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::kShelfPreferredSize.
  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     int32 page_id,
  45     const std::vector<content::FaviconURL>& candidates) OVERRIDE;
  46
  47  private:
  48   void DidDownloadFavicon(
  49       int id,
  50       int http_status_code,
  51       const GURL& image_url,
  52       const std::vector<SkBitmap>& bitmaps,
  53       const std::vector<gfx::Size>& original_bitmap_sizes);
  54
  55   void AddFavicon(const GURL& image_url, const SkBitmap& new_bitmap);
  56
  57   LauncherFaviconLoader::Delegate* delegate_;
  58
  59   content::WebContents* web_contents_;
  60
  61   typedef std::set<GURL> UrlSet;
  62   // Map of pending download urls.
  63   UrlSet pending_requests_;
  64   // Map of processed urls.
  65   UrlSet processed_requests_;
  66   // Current bitmap and source url.
  67   SkBitmap bitmap_;
  68   GURL bitmap_url_;
  69
  70   base::WeakPtrFactory<FaviconBitmapHandler> weak_ptr_factory_;
  71
  72   DISALLOW_COPY_AND_ASSIGN(FaviconBitmapHandler);
  73 };
  74
  75 void FaviconBitmapHandler::DidUpdateFaviconURL(
  76     int32 page_id,
  77     const std::vector<content::FaviconURL>& candidates) {
  78   // This function receives a complete list of faviocn urls for the page.
  79   // It may get called multiple times with the same list, and will also get
  80   // called any time an item is added or removed. As such, we track processed
  81   // and pending urls, but only until they are removed from the list.
  82   UrlSet new_pending, new_processed;
  83   // Create a map of valid favicon urls.
  84   std::set<GURL> urls;
  85   std::vector<content::FaviconURL>::const_iterator iter;
  86   for (iter = candidates.begin(); iter != candidates.end(); ++iter) {
  87     if (iter->icon_type != content::FaviconURL::FAVICON)
  88       continue;
  89     const GURL& url = iter->icon_url;
  90     if (url.is_valid())
  91       urls.insert(url);
  92     // Preserve matching pending requests amd processed requests.
  93     if (pending_requests_.find(url) != pending_requests_.end())
  94       new_pending.insert(url);
  95     if (processed_requests_.find(url) != processed_requests_.end())
  96       new_processed.insert(url);
  97   }
  98   pending_requests_ = new_pending;
  99   processed_requests_ = new_processed;
 100   // Reset bitmap_ if no longer valid (i.e. not in the list of urls).
 101   if (urls.find(bitmap_url_) == urls.end()) {
 102     bitmap_url_ = GURL();
 103     bitmap_.reset();
 104   }
 105   // Request any new urls.
 106   for (std::set<GURL>::iterator iter = urls.begin();
 107        iter != urls.end(); ++iter) {
 108     if (processed_requests_.find(*iter) != processed_requests_.end())
 109       continue;  // Skip already processed downloads.
 110     if (pending_requests_.find(*iter) != pending_requests_.end())
 111       continue;  // Skip already pending downloads.
 112     pending_requests_.insert(*iter);
 113     web_contents_->DownloadImage(
 114         *iter,
 115         true,  // is a favicon
 116         0,     // no maximum size
 117         base::Bind(&FaviconBitmapHandler::DidDownloadFavicon,
 118                    weak_ptr_factory_.GetWeakPtr()));
 119   }
 120 }
 121
 122 bool FaviconBitmapHandler::HasPendingDownloads() const {
 123   return !pending_requests_.empty();
 124 }
 125
 126 void FaviconBitmapHandler::DidDownloadFavicon(
 127     int id,
 128     int http_status_code,
 129     const GURL& image_url,
 130     const std::vector<SkBitmap>& bitmaps,
 131     const std::vector<gfx::Size>& original_bitmap_sizes) {
 132   UrlSet::iterator iter = pending_requests_.find(image_url);
 133   if (iter == pending_requests_.end()) {
 134     // Updates are received for all downloads; ignore unrequested urls.
 135     return;
 136   }
 137   pending_requests_.erase(iter);
 138
 139   // Favicon bitmaps are ordered by decreasing width.
 140   if (!bitmaps.empty())
 141     AddFavicon(image_url, bitmaps[0]);
 142 }
 143
 144 void FaviconBitmapHandler::AddFavicon(const GURL& image_url,
 145                                       const SkBitmap& new_bitmap) {
 146   processed_requests_.insert(image_url);
 147   if (new_bitmap.height() > kMaxBitmapSize ||
 148       new_bitmap.width() > kMaxBitmapSize)
 149     return;
 150   if (new_bitmap.height() < ash::kShelfPreferredSize)
 151     return;
 152   if (!bitmap_.isNull()) {
 153     // We want the smallest icon that is large enough.
 154     if (new_bitmap.height() > bitmap_.height())
 155       return;
 156   }
 157   bitmap_url_ = image_url;
 158   bitmap_ = new_bitmap;
 159   delegate_->FaviconUpdated();
 160 }
 161
 162 }  // namespace internal
 163
 164 ////////////////////////////////////////////////////////////////////////////////
 165
 166 LauncherFaviconLoader::LauncherFaviconLoader(Delegate* delegate,
 167                                              content::WebContents* web_contents)
 168     : web_contents_(web_contents) {
 169   favicon_handler_.reset(
 170       new internal::FaviconBitmapHandler(web_contents, delegate));
 171 }
 172
 173 LauncherFaviconLoader::~LauncherFaviconLoader() {
 174 }
 175
 176 SkBitmap LauncherFaviconLoader::GetFavicon() const {
 177   return favicon_handler_->bitmap();
 178 }
 179
 180 bool LauncherFaviconLoader::HasPendingDownloads() const {
 181   return favicon_handler_->HasPendingDownloads();
 182 }