shortcuts_provider.h revision 5821806d5e7f356e8fa4b058a389a808ea183019 
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/history/shortcuts_backend.h"
15
16class Profile;
17
18// Provider of recently autocompleted links. Provides autocomplete suggestions
19// from previously selected suggestions. The more often a user selects a
20// suggestion for a given search term the higher will be that suggestion's
21// ranking for future uses of that search term.
22class ShortcutsProvider
23    : public AutocompleteProvider,
24      public history::ShortcutsBackend::ShortcutsBackendObserver {
25 public:
26  ShortcutsProvider(AutocompleteProviderListener* listener, Profile* profile);
27
28  // Performs the autocompletion synchronously. Since no asynch completion is
29  // performed |minimal_changes| is ignored.
30  virtual void Start(const AutocompleteInput& input,
31                     bool minimal_changes) OVERRIDE;
32
33  virtual void DeleteMatch(const AutocompleteMatch& match) OVERRIDE;
34
35 private:
36  friend class ClassifyTest;
37  friend class ShortcutsProviderTest;
38  FRIEND_TEST_ALL_PREFIXES(ShortcutsProviderTest, CalculateScore);
39  FRIEND_TEST_ALL_PREFIXES(ShortcutsProviderTest, DeleteMatch);
40
41  typedef std::multimap<char16, string16> WordMap;
42
43  virtual ~ShortcutsProvider();
44
45  // ShortcutsBackendObserver:
46  virtual void OnShortcutsLoaded() OVERRIDE;
47
48  void DeleteMatchesWithURLs(const std::set<GURL>& urls);
49  void DeleteShortcutsWithURLs(const std::set<GURL>& urls);
50
51  // Performs the autocomplete matching and scoring.
52  void GetMatches(const AutocompleteInput& input);
53
54  AutocompleteMatch ShortcutToACMatch(
55      int relevance,
56      const string16& terms,
57      const history::ShortcutsBackend::Shortcut& shortcut);
58
59  // Returns a map mapping characters to groups of words from |text| that start
60  // with those characters, ordered lexicographically descending so that longer
61  // words appear before their prefixes (if any) within a particular
62  // equal_range().
63  static WordMap CreateWordMapForString(const string16& text);
64
65  // Given |text| and a corresponding base set of classifications
66  // |original_class|, adds ACMatchClassification::MATCH markers for all
67  // instances of the words from |find_words| within |text| and returns the
68  // resulting classifications.  (|find_text| is provided as the original string
69  // used to create |find_words|.  This is supplied because it's common for this
70  // to be a prefix of |text|, so we can quickly check for that and mark that
71  // entire substring as a match before proceeding with the more generic
72  // algorithm.)
73  //
74  // For example, given the |text|
75  // "Sports and News at sports.somesite.com - visit us!" and |original_class|
76  // {{0, NONE}, {18, URL}, {37, NONE}} (marking "sports.somesite.com" as a
77  // URL), calling with |find_text| set to "sp ew" would return
78  // {{0, MATCH}, {2, NONE}, {12, MATCH}, {14, NONE}, {18, URL|MATCH},
79  // {20, URL}, {37, NONE}}.
80  //
81  // |find_words| should be as constructed by CreateWordMapForString(find_text).
82  //
83  // |find_text| (and thus |find_words|) are expected to be lowercase.  |text|
84  // will be lowercased in this function.
85  static ACMatchClassifications ClassifyAllMatchesInString(
86      const string16& find_text,
87      const WordMap& find_words,
88      const string16& text,
89      const ACMatchClassifications& original_class);
90
91  // Returns iterator to first item in |shortcuts_map_| matching |keyword|.
92  // Returns shortcuts_map_.end() if there are no matches.
93  history::ShortcutsBackend::ShortcutMap::const_iterator FindFirstMatch(
94      const string16& keyword,
95      history::ShortcutsBackend* backend);
96
97  static int CalculateScore(
98      const string16& terms,
99      const history::ShortcutsBackend::Shortcut& shortcut);
100
101  std::string languages_;
102  bool initialized_;
103};
104
105#endif  // CHROME_BROWSER_AUTOCOMPLETE_SHORTCUTS_PROVIDER_H_
106