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#include "stdafx.h"
#include "WpdObjectEnum.tmh"
WpdObjectEnumerator::WpdObjectEnumerator()
{
}
WpdObjectEnumerator::~WpdObjectEnumerator()
{
}
HRESULT WpdObjectEnumerator::Initialize(_In_ FakeDevice *pFakeDevice)
{
HRESULT hr = S_OK;
if(pFakeDevice == NULL)
{
hr = E_POINTER;
CHECK_HR(hr, "Cannot have NULL parameter");
return hr;
}
m_pFakeDevice = pFakeDevice;
return hr;
}
HRESULT WpdObjectEnumerator::DispatchWpdMessage(_In_ REFPROPERTYKEY Command,
_In_ IPortableDeviceValues* pParams,
_In_ IPortableDeviceValues* pResults)
{
HRESULT hr = S_OK;
if (hr == S_OK)
{
if (Command.fmtid != WPD_CATEGORY_OBJECT_ENUMERATION)
{
hr = E_INVALIDARG;
CHECK_HR(hr, "This object does not support this command category %ws",CComBSTR(Command.fmtid));
}
}
if (hr == S_OK)
{
if (Command.pid == WPD_COMMAND_OBJECT_ENUMERATION_START_FIND.pid)
{
hr = OnStartFind(pParams, pResults);
CHECK_HR(hr, "Failed to begin enumeration");
}
else if (Command.pid == WPD_COMMAND_OBJECT_ENUMERATION_FIND_NEXT.pid)
{
hr = OnFindNext(pParams, pResults);
if(FAILED(hr))
{
CHECK_HR(hr, "Failed to find next object");
}
}
else if (Command.pid == WPD_COMMAND_OBJECT_ENUMERATION_END_FIND.pid)
{
hr = OnEndFind(pParams, pResults);
CHECK_HR(hr, "Failed to end enumeration");
}
else
{
hr = E_NOTIMPL;
CHECK_HR(hr, "This object does not support this command id %d", Command.pid);
}
}
return hr;
}
/**
* This method is called when we receive a WPD_COMMAND_OBJECT_ENUMERATION_START_FIND
* command.
*
* The parameters sent to us are:
* - WPD_PROPERTY_OBJECT_ENUMERATION_PARENT_ID: the parent where we should start
* the enumeration.
* - WPD_PROPERTY_OBJECT_ENUMERATION_FILTER: the filter to use when doing
* enumeration. Since this parameter is optional, it may not exist.
* This driver currently ignores the filter parameter.
*
* The driver should:
* - Create a new context for this enumeration.
* - Return an identifier for the context in WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT.
*
*/
HRESULT WpdObjectEnumerator::OnStartFind(_In_ IPortableDeviceValues* pParams,
_In_ IPortableDeviceValues* pResults)
{
HRESULT hr = S_OK;
LPWSTR pszParentID = NULL;
LPWSTR pszEnumContext = NULL;
IUnknown* pContextMap = NULL;
hr = pParams->GetStringValue(WPD_PROPERTY_OBJECT_ENUMERATION_PARENT_ID, &pszParentID);
if (FAILED(hr))
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing value for WPD_PROPERTY_OBJECT_ENUMERATION_PARENT_ID");
}
if (SUCCEEDED(hr))
{
hr = pParams->GetIUnknownValue(PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP, &pContextMap);
CHECK_HR(hr, "Failed to get PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP");
}
if (SUCCEEDED(hr))
{
hr = CreateEnumContext((ContextMap*)pContextMap, pszParentID, &pszEnumContext);
CHECK_HR(hr, "Failed to create enumeration context");
}
if (SUCCEEDED(hr))
{
hr = pResults->SetStringValue(WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT, pszEnumContext);
CHECK_HR(hr, "Failed to set WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT");
}
// Free the memory. CoTaskMemFree ignores NULLs so no need to check.
CoTaskMemFree(pszParentID);
// Free the memory. CoTaskMemFree ignores NULLs so no need to check.
