chrome_frame/simple_resource_loader.cc

   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 #include "chrome_frame/simple_resource_loader.h"
   6
   7 #include <atlbase.h>
   8
   9 #include <algorithm>
  10
  11 #include "base/base_paths.h"
  12 #include "base/file_path.h"
  13 #include "base/file_util.h"
  14 #include "base/path_service.h"
  15 #include "base/i18n/rtl.h"
  16 #include "base/memory/singleton.h"
  17 #include "base/string_util.h"
  18 #include "base/utf_string_conversions.h"
  19 #include "base/win/i18n.h"
  20 #include "base/win/windows_version.h"
  21 #include "chrome_frame/policy_settings.h"
  22 #include "ui/base/resource/data_pack.h"
  23
  24 namespace {
  25
  26 const wchar_t kLocalesDirName[] = L"Locales";
  27
  28 bool IsInvalidTagCharacter(wchar_t tag_character) {
  29   return !(L'-' == tag_character ||
  30            IsAsciiDigit(tag_character) ||
  31            IsAsciiAlpha(tag_character));
  32 }
  33
  34 // A helper function object that performs a lower-case ASCII comparison between
  35 // two strings.
  36 class CompareInsensitiveASCII
  37     : public std::unary_function<const std::wstring&, bool> {
  38  public:
  39   explicit CompareInsensitiveASCII(const std::wstring& value)
  40       : value_lowered_(WideToASCII(value)) {
  41     StringToLowerASCII(&value_lowered_);
  42   }
  43   bool operator()(const std::wstring& comparand) {
  44     return LowerCaseEqualsASCII(comparand, value_lowered_.c_str());
  45   }
  46
  47  private:
  48   std::string value_lowered_;
  49 };
  50
  51 // Returns true if the value was added.
  52 bool PushBackIfAbsent(
  53     const std::wstring& value,
  54     std::vector<std::wstring>* collection) {
  55   if (collection->end() ==
  56       std::find_if(collection->begin(), collection->end(),
  57                    CompareInsensitiveASCII(value))) {
  58     collection->push_back(value);
  59     return true;
  60   }
  61   return false;
  62 }
  63
  64 // Returns true if the collection is modified.
  65 bool PushBackWithFallbackIfAbsent(
  66     const std::wstring& language,
  67     std::vector<std::wstring>* collection) {
  68   bool modified = false;
  69
  70   if (!language.empty()) {
  71     // Try adding the language itself.
  72     modified = PushBackIfAbsent(language, collection);
  73
  74     // Now try adding its fallback, if it has one.
  75     std::wstring::size_type dash_pos = language.find(L'-');
  76     if (0 < dash_pos && language.size() - 1 > dash_pos)
  77       modified |= PushBackIfAbsent(language.substr(0, dash_pos), collection);
  78   }
  79
  80   return modified;
  81 }
  82
  83 }  // namespace
  84
  85 SimpleResourceLoader::SimpleResourceLoader()
  86     : data_pack_(NULL),
  87       locale_dll_handle_(NULL) {
  88   // Find and load the resource DLL.
  89   std::vector<std::wstring> language_tags;
  90
  91   // First, try the locale dictated by policy and its fallback.
  92   PushBackWithFallbackIfAbsent(
  93       PolicySettings::GetInstance()->ApplicationLocale(),
  94       &language_tags);
  95
  96   // Next, try the thread, process, user, system languages.
  97   GetPreferredLanguages(&language_tags);
  98
  99   // Finally, fall-back on "en-US" (which may already be present in the vector,
 100   // but that's okay since we'll exit with success when the first is tried).
 101   language_tags.push_back(L"en-US");
 102
 103   FilePath locales_path;
 104
 105   DetermineLocalesDirectory(&locales_path);
 106   if (!LoadLocalePack(language_tags, locales_path, &locale_dll_handle_,
 107                       &data_pack_, &language_)) {
 108     NOTREACHED() << "Failed loading any resource dll (even \"en-US\").";
 109   }
 110 }
 111
 112 SimpleResourceLoader::~SimpleResourceLoader() {
 113   delete data_pack_;
 114 }
 115
 116 // static
 117 SimpleResourceLoader* SimpleResourceLoader::GetInstance() {
 118   return Singleton<SimpleResourceLoader>::get();
 119 }
 120
 121 // static
 122 void SimpleResourceLoader::GetPreferredLanguages(
 123     std::vector<std::wstring>* language_tags) {
 124   DCHECK(language_tags);
 125   // The full set of preferred languages and their fallbacks are given priority.
 126   std::vector<std::wstring> languages;
 127   if (base::win::i18n::GetThreadPreferredUILanguageList(&languages)) {
 128     for (std::vector<std::wstring>::const_iterator scan = languages.begin(),
 129              end = languages.end(); scan != end; ++scan) {
 130       PushBackIfAbsent(*scan, language_tags);
 131     }
 132   }
 133   // Use the base i18n routines (i.e., ICU) as a last, best hope for something
 134   // meaningful for the user.
 135   PushBackWithFallbackIfAbsent(ASCIIToWide(base::i18n::GetConfiguredLocale()),
 136                                language_tags);
 137 }
 138
 139 // static
 140 void SimpleResourceLoader::DetermineLocalesDirectory(FilePath* locales_path) {
 141   DCHECK(locales_path);
 142
 143   FilePath module_path;
 144   PathService::Get(base::DIR_MODULE, &module_path);
 145   *locales_path = module_path.Append(kLocalesDirName);
 146
 147   // We may be residing in the "locales" directory's parent, or we might be
 148   // in a sibling directory. Move up one and look for Locales again in the
 149   // latter case.
