chrome/browser/search/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_SEARCH_THUMBNAIL_SOURCE_H_
   6 #define CHROME_BROWSER_SEARCH_THUMBNAIL_SOURCE_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "content/public/browser/url_data_source.h"
  14 #include "url/gurl.h"
  15
  16 class Profile;
  17 class SkBitmap;
  18
  19 namespace base {
  20 class RefCountedMemory;
  21 }
  22
  23 namespace thumbnails {
  24 class ThumbnailService;
  25 }
  26
  27 namespace suggestions {
  28 class ImageFetcher;
  29 }
  30
  31 // ThumbnailSource is the gateway between network-level chrome: requests for
  32 // thumbnails and the history/top-sites backend that serves these.
  33 class ThumbnailSource : public content::URLDataSource {
  34  public:
  35   ThumbnailSource(Profile* profile, bool capture_thumbnails);
  36   ~ThumbnailSource() override;
  37
  38   // content::URLDataSource implementation.
  39   std::string GetSource() const override;
  40   void StartDataRequest(
  41       const std::string& path,
  42       int render_process_id,
  43       int render_frame_id,
  44       const content::URLDataSource::GotDataCallback& callback) override;
  45   std::string GetMimeType(const std::string& path) const override;
  46   base::MessageLoop* MessageLoopForRequestPath(
  47       const std::string& path) const override;
  48   bool ShouldServiceRequest(const net::URLRequest* request) const override;
  49
  50   // Extracts the |page_url| (e.g. cnn.com) and the |fallback_thumbnail_url|
  51   // fetchable from the server, if present, from the |path|. Visible for
  52   // testing.
  53   void ExtractPageAndThumbnailUrls(const std::string& path,
  54                                    GURL* page_url,
  55                                    GURL* fallback_thumbnail_url);
  56
  57  private:
  58   // Returns a JPEG-encoded |bitmap| to the |callback| if valid, or the default
  59   // thumbnail.
  60   void SendFetchedUrlImage(
  61       const content::URLDataSource::GotDataCallback& callback,
  62       const GURL& url,
  63       const SkBitmap* bitmap);
  64
  65   // Raw PNG representation of the thumbnail to show when the thumbnail
  66   // database doesn't have a thumbnail for a webpage.
  67   scoped_refptr<base::RefCountedMemory> default_thumbnail_;
  68
  69   // ThumbnailService.
  70   scoped_refptr<thumbnails::ThumbnailService> thumbnail_service_;
  71
  72   // ImageFetcher.
  73   scoped_ptr<suggestions::ImageFetcher> image_fetcher_;
  74
  75   // Indicate that, when a URL for which we don't have a thumbnail is requested
  76   // from this source, then Chrome should capture a thumbnail next time it
  77   // navigates to this URL. This is useful when the thumbnail URLs are generated
  78   // by an external service rather than TopSites, so Chrome can learn about the
  79   // URLs for which it should get thumbnails. Sources that capture thumbnails
  80   // are also be more lenient when matching thumbnail URLs by checking for
  81   // existing thumbnails in the database that contain a URL matching the prefix
  82   // of the requested URL.
  83   const bool capture_thumbnails_;
  84
  85   base::WeakPtrFactory<ThumbnailSource> weak_ptr_factory_;
  86
  87   DISALLOW_COPY_AND_ASSIGN(ThumbnailSource);
  88 };
  89
  90 #endif  // CHROME_BROWSER_SEARCH_THUMBNAIL_SOURCE_H_