chrome/browser/search/thumbnail_source.cc

   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 #include "chrome/browser/search/thumbnail_source.h"
   6
   7 #include "base/callback.h"
   8 #include "base/memory/ref_counted_memory.h"
   9 #include "base/message_loop/message_loop.h"
  10 #include "chrome/browser/profiles/profile.h"
  11 #include "chrome/browser/search/instant_io_context.h"
  12 #include "chrome/browser/search/suggestions/image_fetcher_impl.h"
  13 #include "chrome/browser/thumbnails/thumbnail_service.h"
  14 #include "chrome/browser/thumbnails/thumbnail_service_factory.h"
  15 #include "chrome/common/url_constants.h"
  16 #include "components/suggestions/image_encoder.h"
  17 #include "net/url_request/url_request.h"
  18 #include "ui/gfx/image/image_skia.h"
  19
  20 // The delimiter between the first url and the fallback url passed to
  21 // StartDataRequest.
  22 const char kUrlDelimiter[] = "?fb=";
  23
  24 // Set ThumbnailService now as Profile isn't thread safe.
  25 ThumbnailSource::ThumbnailSource(Profile* profile, bool capture_thumbnails)
  26     : thumbnail_service_(ThumbnailServiceFactory::GetForProfile(profile)),
  27       capture_thumbnails_(capture_thumbnails),
  28       weak_ptr_factory_(this) {
  29   image_fetcher_.reset(
  30       new suggestions::ImageFetcherImpl(profile->GetRequestContext()));
  31 }
  32
  33 ThumbnailSource::~ThumbnailSource() {
  34 }
  35
  36 std::string ThumbnailSource::GetSource() const {
  37   return capture_thumbnails_ ?
  38       chrome::kChromeUIThumbnailHost2 : chrome::kChromeUIThumbnailHost;
  39 }
  40
  41 void ThumbnailSource::StartDataRequest(
  42     const std::string& path,
  43     int render_process_id,
  44     int render_frame_id,
  45     const content::URLDataSource::GotDataCallback& callback) {
  46   GURL page_url;
  47   GURL fallback_thumbnail_url;
  48   ExtractPageAndThumbnailUrls(path, &page_url, &fallback_thumbnail_url);
  49
  50   scoped_refptr<base::RefCountedMemory> data;
  51   if (page_url.is_valid() &&
  52       thumbnail_service_->GetPageThumbnail(page_url, capture_thumbnails_,
  53                                            &data)) {
  54     // If a local thumbnail is available for the page's URL, provide it.
  55     callback.Run(data.get());
  56   } else if (fallback_thumbnail_url.is_valid()) {
  57     // Otherwise, if a fallback thumbnail URL was provided, fetch it and
  58     // eventually return it.
  59     image_fetcher_->StartOrQueueNetworkRequest(
  60         page_url, fallback_thumbnail_url,
  61         base::Bind(&ThumbnailSource::SendFetchedUrlImage,
  62                    weak_ptr_factory_.GetWeakPtr(), callback));
  63   } else {
  64     callback.Run(default_thumbnail_.get());
  65   }
  66   if (page_url.is_valid() && capture_thumbnails_)
  67     thumbnail_service_->AddForcedURL(page_url);
  68 }
  69
  70 std::string ThumbnailSource::GetMimeType(const std::string&) const {
  71   // We need to explicitly return a mime type, otherwise if the user tries to
  72   // drag the image they get no extension.
  73   return "image/png";
  74 }
  75
  76 base::MessageLoop* ThumbnailSource::MessageLoopForRequestPath(
  77     const std::string& path) const {
  78   // TopSites can be accessed from the IO thread. Otherwise, the URLs should be
  79   // accessed on the UI thread.
  80   return thumbnail_service_.get()
  81              ? NULL
  82              : content::URLDataSource::MessageLoopForRequestPath(path);
  83 }
  84
  85 bool ThumbnailSource::ShouldServiceRequest(
  86     const net::URLRequest* request) const {
  87   if (request->url().SchemeIs(chrome::kChromeSearchScheme))
  88     return InstantIOContext::ShouldServiceRequest(request);
  89   return URLDataSource::ShouldServiceRequest(request);
  90 }
  91
  92 void ThumbnailSource::ExtractPageAndThumbnailUrls(
  93     const std::string& path,
  94     GURL* page_url,
  95     GURL* fallback_thumbnail_url) {
  96   std::string page_url_str(path);
  97   std::string fallback_thumbnail_url_str;
  98
  99   size_t pos = path.find(kUrlDelimiter);
 100   if (pos != std::string::npos) {
 101     page_url_str = path.substr(0, pos);
 102     fallback_thumbnail_url_str = path.substr(pos + strlen(kUrlDelimiter));
 103   }
 104
 105   *page_url = GURL(page_url_str);
 106   *fallback_thumbnail_url = GURL(fallback_thumbnail_url_str);
 107 }
 108
 109 void ThumbnailSource::SendFetchedUrlImage(
 110     const content::URLDataSource::GotDataCallback& callback,
 111     const GURL& url,
 112     const SkBitmap* bitmap) {
 113   if (!bitmap) {
 114     callback.Run(default_thumbnail_.get());
 115     return;
 116   }
 117
 118   scoped_refptr<base::RefCountedBytes> encoded_data(
 119       new base::RefCountedBytes());
 120   if (!suggestions::EncodeSkBitmapToJPEG(*bitmap, &encoded_data->data())) {
 121     callback.Run(default_thumbnail_.get());
 122     return;
 123   }
 124
 125   callback.Run(encoded_data.get());
 126 }