str = "Dialog",
+            message: str = "Message", detail: str = "",
+            buttons: List[str] = None
+        ):
         super().__init__(parent)
         self.setWindowTitle(title)
 
-        self.buttonBox = QDialogButtonBox()
-        for i in range(0, len(buttons)):
-            button = QPushButton(buttons[i])
+        self.button_box = QDialogButtonBox()
+        if buttons is not None:
+            for i, btn in enumerate(buttons, 0):
+                button = QPushButton(btn)
                 button.role = i
-            self.buttonBox.addButton(button, QDialogButtonBox.ButtonRole.NoRole)
+                self.button_box.addButton(button, QDialogButtonBox.NoRole)
 
-        self.buttonBox.clicked.connect(self.handle_click)
+        self.button_box.clicked.connect(self.handle_click)
 
         self.layout = QVBoxLayout()
         self.layout.addWidget(QLabel(message))
         self.layout.addWidget(QLabel(detail))
-        self.layout.addWidget(self.buttonBox)
+        self.layout.addWidget(self.button_box)
 
         self.setLayout(self.layout)
 
     def handle_click(self, button: QAbstractButton):
+        # pylint: disable=missing-function-docstring
         self.done(button.role)
 
-def errorPrompt(err):
+def error_prompt(err):
+    """Prompts a popup dialog on error"""
     if not web_greeter_config["config"]["greeter"]["detect_theme_errors"]:
         return
 
-    dia = Dialog(parent=globals.greeter.window, title="Error",
+    dia = Dialog(parent=globales.greeter.window, title="Error",
                  message="An error ocurred. Do you want to change to default theme?",
                  detail=err,
                  buttons=["Reload theme", "Set default theme", "Cancel"],
@@ -124,13 +144,9 @@ def errorPrompt(err):
     result = dia.result()
 
     if result == 2:  # Cancel
-        return
+        pass
     elif result == 1:  # Default theme
         web_greeter_config["config"]["greeter"]["theme"] = "gruvbox"
-        globals.greeter.load_theme()
-        return
+        globales.greeter.load_theme()
     elif result == 0:  # Reload
-        globals.greeter.load_theme()
-        return
-
-    return
+        globales.greeter.load_theme()

src/browser/interceptor.py

@@ -29,12 +29,14 @@
 from PyQt5.QtWebEngineCore import QWebEngineUrlRequestInterceptor, QWebEngineUrlRequestInfo
 
 class QtUrlRequestInterceptor(QWebEngineUrlRequestInterceptor):
+    """Url request interceptor for web-greeter's protocol"""
 
     def __init__(self, url_scheme: str):
         super().__init__()
         self._url_scheme = url_scheme
 
     def intercept_request(self, info: QWebEngineUrlRequestInfo) -> None:
+        """Intercept request"""
         url = info.requestUrl().toString()
         not_webg_uri = self._url_scheme != info.requestUrl().scheme()
         not_data_uri = 'data' != info.requestUrl().scheme()
@@ -43,14 +45,18 @@ class QtUrlRequestInterceptor(QWebEngineUrlRequestInterceptor):
         # print(url)
 
         not_devtools = (
-            not url.startswith('http://127.0.0.1') and not url.startswith('ws://127.0.0.1')
+            not url.startswith('http://127.0.0.1') and
+            not url.startswith('ws://127.0.0.1')
             and not url.startswith('devtools')
         )
 
-        block_request = not_devtools and not_data_uri and not_webg_uri and not_local_file
+        block_request = (
+            not_devtools and not_data_uri and
+            not_webg_uri and not_local_file
+        )
 
         info.block(block_request) # Block everything that is not allowed
 
     def interceptRequest(self, info: QWebEngineUrlRequestInfo) -> None:
+        # pylint: disable=invalid-name,missing-function-docstring
         self.intercept_request(info)
-

src/browser/url_scheme.py

@@ -38,8 +38,10 @@ from PyQt5.QtWebEngineCore import QWebEngineUrlSchemeHandler, QWebEngineUrlReque
 
 
 class QtUrlSchemeHandler(QWebEngineUrlSchemeHandler):
+    """URL Scheme Handler for web-greeter's protocol"""
 
     def requestStarted(self, job: QWebEngineUrlRequestJob) -> None:
+        # pylint: disable=invalid-name,missing-function-docstring
         path = job.requestUrl().path()
         path = os.path.realpath(path)
 
