unit Unit1; 

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, LResources, Forms, Controls, Graphics, Dialogs,
  StdCtrls, ComCtrls;

type

  { TForm1 }

  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    Edit1: TEdit;
    Edit2: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    OpenDialog1: TOpenDialog;
    ProgressBar1: TProgressBar;
    SaveDialog1: TSaveDialog;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);

  private
    { private declarations }
  public
    { public declarations }
  end; 

var
  Form1: TForm1;

implementation

{ TForm1 }

procedure TForm1.Button1Click(Sender: TObject);
begin
if form1.OpenDialog1.Execute
then
form1.Edit1.Caption:=form1.OpenDialog1.FileName;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  if form1.SaveDialog1.Execute
  then
  form1.Edit2.Caption:=form1.SaveDialog1.FileName;
end;

procedure TForm1.Button3Click(Sender: TObject);
var f1,f2: file of byte;
a,b,c:byte;
fs,fp:int64;
begin

assignFile(f1,form1.Edit1.Text);
reset(f1);
assignfile(f2,form1.Edit2.Text);
rewrite(f2);
fs:=filesize(f1);
                                while not eof(f1) do
                                begin
                                fp:=filepos(f1);
                                      read(f1,a);
                                      b:=a+3;
                                      write(f2,b);
                                      c:=round(fp/fs*100);
                                      form1.ProgressBar1.Position:=c;
                                end;
closefile(f2);
closefile(f1);
end;

procedure TForm1.Button4Click(Sender: TObject);
var f1,f2: file of byte;
a,b,c:byte;
  fs,fp:int64;
begin

assignFile(f2,form1.Edit1.Text);
reset(f2);
assignfile(f1,form1.Edit2.Text);
rewrite(f1);
fs:=filesize(f2);
                                while not eof(f2) do
                                begin
                                                  fp:=filepos(f2);
                                      read(f2,a);
                                      b:=a-3;
                                      write(f1,b);
                                                  c:=round(fp/fs*100);
                                                  form1.ProgressBar1.Position:=c;
                                end;
closefile(f2);
closefile(f1);
end;

procedure TForm1.Button5Click(Sender: TObject);
begin
form1.Close;
end;



initialization
  {$I unit1.lrs}

end.