chromeos: Add support for dimming the screen.

chromeos/dbus/power_manager_client.h

 // Copyright (c) 2012 The Chromium 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 CHROMEOS_DBUS_POWER_MANAGER_CLIENT_H_
 #define CHROMEOS_DBUS_POWER_MANAGER_CLIENT_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 21 matching lines @@
 // Callback used for getting the current screen brightness.  The param is in the
 // range [0.0, 100.0].
 typedef base::Callback<void(double)> GetScreenBrightnessPercentCallback;
 
 // PowerManagerClient is used to communicate with the power manager.
 class CHROMEOS_EXPORT PowerManagerClient {
  public:
   // Interface for observing changes from the power manager.
   class Observer {
    public:
+    enum ScreenDimmingState {
+      SCREEN_DIMMING_NONE = 0,
+      SCREEN_DIMMING_IDLE,
+    };
+
     virtual ~Observer() {}
 
     // Called when the brightness is changed.
     // |level| is of the range [0, 100].
     // |user_initiated| is true if the action is initiated by the user.
     virtual void BrightnessChanged(int level, bool user_initiated) {}
 
     // Called when power supply polling takes place.  |status| is a data
     // structure that contains the current state of the power supply.
     virtual void PowerChanged(const PowerSupplyStatus& status) {}
@@ skipping 16 matching lines @@
     virtual void UnlockScreen() {}
 
     // Called when the screen fails to unlock.
     virtual void UnlockScreenFailed() {}
 
     // Called when we go idle for threshold time.
     virtual void IdleNotify(int64 threshold_secs) {}
 
     // Called when we go from idle to active.
     virtual void ActiveNotify() {}
+
+    // Called when a request is received to dim or undim the screen in software
+    // (as opposed to the more-common method of adjusting the backlight).
+    virtual void ScreenDimmingRequested(ScreenDimmingState state) {}
   };
 
   enum UpdateRequestType {
     UPDATE_INITIAL,  // Initial update request.
     UPDATE_USER,     // User initialted update request.
     UPDATE_POLL      // Update requested by poll signal.
   };
 
   enum PowerStateOverrideType {
     DISABLE_IDLE_DIM = 1,  // Disable screen dimming on idle.
@@ skipping 86 matching lines @@
   // Create() should be used instead.
   PowerManagerClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PowerManagerClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_POWER_MANAGER_CLIENT_H_