First version of the time slicing on the urls. Not ready for review yet.

chrome/browser/ui/webui/ntp/suggestions_page_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_SUGGESTIONS_PAGE_HANDLER_H_
+#define CHROME_BROWSER_UI_WEBUI_NTP_SUGGESTIONS_PAGE_HANDLER_H_
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "chrome/browser/cancelable_request.h"
+#include "chrome/browser/history/history_types.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+#include "content/public/browser/web_ui_message_handler.h"
+
+class GURL;
+class PageUsageData;
+class PrefService;
+
+namespace base {
+class ListValue;
+class Value;
+}
+
+// The handler for Javascript messages related to the "suggestions" 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 SuggestionsHandler : public content::WebUIMessageHandler,
+                           public content::NotificationObserver {
+ public:
+
+  SuggestionsHandler();
+  virtual ~SuggestionsHandler();
+
+  // WebUIMessageHandler override and implementation.
+  virtual void RegisterMessages() OVERRIDE;
+
+  // Callback for the "getSuggestions" message.
+  void HandleGetSuggestions(const base::ListValue* args);
+
+  // Callback for the "blacklistURLFromSuggestions" message.
+  void HandleBlacklistURL(const base::ListValue* args);
+
+  // Callback for the "removeURLsFromSuggestionsBlacklist" message.
+  void HandleRemoveURLsFromBlacklist(const base::ListValue* args);
+
+  // Callback for the "clearSuggestionsURLsBlacklist" message.
+  void HandleClearBlacklist(const base::ListValue* args);
+
+  // content::NotificationObserver implementation.
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
+  static void RegisterUserPrefs(PrefService* prefs);
+
+ private:
+  // Send a request to the HistoryService to get the suggestions pages.
+  void StartQueryForSuggestions();
+
+  // Sets pages_value_ from a format produced by TopSites.
+  void SetPagesValueFromTopSites(const history::MostVisitedURLList& data);
+
+  // Callback for History.
+  void OnSuggestionsURLsAvailable(
+      CancelableRequestProvider::Handle handle,
+      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 to and resets page_value_.
+  void SendPagesValue();
+
+  content::NotificationRegistrar registrar_;
+
+  // Our consumer for the history service.
+  CancelableRequestConsumerTSimple<PageUsageData*> cancelable_consumer_;
+  CancelableRequestConsumer history_consumer_;
+  CancelableRequestConsumer topsites_consumer_;
+
+  // We pre-fetch the first set of result pages.  This variable is false until
+  // we get the first getSuggestions() call.
+  bool got_first_suggestions_request_;
+
+  // Keep the results of the db query here.
+  scoped_ptr<base::ListValue> pages_value_;
+
+  DISALLOW_COPY_AND_ASSIGN(SuggestionsHandler);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_NTP_SUGGESTIONS_PAGE_HANDLER_H_