Convert the power indicator into a service that exports GMenus and GActions in accordance with our indicator-ng design.

Approved by PS Jenkins bot, Ted Gould.

16 files changed, 2716 insertions, 1089 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index b2cf3df..8495233 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,36 +1,88 @@
+BUILT_SOURCES =
+EXTRA_DIST =
 CLEANFILES =
-ACLOCAL_AMFLAGS = -I m4 ${ACLOCAL_FLAGS}
-
-###################
-# Indicator Stuff
-###################
-
-powerlibdir = $(INDICATORDIR)
-powerlib_LTLIBRARIES = libpower.la
-
-libpower_la_SOURCES = \
-        dbus-listener.c \
-        dbus-listener.h \
-        device.c \
-        device.h \
-        indicator-power.h \
-        indicator-power.c
-
-CLEANFILES += .libs/*.gcda .libs/*.gcno *.gcda *.gcno
-
-libpower_la_CFLAGS = \
-        $(UPOWER_CFLAGS) \
-        $(INDICATOR_CFLAGS) \
-        $(COVERAGE_CFLAGS) \
-        -Wall -Werror \
-        -DG_LOG_DOMAIN=\"Indicator-Power\"
-
-libpower_la_LIBADD = \
-        $(UPOWER_LIBS) \
-        $(INDICATOR_LIBS)
-
-libpower_la_LDFLAGS = \
-        $(COVERAGE_LDFLAGS) \
-        -module \
-        -avoid-version
+
+SHARED_CFLAGS = \
+  -Wall -Wextra -Werror \
+  $(SERVICE_DEPS_CFLAGS) \
+  -DG_LOG_DOMAIN=\"Indicator-Power\"
+
+###
+###
+
+upower_dbus_sources = \
+  dbus-upower.c \
+  dbus-upower.h
+
+$(upower_dbus_sources): org.freedesktop.UPower.xml
+	$(AM_V_GEN) gdbus-codegen \
+	  --c-namespace Dbus \
+	  --interface-prefix org.freedesktop \
+	  --generate-c-code dbus-upower \
+          $^
+
+BUILT_SOURCES += $(upower_dbus_sources)
+CLEANFILES += $(upower_dbus_sources)
+EXTRA_DIST += org.freedesktop.UPower.xml
+
+###
+###
+
+upower_device_dbus_sources = \
+  dbus-upower-device.c \
+  dbus-upower-device.h
+
+$(upower_device_dbus_sources): org.freedesktop.UPower.Device.xml
+	$(AM_V_GEN) gdbus-codegen \
+	  --c-namespace Dbus \
+	  --interface-prefix org.freedesktop.UPower \
+	  --generate-c-code dbus-upower-device \
+          $^
+
+BUILT_SOURCES += $(upower_device_dbus_sources)
+CLEANFILES += $(upower_device_dbus_sources)
+EXTRA_DIST += org.freedesktop.UPower.Device.xml
+
+###
+###
+###
+
+noinst_LIBRARIES = libindicatorpower-upower.a libindicatorpower-service.a
+
+libindicatorpower_upower_a_SOURCES = \
+  $(upower_dbus_sources) \
+  $(upower_device_dbus_sources) \
+  device-provider-upower.c \
+  device-provider-upower.h
+
+libindicatorpower_upower_a_CFLAGS = $(SHARED_CFLAGS) -Wno-unused-parameter
+
+libindicatorpower_service_a_SOURCES = \
+  device-provider.c \
+  device-provider.h \
+  device.c \
+  device.h \
+  service.c \
+  service.h
+
+libindicatorpower_service_a_CFLAGS = $(SHARED_CFLAGS) -Wno-missing-field-initializers
+
+###
+###
+###
+
+libexec_PROGRAMS = indicator-power-service
+
+indicator_power_service_SOURCES = main.c
+
+indicator_power_service_CFLAGS = $(SHARED_CFLAGS)
+
+indicator_power_service_LDADD = \
+  libindicatorpower-upower.a \
+  libindicatorpower-service.a \
+  $(SERVICE_DEPS_LIBS)
+
+indicator_power_service_LDFLAGS = \
+  $(COVERAGE_LDFLAGS)
+
 
diff --git a/src/dbus-listener.c b/src/dbus-listener.c
deleted file mode 100644
index b1f64a7..0000000
--- a/src/dbus-listener.c
+++ /dev/null
@@ -1,247 +0,0 @@
-/*
-
-Listens on DBus for Power changes and passes them to an IndicatorPower
-
-Copyright 2012 Canonical Ltd.
-
-Authors:
-    Charles Kerr <charles.kerr@canonical.com>
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU General Public License
-version 3.0 as published by the Free Software Foundation.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License version 3.0 for more details.
-
-You should have received a copy of the GNU General Public
-License along with this library. If not, see
-<http://www.gnu.org/licenses/>.
-*/
-
-#include "dbus-listener.h"
-#include "device.h"
-
-struct _IndicatorPowerDbusListenerPrivate
-{
-  GCancellable * cancellable;
-  GDBusProxy * proxy;
-  guint watcher_id;
-};
-
-#define INDICATOR_POWER_DBUS_LISTENER_GET_PRIVATE(o) (INDICATOR_POWER_DBUS_LISTENER(o)->priv)
-
-/* Signals */
-enum {
-  SIGNAL_DEVICES,
-  SIGNAL_LAST
-};
-static guint signals[SIGNAL_LAST] = { 0 };
-
-
-/* GObject stuff */
-static void indicator_power_dbus_listener_class_init (IndicatorPowerDbusListenerClass *klass);
-static void indicator_power_dbus_listener_init       (IndicatorPowerDbusListener *self);
-static void indicator_power_dbus_listener_dispose    (GObject *object);
-static void indicator_power_dbus_listener_finalize   (GObject *object);
-
-static void gsd_appeared_callback (GDBusConnection *connection, const gchar *name, const gchar *name_owner, gpointer user_data);
-
-/* LCOV_EXCL_START */
-G_DEFINE_TYPE (IndicatorPowerDbusListener, indicator_power_dbus_listener, G_TYPE_OBJECT);
-/* LCOV_EXCL_STOP */
-
-static void
-indicator_power_dbus_listener_class_init (IndicatorPowerDbusListenerClass *klass)
-{
-  GObjectClass *object_class = G_OBJECT_CLASS (klass);
-
-  g_type_class_add_private (klass, sizeof (IndicatorPowerDbusListenerPrivate));
-
-  /* methods */
-  object_class->dispose = indicator_power_dbus_listener_dispose;
-  object_class->finalize = indicator_power_dbus_listener_finalize;
-
-  /**
-   * IndicatorPowerDbusListener::devices-enumerated:
-   *
-   * @listener: the IndicatorPowerDbusListener
-   * @devices: a GSList of #IndicatorPowerDevice objects. (transfer none)
-   *
-   * This is emitted each time a new set of devices is enumerated over the bus.
-   */
-  signals[SIGNAL_DEVICES] = g_signal_new (INDICATOR_POWER_DBUS_LISTENER_DEVICES_ENUMERATED,
-                                          G_TYPE_FROM_CLASS(klass), 0,
-                                          G_STRUCT_OFFSET (IndicatorPowerDbusListenerClass, devices_enumerated),
-                                          NULL, NULL,
-                                          g_cclosure_marshal_VOID__POINTER,
-                                          G_TYPE_NONE, 1, G_TYPE_POINTER);
-}
-
-/* Initialize an instance */
-static void
-indicator_power_dbus_listener_init (IndicatorPowerDbusListener *self)
-{
-  IndicatorPowerDbusListenerPrivate * priv;
-
-  priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
-                                      INDICATOR_POWER_DBUS_LISTENER_TYPE,
-                                      IndicatorPowerDbusListenerPrivate);
-
-  priv->cancellable = g_cancellable_new ();
-
-  priv->watcher_id = g_bus_watch_name (G_BUS_TYPE_SESSION,
-                                       GSD_SERVICE,
-                                       G_BUS_NAME_WATCHER_FLAGS_NONE,
-                                       gsd_appeared_callback,
-                                       NULL,
-                                       self,
-                                       NULL);
-
-  self->priv = priv;
-}
-
-static void
-indicator_power_dbus_listener_dispose (GObject *object)
-{
-  IndicatorPowerDbusListener * self = INDICATOR_POWER_DBUS_LISTENER(object);
-  IndicatorPowerDbusListenerPrivate * priv = self->priv;
-
-  g_clear_object (&priv->proxy);
-
-  if (priv->cancellable != NULL)
-    {
-      g_cancellable_cancel (priv->cancellable);
-      g_clear_object (&priv->cancellable);
-    }
-
-  if (priv->watcher_id)
-    {
-      g_bus_unwatch_name (priv->watcher_id);
-      priv->watcher_id = 0;
-    }
-
-  G_OBJECT_CLASS (indicator_power_dbus_listener_parent_class)->dispose (object);
-}
-
-static void
-indicator_power_dbus_listener_finalize (GObject *object)
-{
-  G_OBJECT_CLASS (indicator_power_dbus_listener_parent_class)->finalize (object);
-}
-
-/***
-****
-***/
-
-static void
-get_devices_cb (GObject      * source_object,
-                GAsyncResult * res,
-                gpointer       user_data)
-{
-  GError *error;
-  GSList * devices = NULL;
-  GVariant * devices_container;
-  IndicatorPowerDbusListener * self = INDICATOR_POWER_DBUS_LISTENER (user_data);
-
-  /* build an array of IndicatorPowerDevices from the DBus response */
-  error = NULL;
-  devices_container = g_dbus_proxy_call_finish (G_DBUS_PROXY (source_object), res, &error);
-  if (devices_container == NULL)
-    {
-      g_message ("Couldn't get devices: %s\n", error->message);
-      g_error_free (error);
-    }
-  else
-    {
-      gsize i;
-      GVariant * devices_variant = g_variant_get_child_value (devices_container, 0);
-      const int device_count = devices_variant ? g_variant_n_children (devices_variant) : 0;
-
-      for (i=0; i<device_count; i++)
-        {
-          GVariant * v = g_variant_get_child_value (devices_variant, i);
-          devices = g_slist_prepend (devices, indicator_power_device_new_from_variant (v));
-          g_variant_unref (v);
-        }
-
-      devices = g_slist_reverse (devices);
-
-      g_variant_unref (devices_variant);
-      g_variant_unref (devices_container);
-    }
-
-  g_signal_emit (self, signals[SIGNAL_DEVICES], (GQuark)0, devices);
-  g_slist_free_full (devices, g_object_unref);
-}
-
-static void
-request_device_list (IndicatorPowerDbusListener * self)
-{
-  g_dbus_proxy_call (self->priv->proxy,
-                     "GetDevices",
-                     NULL,
-                     G_DBUS_CALL_FLAGS_NONE,
-                     -1,
-                     self->priv->cancellable,
-                     get_devices_cb,
-                     self);
-}
-
-static void
-receive_properties_changed (GDBusProxy *proxy                  G_GNUC_UNUSED,
-                            GVariant   *changed_properties     G_GNUC_UNUSED,
-                            GStrv       invalidated_properties G_GNUC_UNUSED,
-                            gpointer    user_data)
-{
-  request_device_list (INDICATOR_POWER_DBUS_LISTENER(user_data));
-}
-
-
-static void
-service_proxy_cb (GObject      *object,
-                  GAsyncResult *res,
-                  gpointer      user_data)
-{
-  GError * error = NULL;
-  IndicatorPowerDbusListener * self = INDICATOR_POWER_DBUS_LISTENER(user_data);
-  IndicatorPowerDbusListenerPrivate * priv = self->priv;
-
-  priv->proxy = g_dbus_proxy_new_for_bus_finish (res, &error);
-
-  if (error != NULL)
-    {
-      g_error ("Error creating proxy: %s", error->message);
-      g_error_free (error);
-      return;
-    }
-
-  /* we want to change the primary device changes */
-  g_signal_connect (priv->proxy, "g-properties-changed",
-                    G_CALLBACK (receive_properties_changed), user_data);
-
-  /* get the initial state */
-  request_device_list (self);
-}
-
-static void
-gsd_appeared_callback (GDBusConnection *connection,
-                       const gchar     *name,
-                       const gchar     *name_owner,
-                       gpointer         user_data)
-{
-  IndicatorPowerDbusListener * self = INDICATOR_POWER_DBUS_LISTENER(user_data);
-  IndicatorPowerDbusListenerPrivate * priv = self->priv;
-
-  g_dbus_proxy_new (connection,
-                    G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
-                    NULL,
-                    name,
-                    GSD_POWER_DBUS_PATH,
-                    GSD_POWER_DBUS_INTERFACE,
-                    priv->cancellable,
-                    service_proxy_cb,
-                    self);
-}
diff --git a/src/dbus-listener.h b/src/dbus-listener.h
deleted file mode 100644
index e4d006b..0000000
--- a/src/dbus-listener.h
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
-
-Listens for Power changes from org.gnome.SettingsDaemon.Power on Dbus
-
-Copyright 2012 Canonical Ltd.
-
-Authors:
-    Javier Jardon <javier.jardon@codethink.co.uk>
-    Charles Kerr <charles.kerr@canonical.com>
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU General Public License
-version 3.0 as published by the Free Software Foundation.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License version 3.0 for more details.
-
-You should have received a copy of the GNU General Public
-License along with this library. If not, see
-<http://www.gnu.org/licenses/>.
