interface.h

VC技术内幕

// interface.h

// definitions that make our code look like MFC code
#define BOOL   int
#define DWORD  unsigned int
#define TRUE   1
#define FALSE  0
#define TRACE  printf
#define ASSERT assert
//----------definitions and macros-----------------------------------
#define CLSID_CSpaceship    10
#define IID_IUnknown        0
#define IID_IClassFactory   1
#define IID_IMotion         2
#define IID_IVisual         3

// this macro for 16-bit Windows only
#define METHOD_PROLOGUE(theClass, localClass) \
    theClass* pThis = ((theClass*)((char*)(this) - \
    offsetof(theClass, m_x##localClass))); \


BOOL GetClassObject(int nClsid, int nIid, void** ppvObj);

//----------interface declarations-----------------------------------
struct IUnknown
{
    IUnknown() { TRACE("Entering IUnknown ctor %p\n", this); }
    virtual BOOL QueryInterface(int nIid, void** ppvObj) = 0;
    virtual DWORD Release() = 0;
    virtual DWORD AddRef() = 0;
};

struct IClassFactory : public IUnknown
{
    IClassFactory()
        { TRACE("Entering IClassFactory ctor %p\n", this); }
    virtual BOOL CreateInstance(int nIid, void** ppvObj) = 0;
};

struct IMotion : public IUnknown
{
    IMotion() { TRACE("Entering IMotion ctor %p\n", this); }
    virtual void Fly() = 0; // pure
    virtual int& GetPosition() = 0;
};

struct IVisual : public IUnknown
{
    IVisual() { TRACE("Entering IVisual ctor %p\n", this); }
    virtual void Display() = 0;
};

class CSimulatedCmdTarget // 'simulated' CSimulatedCmdTarget
{
public:
    DWORD m_dwRef;

protected:
    CSimulatedCmdTarget() {
        TRACE("Entering CSimulatedCmdTarget ctor %p\n", this);
        m_dwRef = 1; // implied first AddRef
    }
    virtual ~CSimulatedCmdTarget()
        { TRACE("Entering CSimulatedCmdTarget dtor %p\n", this); }
    DWORD ExternalRelease() {
        TRACE("Entering CSimulatedCmdTarget::ExternalRelease--RefCount =  %ld\n",m_dwRef);
        if (m_dwRef == 0)
          return 0;
        if(--m_dwRef == 0L) {
          TRACE("deleting\n");
          delete this;
          return 0;
        }
        return m_dwRef;
    }
    DWORD ExternalAddRef() { return ++m_dwRef; }
};