first draft of non-blocking powerd/uscreen brightness impl

8 files changed, 494 insertions, 511 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 9b3d815..f7efb80 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -5,9 +5,8 @@ add_definitions(-DG_LOG_DOMAIN="Indicator-Power")
 
 # handwritten sources
 set(SERVICE_MANUAL_SOURCES
+    brightness.c
     device-provider-upower.c
-    ib-brightness-control.c
-    ib-brightness-uscreen-control.c
     device-provider.c
     device.c
     notifier.c
diff --git a/src/brightness.c b/src/brightness.c
new file mode 100644
index 0000000..070305e
--- /dev/null
+++ b/src/brightness.c
@@ -0,0 +1,393 @@
+/*
+ * Copyright 2014 Canonical Ltd.
+ *
+ * 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/>.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ */
+
+#include "brightness.h"
+
+#include <gio/gio.h>
+
+enum
+{
+  PROP_0,
+  PROP_PERCENTAGE,
+  LAST_PROP
+};
+
+static GParamSpec* properties[LAST_PROP];
+
+typedef struct
+{
+  GDBusConnection * system_bus;
+  GCancellable * cancellable;
+
+  guint powerd_name_tag;
+
+  double percentage;
+
+  /* powerd brightness params */
+  gint powerd_dim;
+  gint powerd_min;
+  gint powerd_max;
+  gint powerd_dflt;
+  gboolean powerd_ab_supported;
+  gboolean have_powerd_params;
+}
+IndicatorPowerBrightnessPrivate;
+
+typedef IndicatorPowerBrightnessPrivate priv_t;
+
+G_DEFINE_TYPE_WITH_PRIVATE(IndicatorPowerBrightness,
+                           indicator_power_brightness,
+                           G_TYPE_OBJECT)
+
+#define get_priv(o) ((priv_t*)indicator_power_brightness_get_instance_private(o))
+
+/***
+****  GObject virtual functions
+***/
+
+static void
+my_get_property (GObject     * o,
+                 guint         property_id,
+                 GValue      * value,
+                 GParamSpec  * pspec)
+{
+  IndicatorPowerBrightness * self = INDICATOR_POWER_BRIGHTNESS(o);
+
+  switch (property_id)
+    {
+      case PROP_PERCENTAGE:
+        g_value_set_double(value, indicator_power_brightness_get_percentage(self));
+        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)
+{
+  IndicatorPowerBrightness * self = INDICATOR_POWER_BRIGHTNESS(o);
+
+  switch (property_id)
+    {
+      case PROP_PERCENTAGE:
+        indicator_power_brightness_set_percentage(self, g_value_get_double(value));
+        break;
+
+      default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID(o, property_id, pspec);
+    }
+}
+
+static void
+my_dispose (GObject * o)
+{
+  IndicatorPowerBrightness * self = INDICATOR_POWER_BRIGHTNESS(o);
+  priv_t * p = get_priv(self);
+
+  if (p->cancellable != NULL)
+    {
+      g_cancellable_cancel (p->cancellable);
+      g_clear_object (&p->cancellable);
+    }
+
+  if (p->powerd_name_tag)
+    {
+      g_bus_unwatch_name(p->powerd_name_tag);
+      p->powerd_name_tag = 0;
+    }
+
+  g_clear_object(&p->system_bus);
+
+  G_OBJECT_CLASS(indicator_power_brightness_parent_class)->dispose(o);
+}
+
+/***
+****  Percentage <-> Brightness Int conversion helpers
+***/
+
+static gdouble
+brightness_to_percentage(IndicatorPowerBrightness * self, int brightness)
+{
+  const priv_t * p;
+  gdouble percentage;
+
+  p = get_priv(self);
+  if (p->have_powerd_params)
+    {
+      const int lo = p->powerd_min;
+      const int hi = p->powerd_max;
+      percentage = (brightness-lo) / (double)(hi-lo);
+    }
+  else
+    {
+      percentage = 0;
+    }
+
+  return percentage;
+}
+
+static int
+percentage_to_brightness(IndicatorPowerBrightness * self, double percentage)
+{
+  const priv_t * p;
+  int brightness;
+
+  p = get_priv(self);
+  if (p->have_powerd_params)
+    {
+      const int lo = p->powerd_min;
+      const int hi = p->powerd_max;
+      brightness = (int)(lo + (percentage*(hi-lo)));
+    }
+  else
+    {
+      brightness = 0;
+    }
+
+  return brightness;
+}
+
+/***
+****  DBus Chatter: com.canonical.powerd
+***/
+
+static void
+on_powerd_brightness_params_ready(GObject      * source,
+                                  GAsyncResult * res,
