base/win/metro.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 "base/win/metro.h"
   6
   7 #include "base/strings/string_util.h"
   8
   9 namespace base {
  10 namespace win {
  11
  12 HMODULE GetMetroModule() {
  13   const HMODULE kUninitialized = reinterpret_cast<HMODULE>(1);
  14   static HMODULE metro_module = kUninitialized;
  15
  16   if (metro_module == kUninitialized) {
  17     // Initialize the cache, note that the initialization is idempotent
  18     // under the assumption that metro_driver is never unloaded, so the
  19     // race to this assignment is safe.
  20     metro_module = GetModuleHandleA("metro_driver.dll");
  21     if (metro_module != NULL) {
  22       // This must be a metro process if the metro_driver is loaded.
  23       DCHECK(IsMetroProcess());
  24     }
  25   }
  26
  27   DCHECK(metro_module != kUninitialized);
  28   return metro_module;
  29 }
  30
  31 bool IsMetroProcess() {
  32   enum ImmersiveState {
  33     kImmersiveUnknown,
  34     kImmersiveTrue,
  35     kImmersiveFalse
  36   };
  37   // The immersive state of a process can never change.
  38   // Look it up once and cache it here.
  39   static ImmersiveState state = kImmersiveUnknown;
  40
  41   if (state == kImmersiveUnknown) {
  42     if (IsProcessImmersive(::GetCurrentProcess())) {
  43       state = kImmersiveTrue;
  44     } else {
  45       state = kImmersiveFalse;
  46     }
  47   }
  48   DCHECK_NE(kImmersiveUnknown, state);
  49   return state == kImmersiveTrue;
  50 }
  51
  52 bool IsProcessImmersive(HANDLE process) {
  53   typedef BOOL (WINAPI* IsImmersiveProcessFunc)(HANDLE process);
  54   HMODULE user32 = ::GetModuleHandleA("user32.dll");
  55   DCHECK(user32 != NULL);
  56
  57   IsImmersiveProcessFunc is_immersive_process =
  58       reinterpret_cast<IsImmersiveProcessFunc>(
  59           ::GetProcAddress(user32, "IsImmersiveProcess"));
  60
  61   if (is_immersive_process)
  62     return is_immersive_process(process) ? true: false;
  63   return false;
  64 }
  65
  66 wchar_t* LocalAllocAndCopyString(const string16& src) {
  67   size_t dest_size = (src.length() + 1) * sizeof(wchar_t);
  68   wchar_t* dest = reinterpret_cast<wchar_t*>(LocalAlloc(LPTR, dest_size));
  69   base::wcslcpy(dest, src.c_str(), dest_size);
  70   return dest;
  71 }
  72
  73 // Metro driver exports for getting the launch type, initial url, initial
  74 // search term, etc.
  75 extern "C" {
  76 typedef const wchar_t* (*GetInitialUrl)();
  77 typedef const wchar_t* (*GetInitialSearchString)();
  78 typedef base::win::MetroLaunchType (*GetLaunchType)(
  79     base::win::MetroPreviousExecutionState* previous_state);
  80 }
  81
  82 MetroLaunchType GetMetroLaunchParams(string16* params) {
  83   HMODULE metro = base::win::GetMetroModule();
  84   if (!metro)
  85     return base::win::METRO_LAUNCH_ERROR;
  86
  87   GetLaunchType get_launch_type = reinterpret_cast<GetLaunchType>(
  88       ::GetProcAddress(metro, "GetLaunchType"));
  89   DCHECK(get_launch_type);
  90
  91   base::win::MetroLaunchType launch_type = get_launch_type(NULL);
  92
  93   if ((launch_type == base::win::METRO_PROTOCOL) ||
  94       (launch_type == base::win::METRO_LAUNCH)) {
  95     GetInitialUrl initial_metro_url = reinterpret_cast<GetInitialUrl>(
  96         ::GetProcAddress(metro, "GetInitialUrl"));
  97     DCHECK(initial_metro_url);
  98     *params = initial_metro_url();
  99   } else if (launch_type == base::win::METRO_SEARCH) {
 100     GetInitialSearchString initial_search_string =
 101         reinterpret_cast<GetInitialSearchString>(
 102             ::GetProcAddress(metro, "GetInitialSearchString"));
 103     DCHECK(initial_search_string);
 104     *params = initial_search_string();
 105   }
 106   return launch_type;
 107 }
 108
 109 }  // namespace win
 110 }  // namespace base