shortcuts_provider.h revision 0529e5d033099cbfc42635f6f6183833b09dff6e 
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
17class Profile;
18class 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.
24class 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_
114