Theme Preferences for Distilled Pages

components/dom_distiller/core/distilled_page_prefs.h

+// Copyright 2014 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 COMPONENTS_DOM_DISTILLER_CORE_DISTILLED_PAGE_PREFS_H_
+#define COMPONENTS_DOM_DISTILLER_CORE_DISTILLED_PAGE_PREFS_H_
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
+
+class PrefService;
+
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
+namespace dom_distiller {
+
+// Interface for preferences used for distilled page.
+class DistilledPagePrefs {
+ public:
+  // Possible themes for distilled page.
+  enum Theme {
+    LIGHT,
+    DARK,
+    SEPIA,
+    THEME_COUNT
+  };
+
+  class Observer {
+   public:
+    virtual void OnChangeTheme(Theme theme) = 0;
+  };
+
+  explicit DistilledPagePrefs(PrefService* pref_service);
+  ~DistilledPagePrefs();
+
+  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
+
+  // Sets the user's preference for the theme of distilled pages.
+  void SetTheme(Theme new_theme);
+  // Returns the user's preference for the theme of distilled pages.
+  Theme GetTheme();
+
+  void AddObserver(Observer* obs);
+  void RemoveObserver(Observer* obs);
+
+ private:
+  // Notifies all Observers of new theme.
+  void NotifyOnChangeTheme(Theme theme);
+
+  PrefService* pref_service_;
+  ObserverList<Observer> observers_;
+
+  base::WeakPtrFactory<DistilledPagePrefs> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(DistilledPagePrefs);
+};
+
+}  // namespace dom_distiller
+
+#endif  // COMPONENTS_DOM_DISTILLER_CORE_DISTILLED_PAGE_PREFS_H_