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      1 // Copyright (c) 2012 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_AUTOCOMPLETE_SHORTCUTS_PROVIDER_H_
      6 #define CHROME_BROWSER_AUTOCOMPLETE_SHORTCUTS_PROVIDER_H_
      7 
      8 #include <map>
      9 #include <set>
     10 #include <string>
     11 
     12 #include "base/gtest_prod_util.h"
     13 #include "chrome/browser/autocomplete/autocomplete_provider.h"
     14 #include "chrome/browser/autocomplete/url_prefix.h"
     15 #include "chrome/browser/history/shortcuts_backend.h"
     16 
     17 class Profile;
     18 
     19 namespace history {
     20 class ShortcutsProviderTest;
     21 }
     22 
     23 // Provider of recently autocompleted links. Provides autocomplete suggestions
     24 // from previously selected suggestions. The more often a user selects a
     25 // suggestion for a given search term the higher will be that suggestion's
     26 // ranking for future uses of that search term.
     27 class ShortcutsProvider
     28     : public AutocompleteProvider,
     29       public history::ShortcutsBackend::ShortcutsBackendObserver {
     30  public:
     31   ShortcutsProvider(AutocompleteProviderListener* listener, Profile* profile);
     32 
     33   // Performs the autocompletion synchronously. Since no asynch completion is
     34   // performed |minimal_changes| is ignored.
     35   virtual void Start(const AutocompleteInput& input,
     36                      bool minimal_changes) OVERRIDE;
     37 
     38   virtual void DeleteMatch(const AutocompleteMatch& match) OVERRIDE;
     39 
     40  private:
     41   friend class ClassifyTest;
     42   friend class history::ShortcutsProviderTest;
     43 
     44   typedef std::multimap<char16, base::string16> WordMap;
     45 
     46   virtual ~ShortcutsProvider();
     47 
     48   // ShortcutsBackendObserver:
     49   virtual void OnShortcutsLoaded() OVERRIDE;
     50 
     51   // Performs the autocomplete matching and scoring.
     52   void GetMatches(const AutocompleteInput& input);
     53 
     54   // Returns an AutocompleteMatch corresponding to |shortcut|. Assigns it
     55   // |relevance| score in the process, and highlights the description and
     56   // contents against |term_string|, which should be the lower-cased version
     57   // of the user's input.  |term_string| and |fixed_up_term_string| are used
     58   // to decide what can be inlined. If |prevent_inline_autocomplete|, no
     59   // matches with inline completions will be allowed to be the default match.
     60   AutocompleteMatch ShortcutToACMatch(
     61       const history::ShortcutsBackend::Shortcut& shortcut,
     62       int relevance,
     63       const base::string16& term_string,
     64       const base::string16& fixed_up_term_string,
     65       const bool prevent_inline_autocomplete);
     66 
     67   // Returns a map mapping characters to groups of words from |text| that start
     68   // with those characters, ordered lexicographically descending so that longer
     69   // words appear before their prefixes (if any) within a particular
     70   // equal_range().
     71   static WordMap CreateWordMapForString(const base::string16& text);
     72 
     73   // Given |text| and a corresponding base set of classifications
     74   // |original_class|, adds ACMatchClassification::MATCH markers for all
     75   // instances of the words from |find_words| within |text| and returns the
     76   // resulting classifications.  (|find_text| is provided as the original string
     77   // used to create |find_words|.  This is supplied because it's common for this
     78   // to be a prefix of |text|, so we can quickly check for that and mark that
     79   // entire substring as a match before proceeding with the more generic
     80   // algorithm.)
     81   //
     82   // For example, given the |text|
     83   // "Sports and News at sports.somesite.com - visit us!" and |original_class|
     84   // {{0, NONE}, {18, URL}, {37, NONE}} (marking "sports.somesite.com" as a
     85   // URL), calling with |find_text| set to "sp ew" would return
     86   // {{0, MATCH}, {2, NONE}, {12, MATCH}, {14, NONE}, {18, URL|MATCH},
     87   // {20, URL}, {37, NONE}}.
     88   //
     89   // |find_words| should be as constructed by CreateWordMapForString(find_text).
     90   //
     91   // |find_text| (and thus |find_words|) are expected to be lowercase.  |text|
     92   // will be lowercased in this function.
     93   static ACMatchClassifications ClassifyAllMatchesInString(
     94       const base::string16& find_text,
     95       const WordMap& find_words,
     96       const base::string16& text,
     97       const ACMatchClassifications& original_class);
     98 
     99   // Returns iterator to first item in |shortcuts_map_| matching |keyword|.
    100   // Returns shortcuts_map_.end() if there are no matches.
    101   history::ShortcutsBackend::ShortcutMap::const_iterator FindFirstMatch(
    102       const base::string16& keyword,
    103       history::ShortcutsBackend* backend);
    104 
    105   int CalculateScore(
    106       const base::string16& terms,
    107       const history::ShortcutsBackend::Shortcut& shortcut,
    108       int max_relevance);
    109 
    110   std::string languages_;
    111   bool initialized_;
    112 };
    113 
    114 #endif  // CHROME_BROWSER_AUTOCOMPLETE_SHORTCUTS_PROVIDER_H_
    115