chrome/browser/ui/alternate_error_tab_observer.h

   1 // Copyright (c) 2012 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_UI_ALTERNATE_ERROR_TAB_OBSERVER_H_
   6 #define CHROME_BROWSER_UI_ALTERNATE_ERROR_TAB_OBSERVER_H_
   7
   8 #include "base/prefs/pref_change_registrar.h"
   9 #include "content/public/browser/notification_observer.h"
  10 #include "content/public/browser/notification_registrar.h"
  11 #include "content/public/browser/web_contents_observer.h"
  12 #include "content/public/browser/web_contents_user_data.h"
  13
  14 class Profile;
  15
  16 namespace user_prefs {
  17 class PrefRegistrySyncable;
  18 }
  19
  20 // Per-tab class to implement alternate error page functionality.
  21 class AlternateErrorPageTabObserver
  22     : public content::WebContentsObserver,
  23       public content::NotificationObserver,
  24       public content::WebContentsUserData<AlternateErrorPageTabObserver> {
  25  public:
  26   virtual ~AlternateErrorPageTabObserver();
  27
  28   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
  29
  30  private:
  31   explicit AlternateErrorPageTabObserver(content::WebContents* web_contents);
  32   friend class content::WebContentsUserData<AlternateErrorPageTabObserver>;
  33
  34   // content::WebContentsObserver overrides:
  35   virtual void RenderViewCreated(
  36       content::RenderViewHost* render_view_host) OVERRIDE;
  37
  38   // content::NotificationObserver overrides:
  39   virtual void Observe(int type,
  40                        const content::NotificationSource& source,
  41                        const content::NotificationDetails& details) OVERRIDE;
  42
  43   // Internal helpers ----------------------------------------------------------
  44
  45   // Returns the server that can provide alternate error pages.  If the returned
  46   // URL is empty, the default error page built into WebKit will be used.
  47   GURL GetAlternateErrorPageURL() const;
  48
  49   void OnAlternateErrorPagesEnabledChanged();
  50
  51   // Send the alternate error page URL to the renderer.
  52   void UpdateAlternateErrorPageURL(content::RenderViewHost* rvh);
  53
  54   Profile* profile_;
  55   content::NotificationRegistrar registrar_;
  56   PrefChangeRegistrar pref_change_registrar_;
  57
  58   DISALLOW_COPY_AND_ASSIGN(AlternateErrorPageTabObserver);
  59 };
  60
  61 #endif  // CHROME_BROWSER_UI_ALTERNATE_ERROR_TAB_OBSERVER_H_