@@ -58,8 +60,8 @@ class QtUrlSchemeHandler(QWebEngineUrlSchemeHandler):
         try:
             with open(path, 'rb') as file:
                 content_type = mimetypes.guess_type(path)
-                if not content_type[0]:
-                    content_type = ["text/plain", None]
+                if content_type[0] is None:
+                    content_type = ("text/plain", None)
                 buffer = QBuffer(parent=self)
 
                 buffer.open(QIODevice.WriteOnly)
@@ -67,8 +69,10 @@ class QtUrlSchemeHandler(QWebEngineUrlSchemeHandler):
                 buffer.seek(0)
                 buffer.close()
 
+                if content_type[0] is None:
+                    job.reply("text/plain", "")
+                else:
                     job.reply(content_type[0].encode(), buffer)
 
         except Exception as err:
             raise err
-

src/browser/window.py

@@ -25,46 +25,56 @@
 #  You should have received a copy of the GNU General Public License
 #  along with Web Greeter; If not, see <http://www.gnu.org/licenses/>.
 
-from PyQt5.QtCore import QFileSystemWatcher, Qt
+from PyQt5.QtCore import Qt
 from PyQt5.QtWidgets import QAction, QMainWindow
-from PyQt5.QtGui import QKeyEvent
 from config import web_greeter_config
 
-import globals
+import globales
 
 class MainWindow(QMainWindow):
+    """Main window for web-greeter"""
+
     def __init__(self):
         super().__init__()
         self.init_actions()
 
     def init_actions(self):
-        devAct = QAction(text="&Toggle Devtools", parent=self)
-        devAct.setShortcut("Shift+Ctrl+I")
-        devAct.triggered.connect(self.toggle_devtools)
+        """Initialize window actions and their shortcuts"""
+        dev_act = QAction(text="&Toggle Devtools", parent=self)
+        dev_act.setShortcut("Shift+Ctrl+I")
+        dev_act.triggered.connect(self.toggle_devtools)
 
-        monBUp = QAction(text="&Increase brightness", parent=self)
-        monBDo = QAction(text="&Decrease brightness", parent=self)
-        monBUp.setShortcut(Qt.Key.Key_MonBrightnessUp)
-        monBDo.setShortcut(Qt.Key.Key_MonBrightnessDown)
-        monBUp.triggered.connect(self.inc_brightness)
-        monBDo.triggered.connect(self.dec_brightness)
+        mon_bright_up = QAction(text="&Increase brightness", parent=self)
+        mon_bright_down = QAction(text="&Decrease brightness", parent=self)
+        mon_bright_up.setShortcut(Qt.Key_MonBrightnessUp)
+        mon_bright_down.setShortcut(Qt.Key_MonBrightnessDown)
+        mon_bright_up.triggered.connect(self.inc_brightness)
+        mon_bright_down.triggered.connect(self.dec_brightness)
 
-        self.addAction(devAct)
-        self.addAction(monBUp)
-        self.addAction(monBDo)
+        self.addAction(dev_act)
+        self.addAction(mon_bright_up)
+        self.addAction(mon_bright_down)
 
-    def toggle_devtools(self):
-        globals.greeter.toggle_devtools()
+    @classmethod
+    def toggle_devtools(cls):
+        """Toggle devtools"""
+        globales.greeter.toggle_devtools()
 