+                                  gpointer       gself)
+{
+  GError * error;
+  GVariant * v;
+
+  error = NULL;
+  v = g_dbus_connection_call_finish(G_DBUS_CONNECTION(source), res, &error);
+  if (v == NULL)
+    {
+      if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+        g_warning("Unable to get system bus: %s", error->message);
+
+      g_error_free(error);
+    }
+  else
+    {
+      IndicatorPowerBrightness * self = INDICATOR_POWER_BRIGHTNESS(gself);
+      priv_t * p = get_priv(self);
+      double percentage;
+
+      p->have_powerd_params = TRUE;
+      g_variant_get(v, "((iiiib))", &p->powerd_dim,
+                                    &p->powerd_min,
+                                    &p->powerd_max,
+                                    &p->powerd_dflt,
+                                    &p->powerd_ab_supported);
+      g_message("powerd brightness settings: dim=%d, min=%d, max=%d, dflt=%d, ab_supported=%d",
+                p->powerd_dim,
+                p->powerd_min,
+                p->powerd_max,
+                p->powerd_dflt,
+                (int)p->powerd_ab_supported);
+
+      /* uscreen doesn't have a get_brightness() function,
+         so the only way to know the value is to initialize it ourselves
+         (and hope nobody changes it :P */
+      percentage = brightness_to_percentage(self, p->powerd_dflt);
+      indicator_power_brightness_set_percentage(self, percentage);
+
+      /* cleanup */
+      g_variant_unref(v);
+    }
+}
+
+static void
+call_powerd_get_brightness_params(IndicatorPowerBrightness * self)
+{
+  priv_t * p = get_priv(self);
+
+  g_dbus_connection_call(p->system_bus,
+                         "com.canonical.powerd",
+                         "/com/canonical/powerd",
+                         "com.canonical.powerd",
+                         "getBrightnessParams",
+                         NULL,
+                         G_VARIANT_TYPE("((iiiib))"),
+                         G_DBUS_CALL_FLAGS_NONE,
+                         -1, /* default timeout */
+                         p->cancellable,
+                         on_powerd_brightness_params_ready,
+                         self);
+}
+
+static void
+on_powerd_appeared(GDBusConnection * connection,
+                   const gchar     * bus_name     G_GNUC_UNUSED,
+                   const gchar     * name_owner   G_GNUC_UNUSED,
+                   gpointer          gself)
+{
+  IndicatorPowerBrightness * self = INDICATOR_POWER_BRIGHTNESS(gself);
+  priv_t * p = get_priv(self);
+
+  /* keep a handle to the system bus */
+  g_clear_object(&p->system_bus);
+  p->system_bus = g_object_ref(connection);
+ 
+  /* get powerd's params */
+  call_powerd_get_brightness_params(self);
+}
+
+static void
+on_powerd_vanished(GDBusConnection * connection  G_GNUC_UNUSED,
+                   const gchar     * bus_name    G_GNUC_UNUSED,
+                   gpointer          gself)
+{
+  priv_t * p = get_priv(INDICATOR_POWER_BRIGHTNESS(gself));
+  p->have_powerd_params = FALSE;
+}
+
+/***
+****  DBus Chatter: com.canonical.Unity.Screen
+***/
+
+/* setUserBrightness doesn't return anything,
+   so this function is just to check for bus error messages */
+static void
+on_set_uscreen_user_brightness_result(GObject      * system_bus,
+                                      GAsyncResult * res,
+                                      gpointer       gself        G_GNUC_UNUSED)
+{
+  GError * error;
+  GVariant * v;
+
+  error = NULL;
+  v = g_dbus_connection_call_finish(G_DBUS_CONNECTION(system_bus), res, &error);
+  if (error != NULL)
+    {
+      if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+        g_warning("Unable to call uscreen.setBrightness: %s", error->message);
+
+      g_error_free(error);
+    }
+
+  g_clear_pointer(&v, g_variant_unref);
+}
+
+void
+set_uscreen_user_brightness(IndicatorPowerBrightness * self,
+                            int                        value)
+{
+  priv_t * p = get_priv(self);
+
+  g_dbus_connection_call(p->system_bus,
+                         "com.canonical.Unity.Screen",
