chrome/browser/autocomplete/shortcuts_provider.h

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