Как объединить два визуальных VCL компонента

Реализация:

unit TestEdit;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls,
  Forms, Dialogs, StdCtrls;

type
  TTestEdit = class(TEdit)
  private
    FButton: TButton;
  protected
    procedure ButtonClick(Sender: TObject);
  public
    constructor Create( AOwner: TComponent ); override;
  published
  end;

procedure Register;

implementation

procedure TTestEdit.ButtonClick(Sender: TObject);
begin
  Text := DateToStr(Now);
end;

constructor TTestEdit.Create( AOwner: TComponent );
begin
  inherited Create(AOwner);
  Text := DateToStr(Now);
  FButton := TButton.Create( self );
  FButton.Visible := true;
  FButton.Parent := self;
  FButton.Height := Height - 2;
  FButton.Width := Height - 2;
  FButton.Left := Width - Height - 2;
  FButton.top := top;
  FButton.OnClick := ButtonClick;
end;

procedure Register;
begin
  RegisterComponents('Standard', [TTestEdit]);
end;

end.