+                         "/com/canonical/Unity/Screen",
+                         "com.canonical.Unity.Screen",
+                         "setUserBrightness",
+                         g_variant_new_int32(value),
+                         NULL, /* no return args */
+                         G_DBUS_CALL_FLAGS_NONE,
+                         -1, /* default timeout */
+                         p->cancellable,
+                         on_set_uscreen_user_brightness_result,
+                         self);
+}
+
+
+/***
+****  Instantiation
+***/
+
+static void
+indicator_power_brightness_init (IndicatorPowerBrightness * self)
+{
+  priv_t * p = get_priv(self);
+
+  p->cancellable = g_cancellable_new();
+
+  p->powerd_name_tag = g_bus_watch_name(G_BUS_TYPE_SYSTEM,
+                                        "com.canonical.powerd",
+                                        G_BUS_NAME_WATCHER_FLAGS_NONE,
+                                        on_powerd_appeared,
+                                        on_powerd_vanished,
+                                        self,
+                                        NULL);
+}
+
+static void
+indicator_power_brightness_class_init (IndicatorPowerBrightnessClass * 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;
+
+  properties[PROP_0] = NULL;
+
+  properties[PROP_PERCENTAGE] = g_param_spec_double("percentage",
+                                                    "Percentage",
+                                                    "Brightness percentage",
+                                                    0.1, /* don't allow completely black */
+                                                    1.0, /* brightest */
+                                                    0.8,
+                                                    G_PARAM_READWRITE|G_PARAM_STATIC_STRINGS);
+
+  g_object_class_install_properties (object_class, LAST_PROP, properties);
+}
+
+/***
+****  Public API
+***/
+
+IndicatorPowerBrightness *
+indicator_power_brightness_new(void)
+{
+  gpointer o = g_object_new (INDICATOR_TYPE_POWER_BRIGHTNESS, NULL);
+
+  return INDICATOR_POWER_BRIGHTNESS(o);
+}
+
+void
+indicator_power_brightness_set_percentage(IndicatorPowerBrightness * self,
+                                          double                     percentage)
+{
+  priv_t * p;
+
+  g_return_if_fail(INDICATOR_IS_POWER_BRIGHTNESS(self));
+
+  p = get_priv(self);
+  if ((int)(p->percentage*100) != (int)(percentage*100))
+    {
+      set_uscreen_user_brightness(self, percentage_to_brightness(self, percentage));
+
+      p->percentage = percentage;
+      g_object_notify_by_pspec(G_OBJECT(self), properties[PROP_PERCENTAGE]);
+    }
+}
+
+double
+indicator_power_brightness_get_percentage(IndicatorPowerBrightness * self)
+{
+  g_return_val_if_fail(INDICATOR_IS_POWER_BRIGHTNESS(self), 0.0);
+
+  return get_priv(self)->percentage;
+}
diff --git a/src/brightness.h b/src/brightness.h
new file mode 100644
index 0000000..d2fcc61
--- /dev/null
+++ b/src/brightness.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2014 Canonical Ltd.
+ *
+ * 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/>.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ */
+
+#ifndef INDICATOR_POWER_BRIGHTNESS__H
+#define INDICATOR_POWER_BRIGHTNESS__H
+
+#include <glib.h>
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+/* standard GObject macros */
+#define INDICATOR_POWER_BRIGHTNESS(o)            (G_TYPE_CHECK_INSTANCE_CAST ((o), INDICATOR_TYPE_POWER_BRIGHTNESS, IndicatorPowerBrightness))
+#define INDICATOR_TYPE_POWER_BRIGHTNESS          (indicator_power_brightness_get_type())
+#define INDICATOR_IS_POWER_BRIGHTNESS(o)         (G_TYPE_CHECK_INSTANCE_TYPE ((o), INDICATOR_TYPE_POWER_BRIGHTNESS))
+
+typedef struct _IndicatorPowerBrightness         IndicatorPowerBrightness;
+typedef struct _IndicatorPowerBrightnessClass    IndicatorPowerBrightnessClass;
+
+/* property keys */
+#define INDICATOR_POWER_BRIGHTNESS_PROP_PERCENTAGE  "percentage"
+
+/**
+ * The Indicator Power Brightness.
+ */
+struct _IndicatorPowerBrightness
