// Unknown.H

// Copyright 1995-1996 Microsoft Corporation.  All Rights Reserved.

// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.


// a class definition for an IUnknown super-class that will support
// aggregation.

#ifndef _UNKNOWN_H_


// UNKNOWNOBJECTINFO

// if you want a simple co-creatable object, with no other guarantees about
// it, then you need to put the following entry in the global table of objects.
// other object types that are more complex, such as automation objects, and
// controls, will also use this information...

typedef struct {

    const CLSID *rclsid;                    // CLSID of your object.      ONLY USE IF YOU'RE CoCreatable!
    LPCSTR       pszObjectName;             // Name of your object.       ONLY USE IF YOU'RE CoCreatable!
    IUnknown    *(*pfnCreate)(IUnknown *);  // pointer to creation fn.    ONLY USE IF YOU'RE CoCreatable!

} UNKNOWNOBJECTINFO;

#define NAMEOFOBJECT(index)       (((UNKNOWNOBJECTINFO *)(g_ObjectInfo[(index)]).pInfo)->pszObjectName)
#define CLSIDOFOBJECT(index)      (*(((UNKNOWNOBJECTINFO *)(g_ObjectInfo[(index)]).pInfo)->rclsid))
#define CREATEFNOFOBJECT(index)   (((UNKNOWNOBJECTINFO *)(g_ObjectInfo[(index)]).pInfo)->pfnCreate)

#ifndef INITOBJECTS

#define DEFINE_UNKNOWNOBJECT(name, clsid, objname, fn) \
extern UNKNOWNOBJECTINFO name##Object \

#else
#define DEFINE_UNKNOWNOBJECT(name, clsid, objname, fn) \
    UNKNOWNOBJECTINFO name##Object = { clsid, objname, fn } \

#endif // INITOBJECTS



// DECLARE_STANDARD_UNKNOWN

// All objects that are going to inherit from CUnknown for their IUnknown
// implementation should put this in their class declaration instead of the
// three IUnknown methods.

#define DECLARE_STANDARD_UNKNOWN() \
    STDMETHOD(QueryInterface)(REFIID riid, void **ppvObjOut) { \
        return ExternalQueryInterface(riid, ppvObjOut); \
    } \
    STDMETHOD_(ULONG, AddRef)(void) { \
        return ExternalAddRef(); \
    } \
    STDMETHOD_(ULONG, Release)(void) { \
        return ExternalRelease(); \
    } \

// global variable where we store the current lock count on our DLL.  This resides
// in InProcServer.Cpp

extern LONG g_cLocks;




// this class doesn't inherit from IUnknown since people inheriting from it
// are going to do so, and just delegate their IUnknown calls to the External*
// member functions on this object.  the internal private unknown object does
// need to inherit from IUnknown, since it will be used directly as an IUnknown
// object.

class CUnknownObject {

  public:
    CUnknownObject(IUnknown *pUnkOuter, void *pvInterface)
        : m_pvInterface(pvInterface),
          m_pUnkOuter((pUnkOuter) ? pUnkOuter : &m_UnkPrivate)
        {  InterlockedIncrement(&g_cLocks); }

    virtual ~CUnknownObject() { InterlockedDecrement(&g_cLocks); }

    // these are all protected so that classes that inherit from this can
    // at get at them.

  protected:
    // IUnknown methods.  these just delegate to the controlling
    // unknown.

    HRESULT ExternalQueryInterface(REFIID riid, void **ppvObjOut) {
        return m_pUnkOuter->QueryInterface(riid, ppvObjOut);
    }
    ULONG ExternalAddRef(void) {
        return m_pUnkOuter->AddRef();
    }
    ULONG ExternalRelease(void) {
        return m_pUnkOuter->Release();
    }

    // people should use this during creation to return their private
    // unknown

    inline IUnknown *PrivateUnknown (void) {
        return &m_UnkPrivate;
    }

    virtual HRESULT InternalQueryInterface(REFIID riid, void **ppvObjOut);

    IUnknown *m_pUnkOuter;            // outer controlling Unknown
    void     *m_pvInterface;          // the real interface we're working with.

  private:
    // the inner, private unknown implementation is for the aggregator
    // to control the lifetime of this object, and for those cases where
    // this object isn't aggregated.

    class CPrivateUnknownObject : public IUnknown {
      public:
        STDMETHOD(QueryInterface)(REFIID riid, void **ppvObjOut);
        STDMETHOD_(ULONG, AddRef)(void);
        STDMETHOD_(ULONG, Release)(void);

        // constructor is remarkably trivial

        CPrivateUnknownObject() : m_cRef(1) {}

      private:
        CUnknownObject *m_pMainUnknown();
        ULONG m_cRef;
    } m_UnkPrivate;

    // so they can reference themselves in CUnknownObject from pMainUnknown()

    friend class CPrivateUnknownObject;

    // by overriding this, people inheriting from this unknown can implement
    // additional interfaces.  declared as private here so they have to use their
    // own version.

};




#define _UNKNOWN_H_
#endif // _UNKNOWN_H_