Move TranslateHelper to the translate component.

chrome/renderer/translate/translate_helper.h

-// Copyright (c) 2011 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_RENDERER_TRANSLATE_TRANSLATE_HELPER_H_
-#define CHROME_RENDERER_TRANSLATE_TRANSLATE_HELPER_H_
-
-#include <string>
-
-#include "base/gtest_prod_util.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
-#include "base/strings/string16.h"
-#include "base/time/time.h"
-#include "components/translate/content/renderer/renderer_cld_data_provider.h"
-#include "components/translate/core/common/translate_errors.h"
-#include "content/public/renderer/render_view_observer.h"
-#include "url/gurl.h"
-
-namespace blink {
-class WebDocument;
-class WebFrame;
-}
-
-namespace content {
-class RendererCldDataProvider;
-}
-
-// This class deals with page translation.
-// There is one TranslateHelper per RenderView.
-//
-// This class provides metrics that allow tracking the user experience impact
-// of non-static CldDataProvider implementations. For background on the data
-// providers, please refer to the following documentation:
-// http://www.chromium.org/developers/how-tos/compact-language-detector-cld-data-source-configuration
-//
-// Available metrics (from the LanguageDetectionTiming enum):
-// 1. ON_TIME
-//    Recorded if PageCaptured(...) is invoked after CLD is available. This is
-//    the ideal case, indicating that CLD is available before it is needed.
-// 2. DEFERRED
-//    Recorded if PageCaptured(...) is invoked before CLD is available.
-//    Sub-optimal case indicating that CLD wasn't available when it was needed,
-//    so the request for detection has been deferred until CLD is available or
-//    until the user navigates to a different page.
-// 3. RESUMED
-//    Recorded if CLD becomes available after a language detection request was
-//    deferred, but before the user navigated to a different page. Language
-//    detection is ultimately completed, it just didn't happen on time.
-//
-// Note that there is NOT a metric that records the number of times that
-// language detection had to be aborted because CLD never became available in
-// time. This is because there is no reasonable way to cover all the cases
-// under which this could occur, particularly the destruction of the renderer
-// for which this object was created. However, this value can be synthetically
-// derived, using the logic below.
-//
-// Every page load that triggers language detection will result in the
-// recording of exactly one of the first two events: ON_TIME or DEFERRED. If
-// CLD is available in time to satisfy the request, the third event (RESUMED)
-// will be recorded; thus, the number of times when language detection
-// ultimately fails because CLD isn't ever available is implied as the number of
-// times that detection is deferred minus the number of times that language
-// detection is late:
-//
-//   count(FAILED) ~= count(DEFERRED) - count(RESUMED)
-//
-// Note that this is not 100% accurate: some renderer process are so short-lived
-// that language detection wouldn't have been relevant anyway, and so a failure
-// to detect the language in a timely manner might be completely innocuous. The
-// overall problem with language detection is that it isn't possible to know
-// whether it was required or not until after it has been performed!
-//
-// We use histograms for recording these metrics. On Android, the renderer can
-// be killed without the chance to clean up or transmit these histograms,
-// leading to dropped metrics. To work around this, this method forces an IPC
-// message to be sent to the browser process immediately.
-class TranslateHelper : public content::RenderViewObserver {
- public:
-  explicit TranslateHelper(content::RenderView* render_view);
-  virtual ~TranslateHelper();
-
-  // Informs us that the page's text has been extracted.
-  void PageCaptured(const base::string16& contents);
-
-  // Lets the translation system know that we are preparing to navigate to
-  // the specified URL. If there is anything that can or should be done before
-  // this URL loads, this is the time to prepare for it.
-  void PrepareForUrl(const GURL& url);
-
- protected:
-  // The following methods are protected so they can be overridden in
-  // unit-tests.
-  void OnTranslatePage(int page_seq_no,
-                       const std::string& translate_script,
-                       const std::string& source_lang,
-                       const std::string& target_lang);
-  void OnRevertTranslation(int page_seq_no);
-
-  // Returns true if the translate library is available, meaning the JavaScript
-  // has already been injected in that page.
-  virtual bool IsTranslateLibAvailable();
-
-  // Returns true if the translate library has been initialized successfully.
-  virtual bool IsTranslateLibReady();
-
-  // Returns true if the translation script has finished translating the page.
-  virtual bool HasTranslationFinished();
-
-  // Returns true if the translation script has reported an error performing the
-  // translation.
-  virtual bool HasTranslationFailed();
-
-  // Starts the translation by calling the translate library.  This method
-  // should only be called when the translate script has been injected in the
-  // page.  Returns false if the call failed immediately.
-  virtual bool StartTranslation();
-
-  // Asks the Translate element in the page what the language of the page is.
-  // Can only be called if a translation has happened and was successful.
-  // Returns the language code on success, an empty string on failure.
-  virtual std::string GetOriginalPageLanguage();
-
-  // Adjusts a delay time for a posted task. This is used in tests to do tasks
-  // immediately by returning 0.
-  virtual base::TimeDelta AdjustDelay(int delayInMs);
-
-  // Executes the JavaScript code in |script| in the main frame of RenderView.
-  virtual void ExecuteScript(const std::string& script);
-
-  // Executes the JavaScript code in |script| in the main frame of RenderView,
-  // and returns the boolean returned by the script evaluation if the script was
-  // run successfully. Otherwise, returns |fallback| value.
