// Copyright (c) 2004-2009 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:

 // e32\euser\cbase\ub_tque.cpp

 // 

 //

 #include <e32std.h>

 #include <e32std_private.h>

 // Class TTickCountQue

 /**

 @internalComponent

 @released

 Constructs an empty list header

 */

 TTickCountQue::TTickCountQue()

 	{}

 /**

 @internalComponent

 @released

 Adds the specified list element.

 The element is added into the list in order of its tick count.

 @param aRef The list element to be inserted.

 */

 void TTickCountQue::Add(TTickCountQueLink& aRef)

 	{

 	TTickCountQueLink* currentLink = (TTickCountQueLink*)(iHead.iNext);

 	TTickCountQueLink* addLink = &aRef;

 	while (	(currentLink != (TTickCountQueLink*)&iHead) &&

 			(((TInt)(addLink->iTickCount - currentLink->iTickCount)) >= 0)

 		)

 		{

 		currentLink = (TTickCountQueLink*)currentLink->iNext;

 		}

 	addLink->Enque(currentLink->iPrev);

 	}

 /**

 @internalComponent

 @released

 Removes the first list element from the linked list if its tick count

 is prior to the current tick count.

 @param aTickCount The current tick count.

 @return A pointer to the element removed from the linked list. This is NULL 

         if the first element has yet to expire or the queue is empty.

 */

 TTickCountQueLink* TTickCountQue::RemoveFirst(TUint aTickCount)

 	{

 	TTickCountQueLink* firstLink = (TTickCountQueLink*)iHead.iNext;

 	if (((TInt)(firstLink->iTickCount - aTickCount)) <= 0)

 		{

 		return RemoveFirst();

 		}

 	else

 		{

 		return NULL;

 		}

 	}

 /**

 @internalComponent

 @released

 Removes the first list element from the linked list, if any.

 @return A pointer to the element removed from the linked list. This is NULL, 

         if the queue is empty.

 */

 TTickCountQueLink* TTickCountQue::RemoveFirst()

 	{

 	TTickCountQueLink* firstLink = (TTickCountQueLink*)iHead.iNext;

 	if (firstLink != (TTickCountQueLink*)&iHead)

 		{

 		firstLink->Deque();

 		return firstLink;

 		}

 	return NULL;

 	}

 /**

 @internalComponent

 @released

 Gets a pointer to the first list element in the doubly linked list.

 @return A pointer to the first list element in the doubly linked list. If 

         the list is empty, this pointer is not necessarily NULL and must not

 		be assumed to point to a valid object.

 */

 TTickCountQueLink* TTickCountQue::First() const

 	{

 #if defined (_DEBUG)

 	__DbgTestEmpty();

 #endif

     return((TTickCountQueLink*)iHead.iNext);

     }