Let the components dropped on my control in the IDE become children of my control

I have a descendant TWinControl

(which is actually the case now) and I registered it as a component in the IDE:

type
  TGroupPanel = class(TWinControl);

      

        
        
        
      

    

But when I drop other components onto it, they attach to the form instead of my control. In other words, I want my custom control to behave like TPanel

so that the components dropped on it become its children.

If I create components at runtime and assign them manually to my control like in the code below, then it works:

  TForm1 = class(TForm)
    Group: TGroupPanel;
    procedure FormCreate(Sender: TObject);
  private
    Panel: TPanel;
  end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Panel := TPanel.Create(Group);
  Panel.Parent := Group;
  Panel.Align := alClient;
end;

      

        
        
        
      

    

So what do I need to do to make components dropped to TWinControl

at design time become children of this control?

(I'm trying to make special control for grouping other components, so I can align them and put them together. Of course I can do this with a regular panel, but I want to do it with a lightweight control that doesn't draw anything, and in TWinControl

I found a solution.)