"""
Helpers for terminal color support.
"""
import jinja2.defaults
# Type annotations
# pylint: disable=unused-import,wrong-import-order
from typing import Any, Callable, Dict, Optional, Tuple # noqa
try:
import colorama
COLOR_SUPPORT = True
_FG_COLORS = ('red', 'green', 'yellow', 'blue', 'magenta', 'cyan', 'white')
_BG_COLORS = ('black', 'red', 'green', 'yellow', 'blue', 'magenta', 'cyan', 'white')
_FG = {
color: getattr(colorama.Fore, color.upper()) for color in _FG_COLORS
} # type: Dict[str, str]
_BG = {
color: getattr(colorama.Back, color.upper()) for color in _BG_COLORS
} # type: Dict[str, str]
except ImportError:
COLOR_SUPPORT = False
[docs]def _style_plain(text, **kwargs):
# type: (str, **str) -> str
# pylint: disable=unused-argument
return text
# pylint: disable=invalid-name
[docs]def _style_colors(text, fg=None, bg=None, reset=True):
# type: (str, Optional[str], Optional[str], Optional[bool]) -> str
fg_code = getattr(colorama.Fore, fg.upper()) if fg in _FG_COLORS else ''
bg_code = getattr(colorama.Back, bg.upper()) if bg in _BG_COLORS else ''
reset_code = colorama.Style.RESET_ALL if reset else ''
return '{}{}{}{}'.format(fg_code, bg_code, text, reset_code)
# Make `style` a static method, to allow its change on the "global" level while letting
# its users to notice it changed by not using it directly but via `Colors.style`.
[docs]class Colors(object):
# pylint: disable=too-few-public-methods
style = None # type: Callable[..., str]
[docs]def switch(enabled):
# type: (bool) -> None
"""
Enable or disable output colors.
:param bool enabled: whether terminal output should be colorized.
"""
if enabled and not COLOR_SUPPORT:
# pylint: disable=cyclic-import
from .log import Logging
Logging.get_logger().warning("Unable to turn on colorized terminal messages, please install 'colorama' package")
return
Colors.style = staticmethod(_style_colors if enabled else _style_plain) # type: ignore # types are compatible
jinja2.defaults.DEFAULT_FILTERS['style'] = Colors.style
# Disable colors until told otherwise
switch(False)