-    def inc_brightness(self):
-        if globals.greeter:
+    @classmethod
+    def inc_brightness(cls):
+        """Increase brightness"""
+        if globales.greeter:
             value = web_greeter_config["config"]["features"]["backlight"]["value"]
-            globals.greeter.greeter.inc_brightness(value)
-    def dec_brightness(self):
-        if globals.greeter:
+            globales.greeter.greeter.inc_brightness(value)
+    @classmethod
+    def dec_brightness(cls):
+        """Decrease brightness"""
+        if globales.greeter:
             value = web_greeter_config["config"]["features"]["backlight"]["value"]
-            globals.greeter.greeter.dec_brightness(value)
+            globales.greeter.greeter.dec_brightness(value)
 
-    def updateBrightness(self):
-        if globals.greeter:
-            globals.greeter.greeter.brightness_update.emit()
+    @classmethod
+    def update_brightness(cls):
+        """Updates brightness"""
+        if globales.greeter:
+            globales.greeter.greeter.brightness_update.emit()

src/config.py

@@ -26,16 +26,13 @@
 #  along with Web Greeter; If not, see <http://www.gnu.org/licenses/>.
 # Standard lib
 
-import sys
 import os
-import ruamel.yaml as yaml
+from ruamel import yaml
 
-import globals
 from logger import logger
 
-path_to_config = "/etc/lightdm/web-greeter.yml"
+PATH_TO_CONFIG = "/etc/lightdm/web-greeter.yml"
 
-global web_greeter_config
 web_greeter_config = {
     "config": {
         "branding": {
@@ -77,13 +74,13 @@ web_greeter_config = {
 }
 
 def load_config():
+    """Load web-greeter's config"""
     try:
-        if (not os.path.exists(path_to_config)):
+        if not os.path.exists(PATH_TO_CONFIG):
             raise Exception("Config file not found")
-        file = open(path_to_config, "r")
+        with open(PATH_TO_CONFIG, "r", encoding="utf-8") as file:
             web_greeter_config["config"] = yaml.safe_load(file)
-    except Exception as err:
-        logger.error("Config was not loaded:\n\t{0}".format(err))
-    pass
+    except IOError as err:
+        logger.error("Config was not loaded:\n\t%s", err)
 
 load_config()

src/globales.py

@@ -0,0 +1,5 @@
+"""Global variables"""
+
+from browser.browser import Browser
+
+greeter: Browser # pylint: disable=invalid-name

src/globals.py

@@ -1 +0,0 @@
-global greeter # type: Browser

src/logger.py

@@ -33,14 +33,13 @@ from logging import (
     StreamHandler
 )
 
-log_format = ''.join([
+LOG_FORMAT = ''.join([
     '%(asctime)s [ %(levelname)s ] %(module)s - %(filename)s:%(',
     'lineno)d : %(funcName)s | %(message)s'
 ])
-formatter = Formatter(fmt=log_format, datefmt="%Y-%m-%d %H:%M:%S")
+formatter = Formatter(fmt=LOG_FORMAT, datefmt="%Y-%m-%d %H:%M:%S")
 stream_handler = StreamHandler()
 
-global logger
 logger = getLogger("debug")
 
 stream_handler.setLevel(DEBUG)