-*/
-
-#ifndef __INDICATOR_POWER_DBUS_LISTENER_H__
-#define __INDICATOR_POWER_DBUS_LISTENER_H__
-
-#include <glib-object.h>
-#include <libupower-glib/upower.h>
-
-G_BEGIN_DECLS
-
-#define INDICATOR_POWER_DBUS_LISTENER_TYPE            (indicator_power_dbus_listener_get_type ())
-#define INDICATOR_POWER_DBUS_LISTENER(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), INDICATOR_POWER_DBUS_LISTENER_TYPE, IndicatorPowerDbusListener))
-#define INDICATOR_POWER_DBUS_LISTENER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  INDICATOR_POWER_DBUS_LISTENER_TYPE, IndicatorPowerDbusListenerClass))
-#define INDICATOR_IS_POWER_DBUS_LISTENER(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), INDICATOR_POWER_DBUS_LISTENER_TYPE))
-#define INDICATOR_IS_POWER_DBUS_LISTENER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  INDICATOR_POWER_DBUS_LISTENER_TYPE))
-#define INDICATOR_POWER_DBUS_LISTENER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  INDICATOR_POWER_DBUS_LISTENER_TYPE, IndicatorPowerDbusListenerClass))
-
-typedef struct _IndicatorPowerDbusListener IndicatorPowerDbusListener;
-typedef struct _IndicatorPowerDbusListenerClass IndicatorPowerDbusListenerClass;
-typedef struct _IndicatorPowerDbusListenerPrivate IndicatorPowerDbusListenerPrivate;
-
-#define GSD_SERVICE               "org.gnome.SettingsDaemon"
-#define GSD_PATH                  "/org/gnome/SettingsDaemon"
-#define GSD_POWER_DBUS_INTERFACE  GSD_SERVICE ".Power"
-#define GSD_POWER_DBUS_PATH       GSD_PATH "/Power"
-
-/* signals */
-#define INDICATOR_POWER_DBUS_LISTENER_DEVICES_ENUMERATED  "devices-enumerated"
-
-/**
- * IndicatorPowerDbusListenerClass:
- * @parent_class: #GObjectClass
- */
-struct _IndicatorPowerDbusListenerClass
-{
-  GObjectClass parent_class;
-
-  void (* devices_enumerated) (IndicatorPowerDbusListener*, GSList * devices);
-};
-
-/**
- * IndicatorPowerDbusListener:
- * @parent: #GObject
- * @priv: A cached reference to the private data for the instance.
-*/
-struct _IndicatorPowerDbusListener
-{
-  GObject parent;
-  IndicatorPowerDbusListenerPrivate * priv;
-};
-
-/***
-****
-***/
-
-GType indicator_power_dbus_listener_get_type (void);
-
-G_END_DECLS
-
-#endif
diff --git a/src/device-provider-upower.c b/src/device-provider-upower.c
new file mode 100644
index 0000000..05faeab
--- /dev/null
+++ b/src/device-provider-upower.c
@@ -0,0 +1,424 @@
+/*
+ * Copyright 2013 Canonical Ltd.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include "dbus-upower.h"
+#include "dbus-upower-device.h"
+#include "device.h"
+#include "device-provider.h"
+#include "device-provider-upower.h"
+
+#define BUS_NAME "org.freedesktop.UPower"
+#define BUS_PATH "/org/freedesktop/UPower"
+
+/***
+****  private struct
+***/
+
+struct _IndicatorPowerDeviceProviderUPowerPriv
+{
+  DbusUPower * upower_proxy;
+  GHashTable * devices; /* dbus object path --> IndicatorPowerDevice */
+  GCancellable * cancellable;
+
+  /* a hashset of paths whose devices need to be refreshed */
+  GHashTable * queued_paths;
+
+  /* when this timer fires, the queued_paths will be refreshed */
+  guint queued_paths_timer;
+};
+
+typedef IndicatorPowerDeviceProviderUPowerPriv priv_t;
+
+/***
+****  GObject boilerplate
+***/
+
+static void indicator_power_device_provider_interface_init (
+                                IndicatorPowerDeviceProviderInterface * iface);
+
+G_DEFINE_TYPE_WITH_CODE (
+  IndicatorPowerDeviceProviderUPower,
+  indicator_power_device_provider_upower,
+  G_TYPE_OBJECT,
+  G_IMPLEMENT_INTERFACE (INDICATOR_TYPE_POWER_DEVICE_PROVIDER,
+                         indicator_power_device_provider_interface_init));
+
+/***
+****  UPOWER DBUS
+***/
+
+static void
+emit_devices_changed (IndicatorPowerDeviceProviderUPower * self)
+{
+  indicator_power_device_provider_emit_devices_changed (INDICATOR_POWER_DEVICE_PROVIDER (self));
+}
+
+static void
+on_upower_device_proxy_ready (GObject * o, GAsyncResult * res, gpointer gself)
+{
+  GError * err;
+  DbusDevice * tmp;
+
+  err = NULL;
+  tmp = dbus_device_proxy_new_for_bus_finish (res, &err);
+  if (err != NULL)
+    {
+      g_warning ("Unable to get UPower Device Proxy: %s", err->message);
+      g_error_free (err);
+    }
+  else
+    {
+      /* use this proxy's properties to update our own IndicatorPowerDevice */
+
+      IndicatorPowerDevice * device;
+      IndicatorPowerDeviceProviderUPower * self;
+      priv_t * p;
+
+      self = INDICATOR_POWER_DEVICE_PROVIDER_UPOWER (gself);
+      p = self->priv;
+
+      const guint kind = dbus_device_get_type_ (tmp);
+      const gdouble percentage = dbus_device_get_percentage (tmp);
+      const guint state = dbus_device_get_state (tmp);
+      const gint64 time_to_empty = dbus_device_get_time_to_empty (tmp);
+      const gint64 time_to_full = dbus_device_get_time_to_full (tmp);
+      const time_t time = time_to_empty ? time_to_empty : time_to_full;
+      const char * path = g_dbus_proxy_get_object_path (G_DBUS_PROXY (tmp));
+
+      device = indicator_power_device_new (path,
+                                           kind,
+                                           percentage,
+                                           state,
+                                           time);
+
+      g_hash_table_insert (p->devices,
+                           g_strdup (path),
+                           g_object_ref (device));
+
+      emit_devices_changed (self);
+
+      g_object_unref (device);
+      g_object_unref (tmp);
+    }
+}
+
+static void
+update_device_from_object_path (IndicatorPowerDeviceProviderUPower * self,
+                                const char                         * path)
+{
+  dbus_device_proxy_new_for_bus (G_BUS_TYPE_SYSTEM,
+                                 G_DBUS_PROXY_FLAGS_NONE,
+                                 BUS_NAME,
+                                 path,
+                                 self->priv->cancellable,
+                                 on_upower_device_proxy_ready,
+                                 self);
+}
+
+/*
+ * UPower doesn't seem to be sending PropertyChanged signals.
+ *
+ * Instead, it's got a DIY mechanism for notification: a DeviceChanged signal
+ * that doesn't tell us which property changed, so to refresh we need to
+ * rebuild all the properties with a GetAll() call.
+ *
+ * To make things worse, these DeviceChanged signals come fast and furious
+ * in common situations like disconnecting a power cable.
+ *
+ * This code tries to reduce bus traffic by adding a timer to wait a small bit
+ * before rebuilding our proxy's properties. This helps to fold multiple
+ * DeviceChanged events into a single rebuild.
+ */
+
+/* rebuild all the proxies listed in our queued_paths hashset */
+static gboolean
+on_queued_paths_timer (gpointer gself)
+{
+  gpointer path;
+  GHashTableIter iter;
+  IndicatorPowerDeviceProviderUPower * self;
+  priv_t * p;
+
+  self = INDICATOR_POWER_DEVICE_PROVIDER_UPOWER (gself);
+  p = self->priv;
+
+  /* create new proxies for all the queued paths */
+  g_hash_table_iter_init (&iter, p->queued_paths);
+  while (g_hash_table_iter_next (&iter, &path, NULL))
+    update_device_from_object_path (self, path);
+
+  /* cleanup */
+  g_hash_table_remove_all (p->queued_paths);
+  p->queued_paths_timer = 0;
+  return G_SOURCE_REMOVE;
+}
+
+/* add the path to our queued_paths hashset and ensure the timer's running */
+static void
+refresh_device_soon (IndicatorPowerDeviceProviderUPower * self,
+                     const char                         * object_path)
+{
+  priv_t * p = self->priv;
+
+  g_hash_table_add (p->queued_paths, g_strdup (object_path));
+
+  if (p->queued_paths_timer == 0)
+    p->queued_paths_timer = g_timeout_add (500, on_queued_paths_timer, self);
+}
+
+/***
+****
+***/
+
+static void
+on_upower_device_enumerations_ready (GObject       * proxy,
+                                     GAsyncResult  * res,
+                                     gpointer        gself)
+{
+  GError * err;
+  char ** object_paths;
+
+  err = NULL;
+  dbus_upower_call_enumerate_devices_finish (DBUS_UPOWER(proxy),
+                                             &object_paths,
+                                             res,
+                                             &err);
+
+  if (err != NULL)
+    {
+      g_warning ("Unable to get UPower devices: %s", err->message);
+      g_error_free (err);
+    }
+  else
+    {
+      guint i;
+
+      for (i=0; object_paths && object_paths[i]; i++)
+        refresh_device_soon (gself, object_paths[i]);
+
+      g_strfreev (object_paths);
+    }
+}
+
+static void
+on_upower_device_changed (DbusUPower * unused G_GNUC_UNUSED,
+                          const char * object_path,
+                          gpointer     gself)
+{
+  refresh_device_soon (gself, object_path);
+}
+
+static void
+on_upower_device_added (DbusUPower * unused G_GNUC_UNUSED,
+                        const char * object_path,
+                        gpointer     gself)
+{
+  refresh_device_soon (gself, object_path);
+}
+
+static void
+on_upower_device_removed (DbusUPower * unused G_GNUC_UNUSED,
+                          const char * object_path,
+                          gpointer     gself)
+{
+  IndicatorPowerDeviceProviderUPower * self;
+
+  self = INDICATOR_POWER_DEVICE_PROVIDER_UPOWER (gself);
+  g_hash_table_remove (self->priv->devices, object_path);
+  g_hash_table_remove (self->priv->queued_paths, object_path);
+
+  emit_devices_changed (self);
+}
+
+static void
+on_upower_proxy_ready (GObject        * source G_GNUC_UNUSED,
+                       GAsyncResult   * res,
+                       gpointer         gself)
+{
+  GError * err;
+  DbusUPower * proxy;
+
+  err = NULL;
+  proxy = dbus_upower_proxy_new_for_bus_finish (res, &err);
+  if (err != NULL)
+    {
+      g_warning ("Unable to get UPower proxy: %s", err->message);
+      g_error_free (err);
+    }
+  else
+    {
+      IndicatorPowerDeviceProviderUPower * self;
+      priv_t * p;
+
+      self = INDICATOR_POWER_DEVICE_PROVIDER_UPOWER (gself);
+      p = self->priv;
+
+      p->upower_proxy = proxy;
+      g_signal_connect (proxy, "device-changed",
+                        G_CALLBACK (on_upower_device_changed), self);
+      g_signal_connect (proxy, "device-added",
+                        G_CALLBACK (on_upower_device_added), self);
+      g_signal_connect (proxy, "device-removed",
+                        G_CALLBACK (on_upower_device_removed), self);
+
+      dbus_upower_call_enumerate_devices (p->upower_proxy,
+                                          p->cancellable,
+                                          on_upower_device_enumerations_ready,
+                                          self);
+    }
+}
+
+/***
+****  IndicatorPowerDeviceProvider virtual functions
+***/
+
+static GList *
+my_get_devices (IndicatorPowerDeviceProvider * provider)
+{
+  GList * devices;
+  IndicatorPowerDeviceProviderUPower * self;
+
+  self = INDICATOR_POWER_DEVICE_PROVIDER_UPOWER(provider);
+
+  devices = g_hash_table_get_values (self->priv->devices);
+  g_list_foreach (devices, (GFunc)g_object_ref, NULL);
+  return devices;
+}
+
+/***
+****  GObject virtual functions
+***/
+
+static void
+my_dispose (GObject * o)
+{
+  IndicatorPowerDeviceProviderUPower * self;
+  priv_t * p;
+
+  self = INDICATOR_POWER_DEVICE_PROVIDER_UPOWER(o);
+  p = self->priv;
+
+  if (p->cancellable != NULL)
+    {
+      g_cancellable_cancel (p->cancellable);
+
+      g_clear_object (&p->cancellable);
+    }
+
+  if (p->queued_paths_timer != 0)
+    {
+      g_source_remove (p->queued_paths_timer);
+
+      p->queued_paths_timer = 0;
+    }
+
+  if (p->upower_proxy != NULL)
+    {
+      g_signal_handlers_disconnect_by_data (p->upower_proxy, self);
+
+      g_clear_object (&p->upower_proxy);
+    }
+
+  g_hash_table_remove_all (p->devices);
+
+  G_OBJECT_CLASS (indicator_power_device_provider_upower_parent_class)->dispose (o);
+}
+
+static void
+my_finalize (GObject * o)
+{
+  IndicatorPowerDeviceProviderUPower * self;
+  priv_t * p;
+
+  self = INDICATOR_POWER_DEVICE_PROVIDER_UPOWER(o);
+  p = self->priv;
+
+  g_hash_table_destroy (p->devices);
+  g_hash_table_destroy (p->queued_paths);
+
+  G_OBJECT_CLASS (indicator_power_device_provider_upower_parent_class)->dispose (o);
+}
+
+/***
+****  Instantiation
+***/
+
+static void
+indicator_power_device_provider_upower_class_init (IndicatorPowerDeviceProviderUPowerClass * klass)
+{
+  GObjectClass * object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = my_dispose;
+  object_class->finalize = my_finalize;
+
+  g_type_class_add_private (klass,
+                            sizeof (IndicatorPowerDeviceProviderUPowerPriv));
+}
+
+static void
+indicator_power_device_provider_interface_init (IndicatorPowerDeviceProviderInterface * iface)
+{
+  iface->get_devices = my_get_devices;
+}
+
+static void
+indicator_power_device_provider_upower_init (IndicatorPowerDeviceProviderUPower * self)
+{
+  IndicatorPowerDeviceProviderUPowerPriv * p;
+
+  p = G_TYPE_INSTANCE_GET_PRIVATE (self,
+                                   INDICATOR_TYPE_POWER_DEVICE_PROVIDER_UPOWER,
+                                   IndicatorPowerDeviceProviderUPowerPriv);
+
+  self->priv = p;
+
+  p->cancellable = g_cancellable_new ();
+
+  p->devices = g_hash_table_new_full (g_str_hash,
+                                      g_str_equal,
+                                      g_free,
+                                      g_object_unref);
+
+  p->queued_paths = g_hash_table_new_full (g_str_hash,
+                                           g_str_equal,
+                                           g_free,
+                                           NULL);
+
+  dbus_upower_proxy_new_for_bus (G_BUS_TYPE_SYSTEM,
+                                 G_DBUS_PROXY_FLAGS_GET_INVALIDATED_PROPERTIES,
+                                 BUS_NAME,
+                                 BUS_PATH,
+                                 p->cancellable,
+                                 on_upower_proxy_ready,
+                                 self);
+}
+
+/***
+****  Public API
+***/
+
+IndicatorPowerDeviceProvider *
+indicator_power_device_provider_upower_new (void)
+{
+  gpointer o = g_object_new (INDICATOR_TYPE_POWER_DEVICE_PROVIDER_UPOWER, NULL);
+
+  return INDICATOR_POWER_DEVICE_PROVIDER (o);
+}
diff --git a/src/device-provider-upower.h b/src/device-provider-upower.h
new file mode 100644
index 0000000..7bdd5d5
--- /dev/null
+++ b/src/device-provider-upower.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2013 Canonical Ltd.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __INDICATOR_POWER_DEVICE_PROVIDER_UPOWER__H__
+#define __INDICATOR_POWER_DEVICE_PROVIDER_UPOWER__H__
+
+#include <glib-object.h> /* parent class */
+
+#include "device-provider.h"
+
+G_BEGIN_DECLS
+
+#define INDICATOR_TYPE_POWER_DEVICE_PROVIDER_UPOWER \
+  (indicator_power_device_provider_upower_get_type())
+
+#define INDICATOR_POWER_DEVICE_PROVIDER_UPOWER(o) \
+  (G_TYPE_CHECK_INSTANCE_CAST ((o), \
+                               INDICATOR_TYPE_POWER_DEVICE_PROVIDER_UPOWER, \
+                               IndicatorPowerDeviceProviderUPower))
+
+#define INDICATOR_POWER_DEVICE_PROVIDER_UPOWER_GET_CLASS(o) \
+ (G_TYPE_INSTANCE_GET_CLASS ((o), \
+                             INDICATOR_TYPE_POWER_DEVICE_PROVIDER_UPOWER, \
+                             IndicatorPowerDeviceProviderUPowerClass))
+
+#define INDICATOR_IS_POWER_DEVICE_PROVIDER_UPOWER(o) \
+  (G_TYPE_CHECK_INSTANCE_TYPE ((o), \
+                               INDICATOR_TYPE_POWER_DEVICE_PROVIDER_UPOWER))
+
+typedef struct _IndicatorPowerDeviceProviderUPower
+                IndicatorPowerDeviceProviderUPower;
+typedef struct _IndicatorPowerDeviceProviderUPowerPriv
+                IndicatorPowerDeviceProviderUPowerPriv;
+typedef struct _IndicatorPowerDeviceProviderUPowerClass
+                IndicatorPowerDeviceProviderUPowerClass;
+
+/**
+ * An IndicatorPowerDeviceProvider which gets its devices from UPower.
