sl@0: // Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of the License "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: // e32\euser\cbase\ub_tque.cpp
sl@0: // 
sl@0: //
sl@0: 
sl@0: #include <e32std.h>
sl@0: #include <e32std_private.h>
sl@0: 
sl@0: 
sl@0: 
sl@0: 
sl@0: // Class TTickCountQue
sl@0: /**
sl@0: @internalComponent
sl@0: @released
sl@0: 
sl@0: Constructs an empty list header
sl@0: */
sl@0: TTickCountQue::TTickCountQue()
sl@0: 	{}
sl@0: 
sl@0: 
sl@0: 
sl@0: 
sl@0: /**
sl@0: @internalComponent
sl@0: @released
sl@0: 
sl@0: Adds the specified list element.
sl@0: 
sl@0: The element is added into the list in order of its tick count.
sl@0: 
sl@0: @param aRef The list element to be inserted.
sl@0: */
sl@0: void TTickCountQue::Add(TTickCountQueLink& aRef)
sl@0: 	{
sl@0: 	TTickCountQueLink* currentLink = (TTickCountQueLink*)(iHead.iNext);
sl@0: 	TTickCountQueLink* addLink = &aRef;
sl@0: 
sl@0: 	while (	(currentLink != (TTickCountQueLink*)&iHead) &&
sl@0: 			(((TInt)(addLink->iTickCount - currentLink->iTickCount)) >= 0)
sl@0: 		)
sl@0: 		{
sl@0: 		currentLink = (TTickCountQueLink*)currentLink->iNext;
sl@0: 		}
sl@0: 
sl@0: 	addLink->Enque(currentLink->iPrev);
sl@0: 	}
sl@0: 
sl@0: 
sl@0: 
sl@0: 
sl@0: /**
sl@0: @internalComponent
sl@0: @released
sl@0: 
sl@0: Removes the first list element from the linked list if its tick count
sl@0: is prior to the current tick count.
sl@0: 
sl@0: @param aTickCount The current tick count.
sl@0: 
sl@0: @return A pointer to the element removed from the linked list. This is NULL 
sl@0:         if the first element has yet to expire or the queue is empty.
sl@0: */
sl@0: TTickCountQueLink* TTickCountQue::RemoveFirst(TUint aTickCount)
sl@0: 	{
sl@0: 	TTickCountQueLink* firstLink = (TTickCountQueLink*)iHead.iNext;
sl@0: 
sl@0: 	if (((TInt)(firstLink->iTickCount - aTickCount)) <= 0)
sl@0: 		{
sl@0: 		return RemoveFirst();
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		return NULL;
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: 
sl@0: /**
sl@0: @internalComponent
sl@0: @released
sl@0: 
sl@0: Removes the first list element from the linked list, if any.
sl@0: 
sl@0: @return A pointer to the element removed from the linked list. This is NULL, 
sl@0:         if the queue is empty.
sl@0: */
sl@0: TTickCountQueLink* TTickCountQue::RemoveFirst()
sl@0: 	{
sl@0: 	TTickCountQueLink* firstLink = (TTickCountQueLink*)iHead.iNext;
sl@0: 
sl@0: 	if (firstLink != (TTickCountQueLink*)&iHead)
sl@0: 		{
sl@0: 		firstLink->Deque();
sl@0: 		return firstLink;
sl@0: 		}
sl@0: 
sl@0: 	return NULL;
sl@0: 	}
sl@0: 
sl@0: 
sl@0: 
sl@0: 
sl@0: /**
sl@0: @internalComponent
sl@0: @released
sl@0: 
sl@0: Gets a pointer to the first list element in the doubly linked list.
sl@0: 
sl@0: @return A pointer to the first list element in the doubly linked list. If 
sl@0:         the list is empty, this pointer is not necessarily NULL and must not
sl@0: 		be assumed to point to a valid object.
sl@0: */
sl@0: TTickCountQueLink* TTickCountQue::First() const
sl@0: 	{
sl@0: #if defined (_DEBUG)
sl@0: 	__DbgTestEmpty();
sl@0: #endif
sl@0:     return((TTickCountQueLink*)iHead.iNext);
sl@0:     }