src/utils/acpi.py

@@ -0,0 +1,63 @@
+
+import subprocess
+from threading import Thread
+from typing import List, Callable, Any
+from shutil import which
+from logger import logger
+
+Callback = Callable[[str], Any]
+
+class ACPIController:
+    """ACPI controller"""
+
+    tries = 0
+    callbacks: List[Callback] = []
+
+    def __init__(self):
+        if self.check_acpi():
+            self.listen()
+        else:
+            logger.error("ACPI: acpi_listen does not exists")
+
+    @staticmethod
+    def check_acpi() -> bool:
+        """Checks if acpi_listen does exists"""
+        if which("acpi_listen"):
+            return True
+        return False
+
+    def connect(self, callback: Callback):
+        """Connect callback to ACPI controller"""
+        self.callbacks.append(callback)
+
+    def disconnect(self, callback: Callback):
+        """Disconnect callback from ACPI controller"""
+        self.callbacks.remove(callback)
+
+    def _listen(self):
+        try:
+            with subprocess.Popen("acpi_listen",
+                                  stdout = subprocess.PIPE,
+                                  text = True) as process:
+                if not process.stdout:
+                    raise IOError("No stdout")
+                while True:
+                    line = process.stdout.readline().strip()
+                    if not line:
+                        continue
+                    for _, callback in enumerate(self.callbacks):
+                        callback(line)
+        except IOError as err:
+            logger.error("ACPI: %s", err)
+            if self.tries < 5:
+                self.tries += 1
+                logger.debug("Restarting acpi_listen")
+                self._listen()
+
+    def listen(self):
+        """Listens to acpi_listen"""
+        self.thread = Thread(target = self._listen)
+        self.thread.daemon = True
+        self.thread.start()
+
+ACPI = ACPIController()

src/utils/battery.py

@@ -1,48 +1,40 @@
-import subprocess
-import shlex
+import os
 import re
 import math
-from threading import Thread
 import time
-from logger import logger
-from shutil import which
-
-running = False
+from typing import Union
+import globales
+from utils.acpi import ACPI
 
 class Battery:
+    # pylint: disable=too-many-instance-attributes
+    """Battery controller"""
 
-    _batteries = []
-    ac = "AC0"
+    batteries = []
+    ac_path = "AC0"
     pspath = "/sys/class/power_supply/"
     perc = -1
     status = "N/A"
     capacity = 0
     time = ""
     watt = 0
-
-    callbacks = []
+    running_update = False
 
     def __init__(self):
-        if len(self._batteries) == 0:
+        if len(self.batteries) == 0:
             scandir_line(self.pspath, self._update_batteries)
-        start_timer(self.full_update, self.onerror)
+        ACPI.connect(self.acpi_listen)
         self.full_update()
 
-    def connect(self, callback):
-        self.callbacks.append(callback)
-
-    def disconnect(self, callback):
-        self.callbacks.remove(callback)
-
-    def onerror(self):
-        self._batteries = []
-        for cb in self.callbacks:
-            cb()
+    def acpi_listen(self, data: str):
+        """Listens"""
+        if re.match(r"battery|ac_adapter", data):
+            self.full_update()
 
     def _update_batteries(self, line):
         bstr = re.match(r"BAT\w+", line)
         if bstr:
-            self._batteries.append(dict(
+            self.batteries.append(dict(
                 name = bstr.group(),
                 status = "N/A",
                 perc = 0,
@@ -50,17 +42,18 @@ class Battery:
             ))
         else:
             match = re.match(r"A\w+", line)
-            self.ac = match.group() if match else self.ac
+            self.ac_path = match.group() if match else self.ac_path
 
     # Based on "bat" widget from "lain" awesome-wm library
     # * (c) 2013,      Luca CPZ
     # * (c) 2010-2012, Peter Hofmann
     # @see https://github.com/lcpz/lain/blob/master/widget/bat.lua
     def full_update(self):
-        global running
-        if running:
+        # pylint: disable=too-many-locals,too-many-statements,too-many-branches
+        """Do a full update"""
+        if self.running_update:
             return
-        running = True
+        self.running_update = True
 
         sum_rate_current = 0
         sum_rate_voltage = 0
@@ -71,8 +64,7 @@ class Battery:
         sum_charge_full = 0
         sum_charge_design = 0
 
-        for i in range(len(self._batteries)):
-            battery = self._batteries[i]
+        for i, battery in enumerate(self.batteries):
             bstr = self.pspath + battery["name"]
             present = read_first_line(bstr + "/present")
 
@@ -89,33 +81,34 @@ class Battery:
                 energy_percentage = tonumber(read_first_line(bstr + "/capacity")
                                  or math.floor(energy_now / energy_full * 100)) or 0
 