+ */
+struct _IndicatorPowerDeviceProviderUPower
+{
+  GObject parent_instance;
+
+  IndicatorPowerDeviceProviderUPowerPriv * priv;
+};
+
+struct _IndicatorPowerDeviceProviderUPowerClass
+{
+  GObjectClass parent_class;
+};
+
+IndicatorPowerDeviceProvider * indicator_power_device_provider_upower_new (void);
+
+G_END_DECLS
+
+#endif /* __INDICATOR_POWER_DEVICE_PROVIDER_UPOWER__H__ */
diff --git a/src/device-provider.c b/src/device-provider.c
new file mode 100644
index 0000000..5ccf588
--- /dev/null
+++ b/src/device-provider.c
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2013 Canonical Ltd.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "device-provider.h"
+
+enum
+{
+  SIGNAL_DEVICES_CHANGED,
+  SIGNAL_LAST
+};
+
+static guint signals[SIGNAL_LAST] = { 0 };
+
+G_DEFINE_INTERFACE (IndicatorPowerDeviceProvider,
+                    indicator_power_device_provider,
+                    0);
+
+static void
+indicator_power_device_provider_default_init (IndicatorPowerDeviceProviderInterface * klass)
+{
+  signals[SIGNAL_DEVICES_CHANGED] = g_signal_new (
+      "devices-changed",
+      G_TYPE_FROM_CLASS(klass),
+      G_SIGNAL_RUN_LAST,
+      G_STRUCT_OFFSET (IndicatorPowerDeviceProviderInterface, devices_changed),
+      NULL, NULL,
+      g_cclosure_marshal_VOID__VOID,
+      G_TYPE_NONE, 0);
+}
+
+/***
+****  PUBLIC API
+***/
+
+/**
+ * Get a list of devices
+ *
+ * An easy way to free the list properly in one step is as follows:
+ *
+ *   g_slist_free_full (list, (GDestroyNotify)g_object_unref);
+ * 
+ * Return value: (element-type IndicatorPowerDevice)
+ *               (transfer full):
+ *               list of devices
+ */
+GList *
+indicator_power_device_provider_get_devices (IndicatorPowerDeviceProvider * self)
+{
+  GList * devices;
+  IndicatorPowerDeviceProviderInterface * iface;
+
+  g_return_val_if_fail (INDICATOR_IS_POWER_DEVICE_PROVIDER (self), NULL);
+  iface = INDICATOR_POWER_DEVICE_PROVIDER_GET_INTERFACE (self);
+
+  if (iface->get_devices != NULL)
+    devices = iface->get_devices (self);
+  else
+    devices = NULL;
+
+  return devices;
+}
+
+/**
+ * Emits the "devices-changed" signal.
+ *
+ * This should only be called by subclasses.
+ */
+void
+indicator_power_device_provider_emit_devices_changed (IndicatorPowerDeviceProvider * self)
+{
+  g_return_if_fail (INDICATOR_IS_POWER_DEVICE_PROVIDER (self));
+
+  g_signal_emit (self, signals[SIGNAL_DEVICES_CHANGED], 0, NULL);
+}
diff --git a/src/device-provider.h b/src/device-provider.h
new file mode 100644
index 0000000..edef6f2
--- /dev/null
+++ b/src/device-provider.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2013 Canonical Ltd.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __INDICATOR_POWER_DEVICE_PROVIDER__H__
+#define __INDICATOR_POWER_DEVICE_PROVIDER__H__
+
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+#define INDICATOR_TYPE_POWER_DEVICE_PROVIDER \
+  (indicator_power_device_provider_get_type ())
+
+#define INDICATOR_POWER_DEVICE_PROVIDER(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
+                               INDICATOR_TYPE_POWER_DEVICE_PROVIDER, \
+                               IndicatorPowerDeviceProvider))
+
+#define INDICATOR_IS_POWER_DEVICE_PROVIDER(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE ((obj), INDICATOR_TYPE_POWER_DEVICE_PROVIDER))
+
+#define INDICATOR_POWER_DEVICE_PROVIDER_GET_INTERFACE(inst) \
+  (G_TYPE_INSTANCE_GET_INTERFACE ((inst), \
+                                  INDICATOR_TYPE_POWER_DEVICE_PROVIDER, \
+                                  IndicatorPowerDeviceProviderInterface))
+
+typedef struct _IndicatorPowerDeviceProvider
+                IndicatorPowerDeviceProvider;
+
+typedef struct _IndicatorPowerDeviceProviderInterface
+                IndicatorPowerDeviceProviderInterface;
+
+/**
+ * An interface class for an object that provides IndicatorPowerDevices.
+ *
+ * Example uses:
+ *  - in unit tests, a mock that feeds fake devices to the service
+ *  - in production, an implementation that monitors upower
+ *  - in the future, upower can be replaced by changing providers
+ */
+struct _IndicatorPowerDeviceProviderInterface
+{
+  GTypeInterface parent_iface;
+
+  /* signals */
+  void (*devices_changed) (IndicatorPowerDeviceProvider * self);
+
+  /* virtual functions */
+  GList* (*get_devices) (IndicatorPowerDeviceProvider * self);
+};
+
+GType indicator_power_device_provider_get_type (void);
+
+/***
+****
+***/
+
+GList * indicator_power_device_provider_get_devices          (IndicatorPowerDeviceProvider * self);
+
+void    indicator_power_device_provider_emit_devices_changed (IndicatorPowerDeviceProvider * self);
+
+G_END_DECLS
+
+#endif /* __INDICATOR_POWER_DEVICE_PROVIDER__H__ */
diff --git a/src/device.c b/src/device.c
index d028ab7..02c9e65 100644
--- a/src/device.c
+++ b/src/device.c
@@ -26,6 +26,7 @@ License along with this library. If not, see
 #endif
 
 #include <glib/gi18n-lib.h>
+#include <gio/gio.h>
 
 #include "device.h"
 
@@ -301,6 +302,26 @@ get_device_icon_index (gdouble percentage)
   return "000";
 }
 
+static const char *
+device_kind_to_string (UpDeviceKind kind)
+{
+  switch (kind)
+    {
+      case UP_DEVICE_KIND_LINE_POWER: return "line-power";
+      case UP_DEVICE_KIND_BATTERY: return "battery";
+      case UP_DEVICE_KIND_UPS: return "ups";
+      case UP_DEVICE_KIND_MONITOR: return "monitor";
+      case UP_DEVICE_KIND_MOUSE: return "mouse";
+      case UP_DEVICE_KIND_KEYBOARD: return "keyboard";
+      case UP_DEVICE_KIND_PDA: return "pda";
+      case UP_DEVICE_KIND_PHONE: return "phone";
+      case UP_DEVICE_KIND_MEDIA_PLAYER: return "media-player";
+      case UP_DEVICE_KIND_TABLET: return "tablet";
+      case UP_DEVICE_KIND_COMPUTER: return "computer";
+      default: return "unknown";
+    }
+}
+
 /**
   indicator_power_device_get_icon_names:
   @device: #IndicatorPowerDevice from which to generate the icon names
@@ -334,7 +355,7 @@ indicator_power_device_get_icon_names (const IndicatorPowerDevice * device)
   gdouble percentage = indicator_power_device_get_percentage (device);
   const UpDeviceKind kind = indicator_power_device_get_kind (device);
   const UpDeviceState state = indicator_power_device_get_state (device);
-  const gchar * kind_str = up_device_kind_to_string (kind);
+  const gchar * kind_str = device_kind_to_string (kind);
 
   GPtrArray * names = g_ptr_array_new ();
 
@@ -534,7 +555,7 @@ device_kind_to_localised_string (UpDeviceKind kind)
       break;
     default:
       g_warning ("enum unrecognised: %i", kind);
-      text = up_device_kind_to_string (kind);
+      text = device_kind_to_string (kind);
     }
 
   return text;
diff --git a/src/device.h b/src/device.h
index 3f7bbee..ffbb5da 100644
--- a/src/device.h
+++ b/src/device.h
@@ -25,7 +25,6 @@ License along with this library. If not, see
 #define __INDICATOR_POWER_DEVICE_H__
 
 #include <glib-object.h>
-#include <libupower-glib/upower.h>
 
 G_BEGIN_DECLS
 
@@ -46,6 +45,38 @@ typedef struct _IndicatorPowerDevicePrivate IndicatorPowerDevicePrivate;
 #define INDICATOR_POWER_DEVICE_PERCENTAGE   "percentage"
 #define INDICATOR_POWER_DEVICE_TIME         "time"
 
+typedef enum
+{
+  UP_DEVICE_KIND_UNKNOWN,
+  UP_DEVICE_KIND_LINE_POWER,
+  UP_DEVICE_KIND_BATTERY,
+  UP_DEVICE_KIND_UPS,
+  UP_DEVICE_KIND_MONITOR,
+  UP_DEVICE_KIND_MOUSE,
+  UP_DEVICE_KIND_KEYBOARD,
+  UP_DEVICE_KIND_PDA,
+  UP_DEVICE_KIND_PHONE,
+  UP_DEVICE_KIND_MEDIA_PLAYER,
+  UP_DEVICE_KIND_TABLET,
+  UP_DEVICE_KIND_COMPUTER,
+  UP_DEVICE_KIND_LAST
+}
+UpDeviceKind;
+
+typedef enum
+{
+  UP_DEVICE_STATE_UNKNOWN,
+  UP_DEVICE_STATE_CHARGING,
+  UP_DEVICE_STATE_DISCHARGING,
+  UP_DEVICE_STATE_EMPTY,
+  UP_DEVICE_STATE_FULLY_CHARGED,
+  UP_DEVICE_STATE_PENDING_CHARGE,
+  UP_DEVICE_STATE_PENDING_DISCHARGE,
+  UP_DEVICE_STATE_LAST
+}
+UpDeviceState;
+
+
 /**
  * IndicatorPowerDeviceClass:
  * @parent_class: #GObjectClass
diff --git a/src/indicator-power.c b/src/indicator-power.c
deleted file mode 100644
index 729c7cf..0000000
--- a/src/indicator-power.c
+++ /dev/null
@@ -1,663 +0,0 @@
-/*
-An indicator to power related information in the menubar.
-
-Copyright 2011 Canonical Ltd.
-
-Authors:
-    Javier Jardon <javier.jardon@codethink.co.uk>
-
-This program is free software: you can redistribute it and/or modify it
-under the terms of the GNU General Public License version 3, as published 
-by the Free Software Foundation.
