HRESULT FakeDevice::FindNext(
const DWORD dwNumObjectsRequested,
_In_ WpdObjectEnumeratorContext* pEnumContext,
_In_ IPortableDevicePropVariantCollection* pObjectIDCollection,
_Out_opt_ DWORD* pdwNumObjectsEnumerated)
{
HRESULT hr = S_OK;
DWORD NumObjectsEnumerated = 0;
if ((pEnumContext == NULL) ||
(pObjectIDCollection == NULL))
{
hr = E_POINTER;
CHECK_HR(hr, "Cannot have NULL parameter");
return hr;
}
if (pdwNumObjectsEnumerated)
{
*pdwNumObjectsEnumerated = 0;
}
// If the enumeration context reports that their are more objects to return, then continue, if not,
// return an empty results set.
if (pEnumContext->HasMoreChildrenToEnumerate())
{
if (pEnumContext->m_strParentObjectID.CompareNoCase(L"") == 0)
{
// We are being asked for the device
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, m_DeviceContent.ObjectID);
CHECK_HR(hr, "Failed to add 'DEVICE' object ID to enumeration collection");
// Update the the number of children we are returning for this enumeration call
NumObjectsEnumerated++;
}
else
{
FakeContent* pContent = NULL;
HRESULT hrGet = GetContent(pEnumContext->m_Scope, pEnumContext->m_strParentObjectID, &pContent);
CHECK_HR(hrGet, "Failed to get content '%ws'", pEnumContext->m_strParentObjectID);
if (hrGet == S_OK)
{
DWORD dwStartIndex = pEnumContext->m_ChildrenEnumerated;
for (DWORD i=0; i<dwNumObjectsRequested; i++)
{
FakeContent* pChild = NULL;
if (pContent->FindNext(pEnumContext->m_Scope, dwStartIndex, &pChild))
{
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, pChild->ObjectID);
CHECK_HR(hr, "Failed to add object [%ws]", pChild->ObjectID);
if (hr == S_OK)
{
// Update the the number of children we are returning for this enumeration call
dwStartIndex++;
NumObjectsEnumerated++;
}
}
else
{
// no more children
break;
}
}
}
}
}
if (hr == S_OK && pdwNumObjectsEnumerated)
{
*pdwNumObjectsEnumerated = NumObjectsEnumerated;
}
return hr;
}
HRESULT WpdObjectEnumerator::OnFindNext(IPortableDeviceValues* pParams,
IPortableDeviceValues* pResults)
{
HRESULT hr = S_OK;
LPWSTR wszEnumContext = NULL;
DWORD dwNumObjectsRequested = 0;
ContextMap* pContextMap = NULL;
WpdObjectEnumeratorContext* pEnumeratorContext = NULL;
DWORD NumObjectsEnumerated = 0;
CComPtr<IPortableDevicePropVariantCollection> pObjectIDCollection;
// First get ALL parameters for this command. If we cannot get ALL parameters
// then E_INVALIDARG should be returned and no further processing should occur.
// Get the enumeration context identifier for this enumeration operation.
// The enumeration context identifier is needed to lookup the specific
// enumeration context in the client context map for this enumeration operation.
// NOTE that more than one enumeration may be in progress.
hr = pParams->GetStringValue(WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT, &wszEnumContext);
if (hr != S_OK)
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing value for WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT");
}
// Get the number of objects requested for this enumeration call.
// The driver should always attempt to meet this requested value.
// If there are fewer children than requested, the driver should return the remaining
// children and a return code of S_FALSE.
hr = pParams->GetUnsignedIntegerValue(WPD_PROPERTY_OBJECT_ENUMERATION_NUM_OBJECTS_REQUESTED, &dwNumObjectsRequested);
if (hr != S_OK)
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing value for WPD_PROPERTY_OBJECT_ENUMERATION_NUM_OBJECTS_REQUESTED");
}
// Get the client context map so we can retrieve the enumeration context for this enumeration
// operation.
if (hr == S_OK)
{
hr = pParams->GetIUnknownValue(PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP, (IUnknown**)&pContextMap);
CHECK_HR(hr, "Failed to get PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP");
}
if (hr == S_OK)
{
pEnumeratorContext = (WpdObjectEnumeratorContext*)pContextMap->GetContext(wszEnumContext);
if (pEnumeratorContext == NULL)
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing enumeration context");
}
}
// CoCreate a collection to store the object identifiers being returned for this enumeration call.
if (hr == S_OK)
{
hr = CoCreateInstance(CLSID_PortableDevicePropVariantCollection,
NULL,
CLSCTX_INPROC_SERVER,
IID_IPortableDevicePropVariantCollection,
(VOID**) &pObjectIDCollection);
CHECK_HR(hr, "Failed to CoCreate CLSID_PortableDevicePropVariantCollection");
}
// If the enumeration context reports that their are more objects to return, then continue, if not,
// return an empty results set.
if ((hr == S_OK) && (pEnumeratorContext != NULL) && (pEnumeratorContext->HasMoreChildrenToEnumerate() == TRUE))
{
if (pEnumeratorContext->m_strParentObjectID.CompareNoCase(L"") == 0)
{
// We are being asked for the WPD_DEVICE_OBJECT_ID
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, WPD_DEVICE_OBJECT_ID);
CHECK_HR(hr, "Failed to add 'DEVICE' object ID to enumeration collection");
// Update the the number of children we are returning for this enumeration call
NumObjectsEnumerated++;
}
else if (pEnumeratorContext->m_strParentObjectID.CompareNoCase(WPD_DEVICE_OBJECT_ID) == 0)
{
// We are being asked for direct children of the WPD_DEVICE_OBJECT_ID
switch (m_pBaseDriver->m_SensorType)
{
case WpdBaseDriver::UNKNOWN:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::COMPASS:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, COMPASS_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::SENSIRON:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, TEMP_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::FLEX:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, FLEX_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::PING:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, PING_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::PIR:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, PIR_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::MEMSIC:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, MEMSIC_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::QTI:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, QTI_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::PIEZO:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, PIEZO_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::HITACHI:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, HITACHI_SENSOR_OBJECT_ID);
break;
default:
break;
}
CHECK_HR(hr, "Failed to add storage object ID to enumeration collection");
// Update the the number of children we are returning for this enumeration call
NumObjectsEnumerated++;
}
}
// Set the collection of object identifiers enumerated in the results
if (hr == S_OK)
{
hr = pResults->SetIPortableDevicePropVariantCollectionValue(WPD_PROPERTY_OBJECT_ENUMERATION_OBJECT_IDS, pObjectIDCollection);
CHECK_HR(hr, "Failed to set WPD_PROPERTY_OBJECT_ENUMERATION_OBJECT_IDS");
}
// If the enumeration context reports that their are no more objects to return then return S_FALSE indicating to the
// caller that we are finished.
if (hr == S_OK)
{
if (pEnumeratorContext != NULL)
{
// Update the number of children we have enumerated and returned to the caller
pEnumeratorContext->m_ChildrenEnumerated += NumObjectsEnumerated;
// Check the number requested against the number enumerated and set the HRESULT
// accordingly.
if (NumObjectsEnumerated < dwNumObjectsRequested)
{
// We returned less than the number of objects requested to the caller
hr = S_FALSE;
}
else
{
// We returned exactly the number of objects requested to the caller
hr = S_OK;
}
}
}
// Free the memory.
CoTaskMemFree(wszEnumContext);
wszEnumContext = NULL;
SAFE_RELEASE(pContextMap);
return hr;
}