+{
+  /*< private >*/
+  GObject parent;
+};
+
+struct _IndicatorPowerBrightnessClass
+{
+  GObjectClass parent_class;
+};
+
+/***
+****
+***/
+
+GType indicator_power_brightness_get_type(void);
+
+IndicatorPowerBrightness * indicator_power_brightness_new(void);
+
+void indicator_power_brightness_set_percentage(IndicatorPowerBrightness * self, double percentage);
+
+double indicator_power_brightness_get_percentage(IndicatorPowerBrightness * self);
+
+G_END_DECLS
+
+#endif /* INDICATOR_POWER_BRIGHTNESS__H */
diff --git a/src/ib-brightness-control.c b/src/ib-brightness-control.c
deleted file mode 100644
index 67da10c..0000000
--- a/src/ib-brightness-control.c
+++ /dev/null
@@ -1,156 +0,0 @@
-/*
- * Copyright 2012 Canonical Ltd.
- *
- * 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/>.
- *
- * Authors:
- *     Renato Araujo Oliveira Filho <renato@canonical.com>
- */
-
-#include <gudev/gudev.h>
-
-#include <errno.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <string.h>
-
-#include "ib-brightness-control.h"
-
-struct _IbBrightnessControl
-{
-    gchar *path;
-};
-
-IbBrightnessControl*
-ib_brightness_control_new (void)
-{
-    IbBrightnessControl *control;
-    GUdevClient *client;
-    gchar *path = NULL;
-    GList *devices;
-
-    // detect device
-    client = g_udev_client_new (NULL);
-    devices = g_udev_client_query_by_subsystem (client, "backlight");
-    if (devices != NULL) {
-        GList *device;
-        const gchar *device_type;
-
-        for (device = devices; device != NULL; device = device->next) {
-            device_type = g_udev_device_get_sysfs_attr (device->data, "type");
-            if ((g_strcmp0 (device_type, "firmware") == 0) ||
-                (g_strcmp0 (device_type, "platform") == 0) ||
-                (g_strcmp0 (device_type, "raw") == 0)) {
-                path = g_strdup (g_udev_device_get_sysfs_path (device->data));
-                g_debug ("found: %s", path);
-                break;
-            }
-        }
-
-        g_list_free_full (devices, g_object_unref);
-    }
-    else {
-        g_warning ("Fail to query backlight devices.");
-    }
-
-    control = g_new0 (IbBrightnessControl, 1);
-    control->path = path;
-
-    g_object_unref (client);
-    return control;
-}
-
-void
-ib_brightness_control_set_value (IbBrightnessControl* self, gint value)
-{
-    gint fd;
-    gchar *filename;
-    gchar *svalue;
-    size_t length;
-    gint err;
-
-    if (self->path == NULL)
-      return;
-
-    filename = g_build_filename (self->path, "brightness", NULL);
-    fd = open(filename, O_WRONLY);
-    if (fd < 0) {
-        g_warning ("Fail to set brightness.");
-        g_free (filename);
-        return;
-    }
-
-    svalue = g_strdup_printf ("%i", value);
-    length = strlen (svalue);
-
-    err = errno;
-    errno = 0;
-    if (write (fd, svalue, length) != (ssize_t)length) {
-        g_warning ("Fail to write brightness information: %s", g_strerror(errno));
-    }
-    errno = err;
-
-    close (fd);
-    g_free (svalue);
-    g_free (filename);
-}
-
-static gint
-ib_brightness_control_get_value_from_file (IbBrightnessControl *self, const gchar *file)
-{
-    GError *error;
-    gchar *svalue;
-    gint value;
-    gchar *filename;
-
-    if (self->path == NULL)
-      return 0;
-
-    svalue = NULL;
-    error = NULL;
-    filename = g_build_filename (self->path, file, NULL);
-    g_file_get_contents (filename, &svalue, NULL, &error);
-    if (error) {
-        g_warning ("Fail to get brightness value: %s", error->message);
-        value = -1;
-        g_error_free (error);
-    } else {
-        value = atoi (svalue);
-        g_free (svalue);
-    }
-
-    g_free (filename);
-
-    return value;
-
-}
-
-gint
-ib_brightness_control_get_value (IbBrightnessControl* self)
-{
-    return ib_brightness_control_get_value_from_file (self, "brightness");
-}
-
-gint
-ib_brightness_control_get_max_value (IbBrightnessControl* self)
-{
-    return ib_brightness_control_get_value_from_file (self, "max_brightness");
-}
-
-void
