chrome/browser/thumbnails/thumbnail_tab_helper.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_THUMBNAILS_THUMBNAIL_TAB_HELPER_H_
   6 #define CHROME_BROWSER_THUMBNAILS_THUMBNAIL_TAB_HELPER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "chrome/browser/thumbnails/thumbnailing_context.h"
  10 #include "content/public/browser/notification_observer.h"
  11 #include "content/public/browser/notification_registrar.h"
  12 #include "content/public/browser/web_contents_observer.h"
  13 #include "content/public/browser/web_contents_user_data.h"
  14
  15 namespace content {
  16 class RenderViewHost;
  17 class RenderWidgetHost;
  18 }
  19
  20 class ThumbnailTabHelper
  21     : public content::NotificationObserver,
  22       public content::WebContentsObserver,
  23       public content::WebContentsUserData<ThumbnailTabHelper> {
  24  public:
  25   virtual ~ThumbnailTabHelper();
  26
  27   // Enables or disables the function of taking thumbnails.
  28   // A disabled ThumbnailTabHelper generates no thumbnails although it still
  29   // continues to receive the notifications from the web contents.
  30   void set_enabled(bool enabled) { enabled_ = enabled; }
  31
  32  private:
  33   explicit ThumbnailTabHelper(content::WebContents* contents);
  34   friend class content::WebContentsUserData<ThumbnailTabHelper>;
  35
  36   // content::NotificationObserver overrides.
  37   virtual void Observe(int type,
  38                        const content::NotificationSource& source,
  39                        const content::NotificationDetails& details) OVERRIDE;
  40
  41   // content::WebContentsObserver overrides.
  42   virtual void RenderViewDeleted(
  43       content::RenderViewHost* render_view_host) OVERRIDE;
  44   virtual void DidStartLoading(
  45       content::RenderViewHost* render_view_host) OVERRIDE;
  46   virtual void NavigationStopped() OVERRIDE;
  47
  48   // Update the thumbnail of the given tab contents if necessary.
  49   void UpdateThumbnailIfNecessary(content::WebContents* web_contents);
  50
  51   // Called when a render view host was created for a WebContents.
  52   void RenderViewHostCreated(content::RenderViewHost* renderer);
  53
  54   // Indicates that the given widget has changed is visibility.
  55   void WidgetHidden(content::RenderWidgetHost* widget);
  56
  57   bool enabled_;
  58
  59   content::NotificationRegistrar registrar_;
  60
  61   bool load_interrupted_;
  62
  63   DISALLOW_COPY_AND_ASSIGN(ThumbnailTabHelper);
  64 };
  65
  66 #endif  // CHROME_BROWSER_THUMBNAILS_THUMBNAIL_TAB_HELPER_H_