dll/shellext/acppage/CLayerUIPropPage.cpp

   1 /*
   2  * PROJECT:     ReactOS Compatibility Layer Shell Extension
   3  * LICENSE:     GPL-2.0+ (https://spdx.org/licenses/GPL-2.0+)
   4  * PURPOSE:     CLayerUIPropPage implementation
   5  * COPYRIGHT:   Copyright 2015-2018 Mark Jansen (mark.jansen@reactos.org)
   6  */
   7
   8 #include "precomp.h"
   9
  10 #include <shlwapi.h>
  11 #include <shellapi.h>
  12 #include <shellutils.h>
  13 #include <strsafe.h>
  14 #include <apphelp.h>
  15 #include <windowsx.h>
  16 #include <sfc.h>
  17
  18 const GUID CLSID_CLayerUIPropPage = { 0x513D916F, 0x2A8E, 0x4F51, { 0xAE, 0xAB, 0x0C, 0xBC, 0x76, 0xFB, 0x1A, 0xF8 } };
  19 #define ACP_WNDPROP L"{513D916F-2A8E-4F51-AEAB-0CBC76FB1AF8}.Prop"
  20
  21 #define GPLK_USER 1
  22 #define GPLK_MACHINE 2
  23 #define MAX_LAYER_LENGTH 256
  24
  25 static struct {
  26     const PCWSTR Display;
  27     const PCWSTR Name;
  28 } g_CompatModes[] = {
  29     { L"Windows 95", L"WIN95" },
  30     { L"Windows 98/ME", L"WIN98" },
  31     { L"Windows NT 4.0 (SP5)", L"NT4SP5" },
  32     { L"Windows 2000", L"WIN2000" },
  33     { L"Windows XP (SP2)", L"WINXPSP2" },
  34     { L"Windows XP (SP3)", L"WINXPSP3" },
  35     { L"Windows Server 2003 (SP1)", L"WINSRV03SP1" },
  36     { L"Windows Server 2008 (SP1)", L"WINSRV08SP1" },
  37     { L"Windows Vista", L"VISTARTM" },
  38     { L"Windows Vista (SP1)", L"VISTASP1" },
  39     { L"Windows Vista (SP2)", L"VISTASP2" },
  40     { L"Windows 7", L"WIN7RTM" },
  41     { NULL, NULL }
  42 };
  43
  44 static struct {
  45     const PCWSTR Name;
  46     DWORD Id;
  47 } g_Layers[] = {
  48     { L"256COLOR", IDC_CHKRUNIN256COLORS },
  49     { L"640X480", IDC_CHKRUNIN640480RES },
  50     { L"DISABLETHEMES", IDC_CHKDISABLEVISUALTHEMES },
  51 #if 0
  52     { L"DISABLEDWM", IDC_??, TRUE },
  53     { L"HIGHDPIAWARE", IDC_??, TRUE },
  54     { L"RUNASADMIN", IDC_??, TRUE },
  55 #endif
  56     { NULL, 0 }
  57 };
  58
  59 static const WCHAR* g_AllowedExtensions[] = {
  60     L".exe",
  61     L".msi",
  62     L".pif",
  63     L".bat",
  64     L".cmd",
  65     0
  66 };
  67
  68 BOOL IsBuiltinLayer(PCWSTR Name)
  69 {
  70     size_t n;
  71
  72     for (n = 0; g_Layers[n].Name; ++n)
  73     {
  74         if (!wcsicmp(g_Layers[n].Name, Name))
  75         {
  76             return TRUE;
  77         }
  78     }
  79
  80     for (n = 0; g_CompatModes[n].Name; ++n)
  81     {
  82         if (!wcsicmp(g_CompatModes[n].Name, Name))
  83         {
  84             return TRUE;
  85         }
  86     }
  87     return FALSE;
  88 }
  89
  90
  91 void ACDBG_FN(PCSTR FunctionName, PCWSTR Format, ...)