-ib_brightness_control_free (IbBrightnessControl *self)
-{
-    g_free (self->path);
-    g_free (self);
-}
-
diff --git a/src/ib-brightness-control.h b/src/ib-brightness-control.h
deleted file mode 100644
index 87711e4..0000000
--- a/src/ib-brightness-control.h
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Copyright 2012 Canonical Ltd.
- *
- * 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/>.
- *
- * Authors:
- *     Renato Araujo Oliveira Filho <renato@canonical.com>
- */
-
-#ifndef __IB_BRIGHTNESS_CONTROL_H__
-#define __IB_BRIGHTNESS_CONTROL_H__
-
-#include <gio/gio.h>
-
-typedef struct _IbBrightnessControl IbBrightnessControl;
-
-IbBrightnessControl*  ib_brightness_control_new (void);
-void                  ib_brightness_control_set_value (IbBrightnessControl* self, gint value);
-gint                  ib_brightness_control_get_value (IbBrightnessControl* self);
-gint                  ib_brightness_control_get_max_value (IbBrightnessControl* self);
-void                  ib_brightness_control_free (IbBrightnessControl *self);
-
-#endif
diff --git a/src/ib-brightness-uscreen-control.c b/src/ib-brightness-uscreen-control.c
deleted file mode 100644
index ad2c155..0000000
--- a/src/ib-brightness-uscreen-control.c
+++ /dev/null
@@ -1,202 +0,0 @@
-/*
- * Copyright 2014 Canonical Ltd.
- *
- * 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/>.
- *
- * Authors:
- *     Yuan-Chen Cheng <yc.cheng@canonical.com>
- */
-
-#include "ib-brightness-uscreen-control.h"
-
-static gboolean getBrightnessParams(GDBusProxy* powerd_proxy, int *dim, int *min,
-    int *max, int *dflt, gboolean *ab_supported);
-
-GDBusProxy*
-uscreen_get_proxy(brightness_params_t *params)
-{
-    GError *error = NULL;
-    gboolean ret;
-
-    g_return_val_if_fail (params != NULL, NULL);
-
-    /* For now we still need to obtain the brigthness params from powerd */
-    GDBusProxy* powerd_proxy = g_dbus_proxy_new_for_bus_sync(G_BUS_TYPE_SYSTEM,
-                G_DBUS_PROXY_FLAGS_NONE,
-                NULL,
-                "com.canonical.powerd",
-                "/com/canonical/powerd",
-                "com.canonical.powerd",
-                NULL,
-                &error);
-
-    if (error != NULL)
-    {
-        g_debug ("could not connect to powerd: %s", error->message);
-        g_error_free (error);
-        return NULL;
-    }
-
-    ret = getBrightnessParams(powerd_proxy, &(params->dim), &(params->min),
-        &(params->max), &(params->dflt), &(params->ab_supported));
-
-    if (! ret)
-    {
-        g_debug ("can't get brightness parameters from powerd");
-        g_object_unref (powerd_proxy);
-        return NULL;
-    }
-
-    g_clear_object (&powerd_proxy);
-
-    GDBusProxy* uscreen_proxy = g_dbus_proxy_new_for_bus_sync(G_BUS_TYPE_SYSTEM,
-                G_DBUS_PROXY_FLAGS_NONE,
-                NULL,
-                "com.canonical.Unity.Screen",
-                "/com/canonical/Unity/Screen",
-                "com.canonical.Unity.Screen",
-                NULL,
-                &error);
-
-    if (error != NULL)
-    {
-        g_debug ("could not connect to unity screen: %s", error->message);
-        g_error_free (error);
-        return NULL;
-    }
-
-    return uscreen_proxy;
-}
-
-
-static gboolean
-getBrightnessParams(GDBusProxy* powerd_proxy, int *dim, int *min, int *max, int *dflt, gboolean *ab_supported)
-{
-    GVariant *ret = NULL;
-    GError *error = NULL;
-
-    ret = g_dbus_proxy_call_sync(powerd_proxy,
-            "getBrightnessParams",
-            NULL,
-            G_DBUS_CALL_FLAGS_NONE,
-            400, NULL, &error); // timeout: 400 ms
-    if (!ret)
-    {
-        if (error != NULL)
-        {
-            if (!g_error_matches(error, G_DBUS_ERROR, G_DBUS_ERROR_SERVICE_UNKNOWN))
-            {
-                g_warning("getBrightnessParams from powerd failed: %s", error->message);
-            }
-            g_error_free(error);
-        }
-        return FALSE;
-    }
-
-    g_variant_get(ret, "((iiiib))", dim, min, max, dflt, ab_supported);
-    g_variant_unref(ret);
