show notification on locale change

chrome/browser/chromeos/locale_change_guard.h

+// Copyright (c) 2011 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_CHROMEOS_LOCALE_CHANGE_GUARD_H_
+#define CHROME_BROWSER_CHROMEOS_LOCALE_CHANGE_GUARD_H_
+#pragma once
+
+#include "base/lazy_instance.h"
+#include "base/scoped_ptr.h"
+#include "chrome/browser/chromeos/notifications/system_notification.h"
+#include "chrome/browser/notifications/notification_delegate.h"
+#include "chrome/browser/profiles/profile.h"
+
+class ListValue;
+class TabContents;
+
+namespace chromeos {
+
+class LocaleChangeGuard {
+ public:
+  // When called first time for user profile: performs check whether
+  // locale has been changed automatically recently (based on synchronized user
+  // preference).  If so: shows notification that allows user to revert change.
+  // On subsequent calls: does nothing (hopefully fast).
+  static void Check(TabContents* tab_contents);
+
+ private:
+  class Delegate : public NotificationDelegate {
+   public:
+    explicit Delegate(chromeos::LocaleChangeGuard* master) : master_(master) {}
+    void Close(bool by_user);
+    void Display() {}
+    void Error() {}
+    void Click() {}
+    std::string id() const;
+
+   private:
+    chromeos::LocaleChangeGuard* master_;
+
+    DISALLOW_COPY_AND_ASSIGN(Delegate);
+  };
+
+  LocaleChangeGuard();
+  void CheckLocaleChange(TabContents* tab_contents);
+  void RevertLocaleChange(const ListValue* list);
+  void AcceptLocaleChange();
+
+  std::string from_locale_;
+  std::string to_locale_;
+  ProfileId profile_id_;
+  TabContents* tab_contents_;
+  scoped_ptr<chromeos::SystemNotification> note_;
+  bool reverted_;
+
+  friend struct base::DefaultLazyInstanceTraits<LocaleChangeGuard>;
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOCALE_CHANGE_GUARD_H_