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      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 // FaviconRawBitmapHandler fetchs all bitmaps with the 'icon' (or 'shortcut
     22 // icon')
     23 // link tag, storing the one that best matches ash::kShelfSize.
     24 // These icon bitmaps are not resized and are not cached beyond the lifetime
     25 // of the class. Bitmaps larger than kMaxBitmapSize are ignored.
     26 
     27 class FaviconRawBitmapHandler : public content::WebContentsObserver {
     28  public:
     29   FaviconRawBitmapHandler(content::WebContents* web_contents,
     30                           LauncherFaviconLoader::Delegate* delegate)
     31       : content::WebContentsObserver(web_contents),
     32         delegate_(delegate),
     33         web_contents_(web_contents),
     34         weak_ptr_factory_(this) {}
     35 
     36   virtual ~FaviconRawBitmapHandler() {}
     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<FaviconRawBitmapHandler> weak_ptr_factory_;
     70 
     71   DISALLOW_COPY_AND_ASSIGN(FaviconRawBitmapHandler);
     72 };
     73 
     74 void FaviconRawBitmapHandler::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(&FaviconRawBitmapHandler::DidDownloadFavicon,
    116                    weak_ptr_factory_.GetWeakPtr()));
    117   }
    118 }
    119 
    120 bool FaviconRawBitmapHandler::HasPendingDownloads() const {
    121   return !pending_requests_.empty();
    122 }
    123 
    124 void FaviconRawBitmapHandler::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 FaviconRawBitmapHandler::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::FaviconRawBitmapHandler(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 }
    181