-    return TRUE;
-}
-
-static gboolean setUserBrightness(GDBusProxy* uscreen_proxy, GCancellable *gcancel, int brightness)
-{
-    GVariant *ret = NULL;
-    GError *error = NULL;
-
-    ret = g_dbus_proxy_call_sync(uscreen_proxy,
-            "setUserBrightness",
-            g_variant_new("(i)", brightness),
-            G_DBUS_CALL_FLAGS_NONE,
-            -1, gcancel, &error);
-    if (!ret) {
-        g_warning("setUserBrightness via unity.screen failed: %s", error->message);
-        g_error_free(error);
-        return FALSE;
-    } else {
-        g_variant_unref(ret);
-        return TRUE;
-    }
-}
-
-struct _IbBrightnessUScreenControl
-{
-    GDBusProxy *uscreen_proxy;
-    GCancellable *gcancel;
-
-    int dim;
-    int min;
-    int max;
-    int dflt; // defalut value
-    gboolean ab_supported;
-
-    int current;
-};
-
-IbBrightnessUscreenControl*
-ib_brightness_uscreen_control_new (GDBusProxy* uscreen_proxy, brightness_params_t params)
-{
-    IbBrightnessUscreenControl *control;
-
-    control = g_new0 (IbBrightnessUscreenControl, 1);
-    control->uscreen_proxy = uscreen_proxy;
-    control->gcancel = g_cancellable_new();
-
-    control->dim = params.dim;
-    control->min = params.min;
-    control->max = params.max;
-    control->dflt = params.dflt;
-    control->ab_supported = params.ab_supported;
-
-    // XXX: set the brightness value is the only way to sync the brightness value with
-    // unity.screen, and we should set the user prefered / last set brightness value upon startup.
-    // Before we have code to store last set brightness value or other mechanism, we set
-    // it to default brightness that powerd proposed.
-    ib_brightness_uscreen_control_set_value(control, control->dflt);
-
-    return control;
-}
-
-void
-ib_brightness_uscreen_control_set_value (IbBrightnessUscreenControl* self, gint value)
-{
-    gboolean ret;
-
-    value = CLAMP(value, self->min, self->max);
-    ret = setUserBrightness(self->uscreen_proxy, self->gcancel, value);
-    if (ret)
-    {
-        self->current = value;
-    }
-}
-
-gint
-ib_brightness_uscreen_control_get_value (IbBrightnessUscreenControl* self)
-{
-    return self->current;
-}
-
-gint
-ib_brightness_uscreen_control_get_max_value (IbBrightnessUscreenControl* self)
-{
-    return self->max;
-}
-
-void
-ib_brightness_uscreen_control_free (IbBrightnessUscreenControl *self)
-{
-    g_cancellable_cancel (self->gcancel);
-    g_object_unref (self->gcancel);
-    g_object_unref (self->uscreen_proxy);
-    g_free (self);
-}
-
diff --git a/src/ib-brightness-uscreen-control.h b/src/ib-brightness-uscreen-control.h
deleted file mode 100644
index 3d026a9..0000000
--- a/src/ib-brightness-uscreen-control.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Copyright 2014 Canonical Ltd.
- *
- * 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/>.
- *
- * Authors:
- *     Y.C Cheng <yc.cheng@canonical.com>
- */
-
-#ifndef __IB_BRIGHTNESS_USCREEN_CONTROL_H__
-#define __IB_BRIGHTNESS_USCREEN_CONTROL_H__
-
-#include <gio/gio.h>
-
-typedef struct {
-    int dim;
-    int min;
-    int max;
-    int dflt;
-    gboolean ab_supported;
-} brightness_params_t;
-
-GDBusProxy* uscreen_get_proxy(brightness_params_t *);
-
-typedef struct _IbBrightnessUScreenControl IbBrightnessUscreenControl;
-
-IbBrightnessUscreenControl* ib_brightness_uscreen_control_new (GDBusProxy* uscreen_proxy, brightness_params_t params);
-void                       ib_brightness_uscreen_control_set_value (IbBrightnessUscreenControl* self, gint value);
-gint                       ib_brightness_uscreen_control_get_value (IbBrightnessUscreenControl* self);
-gint                       ib_brightness_uscreen_control_get_max_value (IbBrightnessUscreenControl* self);
-void                       ib_brightness_uscreen_control_free (IbBrightnessUscreenControl *self);
-
-#endif
diff --git a/src/service.c b/src/service.c
index 0cd448b..35be231 100644
--- a/src/service.c
+++ b/src/service.c
@@ -22,12 +22,11 @@
 #include <gio/gio.h>
 #include <url-dispatcher.h>
 