  92 {
  93     WCHAR Buffer[512];
  94     WCHAR* Current = Buffer;
  95     size_t Length = _countof(Buffer);
  96
  97     StringCchPrintfExW(Current, Length, &Current, &Length, STRSAFE_NULL_ON_FAILURE, L"[%-20S] ", FunctionName);
  98     va_list ArgList;
  99     va_start(ArgList, Format);
 100     StringCchVPrintfExW(Current, Length, &Current, &Length, STRSAFE_NULL_ON_FAILURE, Format, ArgList);
 101     va_end(ArgList);
 102     OutputDebugStringW(Buffer);
 103 }
 104
 105 #define ACDBG(fmt, ...)  ACDBG_FN(__FUNCTION__, fmt, ##__VA_ARGS__ )
 106
 107
 108
 109 CLayerUIPropPage::CLayerUIPropPage()
 110 : m_IsSfcProtected(FALSE)
 111 , m_AllowPermLayer(FALSE)
 112 , m_LayerQueryFlags(GPLK_USER)  /* TODO: When do we read from HKLM? */
 113 , m_RegistryOSMode(0)
 114 , m_OSMode(0)
 115 , m_RegistryEnabledLayers(0)
 116 , m_EnabledLayers(0)
 117 {
 118     CComBSTR title;
 119     title.LoadString(g_hModule, IDS_COMPAT_TITLE);
 120     m_psp.pszTitle = title.Detach();
 121     m_psp.dwFlags |= PSP_USETITLE;
 122 }
 123
 124 CLayerUIPropPage::~CLayerUIPropPage()
 125 {
 126     CComBSTR title;
 127     title.Attach((BSTR)m_psp.pszTitle);
 128 }
 129
 130 HRESULT CLayerUIPropPage::InitFile(PCWSTR Filename)
 131 {
 132     CString ExpandedFilename;
 133     DWORD dwRequired = ExpandEnvironmentStringsW(Filename, NULL, 0);
 134     if (dwRequired > 0)
 135     {
 136         LPWSTR Buffer = ExpandedFilename.GetBuffer(dwRequired);
 137         DWORD dwReturned = ExpandEnvironmentStringsW(Filename, Buffer, dwRequired);
 138         if (dwRequired == dwReturned)
 139         {
 140             ExpandedFilename.ReleaseBufferSetLength(dwReturned - 1);
 141             ACDBG(L"Expanded '%s' => '%s'\r\n", Filename, (PCWSTR)ExpandedFilename);
 142         }
 143         else
 144         {
 145             ExpandedFilename.ReleaseBufferSetLength(0);
 146             ExpandedFilename = Filename;
 147             ACDBG(L"Failed during expansion '%s'\r\n", Filename);
 148         }
 149     }
 150     else
 151     {
 152         ACDBG(L"Failed to expand '%s'\r\n", Filename);
 153         ExpandedFilename = Filename;
 154     }
 155     PCWSTR pwszExt = PathFindExtensionW(ExpandedFilename);
 156     if (!pwszExt)
 157     {
 158         ACDBG(L"Failed to find an extension: '%s'\r\n", (PCWSTR)ExpandedFilename);
 159         return E_FAIL;
 160     }
 161     if (!wcsicmp(pwszExt, L".lnk"))
 162     {
 163         WCHAR Buffer[MAX_PATH];
 164         if (!GetExeFromLnk(ExpandedFilename, Buffer, _countof(Buffer)))
 165         {
 166             ACDBG(L"Failed to read link target from: '%s'\r\n", (PCWSTR)ExpandedFilename);
 167             return E_FAIL;
 168         }
 169         if (!wcsicmp(Buffer, ExpandedFilename))
 170         {
 171             ACDBG(L"Link redirects to itself: '%s'\r\n", (PCWSTR)ExpandedFilename);
 172             return E_FAIL;
 173         }
 174         return InitFile(Buffer);
 175     }
 176
 177     CString tmp;
 178     if (tmp.GetEnvironmentVariable(L"SystemRoot"))
 179     {
 180         tmp += L"\\System32";
 181         if (ExpandedFilename.GetLength() >= tmp.GetLength() &&
 182             ExpandedFilename.Left(tmp.GetLength()).MakeLower() == tmp.MakeLower())
 183         {
