[NumLock]

Код:

unit Unit1;

interface

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

type
  TPopupCustomControl = class(TCustomControl)
  private
    procedure DoMouseDown(Sender: TObject;
      Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
  public
    constructor Create(AOwner: TComponent); override;
  published
    property PopupMenu;
  end;

  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{ TPopupCustomControl }

constructor TPopupCustomControl.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  OnMouseDown:=DoMouseDown;
end;

procedure TPopupCustomControl.DoMouseDown(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  ShowMessage(IntToStr(X)+', '+IntToStr(Y));
end;

{ TForm1 }

procedure TForm1.FormCreate(Sender: TObject);
begin
  with TPopupCustomControl.Create(Self) do
  begin
    Parent:=Self;
    Width:=100;
    Height:=100;
  end;
end;

end.