type
 TCaptionButton = class (TComponent)
 private
   FButtonPosition   : Byte;
   procedure SetButtonPosition( const Value: Byte );
 public
   constructor Create(AOwner: TComponent); override;
   destructor Destroy; override;
 published
   property Position: Byte read FButtonPosition write SetButtonPosition default 4;
 end;

 TFormCaption = class(TComponent)
 private
   FCaptionButton    : TCaptionButton;
   FOnButtonClick    : TNotifyEvent;
   FOnButtonMouseMove: TMouseMoveEvent;
   procedure DrawButton;
 protected
   procedure ButtonClick; dynamic;
   procedure ButtonMouseMove(Shift: TShiftState; X, Y: Integer); dynamic;
 public
   constructor Create(AOwner: TComponent); override;
   destructor  Destroy; override;
   property Button: TCaptionButton read FCaptionButton write FCaptionButton;
   property OnButtonMouseMove: TMouseMoveEvent read FOnButtonMouseMove write FOnButtonMouseMove;
   property OnButtonClick: TNotifyEvent read FOnButtonClick write FOnButtonClick;
 end;

procedure Register;

implementation

constructor TCaptionButton.Create(AOwner: TComponent);
begin
 inherited Create(AOwner);
 FButtonPosition := 4;
end;

destructor TCaptionButton.Destroy;
begin
 inherited Destroy;
end;

procedure TCaptionButton.SetButtonPosition(const Value: Byte);
begin
 if Value <> FButtonPosition then
 begin
   FButtonPosition:=Value;
 end;
end;

constructor TFormCaption.Create(AOwner: TComponent);
begin
 inherited Create(AOwner);
 Button:=TCaptionButton.Create(Self);
end;

procedure Register;
begin
 RegisterComponents('Additional', [TFormCaption]);
 RegisterPropertyEditor( TypeInfo( TCaptionButton ),  TFormCaption, 'Button', TClassProperty ) ;
end;

end.

property Button: TCaptionButton