text: // 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_URL_FETCHER_H_
  #define CHROME_BROWSER_TRANSLATE_TRANSLATE_URL_FETCHER_H_
  
  #include "base/callback.h"
  #include "base/memory/scoped_ptr.h"
  #include "net/url_request/url_fetcher_delegate.h"
  #include "url/gurl.h"
  
  class TranslateURLFetcher : public net::URLFetcherDelegate {
   public:
    // Callback type for Request().
    typedef base::Callback<void(int, bool, const std::string&)> Callback;
  
    // Represents internal state if the fetch is completed successfully.
    enum State {
      IDLE,        // No fetch request was issued.
      REQUESTING,  // A fetch request was issued, but not finished yet.
      COMPLETED,   // The last fetch request was finished successfully.
      FAILED,      // The last fetch request was finished with a failure.
    };
  
    explicit TranslateURLFetcher(int id);
    virtual ~TranslateURLFetcher();
  
    int max_retry_on_5xx() {
      return max_retry_on_5xx_;
    }
    void set_max_retry_on_5xx(int count) {
      max_retry_on_5xx_ = count;
    }
  
    const std::string& extra_request_header() {
      return extra_request_header_;
    }
    void set_extra_request_header(const std::string& header) {
      extra_request_header_ = header;
    }
  
    // Requests to |url|. |callback| will be invoked when the function returns
    // true, and the request is finished asynchronously.
    // Returns false if the previous request is not finished, or the request
    // is omitted due to retry limitation.
    bool Request(const GURL& url, const Callback& callback);
  
    // Gets internal state.
    State state() { return state_; }
  
    // net::URLFetcherDelegate implementation:
    virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
  
   private:
    // URL to send the request.
    GURL url_;
  
    // ID which is assigned to the URLFetcher.
    const int id_;
  
    // Internal state.
    enum State state_;
  
    // URLFetcher instance.
    scoped_ptr<net::URLFetcher> fetcher_;
  
    // Callback passed at Request(). It will be invoked when an asynchronous
    // fetch operation is finished.
    Callback callback_;
  
    // Counts how many times did it try to fetch the language list.
    int retry_count_;
  
    // Max number how many times to retry on the server error
    int max_retry_on_5xx_;
  
    // An extra HTTP request header
    std::string extra_request_header_;
  
    DISALLOW_COPY_AND_ASSIGN(TranslateURLFetcher);
  };
  
  #endif  // CHROME_BROWSER_TRANSLATE_TRANSLATE_URL_FETCHER_H_
  