Translate: split supporting language list handling to TranslateLanguageList

chrome/browser/translate/translate_language_list.h

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_TRANSLATE_TRANSLATE_LANGUAGE_LIST_H_
+#define CHROME_BROWSER_TRANSLATE_TRANSLATE_LANGUAGE_LIST_H_
+
+#include <set>
+#include <string>
+#include <vector>
+
+#include "base/memory/scoped_ptr.h"
+#include "net/url_request/url_fetcher_delegate.h"
+
+namespace net {
+class URLFetcher;
+}
+
+// The TranslateLanguageList class is responsible for maintaining the latest
+// supporting language list.
+// This class is defined to be owned only by TranslateManager.
+class TranslateLanguageList : public net::URLFetcherDelegate {
+ public:
+  TranslateLanguageList();
+  virtual ~TranslateLanguageList();
+
+  // net::URLFetcherDelegate implementation:
+  virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
+
+  // Fills |languages| with the list of languages that the translate server can
+  // translate to and from.
+  void GetSupportedLanguages(std::vector<std::string>* languages);
+
+  // Returns the language code that can be used with the Translate method for a
+  // specified |chrome_locale|.
+  std::string GetLanguageCode(const std::string& chrome_locale);
+
+  // Returns true if |language| is supported by the translation server.
+  bool IsSupportedLanguage(const std::string& language);
+
+  // TODO(toyoshim): Add IsSupportedAlphaLanguage() here.
+
+  // Fetches the language list from the translate server. It will not retry
+  // more than kMaxRetryLanguageListFetch times.
+  void RequestLanguageList();
+
+  // static const values shared with our browser tests.
+  static const char kLanguageListCallbackName[];
+  static const char kTargetLanguagesKey[];
+
+ private:
+  // Parses |language_list| and fills |supported_languages_| with the list of
+  // languages that the translate server can translate to and from.
+  void SetSupportedLanguages(const std::string& language_list);
+
+  // The languages supported by the translation server.
+  std::set<std::string> supported_languages_;
+
+  // URLFetcher runs in IO thread. This object should be destructed explicitly
+  // before killing IO thread because this class is singleton, and it may be

[MAD, 2013/05/27 21:34:35]

Comment about singleton should be updated.

[Takashi Toyoshima, 2013/05/28 07:35:28]

Done.

+  // destructed at problematic timing.
+  scoped_ptr<net::URLFetcher> url_fetcher_;
+
+  DISALLOW_COPY_AND_ASSIGN(TranslateLanguageList);
+};
+
+#endif  // CHROME_BROWSER_TRANSLATE_TRANSLATE_LANGUAGE_LIST_H_