Merge pull request #204 from pandada8/add_scroll_for_backlight

Add scroll support for backlight

i3pystatus/backlight.py

@@ -1,10 +1,15 @@
 from i3pystatus.file import File
+from i3pystatus import Module
+from i3pystatus.core.command import run_through_shell
+import shutil
 
 
 class Backlight(File):
     """
     Screen backlight info
 
+    - Reuqire `xbacklight` installed to change the backlight through the scollwheel.
+
     .. rubric:: Available formatters
 
     * `{brightness}` — current brightness relative to max_brightness
@@ -30,8 +35,18 @@ class Backlight(File):
     transforms = {
         "percentage": lambda cdict: round((cdict["brightness"] / cdict["max_brightness"]) * 100),
     }
+    on_upscroll = "lighter"
+    on_downscroll = "darker"
 
     def init(self):
         self.base_path = self.base_path.format(backlight=self.backlight)
-
+        self.has_xbacklight = shutil.which("xbacklight") is not None
         super().init()
+
+    def lighter(self):
+        if self.has_xbacklight:
+            run_through_shell(["xbacklight", "+5"])
+
+    def darker(self):
+        if self.has_xbacklight:
+            run_through_shell(["xbacklight", "-5"])