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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 "base/memory/scoped_ptr.h" | |
19 #include "chrome/browser/autocomplete/keyword_extensions_delegate.h" | |
20 #include "components/metrics/proto/omnibox_input_type.pb.h" | |
21 #include "components/omnibox/autocomplete_input.h" | |
22 #include "components/omnibox/autocomplete_provider.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 // CHROME_BROWSER_AUTOCOMPLETE_KEYWORD_PROVIDER_H_ | |
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