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/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<base::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_