chrome_frame/simple_resource_loader.h

   1 // Copyright (c) 2011 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 // This class implements a simplified and much stripped down version of
   6 // Chrome's app/resource_bundle machinery. It notably avoids unwanted
   7 // dependencies on things like Skia.
   8 //
   9
  10 #ifndef CHROME_FRAME_SIMPLE_RESOURCE_LOADER_H_
  11 #define CHROME_FRAME_SIMPLE_RESOURCE_LOADER_H_
  12
  13 #include <windows.h>
  14 #include <string>
  15 #include <vector>
  16
  17 #include "base/file_path.h"
  18 #include "base/gtest_prod_util.h"
  19 #include "base/memory/singleton.h"
  20
  21 namespace ui {
  22 class DataPack;
  23 }  // namespace ui
  24
  25 class SimpleResourceLoader {
  26  public:
  27
  28   static SimpleResourceLoader* GetInstance();
  29
  30   // Returns the language tag for the active language.
  31   static std::wstring GetLanguage();
  32
  33   // Helper method to return the string resource identified by message_id
  34   // from the currently loaded locale dll.
  35   static std::wstring Get(int message_id);
  36
  37   // Retrieves the HINSTANCE of the loaded module handle. May be NULL if a
  38   // resource DLL could not be loaded.
  39   HMODULE GetResourceModuleHandle();
  40
  41   // Retrieves the preferred languages for the current thread, adding them to
  42   // |language_tags|.
  43   static void GetPreferredLanguages(std::vector<std::wstring>* language_tags);
  44
  45   // Populates |locales_path| with the path to the "Locales" directory.
  46   static void DetermineLocalesDirectory(FilePath* locales_path);
  47
  48   // Returns false if |language_tag| is malformed.
  49   static bool IsValidLanguageTag(const std::wstring& language_tag);
  50
  51  private:
  52   SimpleResourceLoader();
  53   ~SimpleResourceLoader();
  54
  55   // Finds the most-preferred resource dll and language pack for the laguages
  56   // in |language_tags|
  57   // in |locales_path|.
  58   //
  59   // Returns true on success with a handle to the DLL that was loaded in
  60   // |dll_handle|, the data pack in |data_pack| and the locale language in
  61   // the |language| parameter.
  62   static bool LoadLocalePack(const std::vector<std::wstring>& language_tags,
  63                              const FilePath& locales_path,
  64                              HMODULE* dll_handle,
  65                              ui::DataPack** data_pack,
  66                              std::wstring* language);
  67
  68   // Returns the string resource identified by message_id from the currently
  69   // loaded locale dll.
  70   std::wstring GetLocalizedResource(int message_id);
  71
  72   friend struct DefaultSingletonTraits<SimpleResourceLoader>;
  73
  74   FRIEND_TEST_ALL_PREFIXES(SimpleResourceLoaderTest, LoadLocaleDll);
  75
  76   std::wstring language_;
  77   ui::DataPack* data_pack_;
  78
  79   HINSTANCE locale_dll_handle_;
  80 };
  81
  82 #endif  // CHROME_FRAME_SIMPLE_RESOURCE_LOADER_H_