unit Add;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type
  TAddForm = class(TForm)
    Label1: TLabel;
    Edit1: TEdit;
    Label2: TLabel;
    Edit2: TEdit;
    Label3: TLabel;
    Edit3: TEdit;
    Label4: TLabel;
    Edit4: TEdit;
    Label5: TLabel;
    Button1: TButton;
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
    procedure Edit1Change(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Edit2KeyPress(Sender: TObject; var Key: Char);
    procedure Edit3KeyPress(Sender: TObject; var Key: Char);
    procedure Edit4KeyPress(Sender: TObject; var Key: Char);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  AddForm: TAddForm;

implementation

Uses
   Base, ChangeMenu, Menu, DeleteRef, Change;

{$R *.dfm}

procedure TAddForm.Button1Click(Sender: TObject);
var
   s: String;
   i, kol: Integer;
begin
   kol := 0;
   s := Edit4.Text;
   for i := 1 to length(s) do
      if s[i] = '.' then
         inc(kol);
   if kol <> 2 then
      MessageDlg('Введите дату в формате день.месяц.год', mtError, [mbOK], 0)
   else
   begin
      Inc(n);
      SetLength(Ref, n);
      Ref[n - 1].Topic := Edit1.Text;
      Ref[n - 1].Author := Edit2.Text;
      Ref[n - 1].Str := StrToInt(Edit3.Text);
      Ref[n - 1].Date := Edit4.Text;
      Edit1.Text := '';
      Edit2.Text := '';
      Edit3.Text := '';
      Edit4.Text := '';
      Seek(MyFile, FileSize(MyFile));
      Write(MyFile, Ref[n - 1]);
      BaseForm.Show;
      AddForm.Hide;
   end;
end;

procedure TAddForm.Edit1Change(Sender: TObject);
var
   IsValid1, IsValid2, IsValid3, IsValid4: Boolean;
begin
   if Edit1.Text <> '' then
      IsValid1 := True
   else
      IsValid1 := False;
   if Edit2.Text <> '' then
      IsValid2 := True
   else
      IsValid2 := False;
   if Edit3.Text <> '' then
      IsValid3 := True
   else
      IsValid3 := False;
   if Edit4.Text <> '' then
      IsValid4 := True
   else
      IsValid4 := False;
   if (IsValid1) and (IsValid2) and (IsValid3) and (IsValid4) then
      Button1.Enabled := True
   else
      Button1.Enabled := False;
end;

procedure TAddForm.Edit2KeyPress(Sender: TObject; var Key: Char);
const
   NotDigit: set of Char = ['0'..'9', '.', ','];
begin
   with (Sender as TEdit) do
   begin
      if Key in NotDigit then
         Key := #0;
   end;
end;

procedure TAddForm.Edit3KeyPress(Sender: TObject; var Key: Char);
const
   Digit: set of Char = ['0'..'9', #8];
begin
   with (Sender as TEdit) do
   begin
      if not(Key in Digit) then
         Key := #0;
   end;
end;

procedure TAddForm.Edit4KeyPress(Sender: TObject; var Key: Char);
const
   Digit: set of Char = ['0'..'9', #8, '.'];
begin
   with (Sender as TEdit) do
   begin
      if not(Key in Digit) then
         Key := #0;
   end;
end;

procedure TAddForm.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
   BaseForm.Show;
   MenuForm.Hide;
   ChangeMenuForm.Hide;
   AddForm.Hide;
   DeleteForm.Hide;
   ChangeForm.Hide;
end;

end.