chromeos: Add power management policy prefs.

chromeos/dbus/power_policy_controller.h

+// Copyright (c) 2013 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_POLICY_CONTROLLER_H_
+#define CHROMEOS_DBUS_POWER_POLICY_CONTROLLER_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/time.h"
+#include "chromeos/chromeos_export.h"
+
+namespace chromeos {
+
+class PowerManagerClient;
+
+class CHROMEOS_EXPORT PowerPolicyController {
+ public:
+  // Note: Do not change these values; they are used by preferences.
+  enum OptionalAction {
+    ACTION_UNSET        = -1,

[bartfab (slow), 2013/02/04 10:04:35]

This value is not needed.

[Daniel Erat, 2013/02/04 13:35:45]

I added this because the pref code needed to use it to tell
PowerPolicyController that a given pref was unset.  See below, though -- I agree
that it's not needed if the prefs are passed directly into this class.

+    ACTION_SUSPEND      = 0,
+    ACTION_STOP_SESSION = 1,
+    ACTION_SHUT_DOWN    = 2,
+    ACTION_DO_NOTHING   = 3,
+  };
+
+  // Note: Do not change these values; they are used by preferences.
+  enum OptionalBool {

[bartfab (slow), 2013/02/04 10:04:35]

Not needed.

+    BOOL_UNSET = -1,
+    BOOL_FALSE = 0,
+    BOOL_TRUE  = 1,
+  };
+
+  // Delay in milliseconds that can be used to signify an unset value.
+  static const int kUnsetDelayMs;

[bartfab (slow), 2013/02/04 10:04:35]

Not needed.

+
+  // Presentation idle-delay scaling factor that can be used to signify an
+  // unset value.
+  static const double kUnsetPresentationIdleDelayFactor;

[bartfab (slow), 2013/02/04 10:04:35]

Not needed.

+
+  struct PolicyPrefs {
+    PolicyPrefs();
+
+    base::TimeDelta ac_screen_dim_delay;
+    base::TimeDelta ac_screen_off_delay;
+    base::TimeDelta ac_screen_lock_delay;
+    base::TimeDelta ac_idle_delay;
+    base::TimeDelta battery_screen_dim_delay;
+    base::TimeDelta battery_screen_off_delay;
+    base::TimeDelta battery_screen_lock_delay;
+    base::TimeDelta battery_idle_delay;
+    OptionalAction idle_action;
+    OptionalAction lid_closed_action;
+    OptionalBool use_audio_activity;
+    OptionalBool use_video_activity;
+    double presentation_idle_delay_factor;
+  };
+
+  explicit PowerPolicyController(PowerManagerClient* client);
+  ~PowerPolicyController();
+
+  // Sends an updated policy based on |prefs| to the power manager.
+  void UpdatePolicyFromPrefs(const PolicyPrefs& prefs);

[Daniel Erat, 2013/02/04 03:10:07]

(My intent is that this class will later become responsible for additional
policy changes initiating within Chrome, such as blocking idle suspend before
the OOBE has been completed.  It'll need to combine those changes with the
settings loaded from prefs.)

[bartfab (slow), 2013/02/04 10:04:35]

Why not reference the actual prefs? The PolicyPrefs class ends up duplicating
the values in memory that the actual prefs already hold.

[Daniel Erat, 2013/02/04 13:35:45]

I didn't realize that the prefs code derives from an interface defined in base. 
Just to make sure that we're in agreement, you're suggesting that this method
instead take a bunch of PrefServiceBase::Preference (references?), right?  I
agree that that's much simpler.

[bartfab (slow), 2013/02/04 14:43:52]

Either pass a number of Preferences to this class or, even simpler, give it a
pointer to a PrefServiceBase and let the class request whatever Preferences and
observers it needs. Since Preferences members automatically update and observers
automatically fire when prefs change, you will no longer need to ping the class
on each update either. It should pick up pref changes automagically.

+
+  // Resets |prefs_| and calls SendPolicy().  This resets the power
+  // manager's behavior to the defaults.
+  void ResetPolicy();
+
+ private:
+  // Generates a policy based on |prefs_| and sends it to the power
+  // manager.
+  void SendPolicy();
+
+  PowerManagerClient* client_;  // not owned
+
+  PolicyPrefs prefs_;
+
+  DISALLOW_COPY_AND_ASSIGN(PowerPolicyController);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_DBUS_POWER_POLICY_CONTROLLER_H_