 150   if (!file_util::DirectoryExists(*locales_path)) {
 151     *locales_path = module_path.DirName();
 152     *locales_path = locales_path->Append(kLocalesDirName);
 153   }
 154
 155   // Don't make a second check to see if the dir is in the parent.  We'll notice
 156   // and log that in LoadLocaleDll when we actually try loading DLLs.
 157 }
 158
 159 // static
 160 bool SimpleResourceLoader::IsValidLanguageTag(
 161     const std::wstring& language_tag) {
 162   // "[a-zA-Z]+(-[a-zA-Z0-9]+)*" is a simplification, but better than nothing.
 163   // Rather than pick up the weight of a regex processor, just search for a
 164   // character that isn't in the above set.  This will at least weed out
 165   // attempts at "../../EvilBinary".
 166   return language_tag.end() == std::find_if(language_tag.begin(),
 167                                             language_tag.end(),
 168                                             &IsInvalidTagCharacter);
 169 }
 170
 171 // static
 172 bool SimpleResourceLoader::LoadLocalePack(
 173     const std::vector<std::wstring>& language_tags,
 174     const FilePath& locales_path,
 175     HMODULE* dll_handle,
 176     ui::DataPack** data_pack,
 177     std::wstring* language) {
 178   DCHECK(language);
 179
 180   // The dll should only have resources, not executable code.
 181   const DWORD load_flags =
 182       (base::win::GetVersion() >= base::win::VERSION_VISTA ?
 183           LOAD_LIBRARY_AS_DATAFILE_EXCLUSIVE | LOAD_LIBRARY_AS_IMAGE_RESOURCE :
 184           DONT_RESOLVE_DLL_REFERENCES);
 185
 186   const std::wstring dll_suffix(L".dll");
 187   const std::wstring pack_suffix(L".pak");
 188
 189   bool found_pack = false;
 190
 191   for (std::vector<std::wstring>::const_iterator scan = language_tags.begin(),
 192          end = language_tags.end();
 193        scan != end;
 194        ++scan) {
 195     if (!IsValidLanguageTag(*scan)) {
 196       LOG(WARNING) << "Invalid language tag supplied while locating resources:"
 197                       " \"" << *scan << "\"";
 198       continue;
 199     }
 200
 201     // Attempt to load both the resource pack and the dll. We return success
 202     // only we load both.
 203     FilePath resource_pack_path = locales_path.Append(*scan + pack_suffix);
 204     FilePath dll_path = locales_path.Append(*scan + dll_suffix);
 205
 206     if (file_util::PathExists(resource_pack_path) &&
 207         file_util::PathExists(dll_path)) {
 208       scoped_ptr<ui::DataPack> cur_data_pack(
 209           new ui::DataPack(ui::SCALE_FACTOR_100P));
 210       if (!cur_data_pack->Load(resource_pack_path))
 211         continue;
 212
 213       HMODULE locale_dll_handle = LoadLibraryEx(dll_path.value().c_str(), NULL,
 214                                                 load_flags);
 215       if (locale_dll_handle) {
 216         *dll_handle = locale_dll_handle;
 217         *language = dll_path.BaseName().RemoveExtension().value();
 218         *data_pack = cur_data_pack.release();
 219         found_pack = true;
 220         break;
 221       } else {
 222         *data_pack = NULL;
 223       }
 224     }
 225   }
 226   DCHECK(found_pack || file_util::DirectoryExists(locales_path))
 227       << "Could not locate locales DLL directory.";
 228   return found_pack;
 229 }
 230
 231 std::wstring SimpleResourceLoader::GetLocalizedResource(int message_id) {
 232   if (!data_pack_) {
 233     DLOG(ERROR) << "locale resources are not loaded";
 234     return std::wstring();
 235   }
 236
 237   DCHECK(IS_INTRESOURCE(message_id));
 238
 239   base::StringPiece data;
 240   if (!data_pack_->GetStringPiece(message_id, &data)) {
 241     DLOG(ERROR) << "Unable to find string for resource id:" << message_id;
 242     return std::wstring();
 243   }
 244
 245   // Data pack encodes strings as either UTF8 or UTF16.
 246   string16 msg;
 247   if (data_pack_->GetTextEncodingType() == ui::DataPack::UTF16) {
 248     msg = string16(reinterpret_cast<const char16*>(data.data()),
 249                    data.length() / 2);
 250   } else if (data_pack_->GetTextEncodingType() == ui::DataPack::UTF8) {
 251     msg = UTF8ToUTF16(data);
 252   }
 253   return msg;
 254 }
 255
 256 // static
 257 std::wstring SimpleResourceLoader::GetLanguage() {
 258   return SimpleResourceLoader::GetInstance()->language_;
 259 }
 260
 261 // static
 262 std::wstring SimpleResourceLoader::Get(int message_id) {
 263   SimpleResourceLoader* loader = SimpleResourceLoader::GetInstance();
 264   return loader->GetLocalizedResource(message_id);
 265 }
 266
 267 HMODULE SimpleResourceLoader::GetResourceModuleHandle() {
 268   return locale_dll_handle_;
 269 }