-                self._batteries[i]["status"] = read_first_line(bstr + "/status") or "N/A"
-                self._batteries[i]["perc"] = energy_percentage or self._batteries[i].perc
+                self.batteries[i]["status"] = read_first_line(bstr + "/status") or "N/A"
+                self.batteries[i]["perc"] = energy_percentage or self.batteries[i].perc
 
                 if not charge_design or charge_design == 0:
-                    self._batteries[i]["capacity"] = 0
+                    self.batteries[i]["capacity"] = 0
                 else:
-                    self._batteries[i]["capacity"] = math.floor(
+                    self.batteries[i]["capacity"] = math.floor(
                         charge_full / charge_design * 100)
 
                 sum_rate_current = sum_rate_current + rate_current
                 sum_rate_voltage = sum_rate_voltage + rate_voltage
                 sum_rate_power = sum_rate_power + rate_power
-                sum_rate_energy   = sum_rate_energy + (rate_power or ((rate_voltage * rate_current) / 1e6))
+                sum_rate_energy = sum_rate_energy + (
+                    rate_power or (rate_voltage * rate_current / 1e6)
+                )
                 sum_energy_now = sum_energy_now + energy_now
                 sum_energy_full = sum_energy_full + energy_full
                 sum_charge_full = sum_charge_full + charge_full
                 sum_charge_design = sum_charge_design + charge_design
 
         self.capacity = math.floor(min(100, sum_charge_full / (sum_charge_design or 1) * 100))
-        self.status = len(self._batteries) > 0 and self._batteries[0]["status"] or "N/A"
+        self.status = self.batteries[0]["status"] if len(self.batteries) > 0 else "N/A"
 
-        for i in range(len(self._batteries)):
-            battery = self._batteries[i]
+        for i, battery in enumerate(self.batteries):
             if battery["status"] == "Discharging" or battery["status"] == "Charging":
                 self.status = battery["status"]
 
-        self.ac_status = tonumber(read_first_line(self.pspath + self.ac + "/online")) or "N/A"
+        self.ac_status = tonumber(read_first_line(self.pspath + self.ac_path + "/online")) or 0
 
         if self.status != "N/A":
             if self.status != "Full" and sum_rate_power == 0 and self.ac_status == 1:
@@ -126,117 +119,86 @@ class Battery:
             elif self.status != "Full":
                 rate_time = 0
                 if (sum_rate_power > 0 or sum_rate_current > 0):
-                    div = (sum_rate_power > 0 and sum_rate_power) or sum_rate_current
+                    div = sum_rate_power > 0 or sum_rate_current
 
                     if self.status == "Charging":
                         rate_time = (sum_energy_full - sum_energy_now) / div
                     else:
                         rate_time = sum_energy_now / div
 
-                    if 0 < rate_time and rate_time < 0.01:
+                    if rate_time and rate_time < 0.01:
                         rate_time_magnitude = tonumber(abs(math.floor(math.log10(rate_time)))) or 0
                         rate_time = int(rate_time * 10) ^ (rate_time_magnitude - 2)
 
                     hours   = math.floor(rate_time)
                     minutes = math.floor((rate_time - hours) * 60)
-                    self.perc  = math.floor(min(100, (sum_energy_now / sum_energy_full) * 100) + 0.5)
-                    self.time = "{:02d}:{:02d}".format(hours, minutes)
-                    self.watt = "{:.2f}".format(sum_rate_energy / 1e6)
+                    self.perc  = math.floor(
+                        min(100, (sum_energy_now / sum_energy_full) * 100) + 0.5
+                    )
+                    self.time = f"{hours:02d}:{minutes:02d}"
+                    self.watt = f"{sum_rate_energy/1e6:.2f}"
             elif self.status == "Full":
                 self.perc = 100
                 self.time = "00:00"
                 self.watt = 0
 
