HRESULT CDataAdviseCache::EnumAndAdvise(LPDATAOBJECT pDataDelegate,
BOOL fAdvise)
{
VDATEHEAP();
VDATEIFACE(pDataDelegate);
LPENUMSTATDATA penumAdvise; // enumerator for the data advise holder
DWORD dwDelegate; // delegate connection id for the current connection
STATDATA statdata; // filled in by the penumAdvise enumerator
HRESULT hresult = NOERROR; // current error status
// get an enumerator from the data advise holder
RetErr(m_pDAH->EnumAdvise(&penumAdvise));
// repeat for each advise sink in the data advise holder...
while(NOERROR == penumAdvise->Next(1, &statdata, NULL))
{
if(fAdvise)
{
// It is possible that the delegate's Advise will fail
// even though we allowed the advise on the loaded
// object to succeed(because the delegate is "pickier".)
if(NOERROR==pDataDelegate->DAdvise(&statdata.formatetc,
statdata.advf, statdata.pAdvSink,
&dwDelegate))
{
// we know the key is present; this SetAt
// should not fail
Verify(m_mapClientToDelegate.SetAt(
statdata.dwConnection,
dwDelegate));
}
}
else // unadvise
{
if((hresult=ClientToDelegate(statdata.dwConnection,
&dwDelegate)) != NOERROR)
{
AssertSz(0, "Corrupt mapping");
UtReleaseStatData(&statdata);
goto errRtn;
}
if(dwDelegate != 0)
{
if(NOERROR==pDataDelegate->DUnadvise(
dwDelegate))
{
// we know the key is present; this
// SetAt should not fail
Verify(m_mapClientToDelegate.SetAt(
statdata.dwConnection,
0));
}
else
{
LEDebugOut((DEB_IWARN,
"WARNING: Delegate rejected unadvise\n"));
;
}
}
}
UtReleaseStatData(&statdata);
}
errRtn:
// release the enumerator
penumAdvise->Release();
return hresult;
}
HRESULT CDataAdviseCache::Advise(LPDATAOBJECT pDataObject,
FORMATETC FAR* pFetc, DWORD advf, LPADVISESINK pAdvise,
DWORD FAR* pdwClient)
// first 4 parms are as in DataObject::Advise
{
VDATEHEAP();
DWORD dwDelegate = 0; // the delegate connection number
HRESULT hr;
// if there is a data object, ask to be advised of changes
if(pDataObject != NULL)
RetErr(pDataObject->DAdvise(pFetc, advf, pAdvise, &dwDelegate));
// if there is no data object, (i.e. the object is not active,
// dwDelegate is zero
// Here we are using the data advise holder only to hold advise
// connections. We are not going to use it to send OnDataChange to
// sinks.
// REVIEW, handling of ADVF_ONLYONCE seems broken...
// it's clear that we can't cope with this flag properly; we have
// no way of knowing when the notification takes place, and therefore
// we can't remove the entry from m_pDAH. The notification may have
// taken place above, and it may not have. If the data object wasn't
// around, then the advise request here is lost, and the sink will
// never be notified. Or, if the request isn't PRIMEFIRST, and the
// data object is deactivated, then the data object loses the request,
// and on subsequent activation, we won't readvise it on EnumAndAdvise.
// So, what good are we for ONLYONCE sinks? What does this break?
if(advf & ADVF_ONLYONCE)
return NOERROR;
// keep a local copy of the advise
hr = m_pDAH->Advise(NULL, pFetc, advf, pAdvise, pdwClient);
// if we failed to keep a local reference to the advise sink,
// we won't be able to maintain this mapping, so remove the
// advise on the data object, if there is one
if (hr != NOERROR)
{
Exit1:
if (pDataObject != NULL)
pDataObject->DUnadvise(dwDelegate);
return(hr);
}
// create a map entry from *pdwClient -> dwDelegate
// if the map entry creation failed, undo all work
if (m_mapClientToDelegate.SetAt(*pdwClient, dwDelegate) != TRUE)
{
// map failed to allocate memory, undo advise since we won't
// be able to find this one again
m_pDAH->Unadvise(*pdwClient);
// map entry creation must have failed from lack of allocation
hr = ReportResult(0, E_OUTOFMEMORY, 0, 0);
// undo the advise on the data object
goto Exit1;
}
return(NOERROR);
}