-
-This program is distributed in the hope that it will be useful, but
-WITHOUT ANY WARRANTY; without even the implied warranties of
-MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
-PURPOSE.  See the GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License along
-with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifdef HAVE_CONFIG_H
- #include "config.h"
-#endif
-
-/* GStuff */
-#include <glib-object.h>
-#include <glib/gi18n-lib.h>
-#include <gio/gio.h>
-
-#include "dbus-listener.h"
-#include "device.h"
-#include "indicator-power.h"
-
-#define ICON_POLICY_KEY "icon-policy"
-
-#define DEFAULT_ICON   "gpm-battery-missing"
-
-enum {
-  POWER_INDICATOR_ICON_POLICY_PRESENT,
-  POWER_INDICATOR_ICON_POLICY_CHARGE,
-  POWER_INDICATOR_ICON_POLICY_NEVER
-};
-
-struct _IndicatorPowerPrivate
-{
-  GtkMenu   *menu;
-
-  GtkLabel *label;
-  GtkImage *status_image;
-  gchar    *accessible_desc;
-
-  IndicatorPowerDbusListener * dbus_listener;
-
-  GSList * devices;
-  IndicatorPowerDevice * device;
-
-  GSettings *settings;
-};
-
-
-/* LCOV_EXCL_START */
-INDICATOR_SET_VERSION
-INDICATOR_SET_TYPE (INDICATOR_POWER_TYPE)
-/* LCOV_EXCL_STOP */
-
-/* Prototypes */
-static void             indicator_power_dispose         (GObject *object);
-static void             indicator_power_finalize        (GObject *object);
-
-static GtkLabel*        get_label                       (IndicatorObject * io);
-static GtkImage*        get_image                       (IndicatorObject * io);
-static GtkMenu*         get_menu                        (IndicatorObject * io);
-static const gchar*     get_accessible_desc             (IndicatorObject * io);
-static const gchar*     get_name_hint                   (IndicatorObject * io);
-
-static void             update_visibility               (IndicatorPower * self);
-static gboolean         should_be_visible               (IndicatorPower * self);
-
-static void             on_entry_added                  (IndicatorObject * io, IndicatorObjectEntry * entry, gpointer user_data);
-
-/*
-static void gsd_appeared_callback (GDBusConnection *connection, const gchar *name, const gchar *name_owner, gpointer user_data);
-*/
-
-/* LCOV_EXCL_START */
-G_DEFINE_TYPE (IndicatorPower, indicator_power, INDICATOR_OBJECT_TYPE);
-/* LCOV_EXCL_STOP */
-
-static void
-indicator_power_class_init (IndicatorPowerClass *klass)
-{
-  GObjectClass *object_class = G_OBJECT_CLASS (klass);
-  IndicatorObjectClass *io_class = INDICATOR_OBJECT_CLASS (klass);
-
-  g_type_class_add_private (klass, sizeof (IndicatorPowerPrivate));
-
-  object_class->dispose = indicator_power_dispose;
-  object_class->finalize = indicator_power_finalize;
-
-  io_class->get_label = get_label;
-  io_class->get_image = get_image;
-  io_class->get_menu = get_menu;
-  io_class->get_accessible_desc = get_accessible_desc;
-  io_class->get_name_hint = get_name_hint;
-}
-
-static void
-indicator_power_init (IndicatorPower *self)
-{
-  IndicatorPowerPrivate * priv;
-
-  priv = G_TYPE_INSTANCE_GET_PRIVATE (self, INDICATOR_POWER_TYPE, IndicatorPowerPrivate);
-
-  priv->menu = GTK_MENU(gtk_menu_new());
-
-  priv->accessible_desc = NULL;
-
-  priv->dbus_listener = g_object_new (INDICATOR_POWER_DBUS_LISTENER_TYPE, NULL);
-  g_signal_connect_swapped (priv->dbus_listener, INDICATOR_POWER_DBUS_LISTENER_DEVICES_ENUMERATED,
-                            G_CALLBACK(indicator_power_set_devices), self);
-
-  priv->settings = g_settings_new ("com.canonical.indicator.power");
-  g_signal_connect_swapped (priv->settings, "changed::" ICON_POLICY_KEY,
-                            G_CALLBACK(update_visibility), self);
-  g_object_set (G_OBJECT(self),
-                INDICATOR_OBJECT_DEFAULT_VISIBILITY, FALSE,
-                NULL);
-
-  g_signal_connect (INDICATOR_OBJECT(self), INDICATOR_OBJECT_SIGNAL_ENTRY_ADDED,
-                    G_CALLBACK(on_entry_added), NULL);
-
-  self->priv = priv;
-}
-
-static void
-dispose_devices (IndicatorPower * self)
-{
-  IndicatorPowerPrivate * priv = self->priv;
-
-  g_clear_object (&priv->device);
-  g_slist_free_full (priv->devices, g_object_unref);
-  priv->devices = NULL;
-}
-static void
-indicator_power_dispose (GObject *object)
-{
-  IndicatorPower *self = INDICATOR_POWER(object);
-  IndicatorPowerPrivate * priv = self->priv;
-
-  dispose_devices (self);
-
-  g_clear_object (&priv->label);
-  g_clear_object (&priv->status_image);
-  g_clear_object (&priv->dbus_listener);
-  g_clear_object (&priv->settings);
-
-  G_OBJECT_CLASS (indicator_power_parent_class)->dispose (object);
-}
-
-static void
-indicator_power_finalize (GObject *object)
-{
-  IndicatorPower *self = INDICATOR_POWER(object);
-  IndicatorPowerPrivate * priv = self->priv;
-
-  g_free (priv->accessible_desc);
-
-  G_OBJECT_CLASS (indicator_power_parent_class)->finalize (object);
-}
-
-/***
-****
-***/
-
-static void
-spawn_command_line_async (const char * command)
-{
-  GError * err = NULL;
-  if (!g_spawn_command_line_async (command, &err))
-      g_warning ("Couldn't execute command \"%s\": %s", command, err->message);
-  g_clear_error (&err);
-}
-
-static void
-option_toggled_cb (GtkCheckMenuItem *item, IndicatorPower * self)
-{
-  gtk_widget_set_visible (GTK_WIDGET (self->priv->label),
-                          gtk_check_menu_item_get_active(item));
-}
-
-/* ensure that the entry is using self's accessible description */
-static void
-refresh_entry_accessible_desc (IndicatorPower * self, IndicatorObjectEntry * entry)
-{
-  const char * newval = self->priv->accessible_desc;
-
-  if (entry->accessible_desc != newval)
-  {
-    g_debug ("%s: setting entry %p accessible description to '%s'", G_STRFUNC, entry, newval);
-    entry->accessible_desc = newval;
-    g_signal_emit (self, INDICATOR_OBJECT_SIGNAL_ACCESSIBLE_DESC_UPDATE_ID, 0, entry);
-  }
-}
-
-static void
-on_entry_added (IndicatorObject       * io,
-                IndicatorObjectEntry  * entry,
-                gpointer                user_data G_GNUC_UNUSED)
-{
-  refresh_entry_accessible_desc (INDICATOR_POWER(io), entry);
-}
-
-static void
-set_accessible_desc (IndicatorPower *self, const gchar *desc)
-{
-  g_debug ("%s: setting accessible description to '%s'", G_STRFUNC, desc);
-
-  if (desc && *desc)
-  {
-    /* update our copy of the string */
-    char * oldval = self->priv->accessible_desc;
-    self->priv->accessible_desc = g_strdup (desc);
-
-    /* ensure that the entries are using self's accessible description */
-    GList * l;
-    GList * entries = indicator_object_get_entries(INDICATOR_OBJECT(self));
-    for (l=entries; l!=NULL; l=l->next)
-      refresh_entry_accessible_desc (self, l->data);
-
-    /* cleanup */
-    g_list_free (entries);
-    g_free (oldval);
-  }
-}
-
-static gboolean
-menu_add_device (GtkMenu * menu, const IndicatorPowerDevice * device)
-{
-  gboolean added = FALSE;
-  const UpDeviceKind kind = indicator_power_device_get_kind (device);
-
-  if (kind != UP_DEVICE_KIND_LINE_POWER)
-  {
-    GtkWidget *icon;
-    GtkWidget *item;
-    GtkWidget *details_label;
-    GtkWidget *grid;
-    GIcon *device_gicon;
-    gchar *short_details = NULL;
-    gchar *details = NULL;
-    gchar *accessible_name = NULL;
-    AtkObject *atk_object;
-
-    /* Process the data */
-    device_gicon = indicator_power_device_get_gicon (device);
-    icon = gtk_image_new_from_gicon (device_gicon, GTK_ICON_SIZE_SMALL_TOOLBAR);
-    g_clear_object (&device_gicon);
-
-    indicator_power_device_get_time_details (device, &short_details, &details, &accessible_name);
-
-    /* Create menu item */
-    item = gtk_image_menu_item_new ();
-    atk_object = gtk_widget_get_accessible(item);
-    if (atk_object != NULL)
-      atk_object_set_name (atk_object, accessible_name);
-
-    grid = gtk_grid_new ();
-    gtk_grid_set_column_spacing (GTK_GRID (grid), 6);
-    gtk_grid_attach (GTK_GRID (grid), icon, 0, 0, 1, 1);
-    details_label = gtk_label_new (details);
-    gtk_grid_attach_next_to (GTK_GRID (grid), details_label, icon, GTK_POS_RIGHT, 1, 1);
-    gtk_container_add (GTK_CONTAINER (item), grid);
-    gtk_widget_show (grid);
-
-    gtk_menu_shell_append (GTK_MENU_SHELL (menu), item);
-    added = TRUE;
-
-    g_signal_connect_swapped (G_OBJECT (item), "activate",
-                              G_CALLBACK (spawn_command_line_async), "gnome-power-statistics");
-
-    g_free (short_details);
-    g_free (details);
-    g_free (accessible_name);
-  }
-
-  return added;
-}
-
-static gsize
-menu_add_devices (GtkMenu * menu, GSList * devices)
-{
-  GSList * l;
-  gsize n_added = 0;
-
-  for (l=devices; l!=NULL; l=l->next)
-    if (menu_add_device (menu, l->data))
-      ++n_added;
-
-  return n_added;
-}
-
-static gboolean
-get_greeter_mode (void)
-{
-  const gchar *var;
-  var = g_getenv("INDICATOR_GREETER_MODE");
-  return (g_strcmp0(var, "1") == 0);
-}
-
-static void
-build_menu (IndicatorPower *self)
-{
-  GtkWidget *item;
-  GtkWidget *image;
-  GList *children;
-  gsize n_devices = 0;
-  IndicatorPowerPrivate * priv = self->priv;
-
-  /* remove the existing menuitems */
-  children = gtk_container_get_children (GTK_CONTAINER (priv->menu));
-  g_list_foreach (children, (GFunc) gtk_widget_destroy, NULL);
-  g_list_free (children);
-
-  /* devices */
-  n_devices = menu_add_devices (priv->menu, priv->devices);
-
-  if (!get_greeter_mode ()) {
-    /* only do the separator if we have at least one device */
-    if (n_devices != 0)
-      {
-        item = gtk_separator_menu_item_new ();
-        gtk_menu_shell_append (GTK_MENU_SHELL (priv->menu), item);
-      }
-
-    /* options */
-    item = gtk_check_menu_item_new_with_label (_("Show Time in Menu Bar"));
-    g_signal_connect (item, "toggled", G_CALLBACK(option_toggled_cb), self);
-    g_settings_bind (priv->settings, "show-time", item, "active", G_SETTINGS_BIND_DEFAULT);
-    gtk_menu_shell_append (GTK_MENU_SHELL (priv->menu), item);
-
-    /* preferences */
-    item = gtk_image_menu_item_new_with_label (_("Power Settings…"));
-    image = gtk_image_new_from_icon_name (GTK_STOCK_PREFERENCES, GTK_ICON_SIZE_MENU);
-    gtk_image_menu_item_set_image (GTK_IMAGE_MENU_ITEM (item), image);
-    g_signal_connect_swapped (G_OBJECT (item), "activate",
-                              G_CALLBACK (spawn_command_line_async), "gnome-control-center power");
-    gtk_menu_shell_append (GTK_MENU_SHELL (priv->menu), item);
-  }
-
-  /* show the menu */
-  gtk_widget_show_all (GTK_WIDGET (priv->menu));
-}
-
-/* the higher the weight, the more interesting the device */
-static int
-get_device_kind_weight (const IndicatorPowerDevice * device)
-{
-  UpDeviceKind kind;
-  static gboolean initialized = FALSE;
-  static int weights[UP_DEVICE_KIND_LAST];
-
-  kind = indicator_power_device_get_kind (device);
-  g_return_val_if_fail (0<=kind && kind<UP_DEVICE_KIND_LAST, 0);
-
-  if (G_UNLIKELY(!initialized))
-    {
-      int i;
-
-      initialized = TRUE;
-
-      for (i=0; i<UP_DEVICE_KIND_LAST; i++)
-        weights[i] = 1;
-      weights[UP_DEVICE_KIND_BATTERY] = 2;
-      weights[UP_DEVICE_KIND_LINE_POWER] = 0;
-    }
-
-  return weights[kind];
-}
-
-/* sort devices from most interesting to least interesting on this criteria:
-   1. discharging items from least time remaining until most time remaining
-   2. discharging items with an unknown time remaining
-   3. charging items from most time left to charge to least time left to charge
-   4. charging items with an unknown time remaining
-   5. batteries, then non-line power, then line-power */
-static gint
-device_compare_func (gconstpointer ga, gconstpointer gb)
-{
-  int ret;
-  int state;
-  const IndicatorPowerDevice * a = INDICATOR_POWER_DEVICE(ga);
-  const IndicatorPowerDevice * b = INDICATOR_POWER_DEVICE(gb);
-  const int a_state = indicator_power_device_get_state (a);
-  const int b_state = indicator_power_device_get_state (b);
-  const gdouble a_percentage = indicator_power_device_get_percentage (a);
-  const gdouble b_percentage = indicator_power_device_get_percentage (b);
-  const time_t a_time = indicator_power_device_get_time (a);
-  const time_t b_time = indicator_power_device_get_time (b);
-
-  ret = 0;
-
-  state = UP_DEVICE_STATE_DISCHARGING;
-  if (!ret && ((a_state == state) || (b_state == state)))
-    {
-      if (a_state != state) /* b is discharging */
-        {
-          ret = 1;
-        }
-      else if (b_state != state) /* a is discharging */
-        {
-          ret = -1;
-        }
-      else /* both are discharging; least-time-left goes first */
-        {
-          if (!a_time || !b_time) /* known time always trumps unknown time */
-            ret = a_time ? -1 : 1;
-          else if (a_time != b_time)
-            ret = a_time < b_time ? -1 : 1;
-          else
-            ret = a_percentage < b_percentage ? -1 : 1;
-        }
-    }
-
-  state = UP_DEVICE_STATE_CHARGING;
-  if (!ret && (((a_state == state) && a_time) || ((b_state == state) && b_time)))
-    {
-      if (a_state != state) /* b is charging */
-        {
-          ret = 1;
-        }
-      else if (b_state != state) /* a is charging */
-        {
-          ret = -1;
-        }
-      else /* both are discharging; most-time-to-charge goes first */
-        {
-          if (!a_time || !b_time) /* known time always trumps unknown time */
-            ret = a_time ? -1 : 1;
-          else if (a_time != b_time)
-            ret = a_time > b_time ? -1 : 1;
-          else
-            ret = a_percentage < b_percentage ? -1 : 1;
-        }
-    }
-
-  if (!ret) /* neither device is charging nor discharging... */
-    {
-      const int weight_a = get_device_kind_weight (a);
-      const int weight_b = get_device_kind_weight (b);
-