-        self.perc = self.perc == None and 0 or self.perc
+        self.perc = self.perc if self.perc is not None else 0
 
-        for cb in self.callbacks:
-            cb()
+        if hasattr(globales, "greeter"):
+            globales.greeter.greeter.battery_update.emit()
 
         time.sleep(0.1)
 
-        running = False
+        self.running_update = False
 
     def get_name(self):
-        return self._batteries[0]["name"]
+        """Get name"""
+        return self.batteries[0]["name"]
 
     def get_level(self):
+        """Get level"""
         return self.perc
 
     def get_status(self):
+        """Get status"""
         return self.status
 
     def get_ac_status(self):
+        """Get AC status"""
         return self.ac_status
 
     def get_capacity(self):
+        """Get capacity"""
         return self.capacity
 
     def get_time(self):
+        """Get time"""
         return self.time
 
     def get_watt(self):
+        """Get watt"""
         return self.watt
 
-acpi_tries = 0
-
-def acpi_listen(callback, onerror):
-    if not which("acpi_listen"):
-        return
-
-    global acpi_tries
-    try:
-        main = subprocess.Popen(shlex.split("acpi_listen"),
-                                stdout=subprocess.PIPE, text=True)
-        awky = subprocess.Popen(shlex.split("grep --line-buffered -E 'battery|ac_adapter'"),
-                                stdout=subprocess.PIPE, stdin=main.stdout, text=True)
-        while True:
-            if (awky.stdout == None): continue
-            output = awky.stdout.readline()
-            if output == "" and awky.poll() != None:
-                break
-            if output:
-                callback()
-        logger.warning("acpi_listen terminated")
-        if acpi_tries < 5:
-            acpi_tries += 1
-            logger.debug("Restarting acpi_listen")
-            return acpi_listen(callback, onerror)
-        else:
-            raise Exception("acpi_listen exceeded 5 restarts")
-    except Exception as err:
-        logger.error("Battery error: " + err.__str__())
-        onerror()
-
 def scandir_line(path, callback):
-    main = subprocess.Popen(shlex.split("ls -1 {}".format(path)),
-                            stdout=subprocess.PIPE, text=True)
-    while True:
-        if (main.stdout == None): continue
-        line = main.stdout.readline()
-        if line == "" and main.poll() != None:
-            break
-        if line:
+    """List directory"""
+    lines = os.listdir(path)
+    for _, line in enumerate(lines):
         callback(line)
 
-def read_first_line(path):
+def read_first_line(path) -> Union[str, None]:
+    """Just read the first line of file"""
     try:
-        file = open(path, "r")
         first = None
-        if file:
+        with open(path, "r", encoding = "utf-8") as file:
             first = file.readline()
             first = first.replace("\n", "")
-            file.close()
         return first
-    except Exception:
+    except IOError:
         return None
 
-def tonumber(asa):
+def tonumber(string) -> Union[int, None]:
+    """Converts string to int or None"""
     try:
-        return int(asa)
-    except Exception:
+        return int(string)
+    except (ValueError, TypeError):
         return None
-
-def start_timer(callback, onerror):
-    thread = Thread(target = acpi_listen, args=(callback, onerror,))
-    thread.daemon = True
-    thread.start()

src/utils/brightness.py

@@ -28,16 +28,17 @@
 import os
 import stat
 import time
-import pyinotify
 from typing import List
 from threading import Thread
-import globals
+import pyinotify
 from logger import logger
 from config import web_greeter_config
+import globales
 
 sys_path = ["/sys/class/backlight/"]
 
 def get_controllers() -> List[str]:
+    """Get brightness controllers path"""
     ctrls: List[str] = []
     for dev in sys_path:
         if os.path.exists(dev) and stat.S_ISDIR(os.stat(dev).st_mode):
@@ -47,15 +48,20 @@ def get_controllers() -> List[str]:
     return ctrls
 
 class EventHandler(pyinotify.ProcessEvent):
-    def process_IN_MODIFY(self, event):
-        if globals.greeter:
-            globals.greeter.greeter.brightness_update.emit()
+    """PyInotify handler"""
+    @classmethod
+    def process_IN_MODIFY(cls, _):
+        # pylint: disable=invalid-name,missing-function-docstring
+        if hasattr(globales, "greeter"):
+            globales.greeter.greeter.brightness_update.emit()
 