 184             ACDBG(L"Ignoring System32: %s\r\n", (PCWSTR)ExpandedFilename);
 185             return E_FAIL;
 186         }
 187         tmp.GetEnvironmentVariable(L"SystemRoot");
 188         tmp += L"\\WinSxs";
 189         if (ExpandedFilename.GetLength() >= tmp.GetLength() &&
 190             ExpandedFilename.Left(tmp.GetLength()).MakeLower() == tmp.MakeLower())
 191         {
 192             ACDBG(L"Ignoring WinSxs: %s\r\n", (PCWSTR)ExpandedFilename);
 193             return E_FAIL;
 194         }
 195     }
 196
 197     for (size_t n = 0; g_AllowedExtensions[n]; ++n)
 198     {
 199         if (!wcsicmp(g_AllowedExtensions[n], pwszExt))
 200         {
 201             m_Filename = ExpandedFilename;
 202             ACDBG(L"Got: %s\r\n", (PCWSTR)ExpandedFilename);
 203             m_IsSfcProtected = SfcIsFileProtected(NULL, m_Filename);
 204             m_AllowPermLayer = AllowPermLayer(ExpandedFilename);
 205             return S_OK;
 206         }
 207     }
 208     ACDBG(L"Extension not included: '%s'\r\n", pwszExt);
 209     return E_FAIL;
 210 }
 211
 212 static BOOL GetLayerInfo(PCWSTR Filename, DWORD QueryFlags, PDWORD OSMode, PDWORD Enabledlayers, CSimpleArray<CString>& customLayers)
 213 {
 214     WCHAR wszLayers[MAX_LAYER_LENGTH] = { 0 };
 215     DWORD dwBytes = sizeof(wszLayers);
 216
 217     *OSMode = *Enabledlayers = 0;
 218     customLayers.RemoveAll();
 219     if (!SdbGetPermLayerKeys(Filename, wszLayers, &dwBytes, QueryFlags))
 220         return FALSE;
 221
 222     for (PWCHAR Layer = wcstok(wszLayers, L" "); Layer; Layer = wcstok(NULL, L" "))
 223     {
 224         size_t n;
 225         for (n = 0; g_Layers[n].Name; ++n)
 226         {
 227             if (!wcsicmp(g_Layers[n].Name, Layer))
 228             {
 229                 *Enabledlayers |= (1<<n);
 230                 break;
 231             }
 232         }
 233         /* Did we find it? */
 234         if (g_Layers[n].Name)
 235             continue;
 236
 237         for (n = 0; g_CompatModes[n].Name; ++n)
 238         {
 239             if (!wcsicmp(g_CompatModes[n].Name, Layer))
 240             {
 241                 *OSMode = n+1;
 242                 break;
 243             }
 244         }
 245         /* Did we find it? */
 246         if (g_CompatModes[n].Name)
 247             continue;
 248
 249         /* Must be a 'custom' layer */
 250         customLayers.Add(Layer);
 251     }
 252     return TRUE;
 253 }
 254
 255 int CLayerUIPropPage::OnSetActive()
 256 {
 257     if (!GetLayerInfo(m_Filename, m_LayerQueryFlags, &m_RegistryOSMode, &m_RegistryEnabledLayers, m_RegistryCustomLayers))
 258         m_RegistryOSMode = m_RegistryEnabledLayers = 0;
 259
 260     for (size_t n = 0; g_Layers[n].Name; ++n)
 261         CheckDlgButton(g_Layers[n].Id, (m_RegistryEnabledLayers & (1<<n)) ? BST_CHECKED : BST_UNCHECKED);
 262
 263     CheckDlgButton(IDC_CHKRUNCOMPATIBILITY, m_RegistryOSMode ? BST_CHECKED : BST_UNCHECKED);
 264
 265     if (m_RegistryOSMode)
 266         ComboBox_SetCurSel(GetDlgItem(IDC_COMPATIBILITYMODE), m_RegistryOSMode-1);
 267
 268     m_CustomLayers = m_RegistryCustomLayers;
 269
 270     UpdateControls();
 271
 272     return 0;
 273 }
 274
 275
 276 static BOOL ArrayEquals(const CSimpleArray<CString>& lhs, const CSimpleArray<CString>& rhs)
