chrome/browser/manifest/manifest_icon_downloader.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 CHROME_BROWSER_MANIFEST_MANIFEST_ICON_DOWNLOADER_H_
   6 #define CHROME_BROWSER_MANIFEST_MANIFEST_ICON_DOWNLOADER_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/callback_forward.h"
  12 #include "third_party/skia/include/core/SkBitmap.h"
  13
  14 namespace content {
  15 class WebContents;
  16 }  // namespace content
  17
  18 namespace gfx {
  19 class Size;
  20 }  // namespace gfx
  21
  22 class GURL;
  23
  24 // Helper class which downloads the icon located at a specified. If the icon
  25 // file contains multiple icons then it attempts to pick the one closest in size
  26 // bigger than or equal to ideal_icon_size_in_dp, taking into account the
  27 // density of the device. If a bigger icon is chosen then, the icon is scaled
  28 // down to be equal to ideal_icon_size_in_dp. Smaller icons will be chosen down
  29 // to the value specified by |minimum_icon_size_in_dp|.
  30 class ManifestIconDownloader final {
  31  public:
  32   using IconFetchCallback = base::Callback<void(const SkBitmap&)>;
  33
  34   ManifestIconDownloader() = delete;
  35   ~ManifestIconDownloader() = delete;
  36
  37   // Returns whether the download has started.
  38   // It will return false if the current context or information do not allow to
  39   // download the image.
  40   static bool Download(content::WebContents* web_contents,
  41                        const GURL& icon_url,
  42                        int ideal_icon_size_in_dp,
  43                        int minimum_icon_size_in_dp,
  44                        const IconFetchCallback& callback);
  45
  46  private:
  47   // Callback run after the manifest icon downloaded successfully or the
  48   // download failed.
  49   static void OnIconFetched(int ideal_icon_size_in_px,
  50                             int minimum_icon_size_in_px,
  51                             const IconFetchCallback& callback,
  52                             int id,
  53                             int http_status_code,
  54                             const GURL& url,
  55                             const std::vector<SkBitmap>& bitmaps,
  56                             const std::vector<gfx::Size>& sizes);
  57
  58   static void ScaleIcon(int ideal_icon_size_in_px,
  59                         const SkBitmap& bitmap,
  60                         const IconFetchCallback& callback);
  61
  62   static int FindClosestBitmapIndex(int ideal_icon_size_in_px,
  63                                     int minimum_icon_size_in_px,
  64                                     const std::vector<SkBitmap>& bitmaps);
  65
  66   friend class ManifestIconDownloaderTest;
  67
  68   DISALLOW_COPY_AND_ASSIGN(ManifestIconDownloader);
  69 };
  70
  71 #endif  // CHROME_BROWSER_MANIFEST_MANIFEST_ICON_DOWNLOADER_H_