-  virtual bool ExecuteScriptAndGetBoolResult(const std::string& script,
-                                             bool fallback);
-
-  // Executes the JavaScript code in |script| in the main frame of RenderView,
-  // and returns the string returned by the script evaluation if the script was
-  // run successfully. Otherwise, returns empty string.
-  virtual std::string ExecuteScriptAndGetStringResult(
-      const std::string& script);
-
-  // Executes the JavaScript code in |script| in the main frame of RenderView.
-  // and returns the number returned by the script evaluation if the script was
-  // run successfully. Otherwise, returns 0.0.
-  virtual double ExecuteScriptAndGetDoubleResult(const std::string& script);
-
- private:
-  FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest, AdoptHtmlLang);
-  FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest,
-                           CLDAgreeWithLanguageCodeHavingCountryCode);
-  FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest,
-                           CLDDisagreeWithWrongLanguageCode);
-  FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest,
-                           InvalidLanguageMetaTagProviding);
-  FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest, LanguageCodeTypoCorrection);
-  FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest, LanguageCodeSynonyms);
-  FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest, ResetInvalidLanguageCode);
-  FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest, SimilarLanguageCode);
-  FRIEND_TEST_ALL_PREFIXES(TranslateHelperTest, WellKnownWrongConfiguration);
-
-  enum LanguageDetectionTiming {
-    ON_TIME,   // Language detection was performed as soon as it was requested
-    DEFERRED,  // Language detection couldn't be performed when it was requested
-    RESUMED,   // A deferred language detection attempt was completed later
-    LANGUAGE_DETECTION_TIMING_MAX_VALUE  // The bounding value for this enum
-  };
-
-  // Converts language code to the one used in server supporting list.
-  static void ConvertLanguageCodeSynonym(std::string* code);
-
-  // Returns whether the page associated with |document| is a candidate for
-  // translation.  Some pages can explictly specify (via a meta-tag) that they
-  // should not be translated.
-  static bool IsTranslationAllowed(blink::WebDocument* document);
-
-  // RenderViewObserver implementation.
-  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
-
-  // Informs us that the page's text has been extracted.
-  void PageCapturedImpl(int page_seq_no, const base::string16& contents);
-
-  // Cancels any translation that is currently being performed.  This does not
-  // revert existing translations.
-  void CancelPendingTranslation();
-
-  // Checks if the current running page translation is finished or errored and
-  // notifies the browser accordingly.  If the translation has not terminated,
-  // posts a task to check again later.
-  void CheckTranslateStatus(int page_seq_no);
-
-  // Called by TranslatePage to do the actual translation.  |count| is used to
-  // limit the number of retries.
-  void TranslatePageImpl(int page_seq_no, int count);
-
-  // Sends a message to the browser to notify it that the translation failed
-  // with |error|.
-  void NotifyBrowserTranslationFailed(translate::TranslateErrors::Type error);
-
-  // Convenience method to access the main frame.  Can return NULL, typically
-  // if the page is being closed.
-  blink::WebFrame* GetMainFrame();
-
-  // Do not ask for CLD data any more.
-  void CancelCldDataPolling();
-
-  // Invoked when PageCaptured is called prior to obtaining CLD data. This
-  // method stores the page ID into deferred_page_id_ and COPIES the contents
-  // of the page, then sets deferred_page_capture_ to true. When CLD data is
-  // eventually received (in OnCldDataAvailable), any deferred request will be
-  // "resurrected" and allowed to proceed automatically, assuming that the
-  // page ID has not changed.
-  void DeferPageCaptured(const int page_id, const base::string16& contents);
-
-  // Start polling for CLD data.
-  // Polling will automatically halt as soon as the renderer obtains a
-  // reference to the data file.
-  void SendCldDataRequest(const int delay_millis, const int next_delay_millis);
-
-  // Callback triggered when CLD data becomes available.
-  void OnCldDataAvailable();
-
-  // Record the timing of language detection, immediately sending an IPC-based
-  // histogram delta update to the browser process in case the hosting renderer
-  // process terminates before the metrics would otherwise be transferred.
-  void RecordLanguageDetectionTiming(LanguageDetectionTiming timing);
-
-  // An ever-increasing sequence number of the current page, used to match up
-  // translation requests with responses.
-  int page_seq_no_;
-
-  // The states associated with the current translation.
-  bool translation_pending_;
-  std::string source_lang_;
-  std::string target_lang_;
-
-  // Time when a page langauge is determined. This is used to know a duration
-  // time from showing infobar to requesting translation.
-  base::TimeTicks language_determined_time_;
-
-  // Provides CLD data for this process.
-  scoped_ptr<translate::RendererCldDataProvider> cld_data_provider_;
-
-  // Whether or not polling for CLD2 data has started.
-  bool cld_data_polling_started_;
-
-  // Whether or not CancelCldDataPolling has been called.
-  bool cld_data_polling_canceled_;
-
-  // Whether or not a PageCaptured event arrived prior to CLD data becoming
-  // available. If true, deferred_contents_ contains the most recent contents.
-  bool deferred_page_capture_;
-
-  // The ID of the page most recently reported to PageCaptured if
-  // deferred_page_capture_ is true.
-  int deferred_page_seq_no_;
-
-  // The contents of the page most recently reported to PageCaptured if
-  // deferred_page_capture_ is true.
-  base::string16 deferred_contents_;
-
-  // Method factory used to make calls to TranslatePageImpl.
-  base::WeakPtrFactory<TranslateHelper> weak_method_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(TranslateHelper);
-};
-
-#endif  // CHROME_RENDERER_TRANSLATE_TRANSLATE_HELPER_H_