windows-nt/Source/XPSP1/NT/enduser/stuff/hhctrl/unknown.cpp
2020-09-26 16:20:57 +08:00

104 lines
3.2 KiB
C++

// Copyright (C) 1996-1997 Microsoft Corporation. All rights reserved.
#include "header.h"
#include "Unknown.H"
#include <stddef.h>
//=--------------------------------------------------------------------------=
// CUnknownObject::CPrivateUnknownObject::m_pMainUnknown
//=--------------------------------------------------------------------------=
// this method is used when we're sitting in the private unknown object,
// and we need to get at the pointer for the main unknown. basically, it's
// a little better to do this pointer arithmetic than have to store a pointer
// to the parent, etc.
inline CUnknownObject *CUnknownObject::CPrivateUnknownObject::m_pMainUnknown
(
void
)
{
return (CUnknownObject *)((LPBYTE)this - offsetof(CUnknownObject, m_UnkPrivate));
}
//=--------------------------------------------------------------------------=
// CUnknownObject::CPrivateUnknownObject::QueryInterface
//=--------------------------------------------------------------------------=
// this is the non-delegating internal QI routine.
//
// Parameters:
// REFIID - [in] interface they want
// void ** - [out] where they want to put the resulting object ptr.
//
// Output:
// HRESULT - S_OK, E_NOINTERFACE
STDMETHODIMP CUnknownObject::CPrivateUnknownObject::QueryInterface(REFIID riid, void **ppvObjOut)
{
CHECK_POINTER(ppvObjOut);
// if they're asking for IUnknown, then we have to pass them ourselves.
// otherwise defer to the inheriting object's InternalQueryInterface
//
if (DO_GUIDS_MATCH(riid, IID_IUnknown)) {
m_cRef++;
*ppvObjOut = (IUnknown *)this;
return S_OK;
} else
return m_pMainUnknown()->InternalQueryInterface(riid, ppvObjOut);
// dead code
}
//=--------------------------------------------------------------------------=
// CUnknownObject::CPrivateUnknownObject::AddRef
//=--------------------------------------------------------------------------=
// adds a tick to the current reference count.
//
// Output:
// ULONG - the new reference count
ULONG CUnknownObject::CPrivateUnknownObject::AddRef(void)
{
return ++m_cRef;
}
//=--------------------------------------------------------------------------=
// CUnknownObject::CPrivateUnknownObject::Release
//=--------------------------------------------------------------------------=
// removes a tick from the count, and delets the object if necessary
//
// Output:
// ULONG - remaining refs
ULONG CUnknownObject::CPrivateUnknownObject::Release (void)
{
ULONG cRef = --m_cRef;
if (!m_cRef)
delete m_pMainUnknown();
return cRef;
}
//=--------------------------------------------------------------------------=
// CUnknownObject::InternalQueryInterface
//=--------------------------------------------------------------------------=
// objects that are aggregated use this to support additional interfaces.
// they should call this method on their parent so that any of it's interfaces
// are queried.
//
// Parameters:
// REFIID - [in] interface they want
// void ** - [out] where they want to put the resulting object ptr.
//
// Output:
// HRESULT - S_OK, E_NOINTERFACE
HRESULT CUnknownObject::InternalQueryInterface(REFIID riid, void **ppvObjOut)
{
*ppvObjOut = NULL;
return E_NOINTERFACE;
}