Add brightness module

bumblebee/modules/brightness.py

@@ -0,0 +1,22 @@
+import bumblebee.module
+
+def description():
+    return "Displays brightness percentage"
+
+class Module(bumblebee.module.Module):
+    def __init__(self, output, config, alias):
+        super(Module, self).__init__(output, config, alias)
+        self._brightness = 0
+        self._max = 0
+        self._percent = 0
+
+    def widgets(self):
+        with open("/sys/class/backlight/intel_backlight/brightness") as f:
+            self._brightness = int(f.read())
+        with open("/sys/class/backlight/intel_backlight/max_brightness") as f:
+            self._max = int(f.read())
+        self._brightness = self._brightness if self._brightness < self._max else self._max
+        self._percent = round(self._brightness * 100 / self._max)
+
+        return bumblebee.output.Widget(self, "{:02d}%".format(self._percent))
+