/*

* Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

#include <stdlib.h>

#include <assert.h>

#include "LINKLIST.H"

// LinkedListIterator

LinkedListIterator::LinkedListIterator(ListItem* aItem):

	iCurrentItem(aItem)

	{}

LinkedListIterator::LinkedListIterator(const LinkedList& aList):

	iCurrentItem(aList.iHead)

	{}

ListItem* LinkedListIterator::operator() ()

	{

	ListItem* p = iCurrentItem;

	if(iCurrentItem)

		iCurrentItem = iCurrentItem->iNext;

	return p;

	}

void LinkedListIterator::Reset()

	{

	iCurrentItem = iList->iHead;

	}

// ListItem

ListItem::ListItem():

	iNext(NULL)

	{}

ListItem::~ListItem()

	{}

// LinkedList

LinkedList::LinkedList():

	iHead(NULL),

	iTail(NULL)

	{}

LinkedList::~LinkedList()

	{}

void LinkedList::AddToHead(ListItem* aNewItem)

	{

	if(iHead)

		aNewItem->iNext = iHead;

	else

		iTail = aNewItem;

	iHead = aNewItem;

	}

void LinkedList::AddToTail(ListItem* aNewItem)

	{

	if(iTail)

		iTail->iNext = aNewItem;

	else

		iHead = aNewItem;

	iTail = aNewItem;

	}

void LinkedList::DeleteAll()

	{

	ListItem* item = iHead; 

	while(item)

		{

		ListItem* p = item;

		item=item->iNext;

		delete p;

		}

	iHead = NULL;

	iTail = NULL;

	}

void LinkedList::AddAfter(ListItem* aExistingItem,ListItem* aNewItem)

	{

	if(aExistingItem==NULL)

		AddToHead(aNewItem);

	else if(aExistingItem == iTail)

		AddToTail(aNewItem);

	else

		{

		aNewItem->iNext = aExistingItem->iNext;

		aExistingItem->iNext = aNewItem;

		}

	}

ListItem* LinkedList::Previous(ListItem* aItem)

	{

	assert(aItem != NULL);

	assert(iHead != NULL);

	ListItem* p = iHead;

	if(p == aItem)

		return NULL;

	while(p->iNext != aItem && p->iNext != NULL)

		p = p->iNext;

	assert(p->iNext == aItem);

	return p;		

	}

void LinkedList::RemoveItem(ListItem* aItem)

	{

	assert(aItem != NULL);

	assert(iHead != NULL);

	// If item to remove is at head of list.	

	if (iHead == aItem)

		{

		if(iTail == aItem)	// Item being removed is only item in list

			iTail = NULL;	

		iHead = aItem->iNext;

		return;

		}

    // Search through the list for the item.

	ListItem* p = iHead;

	while( p && (p->iNext!=aItem))

		p = p->iNext;

	assert(p!=NULL);

	if (iTail == p->iNext)

		iTail = p;

	p->iNext = p->iNext->iNext;

	}

ListItem* LinkedList::TailItem()

	{

	return iTail;

	}

int LinkedList::IsEmpty()

	{

	return(iHead==NULL);

	}