 
 # Behavior based on "acpilight"
 # Copyright(c) 2016-2019 by wave++ "Yuri D'Elia" <wavexx@thregr.org>
 # See https://gitlab.com/wavexx/acpilight
 class BrightnessController:
+    # pylint: disable=too-many-instance-attributes
+    """Brightness controller for web-greeter"""
 
     _controllers: List[str] = []
     _available: bool = False
@@ -69,8 +75,8 @@ class BrightnessController:
     def __init__(self):
         self._controllers = get_controllers()
         if (len(self._controllers) == 0 or
-            self._controllers[0] == None or
-            web_greeter_config["config"]["features"]["backlight"]["enabled"] == False):
+            self._controllers[0] is None or
+            not web_greeter_config["config"]["features"]["backlight"]["enabled"]):
             self._available = False
             return
         b_path = self._controllers[0]
@@ -78,8 +84,8 @@ class BrightnessController:
         self._brightness_path = os.path.join(b_path, "brightness")
         self._max_brightness_path = os.path.join(b_path, "max_brightness")
 
-        with open(self._max_brightness_path, "r") as f:
-            self._max_brightness = int(f.read())
+        with open(self._max_brightness_path, "r", encoding = "utf-8") as file:
+            self._max_brightness = int(file.read())
 
         steps = web_greeter_config["config"]["features"]["backlight"]["steps"]
         self.steps = 1 if steps <= 1 else steps
@@ -87,15 +93,17 @@ class BrightnessController:
         self.watch_brightness()
 
     def _watch(self):
-        wm = pyinotify.WatchManager()
+        watch_manager = pyinotify.WatchManager()
         handler = EventHandler()
-        wm.add_watch(self._brightness_path, pyinotify.IN_MODIFY)
+        # pylint: disable-next=no-member
+        watch_manager.add_watch(self._brightness_path, pyinotify.IN_MODIFY)
 
-        notifier = pyinotify.Notifier(wm, handler)
+        notifier = pyinotify.Notifier(watch_manager, handler)
 
         notifier.loop()
 
     def watch_brightness(self):
+        """Starts a thread to watch brightness"""
         if not self._available:
             return
         thread = Thread(target = self._watch)
@@ -104,43 +112,53 @@ class BrightnessController:
 
     @property
     def max_brightness(self) -> int:
+        """Max brightness"""
         return self._max_brightness
 
     @property
     def real_brightness(self) -> int:
-        if not self._available: return -1
+        """Real brightness"""
+        if not self._available:
+            return -1
         try:
-            with open(self._brightness_path, "r") as f:
-                return int(f.read())
+            with open(self._brightness_path, "r", encoding = "utf-8") as file:
+                return int(file.read())
         except OSError:
-            logger.error("Couldn't read from \"" + self._brightness_path + "\"")
+            logger.error("Couldn't read from \"%s\"", self._brightness_path)
             return -1
 
     @real_brightness.setter
-    def real_brightness(self, v: int):
-        if not self._available: return
-        if v > self.max_brightness: v = self.max_brightness
-        elif v <= 0: v = 0
+    def real_brightness(self, value: int):
+        if not self._available:
+            return
+        if value > self.max_brightness:
+            value = self.max_brightness
+        elif value <= 0:
+            value = 0
 
-        if not os.path.exists(self._brightness_path): return
+        if not os.path.exists(self._brightness_path):
+            return
 
         try:
-            with open(self._brightness_path, "w") as f:
-                f.write(str(round(v)))
+            with open(self._brightness_path, "w", encoding = "utf-8") as file:
+                file.write(str(round(value)))
         except OSError:
-            logger.error("Couldn't write to \"" + self._brightness_path + "\"")
+            logger.error("Couldn't write to \"%s\"", self._brightness_path)
 
