unit Change;

interface

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

type
  TChangeForm = class(TForm)
    Refs: TComboBox;
    LTopic: TLabel;
    LSecName: TLabel;
    LStr: TLabel;
    LDate: TLabel;
    Topic: TEdit;
    SecName: TEdit;
    Str: TEdit;
    Date: TEdit;
    Save: TButton;
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
    procedure RefsDropDown(Sender: TObject);
    procedure RefsClick(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure SaveClick(Sender: TObject);
    procedure SecNameKeyPress(Sender: TObject; var Key: Char);
    procedure StrKeyPress(Sender: TObject; var Key: Char);
    procedure DateKeyPress(Sender: TObject; var Key: Char);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  ChangeForm: TChangeForm;
  ChangeIndex: Integer;
  Flag: Boolean;

implementation

Uses
   Base, ChangeMenu, Add, DeleteRef, Menu;

{$R *.dfm}

procedure TChangeForm.SaveClick(Sender: TObject);
var
   i, kol: Integer;
   Temp: TRef;
   s: string;
begin
   kol := 0;
   s := Date.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(ChangeIndex);
      seek(MyFile, ChangeIndex - 1);
      Temp.Topic := Topic.Text;
      Temp.Author := SecName.Text;
      Temp.Str := StrToInt(Str.Text);
      Temp.Date := Date.Text;
      Write(MyFile, Temp);
      Inc(ChangeIndex);
      seek(MyFIle, ChangeIndex - 1);
      for i := n - 1 to FileSize(MyFile) - 2 do
      begin
         seek(MyFile, i + 1);
         Read(MyFIle, temp);
         seek(MyFile, i);
         Write(MyFile, Temp);
      end;
      seek(MyFile, FileSize(myfile));
      truncate(MyFile);
      Reset(MyFile);
      i := 0;
      While not eof(MyFile) do
      begin
         Read(MyFile, Ref[i]);
         Inc(i);
      end;
      n := i;
      Refs.Clear;
      ChangeForm.Hide;
      BaseForm.Show;
   end;
end;

procedure TChangeForm.RefsClick(Sender: TObject);
begin
   Save.Visible := True;
   ChangeIndex := Refs.Items.IndexOf(Refs.Text);
   Topic.Text := Ref[ChangeIndex].Topic;
   SecName.Text := Ref[ChangeIndex].Author;
   Str.Text := IntToStr(Ref[ChangeIndex].Str);
   Date.Text := Ref[ChangeIndex].Date;
   Topic.Visible := True;
   SecName.Visible := True;
   Str.Visible := True;
   Date.Visible := True;
   LTopic.Visible := True;
   LSecName.Visible := True;
   LStr.Visible := True;
   LDate.Visible := True;
end;

procedure TChangeForm.RefsDropDown(Sender: TObject);
var
   i: Integer;
begin
   Refs.Clear;
   for i := 0 to n - 1 do
      Refs.Items.Add(Ref[i].Topic);
end;

procedure TChangeForm.SecNameKeyPress(Sender: TObject; var Key: Char);
const
   Digit: set of Char = ['a'..'z', #8, 'A'..'Z'];
begin
   with (Sender as TEdit) do
   begin
      if not(Key in Digit) then
         Key := #0;
   end;
end;

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

procedure TChangeForm.FormShow(Sender: TObject);
begin
   Refs.Clear;
   Save.Visible := False;
   Topic.Visible := False;
   SecName.Visible := False;
   Str.Visible := False;
   Date.Visible := False;
   LTopic.Visible := False;
   LSecName.Visible := False;
   LStr.Visible := False;
   LDate.Visible := False;
end;

end.