Xsession: show notifications on screen brightness changes

1 files changed, 40 insertions, 0 deletions

diff --git a/bin/brightness_monitor b/bin/brightness_monitor
new file mode 100755
index 0000000..a8617e0
--- /dev/null
+++ b/bin/brightness_monitor
@@ -0,0 +1,40 @@
+#!/usr/bin/python3
+
+import notify2
+import os
+import subprocess
+import sys
+
+if len(sys.argv) < 2:
+    sys.stdout.write('Usage: %s /sys/.../<backlight dir>/\n')
+    sys.exit(0)
+
+path = sys.argv[1]
+
+with open(os.path.join(path, 'max_brightness'), 'r') as f:
+    brightness_max = float(f.read().strip())
+
+notify2.init(os.path.basename(sys.argv[0]))
+
+notification = notify2.Notification('Brightness')
+
+inotify_cmd = ['inotifywait', '--monitor', '--event=close_write',
+               os.path.join(path, 'brightness')]
+
+child = subprocess.Popen(inotify_cmd, stdout = subprocess.PIPE, bufsize = 0)
+
+while True:
+    # wait for updates
+    child.stdout.read(4096)
+    if child.poll() is not None:
+        notification.message = 'inotify monitor has terminated'
+        notification.set_urgency(notify2.URGENCY_CRITICAL)
+        notification.show()
+        sys.stderr.write(notification.message + '\n')
+        break
+
+    with open(os.path.join(path, 'brightness'), 'r') as f:
+        brightness = float(f.read().strip())
+
+    notification.message = '%d%%' % (100 * brightness / brightness_max)
+    notification.show()