unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls, ScktComp;

type
  TForm1 = class(TForm)
    Memo1: TMemo;
    ClientSocket1: TClientSocket;
    ServerSocket1: TServerSocket;
    Edit1: TEdit;
    Button1: TButton;
    Edit2: TEdit;
    Edit3: TEdit;
    Button2: TButton;
    Edit4: TEdit;
    Shape1: TShape;
    Shape2: TShape;
    CheckBox1: TCheckBox;
    procedure ServerSocket1ClientConnect(Sender: TObject;
      Socket: TCustomWinSocket);
    procedure ServerSocket1ClientDisconnect(Sender: TObject;
      Socket: TCustomWinSocket);
    procedure ServerSocket1ClientError(Sender: TObject;
      Socket: TCustomWinSocket; ErrorEvent: TErrorEvent;
      var ErrorCode: Integer);
    procedure ServerSocket1ClientRead(Sender: TObject;
      Socket: TCustomWinSocket);
    procedure ClientSocket1Connect(Sender: TObject;
      Socket: TCustomWinSocket);
    procedure ClientSocket1Disconnect(Sender: TObject;
      Socket: TCustomWinSocket);
    procedure ClientSocket1Read(Sender: TObject; Socket: TCustomWinSocket);
    procedure ClientSocket1Error(Sender: TObject; Socket: TCustomWinSocket;
      ErrorEvent: TErrorEvent; var ErrorCode: Integer);
    procedure Button2Click(Sender: TObject);
    procedure CheckBox1Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.ServerSocket1ClientConnect(Sender: TObject;
  Socket: TCustomWinSocket);
begin
  Shape2.Brush.Color := cllime;
end;

procedure TForm1.ServerSocket1ClientDisconnect(Sender: TObject;
  Socket: TCustomWinSocket);
begin
  Shape2.Brush.Color := clwhite;
end;

procedure TForm1.ServerSocket1ClientError(Sender: TObject;
  Socket: TCustomWinSocket; ErrorEvent: TErrorEvent;
  var ErrorCode: Integer);
begin
  Shape2.Brush.Color := clwhite;
  ErrorCode := 0;
end;

procedure TForm1.ServerSocket1ClientRead(Sender: TObject;
  Socket: TCustomWinSocket);
  var S : string;
begin
  S := Socket.ReceiveText;
  Memo1.Lines.Add(S);
end;

procedure TForm1.ClientSocket1Connect(Sender: TObject;
  Socket: TCustomWinSocket);
begin
  Shape1.Brush.Color := cllime;
end;

procedure TForm1.ClientSocket1Disconnect(Sender: TObject;
  Socket: TCustomWinSocket);
begin
  Shape1.Brush.Color := clwhite;
end;

procedure TForm1.ClientSocket1Read(Sender: TObject;
  Socket: TCustomWinSocket);
var S : string;
begin
  S := Socket.ReceiveText;
  Memo1.Lines.Add(S);
end;

procedure TForm1.ClientSocket1Error(Sender: TObject;
  Socket: TCustomWinSocket; ErrorEvent: TErrorEvent;
  var ErrorCode: Integer);
begin
  Shape1.Brush.Color := clwhite;
  ErrorCode := 0;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  if not ClientSocket1.Active then
  begin
    ClientSocket1.Address := Edit2.Text;
    ClientSocket1.Port := strtoint(Edit3.Text);
    ClientSocket1.Active := true;
  end;
end;

procedure TForm1.CheckBox1Click(Sender: TObject);
begin
  if CheckBox1.Checked then
  begin
    ServerSocket1.Port := strtoint(Edit4.Text);
    ServerSocket1.Active := true;
  end else
  begin
    ServerSocket1.Active := False;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if ClientSocket1.Active then
  ClientSocket1.Socket.SendText(Edit1.Text+#13#10)
  else
  if ServerSocket1.Socket.Connections[0].Connected then
  ServerSocket1.Socket.Connections[0].SendText(Edit1.Text+#13#10);
end;

end.