Interface Implementation By Delegation

InterfaceImplementation? of a ClassInterface? with an ObjectProperty?.

In the DelphiLanguage this is provided by implements keyword

Explain how this is different from other languages or types of inheritance, or DeleteThisPageSoon.

 type

   IXInterface = interface(IUnknown)
   ['{713252E5-4636-11D5-B572-00AA00ACFD08}']
      procedure XStaticMethod;
      procedure XVirtualMethod;
   end;

   IYInterface = interface(IUnknown)
   ['{713252E6-4636-11D5-B572-00AA00ACFD08}']
      procedure YMethod;
   end;

   IZInterface = interface(IUnknown)
   ['{713252E4-4636-11D5-B572-00AA00ACFD08}']
   end;


 type
   TInnerObject = class(TAggregatedObject,IXInterface,IYInterface)
   public
      procedure XStaticMethod;
      procedure XVirtualMethod; virtual;
      procedure YMethod;
   end;

   TSpecialObject = class(TInnerObject,IXInterface,IYInterface)
   public
      procedure XStaticMethod;
      procedure XVirtualMethod; override;
      procedure YMethod;
   end;

   TFoo = class(TObject,IXInterface,IYInterface,IZInterface)
   private
      FInnerX: TInnerObject;
   protected
    function QueryInterface(const IID: TGUID; out Obj): HResult; virtual; stdcall;
    function _AddRef: Integer; stdcall;
    function _Release: Integer; stdcall;
    function GetX: TInnerObject; virtual;
    function GetY: IYInterface;
   public
      constructor Create;
      destructor  Destroy; override;
      property  InnerX: TInnerObject read GetX implements IXInterface;
      property  InnerY: IYInterface  read GetY implements IYInterface;
   end;

   TBar = class(TFoo,IXInterface,IYInterface,IUnknown)
   private
    FX: TSpecialObject;
    FY: IYInterface;
   protected
      function GetX: TInnerObject; override;
   public
      constructor Create;
      destructor  Destroy; override;
      property Y: IYInterface  read FY implements IYInterface;
      property  X: TSpecialObject read FX implements IXInterface;
   end;