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      1 // Copyright 2013 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef CHROME_BROWSER_SEARCH_SEARCH_TERMS_TRACKER_H_
      6 #define CHROME_BROWSER_SEARCH_SEARCH_TERMS_TRACKER_H_
      7 
      8 #include <map>
      9 
     10 #include "base/strings/string16.h"
     11 #include "content/public/browser/notification_observer.h"
     12 #include "content/public/browser/notification_registrar.h"
     13 
     14 namespace content {
     15 class NavigationController;
     16 class WebContents;
     17 }
     18 
     19 namespace chrome {
     20 
     21 // Observes navigation events (and WebContents destructions) to keep track of
     22 // search terms associated with a WebContents. Essentially, as long as there are
     23 // only web-triggerable navigations following a search results page, this class
     24 // will consider the search terms from that SRP as the "current" search terms.
     25 // Any other type of navigation will invalidate the search terms. The search
     26 // terms are being tracked so they can be displayed in the location bar for
     27 // related navigations that occur after a search.
     28 class SearchTermsTracker : public content::NotificationObserver {
     29  public:
     30   SearchTermsTracker();
     31   virtual ~SearchTermsTracker();
     32 
     33   // Returns the current search terms and navigation index of the corresponding
     34   // search results page for the specified WebContents. This function will
     35   // return true if there are valid search terms for |contents|. |search_terms|
     36   // and/or |navigation_index| can be NULL if not needed.
     37   bool GetSearchTerms(const content::WebContents* contents,
     38                       base::string16* search_terms,
     39                       int* navigation_index) const;
     40 
     41   // content::NotificationObserver
     42   virtual void Observe(int type,
     43                        const content::NotificationSource& source,
     44                        const content::NotificationDetails& details) OVERRIDE;
     45 
     46  private:
     47   struct TabData {
     48     TabData() : srp_navigation_index(-1) {}
     49     base::string16 search_terms;
     50     int srp_navigation_index;
     51   };
     52 
     53   // Keeps information about the specified WebContents.
     54   typedef std::map<const content::WebContents*, TabData> TabState;
     55 
     56   // Searches for the most recent search and, if found, fills |tab_data| with
     57   // information about that search and returns true.
     58   bool FindMostRecentSearch(const content::NavigationController* controller,
     59                             TabData* tab_data);
     60 
     61   // Removes the TabData entry associated to the specified |contents|.
     62   void RemoveTabData(const content::WebContents* contents);
     63 
     64   content::NotificationRegistrar registrar_;
     65   TabState tabs_;
     66 
     67   DISALLOW_COPY_AND_ASSIGN(SearchTermsTracker);
     68 };
     69 
     70 }  // namespace chrome
     71 
     72 #endif  // CHROME_BROWSER_SEARCH_SEARCH_TERMS_TRACKER_H_
     73