-      if (weight_a > weight_b)
-        {
-          ret = -1;
-        }
-      else if (weight_a < weight_b)
-        {
-          ret = 1;
-        }
-    }
-
-  if (!ret)
-    ret = a_state - b_state;
-
-  return ret;
-}
-
-IndicatorPowerDevice *
-indicator_power_choose_primary_device (GSList * devices)
-{
-  IndicatorPowerDevice * primary = NULL;
-
-  if (devices != NULL)
-    {
-      GSList * tmp;
-
-      tmp = g_slist_copy (devices);
-      tmp = g_slist_sort (tmp, device_compare_func);
-      primary = g_object_ref (tmp->data);
-
-      g_slist_free (tmp);
-    }
-
-  return primary;
-}
-
-static void
-put_primary_device (IndicatorPower *self, IndicatorPowerDevice *device)
-{
-  IndicatorPowerPrivate * priv = self->priv;
-
-  /* set icon */
-  GIcon * device_gicon = indicator_power_device_get_gicon (device);
-  gtk_image_set_from_gicon (priv->status_image, device_gicon, GTK_ICON_SIZE_LARGE_TOOLBAR);
-  g_clear_object (&device_gicon);
-  gtk_widget_show (GTK_WIDGET (priv->status_image));
-
-  /* get the description */
-  gchar * short_details;
-  gchar * details;
-  gchar * accessible_name;
-  indicator_power_device_get_time_details (device, &short_details, &details, &accessible_name);
-  gtk_label_set_label (GTK_LABEL (priv->label), short_details);
-  set_accessible_desc (self, accessible_name);
-  g_free (accessible_name);
-  g_free (details);
-  g_free (short_details);
-}
-
-void
-indicator_power_set_devices (IndicatorPower * self, GSList * devices)
-{
-  /* LCOV_EXCL_START */
-  g_return_if_fail (IS_INDICATOR_POWER(self));
-  /* LCOV_EXCL_STOP */
-
-  IndicatorPowerPrivate * priv = self->priv;
-
-  /* update our devices & primary device */
-  g_slist_foreach (devices, (GFunc)g_object_ref, NULL);
-  dispose_devices (self);
-  priv->devices = g_slist_copy (devices);
-  priv->device = indicator_power_choose_primary_device (devices);
-
-  /* and our menus/visibility from the new device list */
-  if (priv->device != NULL)
-      put_primary_device (self, priv->device);
-  else
-      g_message ("Couldn't find primary device");
-  build_menu (self);
-  update_visibility (self);
-}
-
-static void
-update_visibility (IndicatorPower * self)
-{
-  indicator_object_set_visible (INDICATOR_OBJECT (self),
-                                should_be_visible (self));
-}
-
-
-/* Grabs the label. Creates it if it doesn't
-   exist already */
-static GtkLabel *
-get_label (IndicatorObject *io)
-{
-  IndicatorPower *self = INDICATOR_POWER (io);
-  IndicatorPowerPrivate * priv = self->priv;
-
-  if (priv->label == NULL)
-    {
-      /* Create the label if it doesn't exist already */
-      priv->label = GTK_LABEL (gtk_label_new (""));
-      g_object_ref_sink (priv->label);
-      gtk_widget_set_visible (GTK_WIDGET (priv->label), FALSE);
-    }
-
-  return priv->label;
-}
-
-static GtkImage *
-get_image (IndicatorObject *io)
-{
-  GIcon *gicon;
-  IndicatorPower *self = INDICATOR_POWER (io);
-  IndicatorPowerPrivate * priv = self->priv;
-
-  if (priv->status_image == NULL)
-  {
-    /* Will create the status icon if it doesn't exist already */
-    gicon = g_themed_icon_new (DEFAULT_ICON);
-    priv->status_image = GTK_IMAGE (gtk_image_new_from_gicon (gicon,
-                                                              GTK_ICON_SIZE_LARGE_TOOLBAR));
-    g_object_ref_sink (priv->status_image);
-    g_object_unref (gicon);
-  }
-
-  return priv->status_image;
-}
-
-static GtkMenu *
-get_menu (IndicatorObject *io)
-{
-  IndicatorPower *self = INDICATOR_POWER (io);
-
-  build_menu (self);
-
-  return GTK_MENU (self->priv->menu);
-}
-
-static const gchar *
-get_accessible_desc (IndicatorObject *io)
-{
-  IndicatorPower *self = INDICATOR_POWER (io);
-
-  return self->priv->accessible_desc;
-}
-
-static const gchar *
-get_name_hint (IndicatorObject *io)
-{
-  return PACKAGE_NAME;
-}
-
-/***
-****
-***/
-
-static void
-count_batteries (GSList * devices, int *total, int *inuse)
-{
-  GSList * l;
-
-  for (l=devices; l!=NULL; l=l->next)
-    {
-      const IndicatorPowerDevice * device = INDICATOR_POWER_DEVICE(l->data);
-
-      if (indicator_power_device_get_kind(device) == UP_DEVICE_KIND_BATTERY ||
-	  indicator_power_device_get_kind(device) == UP_DEVICE_KIND_UPS)
-        {
-          ++*total;
-
-          const UpDeviceState state = indicator_power_device_get_state (device);
-          if ((state == UP_DEVICE_STATE_CHARGING) || (state == UP_DEVICE_STATE_DISCHARGING))
-            ++*inuse;
-        }
-    }
-
-    g_debug("count_batteries found %d batteries (%d are charging/discharging)", *total, *inuse);
-}
-
-static gboolean
-should_be_visible (IndicatorPower * self)
-{
-  gboolean visible = TRUE;
-  IndicatorPowerPrivate * priv = self->priv;
-
-  const int icon_policy = g_settings_get_enum (priv->settings, ICON_POLICY_KEY);
-
-  g_debug ("icon_policy is: %d (present==0, charge==1, never==2)", icon_policy);
-
-  if (icon_policy == POWER_INDICATOR_ICON_POLICY_NEVER)
-    {
-      visible = FALSE;
-    }
-    else
-    {
-      int batteries=0, inuse=0;
-      count_batteries (priv->devices, &batteries, &inuse);
-
-      if (icon_policy == POWER_INDICATOR_ICON_POLICY_PRESENT)
-        {
-          visible = batteries > 0;
-        }
-      else if (icon_policy == POWER_INDICATOR_ICON_POLICY_CHARGE)
-        {
-          visible = inuse > 0;
-        }
-    }
-
-  g_debug ("should_be_visible: %s", visible?"yes":"no");
-  return visible;
-}
diff --git a/src/indicator-power.h b/src/indicator-power.h
deleted file mode 100644
index 34d0d0e..0000000
--- a/src/indicator-power.h
+++ /dev/null
@@ -1,60 +0,0 @@
-/*
-An indicator to power related information in the menubar.
-
-Copyright 2011 Canonical Ltd.
-
-Authors:
-    Javier Jardon <javier.jardon@codethink.co.uk>
-
-This program is free software: you can redistribute it and/or modify it
-under the terms of the GNU General Public License version 3, as published 
-by the Free Software Foundation.
-
-This program is distributed in the hope that it will be useful, but
-WITHOUT ANY WARRANTY; without even the implied warranties of
-MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
-PURPOSE.  See the GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License along
-with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-/* Gtk required */
-#include <gtk/gtk.h>
-
-/* parent class */
-#include <libindicator/indicator.h>
-#include <libindicator/indicator-object.h>
-
-G_BEGIN_DECLS
-
-#define INDICATOR_POWER_TYPE            (indicator_power_get_type ())
-#define INDICATOR_POWER(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), INDICATOR_POWER_TYPE, IndicatorPower))
-#define INDICATOR_POWER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), INDICATOR_POWER_TYPE, IndicatorPowerClass))
-#define IS_INDICATOR_POWER(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), INDICATOR_POWER_TYPE))
-#define IS_INDICATOR_POWER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), INDICATOR_POWER_TYPE))
-#define INDICATOR_POWER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), INDICATOR_POWER_TYPE, IndicatorPowerClass))
-
-typedef struct _IndicatorPower         IndicatorPower;
-typedef struct _IndicatorPowerClass    IndicatorPowerClass;
-typedef struct _IndicatorPowerPrivate  IndicatorPowerPrivate;
-
-struct _IndicatorPowerClass
-{
-  IndicatorObjectClass parent_class;
-};
-
-struct _IndicatorPower
-{
-  IndicatorObject parent_instance;
-  IndicatorPowerPrivate * priv;
-};
-
-GType indicator_power_get_type (void) G_GNUC_CONST;
-
-void indicator_power_set_devices (IndicatorPower         * power,
-                                  GSList                 * devices);
-
-IndicatorPowerDevice* indicator_power_choose_primary_device (GSList * devices);
-
-G_END_DECLS
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..ef615dc
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2013 Canonical Ltd.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <locale.h>
+#include <stdlib.h> /* exit() */
+
+#include <glib/gi18n.h>
+#include <gio/gio.h>
+
+#include "device.h"
+#include "device-provider-upower.h"
+#include "service.h"
+
+/***
+****
+***/
+
+static void
+on_name_lost (gpointer instance G_GNUC_UNUSED, gpointer loop)
+{
+  g_message ("exiting: service couldn't acquire or lost ownership of busname");
+  g_main_loop_quit ((GMainLoop*)loop);
+}
+
+int
+main (int argc G_GNUC_UNUSED, char ** argv G_GNUC_UNUSED)
+{
+  GMainLoop * loop;
+  IndicatorPowerService * service;
+  IndicatorPowerDeviceProvider * device_provider;
+
+  /* boilerplate i18n */
+  setlocale (LC_ALL, "");
+  bindtextdomain (GETTEXT_PACKAGE, GNOMELOCALEDIR);
+  textdomain (GETTEXT_PACKAGE);
+
+  /* run */
+  device_provider = indicator_power_device_provider_upower_new ();
+  service = indicator_power_service_new (device_provider);
+  loop = g_main_loop_new (NULL, FALSE);
+  g_signal_connect (service, INDICATOR_POWER_SERVICE_SIGNAL_NAME_LOST,
+                    G_CALLBACK(on_name_lost), loop);
+  g_main_loop_run (loop);
+
+  /* cleanup */
+  g_clear_object (&device_provider);
+  g_clear_object (&service);
+  g_main_loop_unref (loop);
+  return 0;
+}
diff --git a/src/org.freedesktop.UPower.Device.xml b/src/org.freedesktop.UPower.Device.xml
new file mode 100644
index 0000000..7c9a65b
--- /dev/null
+++ b/src/org.freedesktop.UPower.Device.xml
@@ -0,0 +1,705 @@
+<!DOCTYPE node PUBLIC
+"-//freedesktop//DTD D-BUS Object Introspection 1.0//EN"
+"http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd" [
+  <!ENTITY ERROR_GENERAL "org.freedesktop.UPower.Device.GeneralError">
+]>
+<node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
+  <interface name="org.freedesktop.UPower.Device">
+    <doc:doc>
+      <doc:description>
+        <doc:para>
+          Objects implementing this interface are usually discovered through
+          the <doc:tt>org.freedesktop.UPower</doc:tt> interface on
+          the <doc:tt>/org/freedesktop/UPower</doc:tt> object on
+          the D-Bus system bus service with the well-known
+          name <doc:tt>org.freedesktop.UPower</doc:tt> using
+          the
+          <doc:ref type="method" to="Power.EnumerateDevices">EnumerateDevices</doc:ref>
+          method.
+        </doc:para>
+        <doc:para>
+          <doc:example language="shell" title="simple example">
+            <doc:code>
+$ dbus-send --print-reply \
+            --system \
+            --dest=org.freedesktop.UPower \
+            /org/freedesktop/UPower/devices/battery_BAT0 \
+            org.freedesktop.DBus.Properties.GetAll \
+            string:org.freedesktop.UPower.Device
+
+method return sender=:1.386 -> dest=:1.477 reply_serial=2
+   array [
+      dict entry(
+         string "native-path"
+         variant             string "/sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:01/PNP0C09:00/PNP0C0A:00/power_supply/BAT0"
+      )
+      dict entry(
+         string "vendor"
+         variant             string "SONY"
+      )
+      dict entry(
+         string "model"
+         variant             string "42T4568"
+      )
+      dict entry(
+         string "serial"
+         variant             string "4179"
+      )
+      dict entry(
+         string "update-time"
+         variant             uint64 1226417875
+      )
+      dict entry(
+         string "type"
+         variant             uint 2
+      )
+      dict entry(
+         string "power-supply"
+         variant             boolean true
+      )
+      dict entry(
+         string "has-history"
+         variant             boolean true
+      )
+      dict entry(
+         string "has-statistics"
+         variant             boolean true
+      )
+      dict entry(
+         string "online"
+         variant             boolean false
+      )
+      dict entry(
+         string "energy"
+         variant             double 72.85
+      )
+      dict entry(
+         string "energy-empty"
+         variant             double 0
+      )
+      dict entry(
+         string "energy-full"
+         variant             double 74.55
+      )
+      dict entry(
+         string "energy-full-design"
+         variant             double 74.88
+      )
+      dict entry(
+         string "energy-rate"
+         variant             double 0
+      )
+      dict entry(
+         string "voltage"
+         variant             double 16.415
+      )
+      dict entry(
+         string "time-to-empty"
+         variant             int64 0
+      )
+      dict entry(
+         string "time-to-full"
+         variant             int64 0
+      )
+      dict entry(
+         string "percentage"
+         variant             double 97.7197
+      )
+      dict entry(
+         string "is-present"
+         variant             boolean true
+      )
+      dict entry(
+         string "state"
+         variant             uint 3
+      )
+      dict entry(
+         string "is-rechargeable"
+         variant             boolean true
+      )
+      dict entry(
+         string "capacity"
+         variant             double 100
+      )
+      dict entry(
+         string "technology"
+         variant             uint 1
+      )
+   ]
+            </doc:code>
+          </doc:example>
+        </doc:para>
+        <doc:para>
+          Unless otherwise noted, an empty string or the value 0 in a
+          property on this interface means not set.
+        </doc:para>
+      </doc:description>
+    </doc:doc>
+
+
+    <!-- ************************************************************ -->
+    <method name="Refresh">
+      <annotation name="org.freedesktop.DBus.GLib.Async" value=""/>
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Refreshes the data collected from the power source.
