/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*

 * This file is part of the LibreOffice project.

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/.

 *

 * This file incorporates work covered by the following license notice:

 *

 *   Licensed to the Apache Software Foundation (ASF) under one or more

 *   contributor license agreements. See the NOTICE file distributed

 *   with this work for additional information regarding copyright

 *   ownership. The ASF licenses this file to you under the Apache

 *   License, Version 2.0 (the "License"); you may not use this file

 *   except in compliance with the License. You may obtain a copy of

 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .

 */

#pragma once

#include <algorithm>

#include <vector>

namespace vcl

{

class DeletionListener;

class DeletionNotifier

{

    std::vector< DeletionListener* > m_aListeners;

    protected:

    DeletionNotifier() {}

    ~DeletionNotifier()

    { notifyDelete(); }

    inline void notifyDelete();

    public:

    void addDel( DeletionListener* pListener )

    { m_aListeners.push_back( pListener ); }

    void removeDel( DeletionListener* pListener )

    { std::erase(m_aListeners, pListener); }

};

class DeletionListener

{

    DeletionNotifier*  m_pNotifier;

    public:

    DeletionListener( DeletionNotifier* pNotifier )

    :  m_pNotifier( pNotifier )

       {

           if( m_pNotifier )

               m_pNotifier->addDel( this );

       }

    DeletionListener(const DeletionListener& rOther)

    :  m_pNotifier(rOther.m_pNotifier)

       {

           if (m_pNotifier)

               m_pNotifier->addDel(this);

       }

   ~DeletionListener()

   {

       if( m_pNotifier )

           m_pNotifier->removeDel( this );

   }

   void deleted() { m_pNotifier = nullptr; }

   bool isDeleted() const { return (m_pNotifier == nullptr); }

};

inline void DeletionNotifier::notifyDelete()

{

    for( auto& rListener : m_aListeners )

       rListener->deleted();

    m_aListeners.clear();

}

} // namespace vcl

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