widget/windows/IEnumFE.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef IEnumeFE_h__
   7 #define IEnumeFE_h__
   8
   9 /*
  10  * CEnumFormatEtc - implements IEnumFORMATETC
  11  */
  12
  13 #include <ole2.h>
  14
  15 #include "nsTArray.h"
  16 #include "mozilla/Attributes.h"
  17
  18 // FORMATETC container
  19 class FormatEtc {
  20  public:
  21   FormatEtc() { memset(&mFormat, 0, sizeof(FORMATETC)); }
  22   FormatEtc(const FormatEtc& copy) { CopyIn(&copy.mFormat); }
  23   ~FormatEtc() {
  24     if (mFormat.ptd) CoTaskMemFree(mFormat.ptd);
  25   }
  26
  27   void CopyIn(const FORMATETC* aSrc) {
  28     if (!aSrc) {
  29       memset(&mFormat, 0, sizeof(FORMATETC));
  30       return;
  31     }
  32     mFormat = *aSrc;
  33     if (aSrc->ptd) {
  34       mFormat.ptd = (DVTARGETDEVICE*)CoTaskMemAlloc(sizeof(DVTARGETDEVICE));
  35       *(mFormat.ptd) = *(aSrc->ptd);
  36     }
  37   }
  38
  39   void CopyOut(LPFORMATETC aDest) {
  40     if (!aDest) return;
  41     *aDest = mFormat;
  42     if (mFormat.ptd) {
  43       aDest->ptd = (DVTARGETDEVICE*)CoTaskMemAlloc(sizeof(DVTARGETDEVICE));
  44       *(aDest->ptd) = *(mFormat.ptd);
  45     }
  46   }
  47
  48  private:
  49   FORMATETC mFormat;
  50 };
  51
  52 /*
  53  * CEnumFormatEtc is created within IDataObject::EnumFormatEtc. This object
  54  * lives on its own, that is, QueryInterface only knows IUnknown and
  55  * IEnumFormatEtc, nothing more.  We still use an outer unknown for reference
  56  * counting, because as long as this enumerator lives, the data object should
  57  * live, thereby keeping the application up.
  58  */
  59
  60 class CEnumFormatEtc final : public IEnumFORMATETC {
  61  public:
  62   explicit CEnumFormatEtc(nsTArray<FormatEtc>& aArray);
  63   CEnumFormatEtc();
  64   ~CEnumFormatEtc();
  65
  66   // IUnknown impl.
  67   STDMETHODIMP QueryInterface(REFIID riid, LPVOID* ppv);
  68   STDMETHODIMP_(ULONG) AddRef();
  69   STDMETHODIMP_(ULONG) Release();
  70
  71   // IEnumFORMATETC impl.
  72   STDMETHODIMP Next(ULONG aMaxToFetch, FORMATETC* aResult, ULONG* aNumFetched);
  73   STDMETHODIMP Skip(ULONG aSkipNum);
  74   STDMETHODIMP Reset();
  75   STDMETHODIMP Clone(LPENUMFORMATETC* aResult);  // Addrefs
  76
  77   // Utils
  78   void AddFormatEtc(LPFORMATETC aFormat);
  79
  80  private:
  81   nsTArray<FormatEtc> mFormatList;  // Formats
  82   ULONG mRefCnt;                    // Object reference count
  83   ULONG mCurrentIdx;                // Current element
  84
  85   void SetIndex(uint32_t aIdx);
  86 };
  87
  88 #endif  //_IENUMFE_H_