+          </doc:para>
+        </doc:description>
+        <doc:permission>Callers need the org.freedesktop.upower.refresh-power-source authorization</doc:permission>
+        <doc:errors>
+          <doc:error name="&ERROR_GENERAL;">if an error occured while refreshing</doc:error>
+        </doc:errors>
+      </doc:doc>
+    </method>
+
+    <!-- ************************************************************ -->
+    <signal name="Changed">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Some value on the power source changed.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </signal>
+
+    <!-- ************************************************************ -->
+    <method name="GetHistory">
+      <annotation name="org.freedesktop.DBus.GLib.Async" value=""/>
+      <arg name="type" direction="in" type="s">
+        <doc:doc><doc:summary>The type of history.
+        Valid types are <doc:tt>rate</doc:tt> or <doc:tt>charge</doc:tt>.</doc:summary></doc:doc>
+      </arg>
+      <arg name="timespan" direction="in" type="u">
+        <doc:doc><doc:summary>The amount of data to return in seconds, or 0 for all.</doc:summary></doc:doc>
+      </arg>
+      <arg name="resolution" direction="in" type="u">
+        <doc:doc>
+          <doc:summary>
+            The approximate number of points to return.
+            A higher resolution is more accurate, at the expense of plotting speed.
+          </doc:summary>
+        </doc:doc>
+      </arg>
+      <arg name="data" direction="out" type="a(udu)">
+        <doc:doc><doc:summary>
+            The history data for the power device, if the device supports history.
+            Data is ordered from the earliest in time, to the newest data point.
+            Each element contains the following members:
+            <doc:list>
+              <doc:item>
+                <doc:term>time</doc:term>
+                <doc:definition>
+                  The time value in seconds from the <doc:tt>gettimeofday()</doc:tt> method.
+                </doc:definition>
+              </doc:item>
+              <doc:item>
+                <doc:term>value</doc:term>
+                <doc:definition>
+                  The data value, for instance the rate in W or the charge in %.
+                </doc:definition>
+              </doc:item>
+              <doc:item>
+                <doc:term>state</doc:term>
+                <doc:definition>
+                  The state of the device, for instance <doc:tt>charging</doc:tt> or
+                  <doc:tt>discharging</doc:tt>.
+                </doc:definition>
+              </doc:item>
+            </doc:list>
+        </doc:summary></doc:doc>
+      </arg>
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Gets history for the power device that is persistent across reboots.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </method>
+
+    <!-- ************************************************************ -->
+    <method name="GetStatistics">
+      <annotation name="org.freedesktop.DBus.GLib.Async" value=""/>
+      <arg name="type" direction="in" type="s">
+        <doc:doc><doc:summary>The mode for the statistics.
+        Valid types are <doc:tt>charging</doc:tt> or <doc:tt>discharging</doc:tt>.</doc:summary></doc:doc>
+      </arg>
+      <arg name="data" direction="out" type="a(dd)">
+        <doc:doc><doc:summary>
+            The statistics data for the power device.
+            Each element contains the following members:
+            <doc:list>
+              <doc:item>
+                <doc:term>value</doc:term>
+                <doc:definition>
+                  The value of the percentage point, usually in seconds
+                </doc:definition>
+              </doc:item>
+              <doc:item>
+                <doc:term>accuracy</doc:term>
+                <doc:definition>
+                  The accuracy of the prediction in percent.
+                </doc:definition>
+              </doc:item>
+            </doc:list>
+        </doc:summary></doc:doc>
+      </arg>
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Gets statistics for the power device that may be interesting
+            to show on a graph in the session.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </method>
+
+    <!-- ************************************************************ -->
+    <property name="NativePath" type="s" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            OS specific native path of the power source. On Linux this
+            is the sysfs path, for
+            example <doc:tt>/sys/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT0</doc:tt>. Is
+            blank if the device is being driven by a user space
+            driver.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="Vendor" type="s" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Name of the vendor of the battery.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="Model" type="s" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Name of the model of this battery.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="Serial" type="s" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Unique serial number of the battery.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="UpdateTime" type="t" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            The point in time (seconds since the Epoch Jan 1, 1970
+            0:00 UTC) that data was read from the power source.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="Type" type="u" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Type of power source.
+          </doc:para>
+          <doc:list>
+            <doc:item>
+              <doc:term>0</doc:term><doc:definition>Unknown</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>1</doc:term><doc:definition>Line Power</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>2</doc:term><doc:definition>Battery</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>3</doc:term><doc:definition>Ups</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>4</doc:term><doc:definition>Monitor</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>5</doc:term><doc:definition>Mouse</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>6</doc:term><doc:definition>Keyboard</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>7</doc:term><doc:definition>Pda</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>8</doc:term><doc:definition>Phone</doc:definition>
+            </doc:item>
+          </doc:list>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="PowerSupply" type="b" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            If the power device is used to supply the system.
+            This would be set TRUE for laptop batteries and UPS devices,
+            but set FALSE for wireless mice or PDAs.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="HasHistory" type="b" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            If the power device has history.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="HasStatistics" type="b" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            If the power device has statistics.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="Online" type="b" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Whether power is currently being provided through line power.
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "line-power".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="Energy" type="d" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Amount of energy (measured in Wh) currently available in
+            the power source.
+          </doc:para><doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="EnergyEmpty" type="d" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Amount of energy (measured in Wh) in the power source when
+            it's considered to be empty.
+          </doc:para><doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="EnergyFull" type="d" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Amount of energy (measured in Wh) in the power source when
+            it's considered full.
+          </doc:para><doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="EnergyFullDesign" type="d" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Amount of energy (measured in Wh) the power source is
+            designed to hold when it's considered full.
+          </doc:para><doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="EnergyRate" type="d" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Amount of energy being drained from the source, measured
+            in W. If positive, the source is being discharged, if
+            negative it's being charged.
+          </doc:para><doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="Voltage" type="d" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Voltage in the Cell or being recorded by the meter.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="TimeToEmpty" type="x" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Number of seconds until the power source is considered empty.
+            Is set to 0 if unknown.
+          </doc:para><doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="TimeToFull" type="x" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Number of seconds until the power source is considered full.
+            Is set to 0 if unknown.
+          </doc:para><doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="Percentage" type="d" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            The amount of energy left in the power source expressed as
+            a percentage between 0 and 100. Typically this is the same as
+            (<doc:ref type="property" to="Source:Energy">energy</doc:ref> -
+            <doc:ref type="property" to="Source:EnergyEmpty">energy-empty</doc:ref>) /
+            (<doc:ref type="property" to="Source:EnergyFull">energy-full</doc:ref> -
+            <doc:ref type="property" to="Source:EnergyEmpty">energy-empty</doc:ref>).
+            However, some primitive power sources are capable of only
+            reporting percentages and in this case the energy-*
+            properties will be unset while this property is set.
+          </doc:para><doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="IsPresent" type="b" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            If the power source is present in the bay.
+            This field is required as some batteries are hot-removable, for example
+            expensive UPS and most laptop batteries.
+          </doc:para><doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="State" type="u" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            The battery power state.
+          </doc:para>
+          <doc:list>
+            <doc:item>
+              <doc:term>0</doc:term><doc:definition>Unknown</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>1</doc:term><doc:definition>Charging</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>2</doc:term><doc:definition>Discharging</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>3</doc:term><doc:definition>Empty</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>4</doc:term><doc:definition>Fully charged</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>5</doc:term><doc:definition>Pending charge</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>6</doc:term><doc:definition>Pending discharge</doc:definition>
+            </doc:item>
+          </doc:list>
+          <doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="IsRechargeable" type="b" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            If the power source is rechargeable.
+          </doc:para><doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="Capacity" type="d" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            The capacity of the power source expressed as a percentage between 0 and 100.
+            The capacity of the battery will reduce with age.
+            A capacity value less than 75% is usually a sign that you should renew your battery.
+            Typically this value is the same as
+            (<doc:ref type="property" to="Source:FullDesign">full-design</doc:ref> /
+            <doc:ref type="property" to="Source:Full">full</doc:ref>) * 100.
+            However, some primitive power sources are not capable reporting capacity
+            and in this case the capacity property will be unset.
+          </doc:para><doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="Technology" type="u" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            Technology used in the battery:
+          </doc:para>
+          <doc:list>
+            <doc:item>
+              <doc:term>0</doc:term><doc:definition>Unknown</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>1</doc:term><doc:definition>Lithium ion</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>2</doc:term><doc:definition>Lithium polymer</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>3</doc:term><doc:definition>Lithium iron phosphate</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>4</doc:term><doc:definition>Lead acid</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>5</doc:term><doc:definition>Nickel cadmium</doc:definition>
+            </doc:item>
+            <doc:item>
+              <doc:term>6</doc:term><doc:definition>Nickel metal hydride</doc:definition>
+            </doc:item>
+          </doc:list>
+          <doc:para>
+            This property is only valid if the property
+            <doc:ref type="property" to="Source:Type">type</doc:ref>
+            has the value "battery".
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="RecallNotice" type="b" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            If the device may have been recalled by the vendor due to a suspected
+            fault.
+            This key does not imply the device is faulty, only that it approximatly
+            matches the description from the vendor of units that were recalled.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="RecallVendor" type="s" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            The vendor that is handling the hardware recall.
+          </doc:para>
+          <doc:para>
+            This property is only valid if the property recall-notice is true.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+    <property name="RecallUrl" type="s" access="read">
+      <doc:doc>
+        <doc:description>
+          <doc:para>
+            The URL to visit about the hardware recall.
+          </doc:para>
+          <doc:para>
+            This property is only valid if the property recall-notice is true.
+          </doc:para>
+        </doc:description>
+      </doc:doc>
+    </property>
+
+  </interface>
+
+</node>
diff --git a/src/org.freedesktop.UPower.xml b/src/org.freedesktop.UPower.xml
new file mode 100644
index 0000000..7b73583
