1 // Copyright 2014 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 // This file contains the keyword autocomplete provider. The keyword provider 6 // is responsible for remembering/suggesting user "search keyword queries" 7 // (e.g. "imdb Godzilla") and then fixing them up into valid URLs. An 8 // instance of it gets created and managed by the autocomplete controller. 9 // KeywordProvider uses a TemplateURLService to find the set of keywords. 10 11 #ifndef COMPONENTS_OMNIBOX_KEYWORD_PROVIDER_H_ 12 #define COMPONENTS_OMNIBOX_KEYWORD_PROVIDER_H_ 13 14 #include <string> 15 16 #include "base/basictypes.h" 17 #include "base/compiler_specific.h" 18 #include "base/memory/scoped_ptr.h" 19 #include "components/metrics/proto/omnibox_input_type.pb.h" 20 #include "components/omnibox/autocomplete_input.h" 21 #include "components/omnibox/autocomplete_provider.h" 22 #include "components/omnibox/keyword_extensions_delegate.h" 23 24 class AutocompleteProviderListener; 25 class KeywordExtensionsDelegate; 26 class TemplateURL; 27 class TemplateURLService; 28 29 // Autocomplete provider for keyword input. 30 // 31 // After construction, the autocomplete controller repeatedly calls Start() 32 // with some user input, each time expecting to receive a small set of the best 33 // matches (either synchronously or asynchronously). 34 // 35 // To construct these matches, the provider treats user input as a series of 36 // whitespace-delimited tokens and tries to match the first token as the prefix 37 // of a known "keyword". A keyword is some string that maps to a search query 38 // URL; the rest of the user's input is taken as the input to the query. For 39 // example, the keyword "bug" might map to the URL "http://b/issue?id=%s", so 40 // input like "bug 123" would become "http://b/issue?id=123". 41 // 42 // Because we do prefix matching, user input could match more than one keyword 43 // at once. (Example: the input "f jazz" matches all keywords starting with 44 // "f".) We return the best matches, up to three. 45 // 46 // The resulting matches are shown with content specified by the keyword 47 // (usually "Search [name] for %s"), description "(Keyword: [keyword])", and 48 // action "[keyword] %s". If the user has typed a (possibly partial) keyword 49 // but no search terms, the suggested result is shown greyed out, with 50 // "<enter term(s)>" as the substituted input, and does nothing when selected. 51 class KeywordProvider : public AutocompleteProvider { 52 public: 53 KeywordProvider(AutocompleteProviderListener* listener, 54 TemplateURLService* model); 55 56 void set_extensions_delegate( 57 scoped_ptr<KeywordExtensionsDelegate> extensions_delegate) { 58 extensions_delegate_ = extensions_delegate.Pass(); 59 } 60 61 // Extracts the next whitespace-delimited token from input and returns it. 62 // Sets |remaining_input| to everything after the first token (skipping over 63 // the first intervening whitespace). 64 // If |trim_leading_whitespace| is true then leading whitespace in 65 // |*remaining_input| will be trimmed. 66 static base::string16 SplitKeywordFromInput(const base::string16& input, 67 bool trim_leading_whitespace, 68 base::string16* remaining_input); 69 70 // Returns the replacement string from the user input. The replacement 71 // string is the portion of the input that does not contain the keyword. 72 // For example, the replacement string for "b blah" is blah. 73 // If |trim_leading_whitespace| is true then leading whitespace in 74 // replacement string will be trimmed. 75 static base::string16 SplitReplacementStringFromInput( 76 const base::string16& input, 77 bool trim_leading_whitespace); 78 79 // Returns the matching substituting keyword for |input|, or NULL if there 80 // is no keyword for the specified input. If the matching keyword was found, 81 // updates |input|'s text and cursor position. 82 static const TemplateURL* GetSubstitutingTemplateURLForInput( 83 TemplateURLService* model, 84 AutocompleteInput* input); 85 86 // If |text| corresponds (in the sense of 87 // TemplateURLModel::CleanUserInputKeyword()) to an enabled, substituting 88 // keyword, returns that keyword; returns the empty string otherwise. 89 base::string16 GetKeywordForText(const base::string16& text) const; 90 91 // Creates a fully marked-up AutocompleteMatch for a specific keyword. 92 AutocompleteMatch CreateVerbatimMatch(const base::string16& text, 93 const base::string16& keyword, 94 const AutocompleteInput& input); 95 96 // AutocompleteProvider: 97 virtual void Start(const AutocompleteInput& input, 98 bool minimal_changes) OVERRIDE; 99 virtual void Stop(bool clear_cached_results) OVERRIDE; 100 101 private: 102 friend class KeywordExtensionsDelegateImpl; 103 104 virtual ~KeywordProvider(); 105 106 // Extracts the keyword from |input| into |keyword|. Any remaining characters 107 // after the keyword are placed in |remaining_input|. Returns true if |input| 108 // is valid and has a keyword. This makes use of SplitKeywordFromInput to 109 // extract the keyword and remaining string, and uses 110 // TemplateURLService::CleanUserInputKeyword to remove unnecessary characters. 111 // In general use this instead of SplitKeywordFromInput. 112 // Leading whitespace in |*remaining_input| will be trimmed. 113 static bool ExtractKeywordFromInput(const AutocompleteInput& input, 114 base::string16* keyword, 115 base::string16* remaining_input); 116 117 // Determines the relevance for some input, given its type, whether the user 118 // typed the complete keyword, and whether the user is in "prefer keyword 119 // matches" mode, and whether the keyword supports replacement. 120 // If |allow_exact_keyword_match| is false, the relevance for complete 121 // keywords that support replacements is degraded. 122 static int CalculateRelevance(metrics::OmniboxInputType::Type type, 123 bool complete, 124 bool support_replacement, 125 bool prefer_keyword, 126 bool allow_exact_keyword_match); 127 128 // Creates a fully marked-up AutocompleteMatch from the user's input. 129 // If |relevance| is negative, calculate a relevance based on heuristics. 130 AutocompleteMatch CreateAutocompleteMatch( 131 const TemplateURL* template_url, 132 const AutocompleteInput& input, 133 size_t prefix_length, 134 const base::string16& remaining_input, 135 bool allowed_to_be_default_match, 136 int relevance); 137 138 // Fills in the "destination_url" and "contents" fields of |match| with the 139 // provided user input and keyword data. 140 void FillInURLAndContents(const base::string16& remaining_input, 141 const TemplateURL* element, 142 AutocompleteMatch* match) const; 143 144 TemplateURLService* GetTemplateURLService() const; 145 146 AutocompleteProviderListener* listener_; 147 148 // Model for the keywords. 149 TemplateURLService* model_; 150 151 // Delegate to handle the extensions-only logic for KeywordProvider. 152 // NULL when extensions are not enabled. May be NULL for tests. 153 scoped_ptr<KeywordExtensionsDelegate> extensions_delegate_; 154 155 DISALLOW_COPY_AND_ASSIGN(KeywordProvider); 156 }; 157 158 #endif // COMPONENTS_OMNIBOX_KEYWORD_PROVIDER_H_ 159