CoTaskMemFree(pszEnumContext);
SAFE_RELEASE(pContextMap);
return hr;
}
HRESULT WpdObjectEnumerator::OnFindNext(_In_ IPortableDeviceValues* pParams,
_In_ IPortableDeviceValues* pResults)
{
HRESULT hr = S_OK;
LPWSTR pszEnumContext = NULL;
DWORD dwNumObjects = 0;
ContextMap* pContextMap = NULL;
CComPtr<IPortableDevicePropVariantCollection> pObjectIDCollection;
hr = pParams->GetStringValue(WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT, &pszEnumContext);
if (FAILED(hr))
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing value for WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT");
}
if (SUCCEEDED(hr))
{
hr = pParams->GetUnsignedIntegerValue(WPD_PROPERTY_OBJECT_ENUMERATION_NUM_OBJECTS_REQUESTED, &dwNumObjects);
if (FAILED(hr))
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing value for WPD_PROPERTY_OBJECT_ENUMERATION_NUM_OBJECTS_REQUESTED");
}
}
// Get the context map which the driver stored in pParams for convenience
if (SUCCEEDED(hr))
{
hr = pParams->GetIUnknownValue(PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP, (IUnknown**)&pContextMap);
CHECK_HR(hr, "Failed to get PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP");
}
if (SUCCEEDED(hr))
{
// Find the next objects in the enumeration
hr = GetObjectIDs(pContextMap, dwNumObjects, pszEnumContext, &pObjectIDCollection);
CHECK_HR(hr, "Failed to get the objectIDs");
}
if (SUCCEEDED(hr))
{
hr = pResults->SetIPortableDevicePropVariantCollectionValue(WPD_PROPERTY_OBJECT_ENUMERATION_OBJECT_IDS, pObjectIDCollection);
CHECK_HR(hr, "Failed to set WPD_PROPERTY_OBJECT_ENUMERATION_OBJECT_IDS");
}
if (SUCCEEDED(hr))
{
if(pObjectIDCollection != NULL)
{
ULONG ulCount = 0;
pObjectIDCollection->GetCount(&ulCount);
if(ulCount < dwNumObjects)
{
hr = S_FALSE;
}
}
}
// Free the memory. CoTaskMemFree ignores NULLs so no need to check.
CoTaskMemFree(pszEnumContext);
SAFE_RELEASE(pContextMap);
return hr;
}
/**
* This method is called when we receive a WPD_COMMAND_OBJECT_ENUMERATION_END_FIND
* command.
*
* The parameters sent to us are:
* - WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT: the context the driver returned to
* the client in OnStartFind.
*
* The driver should:
* - Destroy any resources associated with this context.
*/
HRESULT WpdObjectEnumerator::OnEndFind(_In_ IPortableDeviceValues* pParams,
_In_ IPortableDeviceValues* pResults)
{
HRESULT hr = S_OK;
LPWSTR pszEnumContext = NULL;
IUnknown* pContextMap = NULL;
UNREFERENCED_PARAMETER(pResults);
hr = pParams->GetStringValue(WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT, &pszEnumContext);
if (FAILED(hr))
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing value for WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT");
}
if (SUCCEEDED(hr))
{
hr = pParams->GetIUnknownValue(PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP, &pContextMap);
CHECK_HR(hr, "Failed to get PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP");
}
if (SUCCEEDED(hr))
{
hr = DestroyEnumContext((ContextMap*) pContextMap, pszEnumContext);
CHECK_HR(hr, "Failed to destroy enumeration context");
}
// Free the memory. CoTaskMemFree ignores NULLs so no need to check.
