Prioritize smaller favicons over larger ones for tabs, etc.

chrome/browser/favicon/favicon_handler.h

 // Copyright (c) 2011 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 CHROME_BROWSER_FAVICON_FAVICON_HANDLER_H_
 #define CHROME_BROWSER_FAVICON_FAVICON_HANDLER_H_
 #pragma once
 
 #include <map>
 
 #include "base/basictypes.h"
 #include "base/callback_forward.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/cancelable_request.h"
 #include "chrome/browser/favicon/favicon_service.h"
 #include "chrome/browser/favicon/favicon_tab_helper.h"
 #include "chrome/common/favicon_url.h"
 #include "chrome/common/ref_counted_util.h"
 #include "googleurl/src/gurl.h"
 #include "ui/gfx/favicon_size.h"
+#include "ui/gfx/image/image.h"
 
 class FaviconHandlerDelegate;
 class Profile;
 class RefCountedMemory;
 class SkBitmap;
 class TabContents;
 
 namespace content {
 class NavigationEntry;
 }
 
-namespace gfx {
-class Image;
-}
-
 // FaviconHandler works with FaviconTabHelper to fetch the specific type of
 // favicon.
 //
 // FetchFavicon requests the favicon from the favicon service which in turn
 // requests the favicon from the history database. At this point
 // we only know the URL of the page, and not necessarily the url of the
 // favicon. To ensure we handle reloading stale favicons as well as
 // reloading a favicon on page reload we always request the favicon from
 // history regardless of whether the NavigationEntry has a favicon.
 //
@@ skipping 119 matching lines @@
                     const GURL& image_url,
                     const FaviconTabHelper::ImageDownloadCallback& callback,
                     history::IconType icon_type);
 
     GURL url;
     GURL image_url;
     FaviconTabHelper::ImageDownloadCallback callback;
     history::IconType icon_type;
   };
 
+  struct FaviconCandidate {
+    FaviconCandidate();
+    ~FaviconCandidate();
+
+    FaviconCandidate(const GURL& url,
+                     const GURL& image_url,
+                     const gfx::Image& image,
+                     history::IconType icon_type);
+
+    GURL url;
+    GURL image_url;
+    gfx::Image image;
+    history::IconType icon_type;
+  };
+  typedef std::vector<FaviconCandidate> FaviconCandidates;
+
   // See description above class for details.
   void OnFaviconDataForInitialURL(FaviconService::Handle handle,
                                   history::FaviconData favicon);
 
   // If the favicon has expired, asks the renderer to download the favicon.
   // Otherwise asks history to update the mapping between page url and icon
   // url with a callback to OnFaviconData when done.
   void DownloadFaviconOrAskHistory(const GURL& page_url,
                                    const GURL& icon_url,
                                    history::IconType icon_type);
 
   // See description above class for details.
   void OnFaviconData(FaviconService::Handle handle,
                      history::FaviconData favicon);
 
   // Schedules a download for the specified entry. This adds the request to
   // download_requests_.
   int ScheduleDownload(const GURL& url,
                        const GURL& image_url,
                        int image_size,
                        history::IconType icon_type,
                        const FaviconTabHelper::ImageDownloadCallback& callback);
 
-  // Sets the image data for the favicon. This is invoked asynchronously after
-  // we request the TabContents to download the favicon.
+  // Once all candidates are download, this picks one and calls SetFavicon().
+  void SetFaviconFromCandidates();
+
+  // Sets the image data for the favicon.
   void SetFavicon(const GURL& url,
                   const GURL& icon_url,
                   const gfx::Image& image,
                   history::IconType icon_type);
 
   // Converts the FAVICON's image data to an SkBitmap and sets it on the
   // NavigationEntry.
   // If the TabContents has a delegate, it is notified of the new favicon
   // (INVALIDATE_FAVICON).
   void UpdateFavicon(content::NavigationEntry* entry,
                      scoped_refptr<RefCountedMemory> data);
   void UpdateFavicon(content::NavigationEntry* entry, const gfx::Image* image);
 
   // If the image is not already at its preferred size, scales the image such
-  // that either the width and/or height is 16 pixels wide. Does nothing if the
-  // image is empty.
+  // that either the width and/or height == gfx::kFaviconSize. Does nothing if
+  // the image is empty.
   gfx::Image ResizeFaviconIfNeeded(const gfx::Image& image);
 
   void FetchFaviconInternal();
 
   // Return the current candidate if any.
   FaviconURL* current_candidate() {
     return (urls_.size() > current_url_index_) ?
         &urls_[current_url_index_] : NULL;
   }
 
@@ skipping 34 matching lines @@
 
   // The FaviconData from history.
   history::FaviconData history_icon_;
 
   // The Profile associated with this handler.
   Profile* profile_;
 
   // This handler's delegate.
   FaviconHandlerDelegate* delegate_;  // weak
 
+  // Vector of favicon candidates.
+  FaviconCandidates favicon_candidates_;
+
   DISALLOW_COPY_AND_ASSIGN(FaviconHandler);
 };
 
 #endif  // CHROME_BROWSER_FAVICON_FAVICON_HANDLER_H_