Simple Aggregate

This is a simple aggregate that recreates its subcomponents each time it is constructed.

.h

//---------------------------------------------------------------------------

#ifndef AggregatePanelH
#define AggregatePanelH
//---------------------------------------------------------------------------
#include <SysUtils.hpp>
#include <Controls.hpp>
#include <Classes.hpp>
#include <Forms.hpp>
#include <ExtCtrls.hpp>
//---------------------------------------------------------------------------
class PACKAGE TAggregatePanel : public TPanel
{
   /*
      This component class implements a panel with children. The children are
      recreated each time, and their characteristics are not streamed.

      This is a conventional aggregate component
   */

   private:
   protected:

      TButton   *myChildButton;
      TButton *__fastcall CreateChildButton(TComponent *theOwner);

   public:

      __fastcall TAggregatePanel(TComponent* Owner);
      void __fastcall ClickChildButton(TObject *Sender);

   __published:
   
};
//---------------------------------------------------------------------------
#endif



.cpp

//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "AggregatePanel.h"
#pragma package(smart_init)
//---------------------------------------------------------------------------
// ValidCtrCheck is used to assure that the components created do not have
// any pure virtual functions.
//

static inline void ValidCtrCheck(TAggregatePanel *)
{
   new TAggregatePanel(NULL);
}
//---------------------------------------------------------------------------
__fastcall TAggregatePanel::TAggregatePanel(TComponent* Owner)
   : TPanel(Owner)
{
   Parent = dynamic_cast<TWinControl *>(Owner);
   Top = 0;
   Left = 0;
   Width = 200;
   Height = 50;

   myChildButton = CreateChildButton(this);
}
//---------------------------------------------------------------------------
TButton *__fastcall TAggregatePanel::CreateChildButton(TComponent *theOwner)
{
   // This function is shared with the descendants, to make it easier to
   // alter the owner when creating.

   TButton *ChildButton = new TButton(theOwner);
   ChildButton->Parent = this;
   ChildButton->Caption = "Child Button";
   ChildButton->OnClick = ClickChildButton;

   return ChildButton;
}
//---------------------------------------------------------------------------
void __fastcall TAggregatePanel::ClickChildButton(TObject *Sender)
{
   myChildButton->Caption = FormatDateTime("hh:mm:ss",TDateTime::CurrentDateTime());
}
//---------------------------------------------------------------------------
namespace Aggregatepanel
{
   void __fastcall PACKAGE Register()
   {
      TComponentClass classes[1] = {__classid(TAggregatePanel)};
      RegisterComponents("MSC Test", classes, 0);
   }
}
//---------------------------------------------------------------------------