chrome/browser/ui/ash/launcher/launcher_favicon_loader.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/ui/ash/launcher/launcher_favicon_loader.h"
   6
   7 #include "ash/shelf/shelf_constants.h"
   8 #include "base/logging.h"
   9 #include "base/memory/weak_ptr.h"
  10 #include "content/public/browser/render_view_host.h"
  11 #include "content/public/browser/web_contents.h"
  12 #include "content/public/browser/web_contents_observer.h"
  13 #include "third_party/skia/include/core/SkBitmap.h"
  14 #include "url/gurl.h"
  15
  16 namespace internal {
  17
  18 const int kMaxBitmapSize = 256;
  19
  20 ////////////////////////////////////////////////////////////////////////////////
  21 // FaviconBitmapHandler fetchs all bitmaps with the 'icon' (or 'shortcut icon')
  22 // link tag, storing the one that best matches ash::kShelfSize.
  23 // These icon bitmaps are not resized and are not cached beyond the lifetime
  24 // of the class. Bitmaps larger than kMaxBitmapSize are ignored.
  25
  26 class FaviconBitmapHandler : public content::WebContentsObserver {
  27  public:
  28   FaviconBitmapHandler(content::WebContents* web_contents,
  29                        LauncherFaviconLoader::Delegate* delegate)
  30       : content::WebContentsObserver(web_contents),
  31         delegate_(delegate),
  32         web_contents_(web_contents),
  33         weak_ptr_factory_(this) {
  34   }
  35
  36   virtual ~FaviconBitmapHandler() {}
  37
  38   const SkBitmap& bitmap() const { return bitmap_; }
  39
  40   bool HasPendingDownloads() const;
  41
  42   // content::WebContentObserver implementation.
  43   virtual void DidUpdateFaviconURL(
  44     const std::vector<content::FaviconURL>& candidates) OVERRIDE;
  45
  46  private:
  47   void DidDownloadFavicon(
  48       int id,
  49       int http_status_code,
  50       const GURL& image_url,
  51       const std::vector<SkBitmap>& bitmaps,
  52       const std::vector<gfx::Size>& original_bitmap_sizes);
  53
  54   void AddFavicon(const GURL& image_url, const SkBitmap& new_bitmap);
  55
  56   LauncherFaviconLoader::Delegate* delegate_;
  57
  58   content::WebContents* web_contents_;
  59
  60   typedef std::set<GURL> UrlSet;
  61   // Map of pending download urls.
  62   UrlSet pending_requests_;
  63   // Map of processed urls.
  64   UrlSet processed_requests_;
  65   // Current bitmap and source url.
  66   SkBitmap bitmap_;
  67   GURL bitmap_url_;
  68
  69   base::WeakPtrFactory<FaviconBitmapHandler> weak_ptr_factory_;
  70
  71   DISALLOW_COPY_AND_ASSIGN(FaviconBitmapHandler);
  72 };
  73
  74 void FaviconBitmapHandler::DidUpdateFaviconURL(
  75     const std::vector<content::FaviconURL>& candidates) {
  76   // This function receives a complete list of faviocn urls for the page.
  77   // It may get called multiple times with the same list, and will also get
  78   // called any time an item is added or removed. As such, we track processed
  79   // and pending urls, but only until they are removed from the list.
  80   UrlSet new_pending, new_processed;
  81   // Create a map of valid favicon urls.
  82   std::set<GURL> urls;
  83   std::vector<content::FaviconURL>::const_iterator iter;
  84   for (iter = candidates.begin(); iter != candidates.end(); ++iter) {
  85     if (iter->icon_type != content::FaviconURL::FAVICON)
  86       continue;
  87     const GURL& url = iter->icon_url;
  88     if (url.is_valid())
  89       urls.insert(url);
  90     // Preserve matching pending requests amd processed requests.
  91     if (pending_requests_.find(url) != pending_requests_.end())
  92       new_pending.insert(url);
  93     if (processed_requests_.find(url) != processed_requests_.end())
  94       new_processed.insert(url);
  95   }
  96   pending_requests_ = new_pending;
  97   processed_requests_ = new_processed;
  98   // Reset bitmap_ if no longer valid (i.e. not in the list of urls).
  99   if (urls.find(bitmap_url_) == urls.end()) {
 100     bitmap_url_ = GURL();
 101     bitmap_.reset();
 102   }
 103   // Request any new urls.
 104   for (std::set<GURL>::iterator iter = urls.begin();
 105        iter != urls.end(); ++iter) {
 106     if (processed_requests_.find(*iter) != processed_requests_.end())
 107       continue;  // Skip already processed downloads.
 108     if (pending_requests_.find(*iter) != pending_requests_.end())
 109       continue;  // Skip already pending downloads.
 110     pending_requests_.insert(*iter);
 111     web_contents_->DownloadImage(
 112         *iter,
 113         true,  // is a favicon
 114         0,     // no maximum size
 115         base::Bind(&FaviconBitmapHandler::DidDownloadFavicon,
 116                    weak_ptr_factory_.GetWeakPtr()));
 117   }
 118 }
 119
 120 bool FaviconBitmapHandler::HasPendingDownloads() const {
 121   return !pending_requests_.empty();
 122 }
 123
 124 void FaviconBitmapHandler::DidDownloadFavicon(
 125     int id,
 126     int http_status_code,
 127     const GURL& image_url,
 128     const std::vector<SkBitmap>& bitmaps,
 129     const std::vector<gfx::Size>& original_bitmap_sizes) {
 130   UrlSet::iterator iter = pending_requests_.find(image_url);
 131   if (iter == pending_requests_.end()) {
 132     // Updates are received for all downloads; ignore unrequested urls.
 133     return;
 134   }
 135   pending_requests_.erase(iter);
 136
 137   // Favicon bitmaps are ordered by decreasing width.
 138   if (!bitmaps.empty())
 139     AddFavicon(image_url, bitmaps[0]);
 140 }
 141
 142 void FaviconBitmapHandler::AddFavicon(const GURL& image_url,
 143                                       const SkBitmap& new_bitmap) {
 144   processed_requests_.insert(image_url);
 145   if (new_bitmap.height() > kMaxBitmapSize ||
 146       new_bitmap.width() > kMaxBitmapSize)
 147     return;
 148   if (new_bitmap.height() < ash::kShelfSize)
 149     return;
 150   if (!bitmap_.isNull()) {
 151     // We want the smallest icon that is large enough.
 152     if (new_bitmap.height() > bitmap_.height())
 153       return;
 154   }
 155   bitmap_url_ = image_url;
 156   bitmap_ = new_bitmap;
 157   delegate_->FaviconUpdated();
 158 }
 159
 160 }  // namespace internal
 161
 162 ////////////////////////////////////////////////////////////////////////////////
 163
 164 LauncherFaviconLoader::LauncherFaviconLoader(Delegate* delegate,
 165                                              content::WebContents* web_contents)
 166     : web_contents_(web_contents) {
 167   favicon_handler_.reset(
 168       new internal::FaviconBitmapHandler(web_contents, delegate));
 169 }
 170
 171 LauncherFaviconLoader::~LauncherFaviconLoader() {
 172 }
 173
 174 SkBitmap LauncherFaviconLoader::GetFavicon() const {
 175   return favicon_handler_->bitmap();
 176 }
 177
 178 bool LauncherFaviconLoader::HasPendingDownloads() const {
 179   return favicon_handler_->HasPendingDownloads();
 180 }