1// Copyright 2013 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 COMPONENTS_TRANSLATE_CORE_BROWSER_TRANSLATE_LANGUAGE_LIST_H_
6#define COMPONENTS_TRANSLATE_CORE_BROWSER_TRANSLATE_LANGUAGE_LIST_H_
7
8#include <set>
9#include <string>
10#include <vector>
11
12#include "base/callback_list.h"
13#include "base/memory/scoped_ptr.h"
14#include "base/time/time.h"
15
16class GURL;
17
18namespace translate {
19
20struct TranslateEventDetails;
21class TranslateURLFetcher;
22
23// The TranslateLanguageList class is responsible for maintaining the latest
24// supporting language list.
25class TranslateLanguageList {
26 public:
27  static const int kFetcherId = 1;
28
29  TranslateLanguageList();
30  virtual ~TranslateLanguageList();
31
32  // Returns the last-updated time when the language list is fetched from the
33  // Translate server. Returns null time if the list is yet to be fetched.
34  base::Time last_updated() { return last_updated_; }
35
36  // Fills |languages| with the list of languages that the translate server can
37  // translate to and from. |languages| will include alpha languages.
38  void GetSupportedLanguages(std::vector<std::string>* languages);
39
40  // Returns the language code that can be used with the Translate method for a
41  // specified |language|. (ex. GetLanguageCode("en-US") will return "en", and
42  // GetLanguageCode("zh-CN") returns "zh-CN")
43  std::string GetLanguageCode(const std::string& language);
44
45  // Returns true if |language| is supported by the translation server. It also
46  // returns true against alpha languages.
47  bool IsSupportedLanguage(const std::string& language);
48
49  // Returns true if |language| is supported by the translation server as a
50  // alpha language.
51  bool IsAlphaLanguage(const std::string& language);
52
53  // Fetches the language list from the translate server if resource requests
54  // are allowed, and otherwise keeps the request as pending until allowed.
55  void RequestLanguageList();
56
57  // Sets whether requests are allowed. If |allowed| is true, this resumes any
58  // pending request.
59  void SetResourceRequestsAllowed(bool allowed);
60
61  typedef base::Callback<void(const TranslateEventDetails&)> EventCallback;
62  typedef base::CallbackList<void(const TranslateEventDetails&)>
63      EventCallbackList;
64
65  // Registers a callback for translate events related to the language list,
66  // such as updates and download errors.
67  scoped_ptr<EventCallbackList::Subscription> RegisterEventCallback(
68      const EventCallback& callback);
69
70  // Disables the language list updater. This is used only for testing now.
71  static void DisableUpdate();
72
73  // static const values shared with our browser tests.
74  static const char kLanguageListCallbackName[];
75  static const char kTargetLanguagesKey[];
76  static const char kAlphaLanguagesKey[];
77
78 private:
79  // Callback function called when TranslateURLFetcher::Request() is finished.
80  void OnLanguageListFetchComplete(int id,
81                                   bool success,
82                                   const std::string& data);
83
84  // Notifies the callback list of a translate event.
85  void NotifyEvent(int line, const std::string& message);
86
87  // Parses |language_list| containing the list of languages that the translate
88  // server can translate to and from.
89  void SetSupportedLanguages(const std::string& language_list);
90
91  // Returns the url from which to load the list of languages.
92  GURL TranslateLanguageUrl();
93
94  // Callbacks called on translate events.
95  EventCallbackList callback_list_;
96
97  // Whether the language list can be requested.
98  bool resource_requests_allowed_;
99
100  // True if the list has to be fetched when resource requests are allowed.
101  bool request_pending_;
102
103  // All the languages supported by the translation server.
104  std::set<std::string> all_supported_languages_;
105
106  // Alpha languages supported by the translation server.
107  std::set<std::string> alpha_languages_;
108
109  // A LanguageListFetcher instance to fetch a server providing supported
110  // language list including alpha languages.
111  scoped_ptr<TranslateURLFetcher> language_list_fetcher_;
112
113  // The last-updated time when the language list is sent.
114  base::Time last_updated_;
115
116  DISALLOW_COPY_AND_ASSIGN(TranslateLanguageList);
117};
118
119}  // namespace translate
120
121#endif  // COMPONENTS_TRANSLATE_CORE_BROWSER_TRANSLATE_LANGUAGE_LIST_H_
122