GCom.h

#ifndef _GCOM_H_
#define _GCOM_H_

#ifdef __GNUC__
#include <unknwn.h>
#endif
#include <wtypes.h>
#include <oaidl.h>

template <class T>
class GUnknownImpl : public T
{
    int Count;

    class Interface
    {
    public:
        REFIID iid;
        void *pvObject;

        Interface(REFIID i, void *p) : iid(i)
        {
            pvObject = p;
        }
    };

    List<Interface> Interfaces;

protected:
    void AddInterface(REFIID iid, void *pvObject)
    {
        Interface *i = NEW(Interface(iid, pvObject));
        if (i)
        {
            Interfaces.Insert(i);
        }
    }

public:
    GUnknownImpl()
    {
        Count = 0;
    }

    virtual ~GUnknownImpl()
    {
        Interfaces.DeleteObjects();
    }
    
    // IUnknown
    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, void **ppvObject)
    {
        if (memcmp(&IID_IUnknown, &iid, sizeof(IID)) == 0)
        {
            *ppvObject = this;
            AddRef();
            return S_OK;
        }

        for (Interface *i = Interfaces.First(); i; i=Interfaces.Next())
        {
            if (memcmp(&i->iid, &iid, sizeof(IID)) == 0)
            {
                *ppvObject = i->pvObject;
                AddRef();
                return S_OK;
            }
        }

        return E_NOINTERFACE;
    }

    ULONG STDMETHODCALLTYPE AddRef()
    {
        return ++Count;
    }
    
    ULONG STDMETHODCALLTYPE Release()
    {
        int i = --Count;
        if (i <= 0)
        {
            delete this;
        }
        return  i;
    }

    // Helpers
    BSTR VariantToBstr(VARIANT *v)
    {
        if (v)
        {
            if (v->vt == (VT_VARIANT | VT_BYREF)) v = v->pvarVal;
            
            if (v->vt == VT_BSTR) return v->bstrVal;
            if (v->vt == (VT_BSTR | VT_BYREF)) return *v->pbstrVal;
        }

        return 0;
    }
};

template <class T>
class GDispatchImpl : public T
{
public:
    HRESULT STDMETHODCALLTYPE GetTypeInfoCount(UINT __RPC_FAR *pctinfo)
    {
        return S_OK;
    }
    
    HRESULT STDMETHODCALLTYPE GetTypeInfo(UINT iTInfo, LCID lcid, ITypeInfo __RPC_FAR *__RPC_FAR *ppTInfo)
    {
        return S_OK;
    }
    
    HRESULT STDMETHODCALLTYPE GetIDsOfNames(REFIID riid,
                                            LPOLESTR __RPC_FAR *rgszNames,
                                            UINT cNames,
                                            LCID lcid,
                                            DISPID __RPC_FAR *rgDispId)
    {
        return S_OK;
    }
    
    HRESULT STDMETHODCALLTYPE Invoke(       DISPID dispIdMember,
                                            REFIID riid,
                                            LCID lcid,
                                            WORD wFlags,
                                            DISPPARAMS __RPC_FAR *pDispParams,
                                            VARIANT __RPC_FAR *pVarResult,
                                            EXCEPINFO __RPC_FAR *pExcepInfo,
                                            UINT __RPC_FAR *puArgErr)
    {
        return S_OK;
    }
};

#endif

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