michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "IEnumFE.h"
michael@0: #include "nsAlgorithm.h"
michael@0: #include <algorithm>
michael@0: 
michael@0: CEnumFormatEtc::CEnumFormatEtc() :
michael@0:   mRefCnt(0),
michael@0:   mCurrentIdx(0)
michael@0: {
michael@0: }
michael@0: 
michael@0: // Constructor used by Clone()
michael@0: CEnumFormatEtc::CEnumFormatEtc(nsTArray<FormatEtc>& aArray) :
michael@0:   mRefCnt(0),
michael@0:   mCurrentIdx(0)
michael@0: {
michael@0:   // a deep copy, calls FormatEtc's copy constructor on each
michael@0:   mFormatList.AppendElements(aArray);
michael@0: }
michael@0: 
michael@0: CEnumFormatEtc::~CEnumFormatEtc()
michael@0: {
michael@0: }
michael@0: 
michael@0: /* IUnknown impl. */
michael@0: 
michael@0: STDMETHODIMP
michael@0: CEnumFormatEtc::QueryInterface(REFIID riid, LPVOID *ppv)
michael@0: {
michael@0:   *ppv = nullptr;
michael@0: 
michael@0:   if (IsEqualIID(riid, IID_IUnknown) ||
michael@0:       IsEqualIID(riid, IID_IEnumFORMATETC))
michael@0:       *ppv = (LPVOID)this;
michael@0: 
michael@0:   if (*ppv == nullptr)
michael@0:       return E_NOINTERFACE;
michael@0: 
michael@0:   // AddRef any interface we'll return.
michael@0:   ((LPUNKNOWN)*ppv)->AddRef();
michael@0:   return S_OK;
michael@0: }
michael@0: 
michael@0: STDMETHODIMP_(ULONG)
michael@0: CEnumFormatEtc::AddRef()
michael@0: {
michael@0:   ++mRefCnt;
michael@0:   NS_LOG_ADDREF(this, mRefCnt, "CEnumFormatEtc",sizeof(*this));
michael@0:   return mRefCnt;
michael@0: }
michael@0: 
michael@0: STDMETHODIMP_(ULONG)
michael@0: CEnumFormatEtc::Release()
michael@0: {
michael@0:   uint32_t refReturn;
michael@0: 
michael@0:   refReturn = --mRefCnt;
michael@0:   NS_LOG_RELEASE(this, mRefCnt, "CEnumFormatEtc");
michael@0: 
michael@0:   if (mRefCnt == 0)
michael@0:       delete this;
michael@0: 
michael@0:   return refReturn;
michael@0: }
michael@0: 
michael@0: /* IEnumFORMATETC impl. */
michael@0: 
michael@0: STDMETHODIMP
michael@0: CEnumFormatEtc::Next(ULONG aMaxToFetch, FORMATETC *aResult, ULONG *aNumFetched)
michael@0: {
michael@0:   // If the method retrieves the number of items requested, the return
michael@0:   // value is S_OK. Otherwise, it is S_FALSE.
michael@0: 
michael@0:   if (aNumFetched)
michael@0:       *aNumFetched = 0;
michael@0: 
michael@0:   // aNumFetched can be null if aMaxToFetch is 1
michael@0:   if (!aNumFetched && aMaxToFetch > 1)
michael@0:       return S_FALSE;
michael@0: 
michael@0:   if (!aResult)
michael@0:       return S_FALSE;
michael@0: 
michael@0:   // We're done walking the list
michael@0:   if (mCurrentIdx >= mFormatList.Length())
michael@0:       return S_FALSE;
michael@0: 
michael@0:   uint32_t left = mFormatList.Length() - mCurrentIdx;
michael@0: 
michael@0:   if (!aMaxToFetch)
michael@0:       return S_FALSE;
michael@0: 
michael@0:   uint32_t count = std::min(static_cast<uint32_t>(aMaxToFetch), left);
michael@0: 
michael@0:   uint32_t idx = 0;
michael@0:   while (count > 0) {
michael@0:       // Copy out to aResult
michael@0:       mFormatList[mCurrentIdx++].CopyOut(&aResult[idx++]);
michael@0:       count--;
michael@0:   }
michael@0: 
michael@0:   if (aNumFetched)
michael@0:       *aNumFetched = idx;
michael@0: 
michael@0:   return S_OK;
michael@0: }
michael@0: 
michael@0: STDMETHODIMP
michael@0: CEnumFormatEtc::Skip(ULONG aSkipNum)
michael@0: {
michael@0:   // If the method skips the number of items requested, the return value is S_OK.
michael@0:   // Otherwise, it is S_FALSE.
michael@0: 
michael@0:   if ((mCurrentIdx + aSkipNum) >= mFormatList.Length())
michael@0:       return S_FALSE;
michael@0: 
michael@0:   mCurrentIdx += aSkipNum;
michael@0: 
michael@0:   return S_OK;
michael@0: }
michael@0: 
michael@0: STDMETHODIMP
michael@0: CEnumFormatEtc::Reset(void)
michael@0: {
michael@0:   mCurrentIdx = 0;
michael@0:   return S_OK;
michael@0: }
michael@0: 
michael@0: STDMETHODIMP
michael@0: CEnumFormatEtc::Clone(LPENUMFORMATETC *aResult)
michael@0: {
michael@0:   // Must return a new IEnumFORMATETC interface with the same iterative state.
michael@0: 
michael@0:   if (!aResult)
michael@0:       return E_INVALIDARG;
michael@0: 
michael@0:   CEnumFormatEtc * pEnumObj = new CEnumFormatEtc(mFormatList);
michael@0: 
michael@0:   if (!pEnumObj)
michael@0:       return E_OUTOFMEMORY;
michael@0: 
michael@0:   pEnumObj->AddRef();
michael@0:   pEnumObj->SetIndex(mCurrentIdx);
michael@0: 
michael@0:   *aResult = pEnumObj;
michael@0: 
michael@0:   return S_OK;
michael@0: }
michael@0: 
michael@0: /* utils */
michael@0: 
michael@0: void
michael@0: CEnumFormatEtc::AddFormatEtc(LPFORMATETC aFormat)
michael@0: {
michael@0:   if (!aFormat)
michael@0:       return;
michael@0:   FormatEtc * etc = mFormatList.AppendElement();
michael@0:   // Make a copy of aFormat
michael@0:   if (etc)
michael@0:       etc->CopyIn(aFormat);
michael@0: }
michael@0: 
michael@0: /* private */
michael@0: 
michael@0: void
michael@0: CEnumFormatEtc::SetIndex(uint32_t aIdx)
michael@0: {
michael@0:   mCurrentIdx = aIdx;
michael@0: }