/** 
 * @file lltreenode.h
 *
 * $LicenseInfo:firstyear=2005&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LL_LLTREENODE_H
#define LL_LLTREENODE_H

#include "stdtypes.h"
#include "xform.h"
#include "llpointer.h"
#include "llrefcount.h"

#include <vector>

template <class T> class LLTreeNode;
template <class T> class LLTreeTraveler;
template <class T> class LLTreeListener;

template <class T>
class LLTreeListener: public LLRefCount
{
public:
	virtual void handleInsertion(const LLTreeNode<T>* node, T* data) = 0;
	virtual void handleRemoval(const LLTreeNode<T>* node, T* data) = 0;
	virtual void handleDestruction(const LLTreeNode<T>* node) = 0;
	virtual void handleStateChange(const LLTreeNode<T>* node) = 0;
};

template <class T>
class LLTreeNode 
{
public:
	virtual ~LLTreeNode();
	
	virtual bool insert(T* data);
	virtual bool remove(T* data);
	virtual void notifyRemoval(T* data);
	virtual U32 hasListeners() const { return !mListeners.empty(); }
	virtual U32 getListenerCount() const { return mListeners.size(); }
	virtual LLTreeListener<T>* getListener(U32 index) const 
	{
		if (index < mListeners.size())
		{
			return mListeners[index]; 
		}
		return NULL;
	}
	virtual void addListener(LLTreeListener<T>* listener) { mListeners.push_back(listener); }

protected:
	void destroyListeners()
	{
		for (U32 i = 0; i < mListeners.size(); i++)
		{
			mListeners[i]->handleDestruction(this);
		}
		mListeners.clear();
	}
	
public:
	std::vector<LLPointer<LLTreeListener<T> > > mListeners;
};

template <class T>
class LLTreeTraveler
{
public:
	virtual ~LLTreeTraveler() { }; 
	virtual void traverse(const LLTreeNode<T>* node) = 0;
	virtual void visit(const LLTreeNode<T>* node) = 0;
};

template <class T>
LLTreeNode<T>::~LLTreeNode()
{ 
	destroyListeners();
};

template <class T>
bool LLTreeNode<T>::insert(T* data)
{ 
	for (U32 i = 0; i < mListeners.size(); i++)
	{
		mListeners[i]->handleInsertion(this, data);
	}
	return true;
};

template <class T>
bool LLTreeNode<T>::remove(T* data)
{
	return true;
};

template <class T>
void LLTreeNode<T>::notifyRemoval(T* data)
{
	for (U32 i = 0; i < mListeners.size(); i++)
	{
		mListeners[i]->handleRemoval(this, data);
	}
}

#endif