chrome/app/metro_driver_win.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 "metro_driver_win.h"
   6
   7 #include <string.h>
   8
   9 #include "chrome/app/client_util.h"
  10 #include "chrome/common/chrome_constants.h"
  11
  12 namespace {
  13 // This environment variable controls the loading of the metro driver DLL.
  14 const char* kMetroModeEnvVar = "CHROME_METRO_DLL";
  15
  16 typedef int (*InitMetro)(LPTHREAD_START_ROUTINE thread_proc, void* context);
  17
  18 struct Context {
  19   MetroDriver::MainFn fn;
  20   HINSTANCE instance;
  21 };
  22
  23 DWORD WINAPI MainThread(void* param) {
  24   Context* context = reinterpret_cast<Context*>(param);
  25   int rv = context->fn(context->instance);
  26   delete context;
  27   return rv;
  28 }
  29
  30 }  // namespace
  31
  32 MetroDriver::MetroDriver() : init_metro_fn_(NULL) {
  33   if (0 != ::GetEnvironmentVariableA(kMetroModeEnvVar, NULL, 0))
  34     return;
  35   // The metro activation always has the |ServerName| parameter. If we dont
  36   // see it, we are being launched in desktop mode.
  37   if (!wcsstr(::GetCommandLineW(), L" -ServerName:DefaultBrowserServer")) {
  38     ::SetEnvironmentVariableA(kMetroModeEnvVar, "0");
  39     return;
  40   }
  41   // We haven't tried to load the metro driver, this probably means we are the
  42   // browser. Find it or not we set the environment variable because we don't
  43   // want to keep trying in the child processes.
  44   HMODULE metro_dll = ::LoadLibraryW(chrome::kMetroDriverDll);
  45   if (!metro_dll) {
  46     // It is not next to the build output, so this must be an actual deployment
  47     // and in that case we need the mainloader to find the current version
  48     // directory.
  49     base::string16 version(GetCurrentModuleVersion());
  50     if (!version.empty()) {
  51       std::wstring exe_path(GetExecutablePath());
  52       exe_path.append(version).append(L"\\").append(chrome::kMetroDriverDll);
  53       metro_dll = ::LoadLibraryW(exe_path.c_str());
  54     }
  55   }
  56   // We set the environment variable always, so we don't keep trying in
  57   // the child processes.
  58   ::SetEnvironmentVariableA(kMetroModeEnvVar, metro_dll ? "1" : "0");
  59   if (!metro_dll)
  60     return;
  61   init_metro_fn_ = ::GetProcAddress(metro_dll, "InitMetro");
  62 }
  63
  64 int MetroDriver::RunInMetro(HINSTANCE instance, MainFn main_fn) {
  65   Context* context = new Context;
  66   context->fn = main_fn;
  67   context->instance = instance;
  68
  69   return reinterpret_cast<InitMetro>(init_metro_fn_)(&MainThread, context);
  70 }