+#include "brightness.h"
 #include "dbus-shared.h"
 #include "device.h"
 #include "device-provider.h"
 #include "notifier.h"
-#include "ib-brightness-control.h"
-#include "ib-brightness-uscreen-control.h"
 #include "service.h"
 
 #define BUS_NAME "com.canonical.indicator.power"
@@ -104,8 +103,7 @@ struct _IndicatorPowerServicePrivate
 
   GSettings * settings;
 
-  IbBrightnessControl * brightness_control;
-  IbBrightnessUscreenControl * brightness_uscreen_control;
+  IndicatorPowerBrightness * brightness;
 
   guint own_id;
   guint actions_export_id;
@@ -459,53 +457,28 @@ create_phone_devices_section (IndicatorPowerService * self G_GNUC_UNUSED)
 ****
 ***/
 
-static void
-get_brightness_range (IndicatorPowerService * self, gint * low, gint * high)
+static GMenuItem *
+create_brightness_menu_item(void)
 {
-  priv_t * p = self->priv;
-  int max = 0;
-  if (p->brightness_control)
-    {
-      max = ib_brightness_control_get_max_value (self->priv->brightness_control);
-    }
-  else if (p->brightness_uscreen_control)
-    {
-      max = ib_brightness_uscreen_control_get_max_value (self->priv->brightness_uscreen_control);
-    }
-  *low  = (gint)(max * 0.05); /* 5% minimum -- don't let the screen go completely dark */
-  *high = max;
-}
+  GMenuItem * item;
 
-static gdouble
-brightness_to_percentage (IndicatorPowerService * self, int brightness)
-{
-  int lo, hi;
-  get_brightness_range (self,  &lo, &hi);
-  return (brightness-lo) / (double)(hi-lo);
-}
+  item = g_menu_item_new(NULL, "indicator.brightness");
+  g_menu_item_set_attribute(item, "x-canonical-type", "s", "com.canonical.unity.slider");
+  g_menu_item_set_attribute(item, "min-value", "d", 0.1);
+  g_menu_item_set_attribute(item, "max-value", "d", 1.0);
+  g_menu_item_set_attribute(item, "min-icon", "s", "torch-off" );
+  g_menu_item_set_attribute(item, "max-icon", "s", "torch-on" );
 
