components/favicon/core/large_icon_service.h

   1 // Copyright 2015 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 #ifndef COMPONENTS_FAVICON_CORE_LARGE_ICON_SERVICE_H_
   6 #define COMPONENTS_FAVICON_CORE_LARGE_ICON_SERVICE_H_
   7
   8 #include <vector>
   9
  10 #include "base/task/cancelable_task_tracker.h"
  11 #include "components/favicon_base/favicon_callback.h"
  12 #include "components/keyed_service/core/keyed_service.h"
  13
  14 class GURL;
  15
  16 namespace base {
  17 class TaskRunner;
  18 }
  19
  20 namespace favicon {
  21
  22 class FaviconService;
  23
  24 // The large icon service provides methods to access large icons. It relies on
  25 // the favicon service.
  26 class LargeIconService : public KeyedService {
  27  public:
  28   explicit LargeIconService(FaviconService* favicon_service);
  29
  30   ~LargeIconService() override;
  31
  32   // Requests the best large icon for the page at |page_url|.
  33   // Case 1. An icon exists whose size is >= |min_source_size_in_pixel|:
  34   // - If |desired_size_in_pixel| == 0: returns icon as is.
  35   // - Else: returns the icon resized to |desired_size_in_pixel|.
  36   // Case 2. An icon exists whose size is < |min_source_size_in_pixel|:
  37   // - Extracts dominant color of smaller image, returns a fallback icon style
  38   //   that has a matching background.
  39   // Case 3. No icon exists.
  40   // - Returns the default fallback icon style.
  41   // For cases 2 and 3, this function returns the style of the fallback icon
  42   // instead of rendering an icon so clients can render the icon themselves.
  43   base::CancelableTaskTracker::TaskId GetLargeIconOrFallbackStyle(
  44     const GURL& page_url,
  45     int min_source_size_in_pixel,
  46     int desired_size_in_pixel,
  47     const favicon_base::LargeIconCallback& callback,
  48     base::CancelableTaskTracker* tracker);
  49
  50   // Returns TaskRunner used to execute background task.
  51   virtual scoped_refptr<base::TaskRunner> GetBackgroundTaskRunner();
  52
  53  private:
  54   // For testing.
  55   friend class TestLargeIconService;
  56
  57   FaviconService* favicon_service_;
  58
  59   // A pre-populated list of icon types to consider when looking for large
  60   // icons. This is an optimization over populating an icon type vector on each
  61   // request.
  62   std::vector<int> large_icon_types_;
  63
  64   DISALLOW_COPY_AND_ASSIGN(LargeIconService);
  65 };
  66
  67 }  // namespace favicon
  68
  69 #endif  // COMPONENTS_FAVICON_CORE_LARGE_ICON_SERVICE_H_