windows-nt/Source/XPSP1/NT/multimedia/directx/dmusic/dmscript/unkhelp.h
2020-09-26 16:20:57 +08:00

39 lines
1.5 KiB
C++

// Copyright (c) 1999 Microsoft Corporation. All rights reserved.
//
// Helper classes for implementing IUnknown.
//
#pragma once
// Implements AddRef/Release with ref count beginning at 1. Also handles module locking.
class ComRefCount
: public IUnknown
{
public:
ComRefCount();
virtual ~ComRefCount() {}
// IUnknown
STDMETHOD_(ULONG, AddRef)();
STDMETHOD_(ULONG, Release)();
private:
long m_cRef;
};
// Use this macro to declare AddRef and Release in the public section of your derived class. This is necessary because
// the IUnknown section of any interfaces aren't linked to the methods in this base class.
#define ComRefCountAddRefRelease STDMETHOD_(ULONG, AddRef)() { return ComRefCount::AddRef(); } STDMETHOD_(ULONG, Release)() { return ComRefCount::Release(); }
// Implements QueryInterface for a single interface (in addition to IUnknown). You must pass the IID of your interface (iidExpected)
// and a pointer to that interface (pvInterface).
class ComSingleInterface
: public ComRefCount
{
public:
STDMETHOD(QueryInterface)(const IID &iid, void **ppv, const IID&iidExpected, void *pvInterface);
};
// Use this macro to declare AddRef, Release, and QueryInterface function in the public section of your derived class.
#define ComSingleInterfaceUnknownMethods(IMyInterface) ComRefCountAddRefRelease STDMETHOD(QueryInterface)(const IID &iid, void **ppv) { return ComSingleInterface::QueryInterface(iid, ppv, IID_##IMyInterface, static_cast<IMyInterface*>(this)); }