callback.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
 
#ifndef COMMON_CALLBACK_H
#define COMMON_CALLBACK_H
 
namespace Common {
 
template<typename S = void *> class BaseCallback {
public:
    BaseCallback() {}
    virtual ~BaseCallback() {}
    virtual void operator()(S data) = 0; 
};
 
template<typename T> class GlobalFunctionCallback: public BaseCallback<T> {
    typedef void(*GlobalFunction)(T result);
    GlobalFunction _callback;
 
public:
    GlobalFunctionCallback(GlobalFunction cb): _callback(cb) {}
    virtual ~GlobalFunctionCallback() {}
    virtual void operator()(T data) { 
        if (_callback) _callback(data);
    }
};
 
template<class T, typename S = void *> class Callback: public BaseCallback<S> {
protected:
    typedef void(T::*TMethod)(S);
    T *_object;
    TMethod _method;
public:
    Callback(T *object, TMethod method): _object(object), _method(method) {}
    virtual ~Callback() {}
    void operator()(S data) override { (_object->*_method)(data); } 
};
 
template<class T, typename OS, typename S = void *> class CallbackBridge: public BaseCallback<S> {
    typedef void(T::*TCallbackMethod)(BaseCallback<OS> *, S);
    T *_object;
    TCallbackMethod _method;
    BaseCallback<OS> *_outerCallback;
public:
    CallbackBridge(T *object, TCallbackMethod method, BaseCallback<OS> *outerCallback):
        _object(object), _method(method), _outerCallback(outerCallback) {}
    virtual ~CallbackBridge() {}
    void operator()(S data) override { (_object->*_method)(_outerCallback, data); } 
};
 
} // End of namespace Common
 
#endif