unit AddElementsUnit;

interface

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

type
  TAddElementsForm = class(TForm)
    AddBtn: TButton;
    ElementEdit: TEdit;
    InstructionMenu: TMainMenu;
    Instruction: TMenuItem;
    Label1: TLabel;
    procedure AddBtnClick(Sender: TObject);
    procedure ElementEditChange(Sender: TObject);
    procedure ElementEditKeyPress(Sender: TObject; var Key: Char);
    procedure FormShow(Sender: TObject);
    procedure InstructionClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  AddElementsForm: TAddElementsForm;

implementation

{$R *.dfm}

Uses
     MainUnit, LinkedListUnit;


procedure  TAddElementsForm.ElementEditChange(Sender: TObject);

begin
    if ElementEdit.Text <> '' then
        AddBtn.Enabled := true
    else
        AddBtn.Enabled := false;
end;


procedure TAddElementsForm.ElementEditKeyPress(Sender: TObject; var Key: Char);
begin
    if (ElementEdit.Text <> '') and (Key = #13) then
        AddBtnClick(Sender);
    if (ElementEdit.Text = '0') and (Key <> #08) then
        Key := #0;
end;

procedure TAddElementsForm.FormShow(Sender: TObject);
begin
    ElementEdit.Text := '';
    SystemParametersInfo(SPI_SETBEEP, 0, nil, SPIF_SENDWININICHANGE);
end;

procedure TAddElementsForm.InstructionClick(Sender: TObject);

var
    Separator: String;

begin
    Separator := #13#10;
    MessageDlg('Нужно ввессти число в диапазон 0..99.', mtInformation, [mbOK], 0);
end;


procedure TAddElementsForm.AddBtnClick(Sender: TObject);

begin
    TListOperations.push(Header, StrToInt(ElementEdit.Text));
    ElementEdit.Text := '';
    Main.ListMemo.Text := '';
end;


end.