//
//**************************************************************************
// 
// BOleData.h --   Declares a data cache object which is used for delayed
//                 rendering.
//
// Copyright (c) 1993,94 by Borland International, Inc. All rights reserved
//
//**************************************************************************

#ifndef _BOLEDATA_H
#define _BOLEDATA_H 1

#include "BOle.h"
#include "BOleComp.h"

// This is where the cached data actually lives.
//
typedef struct FAR tagBOleDataItem {
	struct FAR tagBOleDataItem FAR *pNext;
	FORMATETC    fmtEtc;
	STGMEDIUM    tymed;
} BOleDataItem;

// BOleData -- Provides a data cache object for use when copying from
//             an embedding.
//
//
//
//
class _ICLASS BOleData : public BOleComponent, 
                         public IDataObject
{
	public:

		BOleData (BOleClassManager *, PIBUnknownMain);
		~BOleData ();

		// IUnknown Methods
		//
		DEFINE_IUNKNOWN (pObjOuter);
		HRESULT _IFUNC QueryInterfaceMain (REFIID iid, LPVOID FAR* pif);

	protected:

		BOleDataItem FAR *pFirstItem;
		BOleDataItem FAR *pLastItem;
		void FreeItems();

		friend  class _ICLASS  BOleEnumFormatEtc;

		// IDataObject methods
		//
		virtual HRESULT _IFUNC GetData (LPFORMATETC, LPSTGMEDIUM);
		virtual HRESULT _IFUNC GetDataHere (LPFORMATETC, LPSTGMEDIUM);
		virtual HRESULT _IFUNC QueryGetData (LPFORMATETC);
		virtual HRESULT _IFUNC GetCanonicalFormatEtc (LPFORMATETC, LPFORMATETC);
		virtual HRESULT _IFUNC SetData (LPFORMATETC, STGMEDIUM FAR *, BOOL);
		virtual HRESULT _IFUNC EnumFormatEtc (DWORD, LPENUMFORMATETC FAR*);
		virtual HRESULT _IFUNC DAdvise (FORMATETC FAR*, DWORD, LPADVISESINK, DWORD FAR*);
		virtual HRESULT _IFUNC DUnadvise (DWORD);
		virtual HRESULT _IFUNC EnumDAdvise (LPENUMSTATDATA FAR*);

};

// BOleEnumFormatEtc -- Provides a "cursor" on the list of formats
//                      offered by BOleData
//
class _ICLASS BOleEnumFormatEtc : public IEnumFORMATETC
{
	public:

	BOleEnumFormatEtc( BOleData *Data );

	// IUnknown methods
	//
	HRESULT _IFUNC QueryInterface(REFIID iid, void FAR* FAR* pif);
	ULONG _IFUNC AddRef();
	ULONG _IFUNC Release();

	// IEnumFORMATETC methods
	//
	HRESULT _IFUNC Next (ULONG celt, FORMATETC FAR * rgelt,
								ULONG FAR* pceltFetched);
	HRESULT _IFUNC Skip (ULONG celt);
	HRESULT _IFUNC Reset ();
	HRESULT _IFUNC Clone (IEnumFORMATETC FAR* FAR* ppenum);

	// Private methods
	//
	void Resync();

	BOleDataItem FAR *pCurItem;
	BOleDataItem FAR *pFirstItem;
	BOleDataItem FAR *pLastItem;
	BOleData *pData;
	LONG nRef;
};

// BOleShadowData -- The execution of EmptyClipboard() causes OLE2 to call
//                   CoDisconnectObject on the data object which has been 
//                   posted to the clipboard. 
//
//                   The consequence is that if we post the original objects
//                   (as opposed to clones of them), OLE2 might FORCE the 
//                   refcount of such objects to zero on our behalf. 
//
//                   To solve this we post a small shadow object which 
//                   delegates IDataObject to the real object, but implements
//                   IUnknown here (stopping CoDisconnectObject from 
//                   decrementing the real object until it goes to zero).
//
class _ICLASS BOleShadowData : public BOleComponent, public IDataObject
{
	public:

		BOleShadowData (BOleClassManager *pCM, LPDATAOBJECT pDeleg);
		virtual ~BOleShadowData();
		LPDATAOBJECT GetRealData() {return pDelegate;}
	
		DEFINE_IUNKNOWN(pObjOuter);

		// IDataObject
		//
		virtual HRESULT _IFUNC GetData (LPFORMATETC, LPSTGMEDIUM);
		virtual HRESULT _IFUNC GetDataHere (LPFORMATETC, LPSTGMEDIUM);
		virtual HRESULT _IFUNC QueryGetData (LPFORMATETC);
		virtual HRESULT _IFUNC GetCanonicalFormatEtc (LPFORMATETC, LPFORMATETC);
		virtual HRESULT _IFUNC SetData (LPFORMATETC, STGMEDIUM FAR *, BOOL);
		virtual HRESULT _IFUNC EnumFormatEtc (DWORD, LPENUMFORMATETC FAR*);
		virtual HRESULT _IFUNC DAdvise (FORMATETC FAR*, DWORD, LPADVISESINK, DWORD FAR*);
		virtual HRESULT _IFUNC DUnadvise (DWORD);
		virtual HRESULT _IFUNC EnumDAdvise (LPENUMSTATDATA FAR*);

		// IUnknown
		//
		virtual HRESULT _IFUNC QueryInterfaceMain(REFIID iid, void FAR* FAR* pif);

	protected:

		LPDATAOBJECT pDelegate;
};

#endif