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// 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 CHROME_BROWSER_AUTOCOMPLETE_KEYWORD_PROVIDER_H_ 12#define CHROME_BROWSER_AUTOCOMPLETE_KEYWORD_PROVIDER_H_ 13 14#include <string> 15 16#include "base/basictypes.h" 17#include "base/compiler_specific.h" 18#include "chrome/browser/autocomplete/autocomplete_input.h" 19#include "chrome/browser/autocomplete/autocomplete_provider.h" 20#include "content/public/browser/notification_observer.h" 21#include "content/public/browser/notification_registrar.h" 22 23class Profile; 24class TemplateURL; 25class TemplateURLService; 26 27// Autocomplete provider for keyword input. 28// 29// After construction, the autocomplete controller repeatedly calls Start() 30// with some user input, each time expecting to receive a small set of the best 31// matches (either synchronously or asynchronously). 32// 33// To construct these matches, the provider treats user input as a series of 34// whitespace-delimited tokens and tries to match the first token as the prefix 35// of a known "keyword". A keyword is some string that maps to a search query 36// URL; the rest of the user's input is taken as the input to the query. For 37// example, the keyword "bug" might map to the URL "http://b/issue?id=%s", so 38// input like "bug 123" would become "http://b/issue?id=123". 39// 40// Because we do prefix matching, user input could match more than one keyword 41// at once. (Example: the input "f jazz" matches all keywords starting with 42// "f".) We return the best matches, up to three. 43// 44// The resulting matches are shown with content specified by the keyword 45// (usually "Search [name] for %s"), description "(Keyword: [keyword])", and 46// action "[keyword] %s". If the user has typed a (possibly partial) keyword 47// but no search terms, the suggested result is shown greyed out, with 48// "<enter term(s)>" as the substituted input, and does nothing when selected. 49class KeywordProvider : public AutocompleteProvider, 50 public content::NotificationObserver { 51 public: 52 KeywordProvider(AutocompleteProviderListener* listener, Profile* profile); 53 // For testing. 54 KeywordProvider(AutocompleteProviderListener* listener, 55 TemplateURLService* model); 56 57 // Extracts the next whitespace-delimited token from input and returns it. 58 // Sets |remaining_input| to everything after the first token (skipping over 59 // the first intervening whitespace). 60 // If |trim_leading_whitespace| is true then leading whitespace in 61 // |*remaining_input| will be trimmed. 62 static string16 SplitKeywordFromInput(const string16& input, 63 bool trim_leading_whitespace, 64 string16* remaining_input); 65 66 // Returns the replacement string from the user input. The replacement 67 // string is the portion of the input that does not contain the keyword. 68 // For example, the replacement string for "b blah" is blah. 69 // If |trim_leading_whitespace| is true then leading whitespace in 70 // replacement string will be trimmed. 71 static string16 SplitReplacementStringFromInput(const string16& input, 72 bool trim_leading_whitespace); 73 74 // Returns the matching substituting keyword for |input|, or NULL if there 75 // is no keyword for the specified input. If the matching keyword was found, 76 // updates |input|'s text and cursor position. 77 static const TemplateURL* GetSubstitutingTemplateURLForInput( 78 TemplateURLService* model, 79 AutocompleteInput* input); 80 81 // If |text| corresponds (in the sense of 82 // TemplateURLModel::CleanUserInputKeyword()) to an enabled, substituting 83 // keyword, returns that keyword; returns the empty string otherwise. 84 string16 GetKeywordForText(const string16& text) const; 85 86 // Creates a fully marked-up AutocompleteMatch for a specific keyword. 87 AutocompleteMatch CreateVerbatimMatch(const string16& text, 88 const string16& keyword, 89 const AutocompleteInput& input); 90 91 // AutocompleteProvider: 92 virtual void Start(const AutocompleteInput& input, 93 bool minimal_changes) OVERRIDE; 94 virtual void Stop(bool clear_cached_results) OVERRIDE; 95 96 private: 97 class ScopedEndExtensionKeywordMode; 98 friend class ScopedEndExtensionKeywordMode; 99 100 virtual ~KeywordProvider(); 101 102 // Extracts the keyword from |input| into |keyword|. Any remaining characters 103 // after the keyword are placed in |remaining_input|. Returns true if |input| 104 // is valid and has a keyword. This makes use of SplitKeywordFromInput to 105 // extract the keyword and remaining string, and uses 106 // TemplateURLService::CleanUserInputKeyword to remove unnecessary characters. 107 // In general use this instead of SplitKeywordFromInput. 108 // Leading whitespace in |*remaining_input| will be trimmed. 109 static bool ExtractKeywordFromInput(const AutocompleteInput& input, 110 string16* keyword, 111 string16* remaining_input); 112 113 // Determines the relevance for some input, given its type, whether the user 114 // typed the complete keyword, and whether the user is in "prefer keyword 115 // matches" mode, and whether the keyword supports replacement. 116 // If |allow_exact_keyword_match| is false, the relevance for complete 117 // keywords that support replacements is degraded. 118 static int CalculateRelevance(AutocompleteInput::Type type, 119 bool complete, 120 bool support_replacement, 121 bool prefer_keyword, 122 bool allow_exact_keyword_match); 123 124 // Creates a fully marked-up AutocompleteMatch from the user's input. 125 // If |relevance| is negative, calculate a relevance based on heuristics. 126 AutocompleteMatch CreateAutocompleteMatch(const TemplateURL* template_url, 127 const AutocompleteInput& input, 128 size_t prefix_length, 129 const string16& remaining_input, 130 bool allowed_to_be_default_match, 131 int relevance); 132 133 // Fills in the "destination_url" and "contents" fields of |match| with the 134 // provided user input and keyword data. 135 void FillInURLAndContents(const string16& remaining_input, 136 const TemplateURL* element, 137 AutocompleteMatch* match) const; 138 139 void EnterExtensionKeywordMode(const std::string& extension_id); 140 void MaybeEndExtensionKeywordMode(); 141 142 // content::NotificationObserver interface. 143 virtual void Observe(int type, 144 const content::NotificationSource& source, 145 const content::NotificationDetails& details) OVERRIDE; 146 147 TemplateURLService* GetTemplateURLService() const; 148 149 // Model for the keywords. This is only non-null when testing, otherwise the 150 // TemplateURLService from the Profile is used. 151 TemplateURLService* model_; 152 153 // Identifies the current input state. This is incremented each time the 154 // autocomplete edit's input changes in any way. It is used to tell whether 155 // suggest results from the extension are current. 156 int current_input_id_; 157 158 // The input state at the time we last asked the extension for suggest 159 // results. 160 AutocompleteInput extension_suggest_last_input_; 161 162 // We remember the last suggestions we've received from the extension in case 163 // we need to reset our matches without asking the extension again. 164 std::vector<AutocompleteMatch> extension_suggest_matches_; 165 166 // If non-empty, holds the ID of the extension whose keyword is currently in 167 // the URL bar while the autocomplete popup is open. 168 std::string current_keyword_extension_id_; 169 170 content::NotificationRegistrar registrar_; 171 172 DISALLOW_COPY_AND_ASSIGN(KeywordProvider); 173}; 174 175#endif // CHROME_BROWSER_AUTOCOMPLETE_KEYWORD_PROVIDER_H_ 176