NTP Zombie Code Slayer Part IV: Most Visited

chrome/browser/ui/webui/ntp/most_visited_handler.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 CHROME_BROWSER_UI_WEBUI_NTP_MOST_VISITED_HANDLER_H_
-#define CHROME_BROWSER_UI_WEBUI_NTP_MOST_VISITED_HANDLER_H_
-
-#include <string>
-#include <vector>
-
-#include "base/memory/weak_ptr.h"
-#include "base/scoped_observer.h"
-#include "components/history/core/browser/history_types.h"
-#include "components/history/core/browser/top_sites_observer.h"
-#include "content/public/browser/web_ui_message_handler.h"
-
-class GURL;
-
-namespace base {
-class ListValue;
-class Value;
-}
-
-namespace user_prefs {
-class PrefRegistrySyncable;
-}
-
-// The handler for Javascript messages related to the "most visited" view.
-//
-// This class manages one preference:
-// - The URL blacklist: URLs we do not want to show in the thumbnails list.  It
-//   is a dictionary for quick access (it associates a dummy boolean to the URL
-//   string).
-class MostVisitedHandler : public content::WebUIMessageHandler,
-                           public history::TopSitesObserver {
- public:
-
-  MostVisitedHandler();
-  ~MostVisitedHandler() override;
-
-  // WebUIMessageHandler override and implementation.
-  void RegisterMessages() override;
-
-  // Callback for the "getMostVisited" message.
-  void HandleGetMostVisited(const base::ListValue* args);
-
-  // Callback for the "blacklistURLFromMostVisited" message.
-  void HandleBlacklistUrl(const base::ListValue* args);
-
-  // Callback for the "removeURLsFromMostVisitedBlacklist" message.
-  void HandleRemoveUrlsFromBlacklist(const base::ListValue* args);
-
-  // Callback for the "clearMostVisitedURLsBlacklist" message.
-  void HandleClearBlacklist(const base::ListValue* args);
-
-  // Callback for the "mostVisitedAction" message.
-  void HandleMostVisitedAction(const base::ListValue* args);
-
-  // Callback for the "mostVisitedSelected" message.
-  void HandleMostVisitedSelected(const base::ListValue* args);
-
-  const std::vector<GURL>& most_visited_urls() const {
-    return most_visited_urls_;
-  }
-
-  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
-
- private:
-  struct MostVisitedPage;
-
-  // Send a request to the HistoryService to get the most visited pages.
-  void StartQueryForMostVisited();
-
-  // Sets pages_value_ from a format produced by TopSites.
-  void SetPagesValueFromTopSites(const history::MostVisitedURLList& data);
-
-  // Callback for TopSites.
-  void OnMostVisitedUrlsAvailable(const history::MostVisitedURLList& data);
-
-  // Puts the passed URL in the blacklist (so it does not show as a thumbnail).
-  void BlacklistUrl(const GURL& url);
-
-  // Returns the key used in url_blacklist_ for the passed |url|.
-  std::string GetDictionaryKeyForUrl(const std::string& url);
-
-  // Sends pages_value_ to the javascript side and resets page_value_.
-  void SendPagesValue();
-
-  // history::TopSitesObserver implementation.
-  void TopSitesLoaded(history::TopSites* top_sites) override;
-  void TopSitesChanged(history::TopSites* top_sites) override;
-
-  // Scoped observer to help with TopSitesObserver registration.
-  ScopedObserver<history::TopSites, history::TopSitesObserver> scoped_observer_;
-
-  // The most visited URLs, in priority order.
-  // Only used for matching up clicks on the page to which most visited entry
-  // was clicked on for metrics purposes.
-  std::vector<GURL> most_visited_urls_;
-
-  // We pre-fetch the first set of result pages.  This variable is false until
-  // we get the first getMostVisited() call.
-  bool got_first_most_visited_request_;
-
-  // Keep the results of the db query here.
-  scoped_ptr<base::ListValue> pages_value_;
-
-  // Whether the user has viewed the 'most visited' pane.
-  bool most_visited_viewed_;
-
-  // Whether the user has performed a "tracked" action to leave the page or not.
-  bool user_action_logged_;
-
-  // For callbacks which may be run after destruction.
-  base::WeakPtrFactory<MostVisitedHandler> weak_ptr_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(MostVisitedHandler);
-};
-
-#endif  // CHROME_BROWSER_UI_WEBUI_NTP_MOST_VISITED_HANDLER_H_