baseinterface.h

//-----------------------------------------------------------------------------
// Copyright (C) 2004 - 2006 ParaEngine Dev Studio, All Rights Reserved.
// Date:    2006.8
// Description: API for interfaces. 
//-----------------------------------------------------------------------------
#pragma once

#include "PEtypes.h"

namespace ParaEngine
{
    class BaseInterface;

    #define BASEINTERFACE_ID Interface_ID(0, 1)

    class InterfaceServer
    {
    public:
        virtual BaseInterface* GetInterface(Interface_ID id) { return NULL; }
    };

    class BaseInterface : public InterfaceServer
    {
    public:
        // from InterfaceServer
        BaseInterface* GetInterface(Interface_ID id) { if (id == BASEINTERFACE_ID) return this; else return NULL; }

        // identification
        virtual Interface_ID    GetID() { return BASEINTERFACE_ID; }

        // interface lifetime management
        //   there is an implied Acquire() whenever an interface is served via a GetInterface()
        enum LifetimeType { noRelease, immediateRelease, wantsRelease, serverControlled }; 

        // LifetimeControl returns noRelease since 
        // AcquireInterface and ReleaseInterface do not perform 
        // any real acquiring and releasing (reference counting, etc.)
        // If the implementation of AcquireInterface and ReleaseInterface changes
        // in this class or derived classes, the return value of LifetimeControl 
        // needs to be updated accordingly.
        // RegisterNotifyCallback returns true if the callback will be called at or before deletion
        virtual LifetimeType    LifetimeControl() { return noRelease; }
        virtual BaseInterface*  AcquireInterface() { return (BaseInterface*)this; };  
        virtual void            ReleaseInterface() { };

        // direct interface delete request
        virtual void            DeleteInterface() { };

        // interface cloning
        virtual BaseInterface*  CloneInterface(void* remapDir = NULL) { return NULL; }
    };
}