chrome/browser/ui/webui/extensions/extension_icon_source.h

   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 #ifndef CHROME_BROWSER_UI_WEBUI_EXTENSIONS_EXTENSION_ICON_SOURCE_H_
   6 #define CHROME_BROWSER_UI_WEBUI_EXTENSIONS_EXTENSION_ICON_SOURCE_H_
   7
   8 #include <map>
   9 #include <string>
  10
  11 #include "base/basictypes.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "base/task/cancelable_task_tracker.h"
  14 #include "components/favicon/core/favicon_service.h"
  15 #include "content/public/browser/url_data_source.h"
  16 #include "extensions/common/extension_icon_set.h"
  17 #include "extensions/common/extension_resource.h"
  18 #include "third_party/skia/include/core/SkBitmap.h"
  19
  20 class ExtensionIconSet;
  21 class Profile;
  22
  23 namespace extensions {
  24 class Extension;
  25
  26 // ExtensionIconSource serves extension icons through network level chrome:
  27 // requests. Icons can be retrieved for any installed extension or app.
  28 //
  29 // The format for requesting an icon is as follows:
  30 //   chrome://extension-icon/<extension_id>/<icon_size>/<match_type>?[options]
  31 //
  32 //   Parameters (<> required, [] optional):
  33 //    <extension_id>  = the id of the extension
  34 //    <icon_size>     = the size of the icon, as the integer value of the
  35 //                      corresponding Extension:Icons enum.
  36 //    <match_type>    = the fallback matching policy, as the integer value of
  37 //                      the corresponding ExtensionIconSet::MatchType enum.
  38 //    [options]       = Optional transformations to apply. Supported options:
  39 //                        grayscale=true to desaturate the image.
  40 //
  41 // Examples:
  42 //   chrome-extension://gbmgkahjioeacddebbnengilkgbkhodg/32/1?grayscale=true
  43 //     (ICON_SMALL, MATCH_BIGGER, grayscale)
  44 //   chrome-extension://gbmgkahjioeacddebbnengilkgbkhodg/128/0
  45 //     (ICON_LARGE, MATCH_EXACTLY)
  46 //
  47 // We attempt to load icons from the following sources in order:
  48 //  1) The icons as listed in the extension / app manifests.
  49 //  2) If a 16px icon was requested, the favicon for extension's launch URL.
  50 //  3) The default extension / application icon if there are still no matches.
  51 //
  52 class ExtensionIconSource : public content::URLDataSource,
  53                             public base::SupportsWeakPtr<ExtensionIconSource> {
  54  public:
  55   explicit ExtensionIconSource(Profile* profile);
  56
  57   // Gets the URL of the |extension| icon in the given |icon_size|, falling back
  58   // based on the |match| type. If |grayscale|, the URL will be for the
  59   // desaturated version of the icon. |exists|, if non-NULL, will be set to true
  60   // if the icon exists; false if it will lead to a default or not-present
  61   // image.
  62   static GURL GetIconURL(const Extension* extension,
  63                          int icon_size,
  64                          ExtensionIconSet::MatchType match,
  65                          bool grayscale,
  66                          bool* exists);
  67
  68   // A public utility function for accessing the bitmap of the image specified
  69   // by |resource_id|.
  70   static SkBitmap* LoadImageByResourceId(int resource_id);
  71
  72   // content::URLDataSource implementation.
  73   std::string GetSource() const override;
  74   std::string GetMimeType(const std::string&) const override;
  75   void StartDataRequest(
  76       const std::string& path,
  77       int render_process_id,
  78       int render_frame_id,
  79       const content::URLDataSource::GotDataCallback& callback) override;
  80
  81  private:
  82   // Encapsulates the request parameters for |request_id|.
  83   struct ExtensionIconRequest;
  84
  85   ~ExtensionIconSource() override;
  86
  87   // Returns the bitmap for the default app image.
  88   const SkBitmap* GetDefaultAppImage();
  89
  90   // Returns the bitmap for the default extension.
  91   const SkBitmap* GetDefaultExtensionImage();
  92
  93   // Performs any remaining transformations (like desaturating the |image|),
  94   // then returns the |image| to the client and clears up any temporary data
  95   // associated with the |request_id|.
  96   void FinalizeImage(const SkBitmap* image, int request_id);
  97
  98   // Loads the default image for |request_id| and returns to the client.
  99   void LoadDefaultImage(int request_id);
 100
 101   // Loads the extension's |icon| for the given |request_id| and returns the
 102   // image to the client.
 103   void LoadExtensionImage(const ExtensionResource& icon,
 104                           int request_id);
 105
 106   // Loads the favicon image for the app associated with the |request_id|. If
 107   // the image does not exist, we fall back to the default image.
 108   void LoadFaviconImage(int request_id);
 109
 110   // FaviconService callback
 111   void OnFaviconDataAvailable(
 112       int request_id,
 113       const favicon_base::FaviconRawBitmapResult& bitmap_result);
 114
 115   // ImageLoader callback
 116   void OnImageLoaded(int request_id, const gfx::Image& image);
 117
 118   // Called when the extension doesn't have an icon. We fall back to multiple
 119   // sources, using the following order:
 120   //  1) The icons as listed in the extension / app manifests.
 121   //  2) If a 16px icon and the extension has a launch URL, see if Chrome
 122   //     has a corresponding favicon.
 123   //  3) If still no matches, load the default extension / application icon.
 124   void LoadIconFailed(int request_id);
 125
 126   // Parses and savse an ExtensionIconRequest for the URL |path| for the
 127   // specified |request_id|.
 128   bool ParseData(const std::string& path,
 129                  int request_id,
 130                  const content::URLDataSource::GotDataCallback& callback);
 131
 132   // Stores the parameters associated with the |request_id|, making them
 133   // as an ExtensionIconRequest via GetData.
 134   void SetData(int request_id,
 135                const content::URLDataSource::GotDataCallback& callback,
 136                const Extension* extension,
 137                bool grayscale,
 138                int size,
 139                ExtensionIconSet::MatchType match);
 140
 141   // Returns the ExtensionIconRequest for the given |request_id|.
 142   ExtensionIconRequest* GetData(int request_id);
 143
 144   // Removes temporary data associated with |request_id|.
 145   void ClearData(int request_id);
 146
 147   Profile* profile_;
 148
 149   // Maps tracker ids to request ids.
 150   std::map<int, int> tracker_map_;
 151
 152   // Maps request_ids to ExtensionIconRequests.
 153   std::map<int, ExtensionIconRequest*> request_map_;
 154
 155   scoped_ptr<SkBitmap> default_app_data_;
 156
 157   scoped_ptr<SkBitmap> default_extension_data_;
 158
 159   base::CancelableTaskTracker cancelable_task_tracker_;
 160
 161   DISALLOW_COPY_AND_ASSIGN(ExtensionIconSource);
 162 };
 163
 164 }  // namespace extensions
 165
 166 #endif  // CHROME_BROWSER_UI_WEBUI_EXTENSIONS_EXTENSION_ICON_SOURCE_H_