FIcmp               := TICMP.Create;
    FIcmp.OnDisplay     := IcmpDisplay;
    FIcmp.OnEchoRequest := IcmpEchoRequest;
    FIcmp.OnEchoReply   := IcmpEchoReply;
    { Delphi 32 bits has threads and VCL is not thread safe.                }
    { We need to do our own way to be thread safe.                          }
    FWindowHandle := XSocketAllocateHWnd(Self);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
destructor TPing.Destroy;
begin
    CancelDnsLookup;                 { Cancel any pending dns lookup      }
    XSocketDeallocateHWnd(FWindowHandle);
    if Assigned(FIcmp) then begin
        FIcmp.Destroy;
        FIcmp := nil;
    end;
    inherited Destroy;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TPing.IcmpDisplay(Sender: TObject; Msg: String);
begin
    if Assigned(FOnDisplay) then
        FOnDisplay(Self, Sender, Msg);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TPing.IcmpEchoReply(Sender: TObject; Error : Integer);
begin
    if Assigned(FOnEchoReply) then
        FOnEchoReply(Self, Sender, Error);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TPing.IcmpEchoRequest(Sender: TObject);
begin
    if Assigned(FOnEchoRequest) then
        FOnEchoRequest(Self, Sender);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TPing.Ping : Integer;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.Ping
    else
        Result := 0;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TPing.CancelDnsLookup;
begin
    if FDnsLookupHandle = 0 then
        Exit;
    if WSACancelAsyncRequest(FDnsLookupHandle) <> 0 then
        raise Exception.CreateFmt('WSACancelAsyncRequest failed, error #%d',
                               [WSAGetLastError]);
    FDnsLookupHandle := 0;
    if Assigned(FOnDnsLookupDone) then
        FOnDnsLookupDone(Self, WSAEINTR);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TPing.DnsLookup(HostName : String);
var
    IPAddr  : TInAddr;
begin
    { Cancel any pending lookup }
    if FDnsLookupHandle <> 0 then
        WSACancelAsyncRequest(FDnsLookupHandle);

    FDnsResult := '';

    IPAddr.S_addr := Inet_addr(@HostName[1]);
    if IPAddr.S_addr <> u_long(INADDR_NONE) then begin
        FDnsResult := StrPas(inet_ntoa(IPAddr));
        if Assigned(FOnDnsLookupDone) then
            FOnDnsLookupDone(Self, 0);
        Exit;
    end;

    FDnsLookupHandle := WSAAsyncGetHostByName(FWindowHandle,
                                              WM_ASYNCGETHOSTBYNAME,
                                              @HostName[1],
                                              @FDnsLookupBuffer,
                                              SizeOf(FDnsLookupBuffer));
    if FDnsLookupHandle = 0 then
        raise Exception.CreateFmt(
                  '%s: can''t start DNS lookup, error #%d',
                  [HostName, WSAGetLastError]);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TPing.SetAddress(Value : String);
begin
    if Assigned(FIcmp) then
        FIcmp.Address := Value;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TPing.GetAddress : String;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.Address
    else
        Result := '';
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TPing.SetSize(Value : Integer);
begin
    if Assigned(FIcmp) then
        FIcmp.Size := Value;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TPing.GetSize : Integer;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.Size
    else
        Result := 0;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TPing.SetTimeout(Value : Integer);
begin
    if Assigned(FIcmp) then
        FIcmp.Timeout := Value;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TPing.GetTimeout : Integer;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.Timeout
    else
        Result := 0;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TPing.SetTTL(Value : Integer);
begin
    if Assigned(FIcmp) then
        FIcmp.TTL := Value;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TPing.GetTTL : Integer;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.TTL
    else
        Result := 0;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TPing.SetFlags(Value : Integer);
begin
    if Assigned(FIcmp) then
        FIcmp.Flags := Value;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TPing.GetFlags : Integer;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.flags
    else
        Result := 0;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TPing.GetReply : TIcmpEchoReply;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.Reply
    else
        FillChar(Result, SizeOf(Result), 0);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TPing.GetErrorCode : Integer;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.ErrorCode
    else
        Result := -1;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TPing.GetErrorString : String;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.ErrorString
    else
        Result := '';
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TPing.GetHostName : String;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.HostName
    else
        Result := '';
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TPing.GetHostIP : String;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.HostIP
    else
        Result := '';
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
{procedure TPing.SetOnDisplay(Value : TICMPDisplay);
begin
    if Assigned(FIcmp) then
        FIcmp.OnDisplay := Value;
end;
}

{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
{function TPing.GetOnDisplay : TICMPDisplay;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.OnDisplay
    else
        Result := nil;
end;
}

{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
{procedure TPing.SetOnEchoRequest(Value : TNotifyEvent);
begin
    if Assigned(FIcmp) then
        FIcmp.OnEchoRequest := Value;
end;
}

{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
{function TPing.GetOnEchoRequest : TNotifyEvent;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.OnEchoRequest
    else
        Result := nil;
end;
}

{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
{procedure TPing.SetOnEchoReply(Value : TICMPReply);
begin
    if Assigned(FIcmp) then
        FIcmp.OnEchoReply := Value;
end;
}

{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
{function TPing.GetOnEchoReply : TICMPReply;
begin
    if Assigned(FIcmp) then
        Result := FIcmp.OnEchoReply
    else
        Result := nil;
end;
}

{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}

end.