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/shortcuts_backend.h"
  14 #include "components/omnibox/autocomplete_provider.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   explicit ShortcutsProvider(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 of
  54   // the user's input. |input| and |fixed_up_input_text| are used to decide
  55   // 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
  62   // Returns a map mapping characters to groups of words from |text| that start
  63   // with those characters, ordered lexicographically descending so that longer
  64   // words appear before their prefixes (if any) within a particular
  65   // equal_range().
  66   static WordMap CreateWordMapForString(const base::string16& text);
  67
  68   // Given |text| and a corresponding base set of classifications
  69   // |original_class|, adds ACMatchClassification::MATCH markers for all
  70   // instances of the words from |find_words| within |text| and returns the
  71   // resulting classifications.  (|find_text| is provided as the original string
  72   // used to create |find_words|.  This is supplied because it's common for this
  73   // to be a prefix of |text|, so we can quickly check for that and mark that
  74   // entire substring as a match before proceeding with the more generic
  75   // algorithm.)
  76   //
  77   // For example, given the |text|
  78   // "Sports and News at sports.somesite.com - visit us!" and |original_class|
  79   // {{0, NONE}, {18, URL}, {37, NONE}} (marking "sports.somesite.com" as a
  80   // URL), calling with |find_text| set to "sp ew" would return
  81   // {{0, MATCH}, {2, NONE}, {12, MATCH}, {14, NONE}, {18, URL|MATCH},
  82   // {20, URL}, {37, NONE}}.
  83   //
  84   // |find_words| should be as constructed by CreateWordMapForString(find_text).
  85   //
  86   // |find_text| (and thus |find_words|) are expected to be lowercase.  |text|
  87   // will be lowercased in this function.
  88   static ACMatchClassifications ClassifyAllMatchesInString(
  89       const base::string16& find_text,
  90       const WordMap& find_words,
  91       const base::string16& text,
  92       const ACMatchClassifications& original_class);
  93
  94   // Returns iterator to first item in |shortcuts_map_| matching |keyword|.
  95   // Returns shortcuts_map_.end() if there are no matches.
  96   ShortcutsBackend::ShortcutMap::const_iterator FindFirstMatch(
  97       const base::string16& keyword,
  98       ShortcutsBackend* backend);
  99
 100   int CalculateScore(const base::string16& terms,
 101                      const history::ShortcutsDatabase::Shortcut& shortcut,
 102                      int max_relevance);
 103
 104   // The default max relevance unless overridden by a field trial.
 105   static const int kShortcutsProviderDefaultMaxRelevance;
 106
 107   Profile* profile_;
 108   std::string languages_;
 109   bool initialized_;
 110 };
 111
 112 #endif  // CHROME_BROWSER_AUTOCOMPLETE_SHORTCUTS_PROVIDER_H_