dbus helper for modules

py3status/dbus_helper.py

@@ -0,0 +1,54 @@
+from threading import Thread
+
+
+class DBus:
+
+    def __init__(self, py3_wrapper):
+        try:
+            from gi.repository import GObject
+            from pydbus import SystemBus, SessionBus
+            self.GObject = GObject
+            self.SessionBus = SessionBus
+            self.SystemBus = SystemBus
+            self.initialized = True
+        except ImportError:
+            # FIXME logging
+            self.initialized = False
+            pass
+        self.py3_wrapper = py3_wrapper
+        self.started = False
+        self.bus_system = None
+        self.bus_session = None
+
+    def get_bus(self, bus):
+        if bus == "system":
+            if self.bus_system is None:
+                self.bus_system = self.SystemBus()
+            return self.bus_system
+        if self.bus_session is None:
+            self.bus_session = self.SessionBus()
+        return self.bus_session
+
+    def start_main_loop(self):
+        self.GObject.threads_init()
+        loop = self.GObject.MainLoop()
+        t = Thread(target=loop.run)
+        t.daemon = True
+        t.start()
+        self.started = True
+
+    def subscribe(self, path, callback, event, bus):
+        if not self.started:
+            self.start_main_loop()
+        bus = self.get_bus(bus)
+        manager = bus.get(path)
+        setattr(manager, event, callback)
+
+    def module_update(self, module):
+        """
+        Create a small helper function that will force a module to update
+        """
+        def update(*args):
+            module.force_update()
+        return update
+

py3status/modules/battery_level.py

@@ -170,6 +170,8 @@ def post_config_hook(self):
         self.py3.log("Measurement mode: " + self.measurement_mode)
         if self.measurement_mode != "acpi" and self.measurement_mode != "sys":
             raise NameError("Invalid measurement mode")
+        # subscribe to dbus power notifications
+        self.py3.dbus_subscribe(".UPower", 'update')
 
     def battery_level(self):
         if not os.listdir(self.sys_battery_path):

py3status/py3.py

@@ -14,6 +14,7 @@
 from uuid import uuid4
 
 from py3status import exceptions
+from py3status.dbus_helper import DBus
 from py3status.constants import COLOR_NAMES
 from py3status.formatter import Formatter, Composite
 from py3status.request import HttpResponse
@@ -92,6 +93,7 @@ class Py3:
     """Show as Warning"""
 
     # Shared by all Py3 Instances
+    _dbus = None
     _formatter = None
     _gradients = Gradiants()
     _none_color = NoneColor()
@@ -131,6 +133,9 @@ def __init__(self, module=None):
             if not self._formatter:
                 self.__class__._formatter = Formatter(module._py3_wrapper)
 
+            if not self._dbus:
+                self.__class__._dbus = DBus(module._py3_wrapper)
+
     def __getattr__(self, name):
         """
         Py3 can provide COLOR constants
@@ -250,6 +255,17 @@ def _report_exception(self, msg, frame_skip=2):
             msg, notify_user=False, error_frame=error_frame
         )
 
+    def dbus_subscribe(
+        self, path, callback, event="onPropertiesChanged", bus="system"
+    ):
+        """
+        subscribe to dbus
+        """
+        if callback == "update":
+            callback = self._dbus.module_update(self._module)
+            self.log(callback)
+        self._dbus.subscribe(path, callback, event=event, bus=bus)
+
     def error(self, msg, timeout=None):
         """
         Raise an error for the module.