Determine whether the computer supports hibernation, the sleep states

Problem/Question/Abstract:

How to determine whether the computer supports hibernation, the sleep states

Answer:

Check if hibernation is allowed

function HibernateAllowed: Boolean;
type
  TIsPwrHibernateAllowed = function: Boolean;
  stdcall;
var
  hPowrprof: HMODULE;
  IsPwrHibernateAllowed: TIsPwrHibernateAllowed;
begin
  Result := False;
  if IsNT4Or95 then
    Exit;
  hPowrprof := LoadLibrary('powrprof.dll');
  if hPowrprof <> 0 then
  begin
    try
      @IsPwrHibernateAllowed := GetProcAddress(hPowrprof, 'IsPwrHibernateAllowed');
      if @IsPwrHibernateAllowed <> nil then
      begin
        Result := IsPwrHibernateAllowed;
      end;
    finally
      FreeLibrary(hPowrprof);
    end;
  end;
end;

Check if suspend is allowed

function SuspendAllowed: Boolean;
type
  TIsPwrSuspendAllowed = function: Boolean;
  stdcall;
var
  hPowrprof: HMODULE;
  IsPwrSuspendAllowed: TIsPwrSuspendAllowed;
begin
  Result := False;
  hPowrprof := LoadLibrary('powrprof.dll');
  if hPowrprof <> 0 then
  begin
    try
      @IsPwrSuspendAllowed := GetProcAddress(hPowrprof, 'IsPwrSuspendAllowed');
      if @IsPwrSuspendAllowed <> nil then
      begin
        Result := IsPwrSuspendAllowed;
      end;
    finally
      FreeLibrary(hPowrprof);
    end;
  end;
end;