Use Signal Callback in Ambient Light Sensor

ambient_light_sensor.h

-// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef POWER_MANAGER_AMBIENT_LIGHT_SENSOR_H_
 #define POWER_MANAGER_AMBIENT_LIGHT_SENSOR_H_
 
 #include <glib.h>
 
 #include "power_manager/backlight_controller.h"
+#include "power_manager/signal_callback.h"
 
 namespace power_manager {
 
 // Get ambient light sensor data and feed it into the backlight interface.
 //
 // Example usage:
 //   // Initialization:
 //   power_manager::BacklightController backlight_ctl(&backlight, &prefs);
 //   CHECK(backlight_ctl.Init()) << "fatal";
 //   power_manager::AmbientLightSensor als(&backlight_ctl);
@@ skipping 19 matching lines @@
   // Initialize the AmbientLightSensor object.
   // Open the lux file so we can read ambient light data.
   // On success, return true; otherwise return false.
   bool Init();
 
   // The backlight controller sends us power state events so we can
   // enable and disable polling.
   void EnableOrDisableSensor(PowerState power, DimState dim);
 
  private:
-  static gboolean ReadAls(gpointer data);
-  static bool DeferredInit(AmbientLightSensor* self);
+  // Handler for a periodic event that reads the ambient light sensor.
+  SIGNAL_CALLBACK_0(AmbientLightSensor, gboolean, ReadAls);
+
+  // Deferred init for the als in case the light sensor starts late.
+  bool DeferredInit();
 
   // Return a luma level normalized to 100 based on the tsl2563 lux value.
   // The luma level will modify the controller's brightness calculation.
   static int64 Tsl2563LuxToLevel(int luxval);
 
   // Use this to send AmbientLightSensor events to BacklightController.
   BacklightController* controller_;
 
   // This is the ambient light sensor file descriptor.
   int als_fd_;
 
   // Record the last read ambient light level to reduce unnecessary events.
   int64 last_level_;
 
   // These flags are used to turn on and off polling.
   bool is_polling_;
   bool disable_polling_;
 
   // Issue reasonable diagnostics about the deferred lux file open.
   bool still_deferring_;
 
   DISALLOW_COPY_AND_ASSIGN(AmbientLightSensor);
 };
 
 }  // namespace power_manager
 
 #endif  // POWER_MANAGER_AMBIENT_LIGHT_SENSOR_H_