Creating a Chat Application (local) with Delphi

Unit1:
unit Unit1;
 
interface
 
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ComCtrls, Sockets, Menus, MPlayer,ShellAPI, ExtCtrls;
 
const
WM_ICONTRAY2 = WM_USER + 1;
edkey = 6539;
 
type
TForm1 = class(TForm)
Host: TEdit;
Button1: TButton;
TcpClient1: TTcpClient;
TcpServer1: TTcpServer;
MediaPlayer1: TMediaPlayer;
Chat: TRichEdit;
Mes: TComboBox;
PopupMenu1: TPopupMenu;
CheckBox1: TCheckBox;
Timer1: TTimer;
SaveDialog1: TSaveDialog;
Clear1: TMenuItem;
Save1: TMenuItem;
procedure TrayMessage(var Msg: TMessage); message WM_ICONTRAY2;
procedure Button1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure TcpServer1Accept(Sender: TObject;
ClientSocket: TCustomIpClient);
procedure Clear1Click(Sender: TObject);
procedure MesKeyPress(Sender: TObject; var Key: Char);
procedure HostKeyPress(Sender: TObject; var Key: Char);
procedure FormKeyPress(Sender: TObject; var Key: Char);
procedure ChatKeyPress(Sender: TObject; var Key: Char);
procedure FormShow(Sender: TObject);
procedure FormPaint(Sender: TObject);
procedure CheckBox1Click(Sender: TObject);
procedure Timer1Timer(Sender: TObject);
procedure Save1Click(Sender: TObject);
procedure FormHide(Sender: TObject);
private
TrayIconData2: TNotifyIconData;
{ Private declarations }
public
{ Public declarations }
end;
 
var
Form1: TForm1;
icon1 : TIcon;
mescount : integer;
implementation
Uses Unit2;
{$R *.dfm}
 
procedure AddColoredLine(ARichEdit: TRichEdit; AText: string; AColor: TColor);
begin
with ARichEdit do
begin
SelStart := Length(Text);
SelAttributes.Color := AColor;
SelAttributes.Size := 8;
SelAttributes.Name := 'MS Sans Serif';
Lines.Add(AText);
end;
end;
 
procedure TForm1.TrayMessage(var Msg: TMessage);
begin
case Msg.lParam of
WM_LBUTTONDOWN:
begin
Form1.Show;
end;
WM_RBUTTONDOWN:
begin
Form1.Show;
end;
end;
end;
 
function GetComputerName: string;
var
buffer: array[0..MAX_COMPUTERNAME_LENGTH + 1] of Char;
Size: Cardinal;
begin
Size := MAX_COMPUTERNAME_LENGTH + 1;
Windows.GetComputerName(@buffer, Size);
Result := StrPas(buffer);
end;
 
procedure TForm1.Button1Click(Sender: TObject);
begin
TcpClient1.RemoteHost := Host.Text;
TcpClient1.Connect;
try
if TcpClient1.Connect then begin
TcpClient1.Sendln(Unit2.Encrypt(Mes.Text,edkey));
sleep(10);
AddColoredLine(Chat,'<<'+TimeToStr(now)+ '>> '+GetComputerName+'-->'+Host.Text+':'+Mes.Text,clBlack);
Shell_NotifyIcon(NIM_DELETE, @TrayIconData2);
end;
finally
TcpClient1.Disconnect;
end;
Mes.Items.Add(Mes.Text);
Mes.SelectAll;
Mes.SetFocus;
end;
 
procedure TForm1.FormCreate(Sender: TObject);
begin
//media file that will be played when you receive a message
MediaPlayer1.FileName := ExtractFilePath(Application.ExeName)+'\Wav\calling.wav';
if FileExists(MediaPlayer1.FileName) then
MediaPlayer1.Open;
TcpClient1.Active := false;
TcpServer1.Active := false;
TcpServer1.LocalPort := '3344';
TcpClient1.RemotePort := '3344';
TcpServer1.Active := true;
TcpClient1.Active := true;
end;
 
procedure TForm1.FormDestroy(Sender: TObject);
begin
TcpClient1.Disconnect;
TcpClient1.Active := false;
TcpServer1.Active := false;
MediaPlayer1.Close;
Shell_NotifyIcon(NIM_DELETE, @TrayIconData2);
end;
 
procedure TForm1.TcpServer1Accept(Sender: TObject;
ClientSocket: TCustomIpClient);
var
s,s1 : string;
j : integer;
crc : string;
begin
inc(mescount);
if mescount > 1 then
CheckBox1.Checked := true;
sleep(200);
//Message.ico is the file of the icon that will appear when you receive a message
if FileExists(ExtractFilePath(Application.ExeName)+'Message.ico') then Begin
icon1 := TIcon.Create;
icon1.LoadFromFile(ExtractFilePath(Application.ExeName)+'Message.ico');
with TrayIconData2 do
begin
cbSize := SizeOf(TrayIconData2);
Wnd := Handle;
uID := 0;
uFlags := NIF_MESSAGE + NIF_ICON + NIF_TIP;
uCallbackMessage := WM_ICONTRAY2;
hIcon := icon1.Handle;
StrPCopy(szTip, Application.Title);
end;
try
Shell_NotifyIcon(NIM_ADD, @TrayIconData2);
finally
icon1.Free;
end;
end;
s := Decrypt(ClientSocket.Receiveln,edkey);
 
while s <> '' do begin
sleep(10);
AddColoredLine(Chat,'<<'+TimeToStr(now)+ '>>'+ClientSocket.LookupHostName(ClientSocket.RemoteHost)+'('+ClientSocket.RemoteHost+'):
'+s,clBlue);
s := Decrypt(ClientSocket.Receiveln,edkey);
if mescount < 2 then
if FileExists(MediaPlayer1.FileName) then begin
MediaPlayer1.Open;
Form1.MediaPlayer1.Play;
end;
end;
end;
 
