// Include file for Free Pascal Compiler
// contains missing declaration from units JclShell & ShlObj

const
  shell32 = 'shell32.dll';

  CSIDL_DESKTOP                       = $0000;
  CSIDL_INTERNET                      = $0001;
  CSIDL_PROGRAMS                      = $0002;
  CSIDL_CONTROLS                      = $0003;
  CSIDL_PRINTERS                      = $0004;
  CSIDL_PERSONAL                      = $0005;
  CSIDL_FAVORITES                     = $0006;
  CSIDL_STARTUP                       = $0007;
  CSIDL_RECENT                        = $0008;
  CSIDL_SENDTO                        = $0009;
  CSIDL_BITBUCKET                     = $000a;
  CSIDL_STARTMENU                     = $000b;
  CSIDL_DESKTOPDIRECTORY              = $0010;
  CSIDL_DRIVES                        = $0011;
  CSIDL_NETWORK                       = $0012;
  CSIDL_NETHOOD                       = $0013;
  CSIDL_FONTS                         = $0014;
  CSIDL_TEMPLATES                     = $0015;
  CSIDL_COMMON_STARTMENU              = $0016;
  CSIDL_COMMON_PROGRAMS               = $0017;
  CSIDL_COMMON_STARTUP                = $0018;
  CSIDL_COMMON_DESKTOPDIRECTORY       = $0019;
  CSIDL_APPDATA                       = $001a;
  CSIDL_PRINTHOOD                     = $001b;
  CSIDL_ALTSTARTUP                = $001d;         // DBCS
  CSIDL_COMMON_ALTSTARTUP         = $001e;         // DBCS
  CSIDL_COMMON_FAVORITES          = $001f;
  CSIDL_INTERNET_CACHE            = $0020;
  CSIDL_COOKIES                   = $0021;
  CSIDL_HISTORY                   = $0022;
  
function SHGetMalloc(var ppMalloc: IMalloc): HResult; stdcall;
  external shell32 name 'SHGetMalloc';
  
function SHGetSpecialFolderLocation(hwndOwner: HWND; nFolder: Integer;
  var ppidl: PItemIDList): HResult; stdcall;
  external shell32 name 'SHGetSpecialFolderLocation';

function SHGetPathFromIDList(pidl: PItemIDList; pszPath: PChar): BOOL; stdcall;
  external shell32 name 'SHGetPathFromIDListA';

//--------------------------------------------------------------------------------------------------

function PidlFree(var IdList: PItemIdList): Boolean;
var
  Malloc: IMalloc;
begin
  Result := False;
  if IdList = nil then
    Result := True
  else
  begin
    if Succeeded(SHGetMalloc(Malloc)) and (Malloc.DidAlloc(IdList) > 0) then
    begin
      Malloc.Free(IdList);
      IdList := nil;
      Result := True;
    end;
  end;
end;

//--------------------------------------------------------------------------------------------------

function PidlToPath(IdList: PItemIdList): string;
begin
  SetLength(Result, MAX_PATH);
  if SHGetPathFromIdList(IdList, PChar(Result)) then
    StrResetLength(Result)
  else
    Result := '';
end;

//--------------------------------------------------------------------------------------------------

function GetSpecialFolderLocation(const Folder: Integer): string;
var
  FolderPidl: PItemIdList;
begin
  if Succeeded(SHGetSpecialFolderLocation(0, Folder, FolderPidl)) then
  begin
    Result := PidlToPath(FolderPidl);
    PidlFree(FolderPidl);
  end
  else
    Result := '';
end;

//--------------------------------------------------------------------------------------------------