 277 {
 278     if (lhs.GetSize() != rhs.GetSize())
 279         return FALSE;
 280
 281     for (int n = 0; n < lhs.GetSize(); ++n)
 282     {
 283         if (lhs[n] != rhs[n])
 284             return FALSE;
 285     }
 286     return TRUE;
 287 }
 288
 289 BOOL CLayerUIPropPage::HasChanges() const
 290 {
 291     if (m_RegistryEnabledLayers != m_EnabledLayers)
 292         return TRUE;
 293
 294     if (m_RegistryOSMode != m_OSMode)
 295         return TRUE;
 296
 297     if (!ArrayEquals(m_RegistryCustomLayers, m_CustomLayers))
 298         return TRUE;
 299
 300     return FALSE;
 301 }
 302
 303 int CLayerUIPropPage::OnApply()
 304 {
 305     if (HasChanges())
 306     {
 307         BOOL bMachine = m_LayerQueryFlags == GPLK_MACHINE;
 308
 309         for (size_t n = 0; g_CompatModes[n].Name; ++n)
 310             SetPermLayerState(m_Filename, g_CompatModes[n].Name, 0, bMachine, (n+1) == m_OSMode);
 311
 312         for (size_t n = 0; g_Layers[n].Name; ++n)
 313         {
 314             SetPermLayerState(m_Filename, g_Layers[n].Name, 0, bMachine, ((1<<n) & m_EnabledLayers) != 0);
 315         }
 316
 317         /* Disable all old values */
 318         for (int j = 0; j < m_RegistryCustomLayers.GetSize(); j++)
 319         {
 320             SetPermLayerState(m_Filename, m_RegistryCustomLayers[j].GetString(), 0, bMachine, FALSE);
 321         }
 322
 323         /* Enable all new values */
 324         for (int j = 0; j < m_CustomLayers.GetSize(); j++)
 325         {
 326             SetPermLayerState(m_Filename, m_CustomLayers[j].GetString(), 0, bMachine, TRUE);
 327         }
 328
 329         SHChangeNotify(SHCNE_UPDATEITEM, SHCNF_PATHW, (PCWSTR)m_Filename, NULL);
 330     }
 331
 332     return PSNRET_NOERROR;
 333 }
 334
 335 LRESULT CLayerUIPropPage::OnInitDialog(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL &bHandled)
 336 {
 337     HWND cboMode = GetDlgItem(IDC_COMPATIBILITYMODE);
 338     for (size_t n = 0; g_CompatModes[n].Display; ++n)
 339         ComboBox_AddString(cboMode, g_CompatModes[n].Display);
 340     ComboBox_SetCurSel(cboMode, 5);
 341
 342     CComBSTR explanation;
 343     if (!m_AllowPermLayer)
 344     {
 345         explanation.LoadString(g_hModule, IDS_FAILED_NETWORK);
 346         DisableControls();
 347         ACDBG(L"AllowPermLayer returned FALSE\r\n");
 348     }
 349     else if (m_IsSfcProtected)
 350     {
 351         explanation.LoadString(g_hModule, IDS_FAILED_PROTECTED);
 352         DisableControls();
 353         ACDBG(L"Protected OS file\r\n");
 354     }
 355     else
 356     {
 357         return TRUE;
 358     }
 359     SetDlgItemTextW(IDC_EXPLANATION, explanation);
 360     return TRUE;
 361 }
 362
 363 INT_PTR CLayerUIPropPage::DisableControls()
 364 {
 365     ::EnableWindow(GetDlgItem(IDC_COMPATIBILITYMODE), 0);
 366     ::EnableWindow(GetDlgItem(IDC_CHKRUNCOMPATIBILITY), 0);
 367     for (size_t n = 0; g_Layers[n].Name; ++n)
 368         ::EnableWindow(GetDlgItem(g_Layers[n].Id), 0);
 369     ::EnableWindow(GetDlgItem(IDC_EDITCOMPATIBILITYMODES), 0);
 370     return TRUE;
 371 }
 372
 373 void CLayerUIPropPage::UpdateControls()
 374 {
 375     m_OSMode = 0, m_EnabledLayers = 0;
 376     BOOL ModeEnabled = IsDlgButtonChecked(IDC_CHKRUNCOMPATIBILITY);
