bumblebee-status/modules/core/brightness.py

# pylint: disable=C0111,R0903

'''Displays the brightness of a display

Parameters:
    * brightness.step: The amount of increase/decrease on scroll in % (defaults to 2)
    * brightness.device_path: The device path (defaults to /sys/class/backlight/intel_backlight), can contain wildcards (in this case, the first matching path will be used)

'''

import glob
import shutil

import core.module
import core.widget
import core.input

class Module(core.module.Module):
    def __init__(self, config):
        super().__init__(config, core.widget.Widget(self.brightness))

        self._brightness = 0
        self._device_path = self.find_device(
            self.parameter('device_path', '/sys/class/backlight/intel_backlight')
        )
        step = self.parameter('step', 2)

        if shutil.which('light'):
            self.register_cmd('light -A {}%'.format(step),
                'light -U {}%'.format(step))
        elif shutil.which('brightnessctl'):
            self.register_cmd('brightnessctl s {}%+'.format(step),
                'brightnessctl s {}%-'.format(step))
        else:
            self.register_cmd('xbacklight +{}%'.format(step),
                'xbacklight -{}%'.format(step))

    def find_device(self, device_path):
        res = glob.glob(device_path)
        if len(res) == 0:
            return device_path
        return res[0]

    def register_cmd(self, up_cmd, down_cmd):
        core.input.register(self, button=core.input.WHEEL_UP, cmd=up_cmd)
        core.input.register(self, button=core.input.WHEEL_DOWN, cmd=down_cmd)

    def brightness(self, widget):
        if isinstance(self._brightness, float):
            return '{:3.0f}%'.format(self._brightness).strip()
        else:
            return 'n/a'

    def update(self):
        try:
            with open('{}/brightness'.format(self._device_path)) as f:
                backlight = int(f.readline())
            with open('{}/max_brightness'.format(self._device_path)) as f:
                max_brightness = int(f.readline())
                self._brightness = float(backlight * 100 / max_brightness)
        except:
            return 'Error'

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