-static int
-percentage_to_brightness (IndicatorPowerService * self, double percentage)
-{
-  int lo, hi;
-  get_brightness_range (self,  &lo, &hi);
-  return (int)(lo + (percentage*(hi-lo)));
+  return item;
 }
 
 static GVariant *
 action_state_for_brightness (IndicatorPowerService * self)
 {
-  priv_t * p = self->priv;
-  gint brightness = 0;
-  if (p->brightness_control)
-    {
-      brightness = ib_brightness_control_get_value (p->brightness_control);
-    }
-  else if (p->brightness_uscreen_control)
-    {
-      brightness = ib_brightness_uscreen_control_get_value (p->brightness_uscreen_control);
-    }
-  return g_variant_new_double (brightness_to_percentage (self, brightness));
+  IndicatorPowerBrightness * b = self->priv->brightness;
+  GVariant * v = g_variant_new_double(indicator_power_brightness_get_percentage(b));
+  g_message("new brightness action state: %s", g_variant_print(v, TRUE));
+  return v;
 }
 
 static void
@@ -521,19 +494,9 @@ on_brightness_change_requested (GSimpleAction * action      G_GNUC_UNUSED,
                                 gpointer        gself)
 {
   IndicatorPowerService * self = INDICATOR_POWER_SERVICE (gself);
-  const gdouble percentage = g_variant_get_double (parameter);
-  const int brightness = percentage_to_brightness (self, percentage);
 
-  if (self->priv->brightness_control)
-    {
-      ib_brightness_control_set_value (self->priv->brightness_control, brightness);
-    }
-  else if (self->priv->brightness_uscreen_control)
-    {
-      ib_brightness_uscreen_control_set_value (self->priv->brightness_uscreen_control, brightness);
-    }
-
-  update_brightness_action_state (self);
+  indicator_power_brightness_set_percentage(self->priv->brightness,
+                                            g_variant_get_double (parameter));
 }
 
 static GMenuModel *
@@ -557,15 +520,21 @@ create_desktop_settings_section (IndicatorPowerService * self G_GNUC_UNUSED)
 }
 
 static GMenuModel *
-create_phone_settings_section (IndicatorPowerService * self)
+create_phone_settings_section(IndicatorPowerService * self)
 {
   GMenu * section;
+  GMenuItem * item;
+
+  section = g_menu_new();
 
-  section = g_menu_new ();
-  update_brightness_action_state (self);
-  g_menu_append (section, _("Battery settings…"), "indicator.activate-phone-settings");
+  item = create_brightness_menu_item();
+  g_menu_append_item(section, item);
+  update_brightness_action_state(self);
+  g_object_unref(item);
 
-  return G_MENU_MODEL (section);
+  g_menu_append(section, _("Battery settings…"), "indicator.activate-phone-settings");
+
+  return G_MENU_MODEL(section);
 }
 
 /***
@@ -1015,16 +984,13 @@ my_dispose (GObject * o)
 
   g_clear_object (&p->notifier);
   g_clear_object (&p->brightness_action);
+  g_clear_object (&p->brightness);
   g_clear_object (&p->battery_level_action);
   g_clear_object (&p->header_action);
   g_clear_object (&p->actions);
 
   g_clear_object (&p->conn);
 
-  // g_clear_pointer has NULL check inside.
-  g_clear_pointer (&p->brightness_control, ib_brightness_control_free);
-  g_clear_pointer (&p->brightness_uscreen_control, ib_brightness_uscreen_control_free);
-
   indicator_power_service_set_device_provider (self, NULL);
 
   G_OBJECT_CLASS (indicator_power_service_parent_class)->dispose (o);
@@ -1037,8 +1003,6 @@ my_dispose (GObject * o)
 static void
 indicator_power_service_init (IndicatorPowerService * self)
 {
-  GDBusProxy *uscreen_proxy;
-  brightness_params_t brightness_params;
   priv_t * p = G_TYPE_INSTANCE_GET_PRIVATE (self,
                                             INDICATOR_TYPE_POWER_SERVICE,
                                             IndicatorPowerServicePrivate);
@@ -1050,15 +1014,9 @@ indicator_power_service_init (IndicatorPowerService * self)
 
   p->notifier = indicator_power_notifier_new ();
 
-  uscreen_proxy = uscreen_get_proxy(&brightness_params);
-  if (uscreen_proxy != NULL)
-    {
-      p->brightness_uscreen_control = ib_brightness_uscreen_control_new(uscreen_proxy, brightness_params);
-    }
-  else
-    {
-      p->brightness_control = ib_brightness_control_new ();
-    }
+  p->brightness = indicator_power_brightness_new();
+  g_signal_connect_swapped(p->brightness, "notify::perentage",
+                           G_CALLBACK(update_brightness_action_state), self);
 
   init_gactions (self);