chrome/browser/ui/webui/ntp/thumbnail_source.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_WEBUI_NTP_THUMBNAIL_SOURCE_H_
   6 #define CHROME_BROWSER_UI_WEBUI_NTP_THUMBNAIL_SOURCE_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "content/public/browser/url_data_source.h"
  13
  14 class Profile;
  15
  16 namespace base {
  17 class RefCountedMemory;
  18 }
  19
  20 namespace thumbnails {
  21 class ThumbnailService;
  22 }
  23
  24 // ThumbnailSource is the gateway between network-level chrome: requests for
  25 // thumbnails and the history/top-sites backend that serves these.
  26 class ThumbnailSource : public content::URLDataSource {
  27  public:
  28   ThumbnailSource(Profile* profile, bool capture_thumbnails);
  29
  30   // content::URLDataSource implementation.
  31   virtual std::string GetSource() const OVERRIDE;
  32   virtual void StartDataRequest(
  33       const std::string& path,
  34       int render_process_id,
  35       int render_frame_id,
  36       const content::URLDataSource::GotDataCallback& callback) OVERRIDE;
  37   virtual std::string GetMimeType(const std::string& path) const OVERRIDE;
  38   virtual base::MessageLoop* MessageLoopForRequestPath(
  39       const std::string& path) const OVERRIDE;
  40   virtual bool ShouldServiceRequest(
  41       const net::URLRequest* request) const OVERRIDE;
  42
  43  private:
  44   virtual ~ThumbnailSource();
  45
  46   // Raw PNG representation of the thumbnail to show when the thumbnail
  47   // database doesn't have a thumbnail for a webpage.
  48   scoped_refptr<base::RefCountedMemory> default_thumbnail_;
  49
  50   // ThumbnailService.
  51   scoped_refptr<thumbnails::ThumbnailService> thumbnail_service_;
  52
  53   // Only used when servicing requests on the UI thread.
  54   Profile* const profile_;
  55
  56   // Indicate that, when a URL for which we don't have a thumbnail is requested
  57   // from this source, then Chrome should capture a thumbnail next time it
  58   // navigates to this URL. This is useful when the thumbnail URLs are generated
  59   // by an external service rather than TopSites, so Chrome can learn about the
  60   // URLs for which it should get thumbnails. Sources that capture thumbnails
  61   // are also be more lenient when matching thumbnail URLs by checking for
  62   // existing thumbnails in the database that contain a URL matching the prefix
  63   // of the requested URL.
  64   const bool capture_thumbnails_;
  65
  66   DISALLOW_COPY_AND_ASSIGN(ThumbnailSource);
  67 };
  68
  69 #endif  // CHROME_BROWSER_UI_WEBUI_NTP_THUMBNAIL_SOURCE_H_