--- /dev/null
+++ b/src/org.freedesktop.UPower.xml
@@ -0,0 +1,43 @@
+<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object Introspection 1.0//EN"
+    "http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd">
+<node>
+    <interface name="org.freedesktop.UPower">
+        <method name="HibernateAllowed">
+            <arg name="allowed" type="b" direction="out"/>
+        </method>
+        <method name="Hibernate">
+        </method>
+        <method name="SuspendAllowed">
+            <arg name="allowed" type="b" direction="out"/>
+        </method>
+        <method name="Suspend">
+        </method>
+        <method name="AboutToSleep">
+        </method>
+        <method name="EnumerateDevices">
+            <arg name="devices" type="ao" direction="out"/>
+        </method>
+        <signal name="Resuming">
+        </signal>
+        <signal name="Sleeping">
+        </signal>
+        <signal name="Changed">
+        </signal>
+        <signal name="DeviceChanged">
+            <arg type="s"/>
+        </signal>
+        <signal name="DeviceRemoved">
+            <arg type="s"/>
+        </signal>
+        <signal name="DeviceAdded">
+            <arg type="s"/>
+        </signal>
+        <property name="LidIsPresent" type="b" access="read"/>
+        <property name="LidIsClosed" type="b" access="read"/>
+        <property name="OnLowBattery" type="b" access="read"/>
+        <property name="OnBattery" type="b" access="read"/>
+        <property name="CanHibernate" type="b" access="read"/>
+        <property name="CanSuspend" type="b" access="read"/>
+        <property name="DaemonVersion" type="s" access="read"/>
+    </interface>
+</node>
\ No newline at end of file
diff --git a/src/service.c b/src/service.c
new file mode 100644
index 0000000..012ef13
--- /dev/null
+++ b/src/service.c
@@ -0,0 +1,1015 @@
+/*
+ * Copyright 2013 Canonical Ltd.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ *   Ted Gould <ted@canonical.com>
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <glib/gi18n.h>
+#include <gio/gio.h>
+
+#include "device.h"
+#include "device-provider.h"
+#include "service.h"
+
+#define BUS_NAME "com.canonical.indicator.power"
+#define BUS_PATH "/com/canonical/indicator/power"
+
+#define SETTINGS_SHOW_TIME_S "show-time"
+#define SETTINGS_ICON_POLICY_S "icon-policy"
+
+G_DEFINE_TYPE (IndicatorPowerService,
+               indicator_power_service,
+               G_TYPE_OBJECT)
+
+enum
+{
+  SIGNAL_NAME_LOST,
+  LAST_SIGNAL
+};
+
+static guint signals[LAST_SIGNAL] = { 0 };
+
+enum
+{
+  PROP_0,
+  PROP_DEVICE_PROVIDER,
+  LAST_PROP
+};
+
+static GParamSpec * properties[LAST_PROP];
+
+enum
+{
+  SECTION_HEADER    = (1<<0),
+  SECTION_DEVICES   = (1<<1),
+  SECTION_SETTINGS  = (1<<2),
+};
+
+enum
+{
+  PROFILE_DESKTOP,
+  PROFILE_GREETER,
+  N_PROFILES
+};
+
+static const char * const menu_names[N_PROFILES] =
+{
+  "desktop",
+  "greeter"
+};
+
+enum
+{
+  POWER_INDICATOR_ICON_POLICY_PRESENT,
+  POWER_INDICATOR_ICON_POLICY_CHARGE,
+  POWER_INDICATOR_ICON_POLICY_NEVER
+};
+
+struct ProfileMenuInfo
+{
+  /* the root level -- the header is the only child of this */
+  GMenu * menu;
+
+  /* parent of the sections. This is the header's submenu */
+  GMenu * submenu;
+
+  guint export_id;
+};
+
+struct _IndicatorPowerServicePrivate
+{
+  GCancellable * cancellable;
+
+  GSettings * settings;
+
+  guint own_id;
+  guint actions_export_id;
+  GDBusConnection * conn;
+
+  struct ProfileMenuInfo menus[N_PROFILES];
+
+  GSimpleActionGroup * actions;
+  GSimpleAction * header_action;
+  GSimpleAction * show_time_action;
+
+  IndicatorPowerDevice * primary_device;
+  GList * devices; /* IndicatorPowerDevice */
+
+  IndicatorPowerDeviceProvider * device_provider;
+};
+
+typedef IndicatorPowerServicePrivate priv_t;
+
+/***
+****
+****  DEVICES
+****
+***/
+
+/* the higher the weight, the more interesting the device */
+static int
+get_device_kind_weight (const IndicatorPowerDevice * device)
+{
+  UpDeviceKind kind;
+  static gboolean initialized = FALSE;
+  static int weights[UP_DEVICE_KIND_LAST];
+
+  kind = indicator_power_device_get_kind (device);
+  g_return_val_if_fail (0<=kind && kind<UP_DEVICE_KIND_LAST, 0);
+
+  if (G_UNLIKELY(!initialized))
+    {
+      int i;
+
+      initialized = TRUE;
+
+      for (i=0; i<UP_DEVICE_KIND_LAST; i++)
+        weights[i] = 1;
+      weights[UP_DEVICE_KIND_BATTERY] = 2;
+      weights[UP_DEVICE_KIND_LINE_POWER] = 0;
+    }
+
+  return weights[kind];
+}
+
+/* sort devices from most interesting to least interesting on this criteria:
+   1. discharging items from least time remaining until most time remaining
+   2. discharging items with an unknown time remaining
+   3. charging items from most time left to charge to least time left to charge
+   4. charging items with an unknown time remaining
+   5. batteries, then non-line power, then line-power */
+static gint
+device_compare_func (gconstpointer ga, gconstpointer gb)
+{
+  int ret;
+  int state;
+  const IndicatorPowerDevice * a = ga;
+  const IndicatorPowerDevice * b = gb;
+  const int a_state = indicator_power_device_get_state (a);
+  const int b_state = indicator_power_device_get_state (b);
+  const gdouble a_percentage = indicator_power_device_get_percentage (a);
+  const gdouble b_percentage = indicator_power_device_get_percentage (b);
+  const time_t a_time = indicator_power_device_get_time (a);
+  const time_t b_time = indicator_power_device_get_time (b);
+
+  ret = 0;
+
+  state = UP_DEVICE_STATE_DISCHARGING;
+  if (!ret && ((a_state == state) || (b_state == state)))
+    {
+      if (a_state != state) /* b is discharging */
+        {
+          ret = 1;
+        }
+      else if (b_state != state) /* a is discharging */
+        {
+          ret = -1;
+        }
+      else /* both are discharging; least-time-left goes first */
+        {
+          if (!a_time || !b_time) /* known time always trumps unknown time */
+            ret = a_time ? -1 : 1;
+          else if (a_time != b_time)
+            ret = a_time < b_time ? -1 : 1;
+          else
+            ret = a_percentage < b_percentage ? -1 : 1;
+        }
+    }
+
+  state = UP_DEVICE_STATE_CHARGING;
+  if (!ret && (((a_state == state) && a_time) ||
+               ((b_state == state) && b_time)))
+    {
+      if (a_state != state) /* b is charging */
+        {
+          ret = 1;
+        }
+      else if (b_state != state) /* a is charging */
+        {
+          ret = -1;
+        }
+      else /* both are discharging; most-time-to-charge goes first */
+        {
+          if (!a_time || !b_time) /* known time always trumps unknown time */
+            ret = a_time ? -1 : 1;
+          else if (a_time != b_time)
+            ret = a_time > b_time ? -1 : 1;
+          else
+            ret = a_percentage < b_percentage ? -1 : 1;
+        }
+    }
+
+  if (!ret) /* neither device is charging nor discharging... */
+    {
+      const int weight_a = get_device_kind_weight (a);
+      const int weight_b = get_device_kind_weight (b);
+
+      if (weight_a > weight_b)
+        {
+          ret = -1;
+        }
+      else if (weight_a < weight_b)
+        {
+          ret = 1;
+        }
+    }
+
+  if (!ret)
+    ret = a_state - b_state;
+
+  return ret;
+}
+
+/***
+****
+****  HEADER SECTION
+****
+***/
+
+static void
+count_batteries (GList * devices, int *total, int *inuse)
+{
+  GList * l;
+
+  for (l=devices; l!=NULL; l=l->next)
+    {
+      const IndicatorPowerDevice * device = INDICATOR_POWER_DEVICE(l->data);
+
+      if (indicator_power_device_get_kind(device) == UP_DEVICE_KIND_BATTERY ||
+          indicator_power_device_get_kind(device) == UP_DEVICE_KIND_UPS)
+        {
+          ++*total;
+
+          const UpDeviceState state = indicator_power_device_get_state (device);
+          if ((state == UP_DEVICE_STATE_CHARGING) ||
+              (state == UP_DEVICE_STATE_DISCHARGING))
+            ++*inuse;
+        }
+    }
+
+  g_debug ("count_batteries found %d batteries (%d are charging/discharging)",
+           *total, *inuse);
+}
+
+static gboolean
+should_be_visible (IndicatorPowerService * self)
+{
+  gboolean visible = TRUE;
+  priv_t * p = self->priv;
+
+  const int policy = g_settings_get_enum (p->settings, SETTINGS_ICON_POLICY_S);
+  g_debug ("policy is: %d (present==0, charge==1, never==2)", policy);
+
+  if (policy == POWER_INDICATOR_ICON_POLICY_NEVER)
+    {
+      visible = FALSE;
+    }
+    else
+    {
+      int batteries=0, inuse=0;
+
+      count_batteries (p->devices, &batteries, &inuse);
+
+      if (policy == POWER_INDICATOR_ICON_POLICY_PRESENT)
+        {
+          visible = batteries > 0;
+        }
+      else if (policy == POWER_INDICATOR_ICON_POLICY_CHARGE)
+        {
+          visible = inuse > 0;
+        }
+    }
+
+  g_debug ("should_be_visible: %s", visible?"yes":"no");
+  return visible;
+}
+
+static GVariant *
+create_header_state (IndicatorPowerService * self)
+{
+  GVariantBuilder b;
+  gchar * label = NULL;
+  gchar * a11y = NULL;
+  GIcon * icon = NULL;
+  priv_t * p = self->priv;
+
+  if (p->primary_device != NULL)
+    {
+      gchar * details;
+
+      indicator_power_device_get_time_details (p->primary_device,
+                                               &label,
+                                               &details,
+                                               &a11y);
+
+      icon = indicator_power_device_get_gicon (p->primary_device);
+
+      g_free (details);
+    }
+
+  g_variant_builder_init (&b, G_VARIANT_TYPE("a{sv}"));
+
+  g_variant_builder_add (&b, "{sv}", "visible",
+                         g_variant_new_boolean (should_be_visible (self)));
+
+  if (label != NULL)
+    {
+      if (g_settings_get_boolean (p->settings, SETTINGS_SHOW_TIME_S))
+        g_variant_builder_add (&b, "{sv}", "label",
+                               g_variant_new_string (label));
+
+      g_free (label);
+    }
+
+  if (icon != NULL)
+    {
+      g_variant_builder_add (&b, "{sv}", "icon", g_icon_serialize (icon));
+
+      g_object_unref (icon);
+    }
+
+  if (a11y != NULL)
+    {
+      g_variant_builder_add (&b, "{sv}", "accessible-desc",
+                             g_variant_new_string (a11y));
+
+      g_free (a11y);
+    }
+
+  return g_variant_builder_end (&b);
+}
+
+
+/***
+****
+****  DEVICE SECTION
+****
+***/
+
+static void
+append_device_to_menu (GMenu * menu, const IndicatorPowerDevice * device)
+{
+  const UpDeviceKind kind = indicator_power_device_get_kind (device);
+
+  if (kind != UP_DEVICE_KIND_LINE_POWER)
+  {
+    char * brief;
+    char * label;
+    char * a11y;
+    GMenuItem * menu_item;
+    GIcon * icon = indicator_power_device_get_gicon (device);
+
+    indicator_power_device_get_time_details (device,
+                                             &brief,
+                                             &label,
+                                             &a11y);
+
+    menu_item = g_menu_item_new (label, "indicator.activate-statistics");
+
+    if (icon != NULL)
+      {
+        g_menu_item_set_attribute_value (menu_item,
+                                         G_MENU_ATTRIBUTE_ICON,
+                                         g_icon_serialize (icon));
+      }
+
+    g_menu_append_item (menu, menu_item);
+    g_object_unref (menu_item);
+
+    g_clear_object (&icon);
+    g_free (brief);
+    g_free (label);
+    g_free (a11y);
+  }
+}
+
+
+static GMenuModel *
+create_devices_section (IndicatorPowerService * self)
+{
+  GList * l;
+  GMenu * menu = g_menu_new ();
+
+  for (l=self->priv->devices; l!=NULL; l=l->next)
+    append_device_to_menu (menu, l->data);
+
+  return G_MENU_MODEL (menu);
+}
+
+
+/***
+****
+****  SETTINGS SECTION
+****
+***/
+
+static GMenuModel *
+create_settings_section (IndicatorPowerService * self G_GNUC_UNUSED)
+{
+  GMenu * menu = g_menu_new ();
+
+  g_menu_append (menu,
+                 _("Show Time in Menu Bar"),
+                 "indicator.show-time");
+
+  g_menu_append (menu,
+                 _("Power Settings\342\200\246"),
+                 "indicator.activate-settings");
+
+  return G_MENU_MODEL (menu);
+}
+
+/***
+****
+****  SECTION REBUILDING
+****
+***/
+
+/**
+ * A small helper function for rebuild_now().
+ * - removes the previous section
+ * - adds and unrefs the new section
+ */
+static void
+rebuild_section (GMenu * parent, int pos, GMenuModel * new_section)
+{
+  g_menu_remove (parent, pos);
+  g_menu_insert_section (parent, pos, NULL, new_section);
+  g_object_unref (new_section);
+}
+
+static void
+rebuild_now (IndicatorPowerService * self, guint sections)
+{
+  priv_t * p = self->priv;
+  struct ProfileMenuInfo * desktop = &p->menus[PROFILE_DESKTOP];
+  struct ProfileMenuInfo * greeter = &p->menus[PROFILE_GREETER];
+
+  if (p->conn == NULL) /* we haven't built the menus yet */
+    return;
+
+  if (sections & SECTION_HEADER)
+    {
+      g_simple_action_set_state (p->header_action, create_header_state (self));
+    }
+
+  if (sections & SECTION_DEVICES)
+    {
+      rebuild_section (desktop->submenu, 0, create_devices_section (self));
+      rebuild_section (greeter->submenu, 0, create_devices_section (self));
+    }
+
+  if (sections & SECTION_SETTINGS)
+    {
+      rebuild_section (desktop->submenu, 1, create_settings_section (self));
+    }
+}
+
+static inline void
+rebuild_header_now (IndicatorPowerService * self)
+{
+  rebuild_now (self, SECTION_HEADER);
+}
+
+static inline void
+rebuild_devices_section_now (IndicatorPowerService * self)
+{
+  rebuild_now (self, SECTION_DEVICES);
+}
+
+static inline void
+rebuild_settings_section_now (IndicatorPowerService * self)
+{
+  rebuild_now (self, SECTION_SETTINGS);
+}
+
+static void
+create_menu (IndicatorPowerService * self, int profile)
+{
+  GMenu * menu;
+  GMenu * submenu;
+  GMenuItem * header;
+  GMenuModel * sections[16];
+  guint i;
+  guint n = 0;
+
+  g_assert (0<=profile && profile<N_PROFILES);
+  g_assert (self->priv->menus[profile].menu == NULL);
+
+  if (profile == PROFILE_DESKTOP)
+    {
+      sections[n++] = create_devices_section (self);
+      sections[n++] = create_settings_section (self);
+    }
+  else if (profile == PROFILE_GREETER)
+    {
+      sections[n++] = create_devices_section (self);
+    }
+
+  /* add sections to the submenu */
+
+  submenu = g_menu_new ();
+
+  for (i=0; i<n; ++i)
+    {
+      g_menu_append_section (submenu, NULL, sections[i]);
+      g_object_unref (sections[i]);
+    }
+
+  /* add submenu to the header */
+  header = g_menu_item_new (NULL, "indicator._header");
+  g_menu_item_set_attribute (header, "x-canonical-type",
+                             "s", "com.canonical.indicator.root");
+  g_menu_item_set_submenu (header, G_MENU_MODEL (submenu));
+  g_object_unref (submenu);
+
+  /* add header to the menu */
+  menu = g_menu_new ();
+  g_menu_append_item (menu, header);
+  g_object_unref (header);
+
+  self->priv->menus[profile].menu = menu;
+  self->priv->menus[profile].submenu = submenu;
+}
+
+/***
+****  GActions
+***/
+