     @property
     def brightness(self) -> int:
-        if not self._available: return -1
+        """Brightness"""
+        if not self._available:
+            return -1
         return round(self.real_brightness * 100 / self.max_brightness)
 
     @brightness.setter
-    def brightness(self, v: int):
-        self.real_brightness = round(v * self.max_brightness / 100)
+    def brightness(self, value: int):
+        self.real_brightness = round(value * self.max_brightness / 100)
 
     def _set_brightness(self, value: int):
-        if not self._available: return
+        if not self._available:
+            return
         steps = self.steps or 1
         sleep = self.delay / steps
         current = self.brightness
@@ -155,11 +173,14 @@ class BrightnessController:
             self.brightness = round(brigh)
 
     def set_brightness(self, value: int):
+        """Set brightness"""
         thread = Thread(target = self._set_brightness, args = (value,))
         thread.start()
 
     def inc_brightness(self, value: int):
+        """Increase brightness"""
         self.set_brightness(self.brightness + value)
 
     def dec_brightness(self, value: int):
+        """Decrease brightness"""
         self.set_brightness(self.brightness - value)

src/utils/screensaver.py

@@ -1,40 +1,55 @@
-from logger import logger
 from Xlib.display import Display
+from Xlib.error import DisplayError
+from logger import logger
+
+class Screensaver:
+    """Screensaver class"""
 
-saved_data: dict = {}
-saved = False
-available = False
+    display: Display
+    available: bool = False
+    saved_data: dict[str, int]
+    saved: bool = False
 
-display: Display
+    def __init__(self):
+        self.init_display()
 
-def init_display():
-    global display, available
+    def init_display(self):
+        """Init display"""
         try:
-        display = Display()
-        available = True
-    except Exception as err:
-        logger.error(f"Xlib error: {err}")
-
-def set_screensaver(timeout: int):
-    global saved_data, saved, available, display
-    if saved or not available:
+            self.display = Display()
+            self.available = True
+        except DisplayError as err:
+            logger.error("Xlib error: %s", err)
+
+    def set_screensaver(self, timeout: int):
+        """Set screensaver timeout"""
+        if self.saved or not self.available:
             return
-    display.sync()
-    display.sync()
-    data: dict[str, int] = display.get_screen_saver()._data or {}
-    saved_data = data
-    saved = True
-
-    display.set_screen_saver(timeout, data["interval"], data["prefer_blanking"], data["allow_exposures"])
-    display.flush()
+        self.display.sync()
+        self.display.sync()
+        # pylint: disable-next=protected-access
+        data: dict[str, int] = self.display.get_screen_saver()._data or {}
+        self.saved_data = data
+        self.saved = True
+
+        self.display.set_screen_saver(timeout,
+                                 data["interval"],
+                                 data["prefer_blanking"],
+                                 data["allow_exposures"])
+        self.display.flush()
         logger.debug("Screensaver timeout set")
 
-def reset_screensaver():
-    global saved_data, saved, available, display
-    if not saved or not available:
+    def reset_screensaver(self):
+        """Reset screensaver"""
+        if not self.saved or not self.available:
             return
-    display.sync()
-    display.set_screen_saver(saved_data["timeout"], saved_data["interval"], saved_data["prefer_blanking"], saved_data["allow_exposures"])
-    display.flush()
-    saved = False
+        self.display.sync()
+        self.display.set_screen_saver(self.saved_data["timeout"],
+                                 self.saved_data["interval"],
+                                 self.saved_data["prefer_blanking"],
+                                 self.saved_data["allow_exposures"])
+        self.display.flush()
+        self.saved = False
         logger.debug("Screensaver reset")
+
+screensaver = Screensaver()