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