chromeos: Add settings to control power management prefs.

chrome/browser/ui/webui/settings/chromeos/device_power_handler.h

 // Copyright 2017 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 CHROME_BROWSER_UI_WEBUI_SETTINGS_CHROMEOS_DEVICE_POWER_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SETTINGS_CHROMEOS_DEVICE_POWER_HANDLER_H_
 
+#include <memory>
+
 #include "ash/system/power/power_status.h"
 #include "base/macros.h"
 #include "base/scoped_observer.h"
 #include "base/strings/string16.h"
 #include "chrome/browser/ui/webui/settings/settings_page_ui_handler.h"
 
+class PrefChangeRegistrar;
+class PrefService;
+
 namespace base {
 class ListValue;
 }
 
 namespace chromeos {
 namespace settings {
 
 // Chrome OS battery status and power settings handler.
 class PowerHandler : public ::settings::SettingsPageUIHandler,
                      public ash::PowerStatus::Observer {
  public:
-  PowerHandler();
+  explicit PowerHandler(PrefService* prefs);
   ~PowerHandler() override;
 
   // SettingsPageUIHandler implementation.
   void RegisterMessages() override;
   void OnJavascriptAllowed() override;
   void OnJavascriptDisallowed() override;
 
   // ash::PowerStatus::Observer implementation.
   void OnPowerStatusChanged() override;
 
  private:
+  // Idle behaviors presented in the UI. These are mapped to preferences by
+  // HandleSetIdleBehavior(). Values are shared with JS.
+  enum class IdleBehavior {
+    DISPLAY_OFF_SLEEP = 0,

[michaelpg, 2017/05/04 17:36:26]

Do these have to be defined in the .h file? (versus, I guess, forward declaring
the enum class, defining it in .cc and setting the default values in the
constructor... is that normal?)

[Daniel Erat, 2017/05/06 00:15:48]

i've shuffled this around a bit.

LidClosedBehavior is no more; i'm just using the
chromeos::PowerPolicyController::Action enum in its place (it didn't make sense
to add an "other" option vs. just being more specific and adding the remaining
two options, "shut down" and "sign out").

IdleBehavior could presumably be defined in the .cc file as you suggest, but as
you also mentioned, i'd need to initialize the member there as well. i'd prefer
to leave it like this (particularly since we refer to the enum name from
javascript) unless you feel strongly.

+    DISPLAY_OFF_STAY_AWAKE = 1,
+    DISPLAY_ON = 2,
+  };
+
+  // Lid-closed behaviors presented in the UI. These are mapped to preferences
+  // by HandleSetLidClosedBehavior(). Values are shared with JS.
+  enum class LidClosedBehavior {
+    SLEEP = 0,
+    STAY_AWAKE = 1,
+  };
+
   // Handler to request updating the power status.
   void HandleUpdatePowerStatus(const base::ListValue* args);
 
   // Handler to change the power source.
   void HandleSetPowerSource(const base::ListValue* args);
 
+  // Handler to request the current power management settings. Just calls
+  // SendPowerManagementSettings().
+  void HandleRequestPowerManagementSettings(const base::ListValue* args);
+
+  // Handlers to change the idle and lid-closed behaviors.
+  void HandleSetIdleBehavior(const base::ListValue* args);
+  void HandleSetLidClosedBehavior(const base::ListValue* args);
+
   // Updates the UI with the current battery status.
   void SendBatteryStatus();
 
   // Updates the UI with a list of available dual-role power sources.
   void SendPowerSources();
 
-  ash::PowerStatus* power_status_;
+  // Updates the UI to display the current power management settings. If the
+  // settings didn't change since the previous call, nothing is sent unless
+  // |force| is true.
+  void SendPowerManagementSettings(bool force);
+
+  PrefService* prefs_;              // Not owned.
+  ash::PowerStatus* power_status_;  // Not owned.
+
+  // Used to watch power management prefs for changes so the UI can be notified.
+  std::unique_ptr<PrefChangeRegistrar> pref_change_registrar_;
 
   ScopedObserver<ash::PowerStatus, PowerHandler> power_observer_;
 
+  // Last values sent by SendPowerManagementSettings(), cached here so
+  // SendPowerManagementSettings() can avoid spamming the UI after this class
+  // changes multiple prefs at once.
+  IdleBehavior last_idle_behavior_ = IdleBehavior::DISPLAY_OFF_SLEEP;
+  LidClosedBehavior last_lid_closed_behavior_ = LidClosedBehavior::SLEEP;
+  bool last_idle_managed_ = false;
+  bool last_lid_closed_managed_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(PowerHandler);
 };
 
 }  // namespace settings
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SETTINGS_CHROMEOS_DEVICE_POWER_HANDLER_H_