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 * 
 * Licensed to the Apache Software Foundation (ASF) under one
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 * 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
 * 
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 #ifndef _VCL_IMPDEL_HXX
 #define _VCL_IMPDEL_HXX
 
 #include <list>
 
 namespace vcl
 {
 
 class DeletionListener;
 
 class DeletionNotifier
 {
	 std::list< DeletionListener* > m_aListeners;
	 protected:
	 DeletionNotifier() {}

	 ~DeletionNotifier()
	 { notifyDelete(); }
	 
	 inline void notifyDelete();

	 public:	 
	 void addDel( DeletionListener* pListener )
	 { m_aListeners.push_back( pListener ); }
	 
	 void removeDel( DeletionListener* pListener )
	 { m_aListeners.remove( pListener ); }
 };
 
 class DeletionListener
 {
	 DeletionNotifier*	m_pNotifier;
	 public:
	 DeletionListener( DeletionNotifier* pNotifier )
	 : 	m_pNotifier( pNotifier )
		{
			if( m_pNotifier )
				m_pNotifier->addDel( this );
		}
	~DeletionListener()
	{
		if( m_pNotifier )
			m_pNotifier->removeDel( this );
	}
	void deleted() { m_pNotifier = NULL; }
	bool isDeleted() const { return (m_pNotifier == NULL); }
 };

 inline void DeletionNotifier::notifyDelete()
 {
	 for( std::list< DeletionListener* >::const_iterator it =
	 		m_aListeners.begin(); it != m_aListeners.end(); ++it )
		(*it)->deleted();
			
	 m_aListeners.clear();
 }
 
 } // namespace vcl
 
 #endif // _VCL_IMPDEL_HXX