Always select best favicon bitmap

components/favicon/core/favicon_handler.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_FAVICON_CORE_FAVICON_HANDLER_H_
 #define COMPONENTS_FAVICON_CORE_FAVICON_HANDLER_H_
 
 #include <stddef.h>
 
 #include <vector>
@@ skipping 112 matching lines @@
 
   // Initiates loading the favicon for the specified url.
   void FetchFavicon(const GURL& url);
 
   // Message Handler.  Must be public, because also called from
   // PrerenderContents. Collects the |image_urls| list.
   void OnUpdateFaviconURL(const GURL& page_url,
                           const std::vector<favicon::FaviconURL>& candidates);
 
   // For testing.
-  const std::vector<favicon::FaviconURL>& image_urls() const {
-    return image_urls_;
-  }
+  const std::vector<GURL> GetIconURLs() const;
 
   // Returns whether the handler is waiting for a download to complete or for
   // data from the FaviconService. Reserved for testing.
   bool HasPendingTasksForTest();
 
-  // Get the maximal icon size in pixels for a icon of type |icon_type| for the
-  // current platform.
-  static int GetMaximalIconSize(favicon_base::IconType icon_type);
+  // Get the maximal icon size in pixels for a handler of type |handler_type|.
+  static int GetMaximalIconSize(
+      FaviconDriverObserver::NotificationIconType handler_type);
 
  private:
   // Used to track a candidate for the favicon.
   struct FaviconCandidate {
-    FaviconCandidate();
-    ~FaviconCandidate();
+    // Builds a scored candidate by selecting the best bitmap sizes.
+    static FaviconCandidate FromFaviconURL(
+        const favicon::FaviconURL& favicon_url,
+        const std::vector<int>& desired_pixel_sizes);
 
-    FaviconCandidate(const GURL& image_url,
-                     const gfx::Image& image,
-                     float score,
-                     favicon_base::IconType icon_type);
+    friend bool operator==(const FaviconCandidate& lhs,
+                           const FaviconCandidate& rhs) {
+      return lhs.icon_url == rhs.icon_url && lhs.icon_type == rhs.icon_type &&
+             lhs.score == rhs.score;
+    }
 
-    GURL image_url;
+    // Compare function used for std::stable_sort to sort in descending order.
+    static bool CompareScore(const FaviconCandidate& lhs,
+                             const FaviconCandidate& rhs) {
+      return lhs.score > rhs.score;
+    }
+
+    GURL icon_url;
+    favicon_base::IconType icon_type = favicon_base::INVALID_ICON;
+    float score = 0;
+  };
+
+  struct DownloadedFavicon {
+    FaviconCandidate candidate;
     gfx::Image image;
-    float score;
-    favicon_base::IconType icon_type;
   };
 
   // Returns the bit mask of favicon_base::IconType based on the handler's type.
   static int GetIconTypesFromHandlerType(
       FaviconDriverObserver::NotificationIconType handler_type);
 
   // Called when the history request for favicon data mapped to |url_| has
   // completed and the renderer has told us the icon URLs used by |url_|
   void OnGotInitialHistoryDataAndIconURLCandidates();
 
@@ skipping 20 matching lines @@
   void OnDidDownloadFavicon(
       favicon_base::IconType icon_type,
       int id,
       int http_status_code,
       const GURL& image_url,
       const std::vector<SkBitmap>& bitmaps,
       const std::vector<gfx::Size>& original_bitmap_sizes);
 
   bool ShouldSaveFavicon();
 
-  // Updates |favicon_candidate_| and returns true if it is an exact match.
-  bool UpdateFaviconCandidate(const GURL& image_url,
-                              const gfx::Image& image,
-                              float score,
-                              favicon_base::IconType icon_type);
+  // Updates |best_favicon_| and returns true if it was considered a satisfying
+  // image (e.g. exact size match).
+  bool UpdateFaviconCandidate(const DownloadedFavicon& downloaded_favicon);
 
   // Sets the image data for the favicon.
   void SetFavicon(const GURL& icon_url,
                   const gfx::Image& image,
                   favicon_base::IconType icon_type);
 
   // Notifies |driver_| that FaviconHandler found an icon which matches the
   // |handler_type_| criteria. NotifyFaviconUpdated() can be called multiple
   // times for the same page if:
   // - a better match is found for |handler_type_| (e.g. newer bitmap data)
   // - Javascript changes the page's icon URLs.
   void NotifyFaviconUpdated(
       const std::vector<favicon_base::FaviconRawBitmapResult>&
           favicon_bitmap_results);
   void NotifyFaviconUpdated(const GURL& icon_url,
                             favicon_base::IconType icon_type,
                             const gfx::Image& image);
 
   // Return the current candidate if any.
-  favicon::FaviconURL* current_candidate() {
-    return current_candidate_index_ < image_urls_.size()
-               ? &image_urls_[current_candidate_index_]
+  const FaviconCandidate* current_candidate() const {
+    return current_candidate_index_ < candidates_.size()
+               ? &candidates_[current_candidate_index_]
                : nullptr;
   }
 
   // Returns the preferred size of the image. 0 means no preference (any size
   // will do).
   int preferred_icon_size() const {
     return download_largest_icon_ ? 0 : gfx::kFaviconSize;
   }
 
   // Used for FaviconService requests.
@@ skipping 23 matching lines @@
   base::CancelableCallback<Delegate::ImageDownloadCallback::RunType>
       download_request_;
 
   // The combination of the supported icon types.
   const int icon_types_;
 
   // Whether the largest icon should be downloaded.
   const bool download_largest_icon_;
 
   // The prioritized favicon candidates from the page back from the renderer.
-  std::vector<favicon::FaviconURL> image_urls_;
+  std::vector<FaviconCandidate> candidates_;
 
   // The icon URL and the icon type of the favicon in the most recent
   // FaviconDriver::OnFaviconAvailable() notification.
   GURL notification_icon_url_;
   favicon_base::IconType notification_icon_type_;
 
   // The FaviconService which implements favicon operations. May be null during
   // testing.
   FaviconService* service_;
 
   // This handler's delegate.
   Delegate* delegate_;
 
   // The index of the favicon URL in |image_urls_| which is currently being
   // requested from history or downloaded.
   size_t current_candidate_index_;
 
   // Best image we've seen so far.  As images are downloaded from the page they
-  // are stored here. When there is an exact match, or no more images are
-  // available the favicon service and the current page are updated (assuming
-  // the image is for a favicon).
-  FaviconCandidate best_favicon_candidate_;
+  // are stored here. When a satisfying icon is found (as defined in
+  // UpdateFaviconCandidate()), the favicon service and the delegate are
+  // notified.
+  DownloadedFavicon best_favicon_;
 
   DISALLOW_COPY_AND_ASSIGN(FaviconHandler);
 };
 
 }  // namespace favicon
 
 #endif  // COMPONENTS_FAVICON_CORE_FAVICON_HANDLER_H_