add battery module (udev)

1 files changed, 63 insertions, 1 deletions

diff --git a/panel.py b/panel.py
index 8a11f9e..93db494 100755
--- a/panel.py
+++ b/panel.py
@@ -336,6 +336,68 @@ class ModInputAvail(Mod):
         self.refreshing = False
         self.repaint()
 
+class ModBattery(Mod):
+    def __init__(self, battery, adapter=None, **kwargs):
+        super().__init__(**kwargs)
+        self.battery = battery
+        self.adapter = adapter
+
+        self._percent = None
+        self._charging = None
+
+    def work(self):
+        # FIXME copied from ModInputAvail. should abstract udev code.
+        p = subprocess.Popen(
+            ('udevadm', 'monitor', '-ups', 'power_supply'),
+            stdout=subprocess.PIPE, text=True)
+
+        with open(f'/sys/class/power_supply/{self.battery}/capacity') as f:
+            percent = f.read().rstrip('\n')
+        charging = None
+        if self.adapter:
+            with open(f'/sys/class/power_supply/{self.adapter}/online') as f:
+                charging = (f.read().rstrip('\n') == '1')
+        self._update_state(percent, charging)
+
+        building = False
+        for line in iter(p.stdout.readline, ''):
+            line = line.rstrip()
+
+            if not building and line.startswith('UDEV'):
+                building = True
+                e = {}
+            elif building:
+                if '=' in line:
+                    k, v = line.split('=', 1)
+                    e[k] = v
+                else:
+                    building = False
+                    if e:
+                        self._process_event(e)
+
+    def _process_event(self, e):
+        if (e.get('ACTION') == 'change' and
+                (name := e.get('POWER_SUPPLY_NAME'))):
+            if (name == self.battery and
+                    (cap := e.get('POWER_SUPPLY_CAPACITY'))):
+                self._update_state(percent=cap)
+            elif (name == self.adapter and
+                    (online := e.get('POWER_SUPPLY_ONLINE'))):
+                self._update_state(charging=(online == '1'))
+
+    def _update_state(self, percent=None, charging=None):
+        self.refreshing = True
+        if percent is not None:
+            self._percent = percent
+        if charging is not None:
+            self._charging = charging
+        buf = f'{self._percent}%%'
+        if self._charging:
+            buf += ' (charging)'
+        self.out = Fmt.labelled('BAT', buf)
+        self.refreshing = False
+        self.repaint()
+
 class IntervalTimer():
     def __init__(self):
         self.t = None
@@ -427,7 +489,7 @@ class Panel:
             mod.run()
 
         self.panel = subprocess.Popen(
-            ('/home/david/lemonbar-xft/lemonbar',
+            ('/home/david/dev/lemonbar-xft/lemonbar',
                 '-bf', 'Monospace:size=10:dpi=96',
                 '-f', 'Monospace:size=10:dpi=96:bold',
                 '-g', f'{self.width}x{self.height}',