procedure TForm1.Clear1Click(Sender: TObject);
begin
Chat.Clear;
end;
 
procedure TForm1.MesKeyPress(Sender: TObject; var Key: Char);
begin
if key = #13 then
Button1.Click;
if key = #27 then
Form1.Hide;
end;
 
procedure TForm1.HostKeyPress(Sender: TObject; var Key: Char);
begin
if key = #27 then
Form1.Hide;
end;
 
procedure TForm1.FormKeyPress(Sender: TObject; var Key: Char);
begin
if key = #27 then
Form1.Hide;
end;
 
procedure TForm1.ChatKeyPress(Sender: TObject; var Key: Char);
begin
if key = #27 then
Form1.Hide;
end;
 
procedure TForm1.FormShow(Sender: TObject);
begin
Form1.Update;
Form1.UpdateControlState;
Form1.*******;
Form1.Repaint;
 
Mes.SelectAll;
Mes.SetFocus;
Chat.Repaint;
Shell_NotifyIcon(NIM_DELETE, @TrayIconData2);
end;
 
procedure TForm1.FormPaint(Sender: TObject);
begin
Chat.Repaint;
end;
 
procedure TForm1.CheckBox1Click(Sender: TObject);
begin
if CheckBox1.Checked = true then
TcpServer1.Active := false
else
TcpServer1.Active := true;
end;
 
procedure TForm1.Timer1Timer(Sender: TObject);
begin
mescount := 0;
if CheckBox1.Checked = true then begin
CheckBox1.Checked := false;
TcpServer1.Active := true;
end;
end;
 
procedure TForm1.Save1Click(Sender: TObject);
begin
if SaveDialog1.Execute then
Chat.Lines.SaveToFile(SaveDialog1.FileName+'.rtf');
end;
 
procedure TForm1.FormHide(Sender: TObject);
begin
Shell_NotifyIcon(NIM_DELETE, @TrayIconData2);
end;
 
end.
 
Unit2:
unit Unit2;
interface
 
function Decrypt(const S: AnsiString; Key: Word): AnsiString;
function Encrypt(const S: AnsiString; Key: Word): AnsiString;
 
implementation
 
const
C1 = 52845;
C2 = 22719;
 
function Decode(const S: AnsiString): AnsiString;
const
Map: array[Char] of Byte = (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 62, 0, 0, 0, 63, 52, 53,
54, 55, 56, 57, 58, 59, 60, 61, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2,
3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
20, 21, 22, 23, 24, 25, 0, 0, 0, 0, 0, 0, 26, 27, 28, 29, 30,
31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45,
46, 47, 48, 49, 50, 51, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0);
var
I: LongInt;
begin
case Length(S) of
2:
begin
I := Map[S[1]] + (Map[S[2]] shl 6);
SetLength(Result, 1);
Move(I, Result[1], Length(Result))
end;
3:
begin
I := Map[S[1]] + (Map[S[2]] shl 6) + (Map[S[3]] shl 12);
SetLength(Result, 2);
Move(I, Result[1], Length(Result))
end;
4:
begin
I := Map[S[1]] + (Map[S[2]] shl 6) + (Map[S[3]] shl 12) +
(Map[S[4]] shl 18);
SetLength(Result, 3);
Move(I, Result[1], Length(Result))
end
end
end;
 
function PreProcess(const S: AnsiString): AnsiString;
var
SS: AnsiString;
begin
SS := S;
Result := '';
while SS <> '' do
begin
Result := Result + Decode(Copy(SS, 1, 4));
Delete(SS, 1, 4)
end
end;
 
function InternalDecrypt(const S: AnsiString; Key: Word): AnsiString;
var
I: Word;
Seed: Word;
begin
Result := S;
Seed := Key;
for I := 1 to Length(Result) do
begin
Result[I] := Char(Byte(Result[I]) xor (Seed shr 8));
Seed := (Byte(S[I]) + Seed) * Word(C1) + Word(C2)
end
end;
 
function Decrypt(const S: AnsiString; Key: Word): AnsiString;
begin
Result := InternalDecrypt(PreProcess(S), Key)
end;
 
function Encode(const S: AnsiString): AnsiString;
const
Map: array[0..63] of Char = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' +
'abcdefghijklmnopqrstuvwxyz0123456789+/';
var
I: LongInt;
begin
I := 0;
Move(S[1], I, Length(S));
case Length(S) of
1:
Result := Map[I mod 64] + Map[(I shr 6) mod 64];
2:
Result := Map[I mod 64] + Map[(I shr 6) mod 64] +
Map[(I shr 12) mod 64];
3:
Result := Map[I mod 64] + Map[(I shr 6) mod 64] +
Map[(I shr 12) mod 64] + Map[(I shr 18) mod 64]
end
end;
 
function PostProcess(const S: AnsiString): AnsiString;
var
SS: AnsiString;
begin
SS := S;
Result := '';
while SS <> '' do
begin
Result := Result + Encode(Copy(SS, 1, 3));
Delete(SS, 1, 3)
end
end;
 
function InternalEncrypt(const S: AnsiString; Key: Word): AnsiString;
var
I: Word;
Seed: Word;
begin
Result := S;
Seed := Key;
for I := 1 to Length(Result) do
begin
Result[I] := Char(Byte(Result[I]) xor (Seed shr 8));
Seed := (Byte(Result[I]) + Seed) * Word(C1) + Word(C2)
end
end;
 
function Encrypt(const S: AnsiString; Key: Word): AnsiString;
begin
Result := PostProcess(InternalEncrypt(S, Key))
end;
 
end.