An ATL Component in C++ that fires COM events

// InterProcessComms.idl : IDL source for InterProcessComms
//

// This file will be processed by the MIDL tool to
// produce the type library (InterProcessComms.tlb) and marshalling code.

#include "olectl.h"
import "oaidl.idl";
import "ocidl.idl";

[
	object,
	uuid(1EA7D7FD-5BC5-46D4-819D-BD520E2A1D0E),
	dual,
	nonextensible,
	helpstring("IIPC Interface"),
	pointer_default(unique)
]
interface IIPC : IDispatch{
	[propget, id(1), helpstring("property msghWnd - the hWnd of the hidden msg window")] 
	  HRESULT msghWnd([out, retval] LONG* pVal);

	[id(2), helpstring("method SendData")]
	  HRESULT SendData([in] LONG lData, [in] BSTR sData, [in, optional, defaultvalue(0)] LONG hWnd);	 
};

[
	uuid(22845CAA-F3B2-4F85-B8EF-CAEAA7EBF796),
	version(1.0),
	helpstring("NBDs InterProcessComms 1.0 Type Library")
]
library InterProcessCommsLib
{
	importlib("stdole2.tlb");
	[
		uuid(B11D3BF6-07E2-432E-95FF-BC46E525C04B),
		helpstring("_IIPCEvents Interface")
	]
	dispinterface _IIPCEvents
	{
		properties:
		methods:
		[id(1), helpstring("method MessageReceived Event")] void MessageReceived([in] LONG lData, [in] BSTR sMsg, [in] LONG lLenght);
	};
	[
		uuid(4B0C2DEB-1C04-4BB8-80A4-B7C2CA85BC8E),
		helpstring("IPC Class")
	]
	coclass IPC
	{
		[default] interface IIPC;
		[default, source] dispinterface _IIPCEvents;
	};
};