chrome/browser/tab_contents/language_state.h

   1 // Copyright (c) 2011 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 CHROME_BROWSER_TAB_CONTENTS_LANGUAGE_STATE_H_
   6 #define CHROME_BROWSER_TAB_CONTENTS_LANGUAGE_STATE_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11
  12 class LanguageStateObserver;
  13
  14 namespace content {
  15 struct LoadCommittedDetails;
  16 class NavigationController;
  17 class WebContents;
  18 }
  19
  20 // This class holds the language state of the current page.
  21 // There is one LanguageState instance per WebContents.
  22 // It is used to determine when navigating to a new page whether it should
  23 // automatically be translated.
  24 // This auto-translate behavior is the expected behavior when:
  25 // - user is on page in language A that they had translated to language B.
  26 // - user clicks a link in that page that takes them to a page also in language
  27 //   A.
  28
  29 class LanguageState {
  30  public:
  31   explicit LanguageState(content::NavigationController* nav_controller);
  32   ~LanguageState();
  33
  34   // Should be called when the page did a new navigation (whether it is a main
  35   // frame or sub-frame navigation).
  36   void DidNavigate(const content::LoadCommittedDetails& details);
  37
  38   // Should be called when the language of the page has been determined.
  39   // |page_needs_translation| when false indicates that the browser should not
  40   // offer to translate the page.
  41   void LanguageDetermined(const std::string& page_language,
  42                           bool page_needs_translation);
  43
  44   // Returns the language the current page should be translated to, based on the
  45   // previous page languages and the transition.  This should be called after
  46   // the language page has been determined.
  47   // Returns an empty string if the page should not be auto-translated.
  48   std::string AutoTranslateTo() const;
  49
  50   // Returns true if the user is navigating through translated links.
  51   bool InTranslateNavigation() const;
  52
  53   // Returns true if the current page in the associated tab has been translated.
  54   bool IsPageTranslated() const { return original_lang_ != current_lang_; }
  55
  56   const std::string& original_language() const { return original_lang_; }
  57
  58   void SetCurrentLanguage(const std::string& language);
  59   const std::string& current_language() const { return current_lang_; }
  60
  61   bool page_needs_translation() const { return page_needs_translation_; }
  62
  63   // Whether the page is currently in the process of being translated.
  64   bool translation_pending() const { return translation_pending_; }
  65   void set_translation_pending(bool value) { translation_pending_ = value; }
  66
  67   // Whether the user has already declined to translate the page.
  68   bool translation_declined() const { return translation_declined_; }
  69   void set_translation_declined(bool value) { translation_declined_ = value; }
  70
  71   // Whether the current page was navigated through an in-page (fragment)
  72   // navigation.
  73   bool in_page_navigation() const { return in_page_navigation_; }
  74
  75   // Whether the translate is enabled. This value is supposed to be used for the
  76   // Translate icon on the Omnibox.
  77   bool translate_enabled() const { return translate_enabled_; }
  78   void SetTranslateEnabled(bool value);
  79
  80   // Whether the current page's language is different from the previous
  81   // language.
  82   bool HasLanguageChanged() const;
  83
  84   void set_observer(LanguageStateObserver* observer) { observer_ = observer; }
  85
  86  private:
  87   void SetIsPageTranslated(bool value);
  88
  89   // Whether the page is translated or not.
  90   bool is_page_translated_;
  91
  92   // The languages this page is in. Note that current_lang_ is different from
  93   // original_lang_ when the page has been translated.
  94   // Note that these might be empty if the page language has not been determined
  95   // yet.
  96   std::string original_lang_;
  97   std::string current_lang_;
  98
  99   // Same as above but for the previous page.
 100   std::string prev_original_lang_;
 101   std::string prev_current_lang_;
 102
 103   // The navigation controller of the tab we are associated with.
 104   content::NavigationController* navigation_controller_;
 105
 106   // Whether it is OK to offer to translate the page.  Some pages explictly
 107   // specify that they should not be translated by the browser (this is the case
 108   // for GMail for example, which provides its own translation features).
 109   bool page_needs_translation_;
 110
 111   // Whether a translation is currently pending (WebContents waiting for the
 112   // PAGE_TRANSLATED notification).  This is needed to avoid sending duplicate
 113   // translate requests to a page.  TranslateManager initiates translations
 114   // when it received the LANGUAGE_DETERMINED notification.  This is sent by
 115   // the renderer with the page contents, every time the load stops for the
 116   // main frame, so we may get several.
 117   // TODO(jcampan): make the renderer send the language just once per navigation
 118   //                then we can get rid of that state.
 119   bool translation_pending_;
 120
 121   // Whether the user has declined to translate the page (by closing the infobar
 122   // for example).  This is necessary as a new infobar could be shown if a new
 123   // load happens in the page after the user closed the infobar.
 124   bool translation_declined_;
 125
 126   // Whether the current navigation is a fragment navigation (in page).
 127   bool in_page_navigation_;
 128
 129   // Whether the Translate is enabled.
 130   bool translate_enabled_;
 131
 132   LanguageStateObserver* observer_;
 133
 134   DISALLOW_COPY_AND_ASSIGN(LanguageState);
 135 };
 136
 137 #endif  // CHROME_BROWSER_TAB_CONTENTS_LANGUAGE_STATE_H_