source: XMLIO_V2/external/src/POCO/Foundation.save/Poco/DefaultStrategy.h @ 80

//
// DefaultStrategy.h
//
// $Id: //poco/1.3/Foundation/include/Poco/DefaultStrategy.h#3 $
//
// Library: Foundation
// Package: Events
// Module:  DefaultStrategy
//
// Implementation of the DefaultStrategy template.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#ifndef  Foundation_DefaultStrategy_INCLUDED
#define  Foundation_DefaultStrategy_INCLUDED


#include "Poco/NotificationStrategy.h"
#include <memory>
#include <set>
#include <vector>


namespace Poco {


template <class TArgs, class TDelegate, class TCompare> 
class DefaultStrategy: public NotificationStrategy<TArgs, TDelegate>
        /// Default notification strategy. Allows one observer
        ///     to register exactly once. The observer must provide an
        /// < (less-than) operator.
{
public:
        typedef std::set<TDelegate*, TCompare>     Delegates;
        typedef typename Delegates::iterator       Iterator;
        typedef typename Delegates::const_iterator ConstIterator;

public:
        DefaultStrategy()
        {
        }

        DefaultStrategy(const DefaultStrategy& s)
        {
                operator = (s);
        }

        ~DefaultStrategy()
        {
                clear();
        }

        void notify(const void* sender, TArgs& arguments)
        {
                std::vector<Iterator> delMe;

                for (Iterator it = _observers.begin(); it != _observers.end(); ++it)
                {
                        if (!(*it)->notify(sender, arguments))
                        {
                                // schedule for deletion
                                delMe.push_back(it);
                        }
                }
                
                while (!delMe.empty())
                {
                        typename std::vector<Iterator>::iterator vit = delMe.end();
                        --vit;
                        delete **vit;
                        _observers.erase(*vit);
                        delMe.pop_back();
                }
        }

        void add(const TDelegate& delegate)
        {
                Iterator it = _observers.find(const_cast<TDelegate*>(&delegate));
                if (it != _observers.end())
                {
                        delete *it;
                        _observers.erase(it);
                }
                std::auto_ptr<TDelegate> pDelegate(delegate.clone());
                bool tmp = _observers.insert(pDelegate.get()).second;
                poco_assert (tmp);
                pDelegate.release();
        }

        void remove(const TDelegate& delegate)
        {
                Iterator it = _observers.find(const_cast<TDelegate*>(&delegate));
                if (it != _observers.end())
                {
                        delete *it;
                        _observers.erase(it);
                }
        }

        DefaultStrategy& operator = (const DefaultStrategy& s)
        {
                if (this != &s)
                {
                        for (ConstIterator it = s._observers.begin(); it != s._observers.end(); ++it)
                        {
                                add(**it);
                        }
                }
                return *this;
        }

        void clear()
        {
                for (Iterator it = _observers.begin(); it != _observers.end(); ++it)
                {
                        delete *it;
                }
                _observers.clear();
        }

        bool empty() const
        {
                return _observers.empty();
        }

protected:
        Delegates _observers;
};


} // namespace Poco


#endif