 377     if (ModeEnabled)
 378         m_OSMode = ComboBox_GetCurSel(GetDlgItem(IDC_COMPATIBILITYMODE))+1;
 379     ::EnableWindow(GetDlgItem(IDC_COMPATIBILITYMODE), ModeEnabled);
 380
 381     for (size_t n = 0; g_Layers[n].Name; ++n)
 382     {
 383         m_EnabledLayers |= IsDlgButtonChecked(g_Layers[n].Id) ? (1<<n) : 0;
 384         ::ShowWindow(GetDlgItem(g_Layers[n].Id), SW_SHOW);
 385     }
 386
 387     CStringW customLayers;
 388     for (int j = 0; j < m_CustomLayers.GetSize(); ++j)
 389     {
 390         if (j > 0)
 391             customLayers += L", ";
 392         customLayers += m_CustomLayers[j];
 393     }
 394     SetDlgItemTextW(IDC_ENABLED_LAYERS, customLayers);
 395
 396     SetModified(HasChanges());
 397 }
 398
 399 LRESULT CLayerUIPropPage::OnCtrlCommand(WORD wNotifyCode, WORD wID, HWND hWndCtl, BOOL &bHandled)
 400 {
 401     UpdateControls();
 402     return 0;
 403 }
 404
 405 LRESULT CLayerUIPropPage::OnEditModes(WORD wNotifyCode, WORD wID, HWND hWndCtl, BOOL &bHandled)
 406 {
 407     if (DialogBoxParamW(g_hModule, MAKEINTRESOURCEW(IDD_EDITCOMPATIBILITYMODES), m_hWnd, EditModesProc, (LPARAM)this) == IDOK)
 408         UpdateControls();
 409     return 0;
 410 }
 411
 412 LRESULT CLayerUIPropPage::OnClickNotify(INT uCode, LPNMHDR hdr, BOOL& bHandled)
 413 {
 414     if (hdr->idFrom == IDC_INFOLINK)
 415         ShellExecute(NULL, L"open", L"https://www.reactos.org/forum/viewforum.php?f=4", NULL, NULL, SW_SHOW);
 416     return 0;
 417 }
 418
 419 static void ListboxChanged(HWND hWnd)
 420 {
 421     int Sel = ListBox_GetCurSel(GetDlgItem(hWnd, IDC_COMPATIBILITYMODE));
 422     EnableWindow(GetDlgItem(hWnd, IDC_EDIT), Sel >= 0);
 423     EnableWindow(GetDlgItem(hWnd, IDC_DELETE), Sel >= 0);
 424 }
 425
 426 static void OnAdd(HWND hWnd)
 427 {
 428     HWND Combo = GetDlgItem(hWnd, IDC_NEWCOMPATIBILITYMODE);
 429
 430     int Length = ComboBox_GetTextLength(Combo);
 431     CComBSTR Str(Length);
 432     ComboBox_GetText(Combo, Str, Length+1);
 433     HWND List = GetDlgItem(hWnd, IDC_COMPATIBILITYMODE);
 434     int Index = ListBox_FindStringExact(List, -1, Str);
 435     if (Index == LB_ERR)
 436         Index = ListBox_AddString(List, Str);
 437     ListBox_SetCurSel(List, Index);
 438     ListboxChanged(hWnd);
 439     ComboBox_SetCurSel(Combo, -1);
 440     SetFocus(Combo);
 441 }
 442
 443 static BOOL ComboHasData(HWND hWnd)
 444 {
 445     HWND Combo = GetDlgItem(hWnd, IDC_NEWCOMPATIBILITYMODE);
 446     if (ComboBox_GetCurSel(Combo) >= 0)
 447         return TRUE;
 448     ULONG Len = ComboBox_GetTextLength(Combo);
 449     return Len > 0;
 450 }
 451
 452 INT_PTR CALLBACK CLayerUIPropPage::EditModesProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 453 {
 454     CLayerUIPropPage* page = NULL;
 455
 456     switch (uMsg)
 457     {
 458     case WM_INITDIALOG:
 459         page = (CLayerUIPropPage*)lParam;
 460         page->AddRef();
 461         ::SetProp(hWnd, ACP_WNDPROP, page);
 462         {
 463             HWND Combo = ::GetDlgItem(hWnd, IDC_NEWCOMPATIBILITYMODE);
 464             CComObject<CLayerStringList> pList;
 465
 466             while (TRUE)
 467             {
 468                 CComHeapPtr<OLECHAR> str;
