gecko-dev/widget/windows/IEnumFE.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * Contributor(s):
 *   Jim Mathies <jmathies@mozilla.com>
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#ifndef IEnumeFE_h__
#define IEnumeFE_h__

/*
 * CEnumFormatEtc - implements IEnumFORMATETC
 */

#include <ole2.h>

#include "nsTArray.h"

// FORMATETC container
class FormatEtc
{
public:
  FormatEtc() { memset(&mFormat, 0, sizeof(FORMATETC)); }
  FormatEtc(const FormatEtc& copy) { CopyIn(&copy.mFormat); }
  ~FormatEtc() { if (mFormat.ptd) CoTaskMemFree(mFormat.ptd); }

  void CopyIn(const FORMATETC *aSrc) {
    if (!aSrc) {
        memset(&mFormat, 0, sizeof(FORMATETC));
        return;
    }
    mFormat = *aSrc;
    if (aSrc->ptd) {
        mFormat.ptd = (DVTARGETDEVICE*)CoTaskMemAlloc(sizeof(DVTARGETDEVICE));
        *(mFormat.ptd) = *(aSrc->ptd);
    }
  }

  void CopyOut(LPFORMATETC aDest) {
    if (!aDest)
        return;
    *aDest = mFormat;
    if (mFormat.ptd) {
        aDest->ptd = (DVTARGETDEVICE*)CoTaskMemAlloc(sizeof(DVTARGETDEVICE));
        *(aDest->ptd) = *(mFormat.ptd);
    }
  }

private:
  FORMATETC mFormat;
};

/*
 * CEnumFormatEtc is created within IDataObject::EnumFormatEtc. This object lives
 * on its own, that is, QueryInterface only knows IUnknown and IEnumFormatEtc,
 * nothing more.  We still use an outer unknown for reference counting, because as
 * long as this enumerator lives, the data object should live, thereby keeping the
 * application up.
 */

class CEnumFormatEtc : public IEnumFORMATETC
{
public:
    CEnumFormatEtc(nsTArray<FormatEtc>& aArray);
    CEnumFormatEtc();
    ~CEnumFormatEtc();

    // IUnknown impl.
    STDMETHODIMP QueryInterface(REFIID riid, LPVOID *ppv);
    STDMETHODIMP_(ULONG) AddRef();
    STDMETHODIMP_(ULONG) Release();

    // IEnumFORMATETC impl.
    STDMETHODIMP Next(ULONG aMaxToFetch, FORMATETC *aResult, ULONG *aNumFetched);
    STDMETHODIMP Skip(ULONG aSkipNum);
    STDMETHODIMP Reset();
    STDMETHODIMP Clone(LPENUMFORMATETC *aResult); // Addrefs

    // Utils 
    void AddFormatEtc(LPFORMATETC aFormat);

private:
    nsTArray<FormatEtc> mFormatList; // Formats
    ULONG mRefCnt; // Object reference count
    ULONG mCurrentIdx; // Current element

    void SetIndex(PRUint32 aIdx);
};


#endif //_IENUMFE_H_