CoTaskMemFree(pszEnumContext);
SAFE_RELEASE(pContextMap);
return hr;
}
HRESULT WpdObjectEnumerator::CreateEnumContext(
_In_ ContextMap* pContextMap,
_In_ LPCWSTR pszParentID,
_Outptr_result_nullonfailure_ LPWSTR* ppszEnumContext)
{
HRESULT hr = S_OK;
GUID guidContext = GUID_NULL;
CComBSTR bstrContext;
EnumContext* pContext = NULL;
if((pContextMap == NULL) ||
(pszParentID == NULL) ||
(ppszEnumContext == NULL))
{
hr = E_POINTER;
CHECK_HR(hr, "Cannot have NULL parameter");
return hr;
}
*ppszEnumContext = NULL;
hr = CoCreateGuid(&guidContext);
if (SUCCEEDED(hr))
{
bstrContext = guidContext;
if(bstrContext.Length() == 0)
{
hr = E_OUTOFMEMORY;
CHECK_HR(hr, "Failed to create BSTR from GUID");
}
}
if (SUCCEEDED(hr))
{
pContext = new EnumContext();
if(pContext != NULL)
{
CAtlStringW strKey = bstrContext;
pContext->ParentID = pszParentID;
hr = pContextMap->Add(strKey, pContext);
CHECK_HR(hr, "Failed to add enumeration context to client context map");
pContext->Release();
}
else
{
hr = E_OUTOFMEMORY;
CHECK_HR(hr, "Failed to allocate enumeration context");
}
}
if (SUCCEEDED(hr))
{
*ppszEnumContext = AtlAllocTaskWideString(bstrContext);
}
return hr;
}
HRESULT WpdObjectEnumerator::DestroyEnumContext(
_In_ ContextMap* pContextMap,
_In_ LPCWSTR pszEnumContext)
{
HRESULT hr = S_OK;
CAtlStringW strKey = pszEnumContext;
pContextMap->Remove(strKey);
return hr;
}
#pragma warning(suppress: 6388) // PREFast bug means here there is a false positive for the call to CComPtr<>::QueryInterface().
HRESULT WpdObjectEnumerator::GetObjectIDs(
_In_ ContextMap* pContextMap,
_In_ const DWORD dwNumObjects,
_In_ LPCWSTR pszEnumContext,
_COM_Outptr_ IPortableDevicePropVariantCollection** ppCollection)
{
HRESULT hr = S_OK;
EnumContext* pContext = NULL;
CComPtr<IPortableDevicePropVariantCollection> pObjectIDs;
if(ppCollection == NULL)
{
hr = E_POINTER;
CHECK_HR(hr, "Cannot have NULL collection parameter");
return hr;
}
*ppCollection = NULL;
hr = CoCreateInstance(CLSID_PortableDevicePropVariantCollection,
NULL,
CLSCTX_INPROC_SERVER,
IID_PPV_ARGS(&pObjectIDs));
CHECK_HR(hr, "Failed to CoCreate CLSID_PortableDevicePropVariantCollection");
if (SUCCEEDED(hr))
{
CAtlStringW strKey = pszEnumContext;
pContext = (EnumContext*) pContextMap->GetContext(strKey);
if(pContext != NULL)
{
for(DWORD dwCount = 0; dwCount < dwNumObjects; dwCount++)
{
CAtlStringW strObjectID;
DWORD dwNextStartIndex = 0;
if(m_pFakeDevice->FindNext(pContext->SearchIndex,
pContext->ParentID,
strObjectID,
&dwNextStartIndex))
{
PropVariantWrapper pvObjectID(strObjectID);
hr = pObjectIDs->Add(&pvObjectID);
CHECK_HR(hr, "Failed to add object [%ws]", pvObjectID.pwszVal);
pContext->SearchIndex = dwNextStartIndex;
}
}
pContext->Release();
}
else
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Cannot find enum context [%ws]", pszEnumContext);
}
}
if (SUCCEEDED(hr))
{
hr = pObjectIDs->QueryInterface(IID_PPV_ARGS(ppCollection));
CHECK_HR(hr, "Failed to QI for IID_IPortableDevicePropVariantCollection on IPortableDevicePropVariantCollection");
}
return hr;
}
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