 469                 HRESULT hr = pList.Next(1, &str, NULL);
 470                 if (hr != S_OK)
 471                     break;
 472                 ComboBox_AddString(Combo, str);
 473             }
 474
 475             HWND List = ::GetDlgItem(hWnd, IDC_COMPATIBILITYMODE);
 476             for (int n = 0; n < page->m_CustomLayers.GetSize(); ++n)
 477             {
 478                 const WCHAR* Str = page->m_CustomLayers[n].GetString();
 479                 int Index = ListBox_FindStringExact(List, -1, Str);
 480                 if (Index == LB_ERR)
 481                     Index = ListBox_AddString(List, Str);
 482             }
 483         }
 484         break;
 485     case WM_ENDSESSION:
 486     case WM_DESTROY:
 487         page = (CLayerUIPropPage*)::GetProp(hWnd, ACP_WNDPROP);
 488         ::RemoveProp(hWnd, ACP_WNDPROP);
 489         page->Release();
 490         break;
 491
 492     case WM_COMMAND:
 493         switch(LOWORD(wParam))
 494         {
 495         case IDC_ADD:
 496             OnAdd(hWnd);
 497             break;
 498         case IDC_EDIT:
 499         {
 500             HWND List = ::GetDlgItem(hWnd, IDC_COMPATIBILITYMODE);
 501             int Cur = ListBox_GetCurSel(List);
 502             int Length = ListBox_GetTextLen(List, Cur);
 503             CComBSTR Str(Length);
 504             ListBox_GetText(List, Cur, Str);
 505             ListBox_DeleteString(List, Cur);
 506             HWND Combo = ::GetDlgItem(hWnd, IDC_NEWCOMPATIBILITYMODE);
 507             ComboBox_SetCurSel(Combo, -1);
 508             ::SetWindowText(Combo,Str);
 509             ListboxChanged(hWnd);
 510             ComboBox_SetEditSel(Combo, 30000, 30000);
 511             ::SetFocus(Combo);
 512         }
 513             break;
 514         case IDC_DELETE:
 515         {
 516             HWND List = ::GetDlgItem(hWnd, IDC_COMPATIBILITYMODE);
 517             ListBox_DeleteString(List, ListBox_GetCurSel(List));
 518             ListboxChanged(hWnd);
 519         }
 520             break;
 521         case IDC_COMPATIBILITYMODE:
 522             ListboxChanged(hWnd);
 523             break;
 524         case IDC_NEWCOMPATIBILITYMODE:
 525         {
 526             ::EnableWindow(::GetDlgItem(hWnd, IDC_ADD), ComboHasData(hWnd));
 527         }
 528             break;
 529         case IDOK:
 530             /* Copy from list! */
 531         {
 532             if (ComboHasData(hWnd))
 533             {
 534                 CComBSTR question, title;
 535                 title.LoadString(g_hModule, IDS_COMPAT_TITLE);
 536                 question.LoadString(g_hModule, IDS_YOU_DID_NOT_ADD);
 537                 int result = ::MessageBoxW(hWnd, question, title, MB_YESNOCANCEL | MB_ICONQUESTION);
 538                 switch (result)
 539                 {
 540                 case IDYES:
 541                     OnAdd(hWnd);
 542                     break;
 543                 case IDNO:
 544                     break;
 545                 case IDCANCEL:
 546                     return FALSE;
 547                 }
 548             }
 549
 550             page = (CLayerUIPropPage*)::GetProp(hWnd, ACP_WNDPROP);
 551
 552             HWND List = ::GetDlgItem(hWnd, IDC_COMPATIBILITYMODE);
 553             int Count = ListBox_GetCount(List);