+/* Run a particular program based on an activation */
+static void
+execute_command (const gchar * cmd)
+{
+  GError * err = NULL;
+
+  g_debug ("Issuing command '%s'", cmd);
+
+  if (!g_spawn_command_line_async (cmd, &err))
+    {
+      g_warning ("Unable to start %s: %s", cmd, err->message);
+      g_error_free (err);
+    }
+}
+
+static void
+on_settings_activated (GSimpleAction * a      G_GNUC_UNUSED,
+                       GVariant      * param  G_GNUC_UNUSED,
+                       gpointer        gself  G_GNUC_UNUSED)
+{
+  execute_command ("gnome-control-center power");
+}
+
+static void
+on_statistics_activated (GSimpleAction * a      G_GNUC_UNUSED,
+                         GVariant      * param  G_GNUC_UNUSED,
+                         gpointer        gself  G_GNUC_UNUSED)
+{
+  execute_command ("gnome-power-statistics");
+}
+
+/* FIXME: use a GBinding to tie the gaction's state and the GSetting together? */
+
+static void
+set_show_time_flag (IndicatorPowerService * self, gboolean b)
+{
+  GVariant * v;
+  priv_t * p = self->priv;
+
+  /* update the settings */
+  if (b != g_settings_get_boolean (p->settings, SETTINGS_SHOW_TIME_S))
+    g_settings_set_boolean (p->settings, SETTINGS_SHOW_TIME_S, b);
+
+  /* update the action state */
+  v = g_action_get_state (G_ACTION(p->show_time_action));
+  if (b != g_variant_get_boolean (v))
+    g_simple_action_set_state (p->show_time_action, g_variant_new_boolean (b));
+  g_variant_unref (v);
+
+  rebuild_header_now (self);
+}
+static void
+on_show_time_setting_changed (GSettings * settings, gchar * key, gpointer gself)
+{
+  set_show_time_flag (INDICATOR_POWER_SERVICE(gself),
+                      g_settings_get_boolean (settings, key));
+}
+
+static void
+on_show_time_action_state_changed (GAction    * action,
+                                   GParamSpec * pspec   G_GNUC_UNUSED,
+                                   gpointer     gself)
+{
+  GVariant * v = g_action_get_state (action);
+  set_show_time_flag (INDICATOR_POWER_SERVICE(gself),
+                      g_variant_get_boolean (v));
+  g_variant_unref (v);
+}
+
+/* toggles the state */
+static void
+on_show_time_action_activated (GSimpleAction * simple,
+                               GVariant      * parameter G_GNUC_UNUSED,
+                               gpointer        unused    G_GNUC_UNUSED)
+{
+  GVariant * v = g_action_get_state (G_ACTION (simple));
+  gboolean flag = g_variant_get_boolean (v);
+  g_simple_action_set_state (simple, g_variant_new_boolean (!flag));
+  g_variant_unref (v);
+}
+
+static void
+init_gactions (IndicatorPowerService * self)
+{
+  GSimpleAction * a;
+  gboolean show_time;
+  priv_t * p = self->priv;
+
+  GActionEntry entries[] = {
+    { "activate-settings", on_settings_activated },
+    { "activate-statistics", on_statistics_activated }
+  };
+
+  p->actions = g_simple_action_group_new ();
+
+  g_action_map_add_action_entries (G_ACTION_MAP(p->actions),
+                                   entries,
+                                   G_N_ELEMENTS(entries),
+                                   self);
+
+  /* add the header action */
+  a = g_simple_action_new_stateful ("_header", NULL, create_header_state (self));
+  g_simple_action_group_insert (p->actions, G_ACTION(a));
+  p->header_action = a;
+
+  /* add the show-time action */
+  show_time = g_settings_get_boolean (p->settings, SETTINGS_SHOW_TIME_S);
+  a = g_simple_action_new_stateful ("show-time",
+                                    NULL,
+                                    g_variant_new_boolean(show_time));
+  g_signal_connect (a, "activate",
+                    G_CALLBACK(on_show_time_action_activated), self);
+  g_signal_connect (a, "notify",
+                    G_CALLBACK(on_show_time_action_state_changed), self);
+  g_simple_action_group_insert (p->actions, G_ACTION(a));
+  p->show_time_action = a;
+
+  rebuild_header_now (self);
+}
+
+/***
+****  GDBus Name Ownership & Menu / Action Exporting
+***/
+
+static void
+on_bus_acquired (GDBusConnection * connection,
+                 const gchar     * name,
+                 gpointer          gself)
+{
+  int i;
+  guint id;
+  GError * err = NULL;
+  IndicatorPowerService * self = INDICATOR_POWER_SERVICE(gself);
+  priv_t * p = self->priv;
+  GString * path = g_string_new (NULL);
+
+  g_debug ("bus acquired: %s", name);
+
+  p->conn = g_object_ref (G_OBJECT (connection));
+
+  /* export the actions */
+  if ((id = g_dbus_connection_export_action_group (connection,
+                                                   BUS_PATH,
+                                                   G_ACTION_GROUP (p->actions),
+                                                   &err)))
+    {
+      p->actions_export_id = id;
+    }
+  else
+    {
+      g_warning ("cannot export action group: %s", err->message);
+      g_clear_error (&err);
+    }
+
+  /* export the menus */
+  for (i=0; i<N_PROFILES; ++i)
+    {
+      struct ProfileMenuInfo * menu = &p->menus[i];
+
+      g_string_printf (path, "%s/%s", BUS_PATH, menu_names[i]);
+
+      if (menu->menu == NULL)
+        create_menu (self, i);
+
+      if ((id = g_dbus_connection_export_menu_model (connection,
+                                                     path->str,
+                                                     G_MENU_MODEL (menu->menu),
+                                                     &err)))
+        {
+          menu->export_id = id;
+        }
+      else
+        {
+          g_warning ("cannot export %s menu: %s", path->str, err->message);
+          g_clear_error (&err);
+        }
+    }
+
+  g_string_free (path, TRUE);
+}
+
+static void
+unexport (IndicatorPowerService * self)
+{
+  int i;
+  priv_t * p = self->priv;
+
+  /* unexport the menus */
+  for (i=0; i<N_PROFILES; ++i)
+    {
+      guint * id = &self->priv->menus[i].export_id;
+
+      if (*id)
+        {
+          g_dbus_connection_unexport_menu_model (p->conn, *id);
+          *id = 0;
+        }
+    }
+
+  /* unexport the actions */
+  if (p->actions_export_id)
+    {
+      g_dbus_connection_unexport_action_group (p->conn, p->actions_export_id);
+      p->actions_export_id = 0;
+    }
+}
+
+static void
+on_name_lost (GDBusConnection * connection G_GNUC_UNUSED,
+              const gchar     * name,
+              gpointer          gself)
+{
+  IndicatorPowerService * self = INDICATOR_POWER_SERVICE (gself);
+
+  g_debug ("%s %s name lost %s", G_STRLOC, G_STRFUNC, name);
+
+  unexport (self);
+
+  g_signal_emit (self, signals[SIGNAL_NAME_LOST], 0, NULL);
+}
+
+/***
+****  Events
+***/
+
+static void
+on_devices_changed (IndicatorPowerService * self)
+{
+  priv_t * p = self->priv;
+
+  /* update the device list */
+  g_list_free_full (p->devices, (GDestroyNotify)g_object_unref);
+  p->devices = indicator_power_device_provider_get_devices (p->device_provider);
+
+  /* update the primary device */
+  g_clear_object (&p->primary_device);
+  p->primary_device = indicator_power_service_choose_primary_device (p->devices);
+
+  rebuild_now (self, SECTION_HEADER | SECTION_DEVICES);
+}
+
+
+/***
+****  GObject virtual functions
+***/
+
+static void
+my_get_property (GObject     * o,
+                  guint         property_id,
+                  GValue      * value,
+                  GParamSpec  * pspec)
+{
+  IndicatorPowerService * self = INDICATOR_POWER_SERVICE (o);
+  priv_t * p = self->priv;
+ 
+  switch (property_id)
+    {
+      case PROP_DEVICE_PROVIDER:
+        g_value_set_object (value, p->device_provider);
+        break;
+
+      default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (o, property_id, pspec);
+    }
+}
+
+static void
+my_set_property (GObject       * o,
+                 guint           property_id,
+                 const GValue  * value,
+                 GParamSpec    * pspec)
+{
+  IndicatorPowerService * self = INDICATOR_POWER_SERVICE (o);
+
+  switch (property_id)
+    {
+      case PROP_DEVICE_PROVIDER:
+        indicator_power_service_set_device_provider (self, g_value_get_object (value));
+        break;
+
+      default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (o, property_id, pspec);
+    }
+}
+
+static void
+my_dispose (GObject * o)
+{
+  IndicatorPowerService * self = INDICATOR_POWER_SERVICE(o);
+  priv_t * p = self->priv;
+
+  if (p->own_id)
+    {
+      g_bus_unown_name (p->own_id);
+      p->own_id = 0;
+    }
+
+  unexport (self);
+
+  if (p->cancellable != NULL)
+    {
+      g_cancellable_cancel (p->cancellable);
+      g_clear_object (&p->cancellable);
+    }
+
+  if (p->settings != NULL)
+    {
+      g_signal_handlers_disconnect_by_data (p->settings, self);
+
+      g_clear_object (&p->settings);
+    }
+
+  if (p->show_time_action != NULL)
+    {
+      g_signal_handlers_disconnect_by_data (p->show_time_action, self);
+
+      g_clear_object (&p->show_time_action);
+    }
+
+  g_clear_object (&p->header_action);
+  g_clear_object (&p->show_time_action);
+  g_clear_object (&p->actions);
+
+  g_clear_object (&p->conn);
+
+  indicator_power_service_set_device_provider (self, NULL);
+
+  G_OBJECT_CLASS (indicator_power_service_parent_class)->dispose (o);
+}
+
+/***
+****  Instantiation
+***/
+
+static void
+indicator_power_service_init (IndicatorPowerService * self)
+{
+  priv_t * p = G_TYPE_INSTANCE_GET_PRIVATE (self,
+                                            INDICATOR_TYPE_POWER_SERVICE,
+                                            IndicatorPowerServicePrivate);
+  self->priv = p;
+
+  p->cancellable = g_cancellable_new ();
+
+  p->settings = g_settings_new ("com.canonical.indicator.power");
+
+  init_gactions (self);
+
+  g_signal_connect_swapped (p->settings, "changed::" SETTINGS_ICON_POLICY_S,
+                            G_CALLBACK(rebuild_header_now), self);
+  g_signal_connect (p->settings, "changed::" SETTINGS_SHOW_TIME_S,
+                    G_CALLBACK(on_show_time_setting_changed), self);
+
+  p->own_id = g_bus_own_name (G_BUS_TYPE_SESSION,
+                              BUS_NAME,
+                              G_BUS_NAME_OWNER_FLAGS_ALLOW_REPLACEMENT,
+                              on_bus_acquired,
+                              NULL,
+                              on_name_lost,
+                              self,
+                              NULL);
+}
+
+static void
+indicator_power_service_class_init (IndicatorPowerServiceClass * klass)
+{
+  GObjectClass * object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = my_dispose;
+  object_class->get_property = my_get_property;
+  object_class->set_property = my_set_property;
+
+  g_type_class_add_private (klass, sizeof (IndicatorPowerServicePrivate));
+
+  signals[SIGNAL_NAME_LOST] = g_signal_new (
+    INDICATOR_POWER_SERVICE_SIGNAL_NAME_LOST,
+    G_TYPE_FROM_CLASS(klass),
+    G_SIGNAL_RUN_LAST,
+    G_STRUCT_OFFSET (IndicatorPowerServiceClass, name_lost),
+    NULL, NULL,
+    g_cclosure_marshal_VOID__VOID,
+    G_TYPE_NONE, 0);
+
+  properties[PROP_0] = NULL;
+
+  properties[PROP_DEVICE_PROVIDER] = g_param_spec_object (
+    "device-provider",
+    "Device Provider",
+    "Source for power devices",
+    G_TYPE_OBJECT,
+    G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
+
+  g_object_class_install_properties (object_class, LAST_PROP, properties);
+}
+
+/***
+****  Public API
+***/
+
+IndicatorPowerService *
+indicator_power_service_new (IndicatorPowerDeviceProvider * device_provider)
+{
+  GObject * o = g_object_new (INDICATOR_TYPE_POWER_SERVICE,
+                              "device-provider", device_provider,
+                              NULL);
+
+  return INDICATOR_POWER_SERVICE (o);
+}
+
+void
+indicator_power_service_set_device_provider (IndicatorPowerService * self,
+                                             IndicatorPowerDeviceProvider * dp)
+{
+  priv_t * p;
+
+  g_return_if_fail (INDICATOR_IS_POWER_SERVICE (self));
+  g_return_if_fail (!dp || INDICATOR_IS_POWER_DEVICE_PROVIDER (dp));
+  p = self->priv;
+
+  if (p->device_provider != NULL)
+    {
+      g_signal_handlers_disconnect_by_func (p->device_provider,
+                                            G_CALLBACK(on_devices_changed),
+                                            self);
+      g_clear_object (&p->device_provider);
+
+      g_clear_object (&p->primary_device);
+
+      g_list_free_full (p->devices, g_object_unref);
+      p->devices = NULL;
+    }
+
+  if (dp != NULL)
+    {
+      p->device_provider = g_object_ref (dp);
+
+      g_signal_connect_swapped (p->device_provider, "devices-changed",
+                                G_CALLBACK(on_devices_changed), self);
+
+      on_devices_changed (self);
+    }
+}
+
+IndicatorPowerDevice *
+indicator_power_service_choose_primary_device (GList * devices)
+{
+  IndicatorPowerDevice * primary = NULL;
+
+  if (devices != NULL)
+    {
+      GList * tmp;
+
+      tmp = g_list_copy (devices);
+      tmp = g_list_sort (tmp, device_compare_func);
+      primary = g_object_ref (tmp->data);
+
+      g_list_free (tmp);
+    }
+
+  return primary;
+}
diff --git a/src/service.h b/src/service.h
new file mode 100644
index 0000000..76ed10f
--- /dev/null
+++ b/src/service.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2013 Canonical Ltd.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 3, as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranties of
+ * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __INDICATOR_POWER_SERVICE_H__
+#define __INDICATOR_POWER_SERVICE_H__
+
+#include <glib.h>
+#include <glib-object.h>
+
+#include "device-provider.h"
+
+G_BEGIN_DECLS
+
+/* standard GObject macros */
+#define INDICATOR_POWER_SERVICE(o)            (G_TYPE_CHECK_INSTANCE_CAST ((o), INDICATOR_TYPE_POWER_SERVICE, IndicatorPowerService))
+#define INDICATOR_TYPE_POWER_SERVICE          (indicator_power_service_get_type())
+#define INDICATOR_IS_POWER_SERVICE(o)         (G_TYPE_CHECK_INSTANCE_TYPE ((o), INDICATOR_TYPE_POWER_SERVICE))
+
+typedef struct _IndicatorPowerService         IndicatorPowerService;
+typedef struct _IndicatorPowerServiceClass    IndicatorPowerServiceClass;
+typedef struct _IndicatorPowerServicePrivate  IndicatorPowerServicePrivate;
+
+/* signal keys */
+#define INDICATOR_POWER_SERVICE_SIGNAL_NAME_LOST   "name-lost"
+
+/**
+ * The Indicator Power Service.
+ */
+struct _IndicatorPowerService
+{
+  /*< private >*/
+  GObject parent;
+  IndicatorPowerServicePrivate * priv;
+};
+
+struct _IndicatorPowerServiceClass
+{
+  GObjectClass parent_class;
+
+  /* signals */
+
+  void (* name_lost)(IndicatorPowerService * self);
+};
+
+/***
+****
+***/
+
+GType indicator_power_service_get_type (void);
+
+IndicatorPowerService * indicator_power_service_new (IndicatorPowerDeviceProvider * provider);
+
+void indicator_power_service_set_device_provider (IndicatorPowerService        * self,
+                                                  IndicatorPowerDeviceProvider * provider);
+
+IndicatorPowerDevice * indicator_power_service_choose_primary_device (GList * devices);
+
+
+
+G_END_DECLS
+
+#endif /* __INDICATOR_POWER_SERVICE_H__ */