xpcom/base/nsWindowsHelpers.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef nsWindowsHelpers_h
   6 #define nsWindowsHelpers_h
   7
   8 #include <windows.h>
   9 #include "nsAutoRef.h"
  10 #include "nscore.h"
  11
  12 // ----------------------------------------------------------------------------
  13 // Critical Section helper class
  14 // ----------------------------------------------------------------------------
  15
  16 class AutoCriticalSection
  17 {
  18 public:
  19   AutoCriticalSection(LPCRITICAL_SECTION section)
  20     : mSection(section)
  21   {
  22     ::EnterCriticalSection(mSection);
  23   }
  24   ~AutoCriticalSection()
  25   {
  26     ::LeaveCriticalSection(mSection);
  27   }
  28 private:
  29   LPCRITICAL_SECTION mSection;
  30 };
  31
  32 template<>
  33 class nsAutoRefTraits<HKEY>
  34 {
  35 public:
  36   typedef HKEY RawRef;
  37   static HKEY Void()
  38   {
  39     return nullptr;
  40   }
  41
  42   static void Release(RawRef aFD)
  43   {
  44     if (aFD != Void()) {
  45       RegCloseKey(aFD);
  46     }
  47   }
  48 };
  49
  50 template<>
  51 class nsAutoRefTraits<SC_HANDLE>
  52 {
  53 public:
  54   typedef SC_HANDLE RawRef;
  55   static SC_HANDLE Void()
  56   {
  57     return nullptr;
  58   }
  59
  60   static void Release(RawRef aFD)
  61   {
  62     if (aFD != Void()) {
  63       CloseServiceHandle(aFD);
  64     }
  65   }
  66 };
  67
  68 template<>
  69 class nsSimpleRef<HANDLE>
  70 {
  71 protected:
  72   typedef HANDLE RawRef;
  73
  74   nsSimpleRef() : mRawRef(nullptr)
  75   {
  76   }
  77
  78   nsSimpleRef(RawRef aRawRef) : mRawRef(aRawRef)
  79   {
  80   }
  81
  82   bool HaveResource() const
  83   {
  84     return mRawRef != nullptr && mRawRef != INVALID_HANDLE_VALUE;
  85   }
  86
  87 public:
  88   RawRef get() const
  89   {
  90     return mRawRef;
  91   }
  92
  93   static void Release(RawRef aRawRef)
  94   {
  95     if (aRawRef != nullptr && aRawRef != INVALID_HANDLE_VALUE) {
  96       CloseHandle(aRawRef);
  97     }
  98   }
  99   RawRef mRawRef;
 100 };
 101
 102
 103 template<>
 104 class nsAutoRefTraits<HMODULE>
 105 {
 106 public:
 107   typedef HMODULE RawRef;
 108   static RawRef Void()
 109   {
 110     return nullptr;
 111   }
 112
 113   static void Release(RawRef aFD)
 114   {
 115     if (aFD != Void()) {
 116       FreeLibrary(aFD);
 117     }
 118   }
 119 };
 120
 121 typedef nsAutoRef<HKEY> nsAutoRegKey;
 122 typedef nsAutoRef<SC_HANDLE> nsAutoServiceHandle;
 123 typedef nsAutoRef<HANDLE> nsAutoHandle;
 124 typedef nsAutoRef<HMODULE> nsModuleHandle;
 125
 126 namespace
 127 {
 128   bool
 129   IsRunningInWindowsMetro()
 130   {
 131     static bool alreadyChecked = false;
 132     static bool isMetro = false;
 133     if (alreadyChecked) {
 134       return isMetro;
 135     }
 136
 137     HMODULE user32DLL = LoadLibraryW(L"user32.dll");
 138     if (!user32DLL) {
 139       return false;
 140     }
 141
 142     typedef BOOL (WINAPI* IsImmersiveProcessFunc)(HANDLE process);
 143     IsImmersiveProcessFunc IsImmersiveProcessPtr =
 144       (IsImmersiveProcessFunc)GetProcAddress(user32DLL,
 145                                               "IsImmersiveProcess");
 146     FreeLibrary(user32DLL);
 147     if (!IsImmersiveProcessPtr) {
 148       // isMetro is already set to false.
 149       alreadyChecked = true;
 150       return false;
 151     }
 152
 153     isMetro = IsImmersiveProcessPtr(GetCurrentProcess());
 154     alreadyChecked = true;
 155     return isMetro;
 156   }
 157
 158   HMODULE
 159   LoadLibrarySystem32(LPCWSTR module)
 160   {
 161     WCHAR systemPath[MAX_PATH + 1] = { L'\0' };
 162
 163     // If GetSystemPath fails we accept that we'll load the DLLs from the
 164     // normal search path.
 165     GetSystemDirectoryW(systemPath, MAX_PATH + 1);
 166     size_t systemDirLen = wcslen(systemPath);
 167
 168     // Make the system directory path terminate with a slash
 169     if (systemDirLen && systemPath[systemDirLen - 1] != L'\\') {
 170       systemPath[systemDirLen] = L'\\';
 171       ++systemDirLen;
 172       // No need to re-nullptr terminate
 173     }
 174
 175     size_t fileLen = wcslen(module);
 176     wcsncpy(systemPath + systemDirLen, module,
 177             MAX_PATH - systemDirLen);
 178     if (systemDirLen + fileLen <= MAX_PATH) {
 179       systemPath[systemDirLen + fileLen] = L'\0';
 180     } else {
 181       systemPath[MAX_PATH] = L'\0';
 182     }
 183     return LoadLibraryW(systemPath);
 184   }
 185 }
 186
 187 #endif