 554             page->m_CustomLayers.RemoveAll();
 555             for (int Cur = 0; Cur < Count; ++Cur)
 556             {
 557                 int Length = ListBox_GetTextLen(List, Cur);
 558                 CString Str;
 559                 LPWSTR Buffer = Str.GetBuffer(Length + 1);
 560                 ListBox_GetText(List, Cur, Buffer);
 561                 Str.ReleaseBuffer(Length);
 562                 page->m_CustomLayers.Add(Str);
 563             }
 564         }
 565         /* Fall trough */
 566         case IDCANCEL:
 567             ::EndDialog(hWnd, LOWORD(wParam));
 568             break;
 569         }
 570         break;
 571     case WM_CLOSE:
 572         ::EndDialog(hWnd, IDCANCEL);
 573         break;
 574     }
 575     return FALSE;
 576 }
 577
 578 static BOOL DisableShellext()
 579 {
 580     HKEY hkey;
 581     LSTATUS ret = RegOpenKeyExW(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Policies\\Microsoft\\Windows\\AppCompat", 0, KEY_QUERY_VALUE, &hkey);
 582     BOOL Disable = FALSE;
 583     if (ret == ERROR_SUCCESS)
 584     {
 585         DWORD dwValue = 0;
 586         DWORD type, size = sizeof(dwValue);
 587         ret = RegQueryValueExW(hkey, L"DisableEngine", NULL, &type, (PBYTE)&dwValue, &size);
 588         if (ret == ERROR_SUCCESS && type == REG_DWORD)
 589         {
 590             Disable = !!dwValue;
 591         }
 592         if (!Disable)
 593         {
 594             size = sizeof(dwValue);
 595             ret = RegQueryValueExW(hkey, L"DisablePropPage", NULL, &type, (PBYTE)&dwValue, &size);
 596             if (ret == ERROR_SUCCESS && type == REG_DWORD)
 597             {
 598                 Disable = !!dwValue;
 599             }
 600         }
 601
 602         RegCloseKey(hkey);
 603     }
 604     return Disable;
 605 }
 606
 607 STDMETHODIMP CLayerUIPropPage::Initialize(LPCITEMIDLIST pidlFolder, LPDATAOBJECT pDataObj, HKEY hkeyProgID)
 608 {
 609     FORMATETC etc = { CF_HDROP, NULL, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
 610     STGMEDIUM stg;
 611
 612     if (DisableShellext())
 613         return E_ACCESSDENIED;
 614
 615     HRESULT hr = pDataObj->GetData(&etc, &stg);
 616     if (FAILED(hr))
 617     {
 618         ACDBG(L"Failed to retrieve Data from pDataObj.\r\n");
 619         return E_INVALIDARG;
 620     }
 621     hr = E_FAIL;
 622     HDROP hdrop = (HDROP)GlobalLock(stg.hGlobal);
 623     if (hdrop)
 624     {
 625         UINT uNumFiles = DragQueryFileW(hdrop, 0xFFFFFFFF, NULL, 0);
 626         if (uNumFiles == 1)
 627         {
 628             WCHAR szFile[MAX_PATH * 2];
 629             if (DragQueryFileW(hdrop, 0, szFile, _countof(szFile)))
 630             {
 631                 this->AddRef();
 632                 hr = InitFile(szFile);
 633             }
 634             else
 635             {
 636                 ACDBG(L"Failed to query the file.\r\n");
 637             }
 638         }
 639         else
 640         {
 641             ACDBG(L"Invalid number of files: %d\r\n", uNumFiles);
 642         }
 643         GlobalUnlock(stg.hGlobal);
 644     }
 645     else
 646     {
 647         ACDBG(L"Could not lock stg.hGlobal\r\n");
 648     }
 649     ReleaseStgMedium(&stg);
 650     return hr;
 651 }