www.pudn.com > XvidQP.rar > list.cpp

//	VirtualDub 2.x (Nina) - Video processing and capture application 
//	Copyright (C) 1998-2001 Avery Lee, All Rights Reserved. 
// 
//	This program is free software; you can redistribute it and/or modify 
//	it under the terms of the GNU General Public License as published by 
//	the Free Software Foundation; either version 2 of the License, or 
//	(at your option) any later version. 
// 
//	This program 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 General Public License for more details. 
// 
//	You should have received a copy of the GNU General Public License 
//	along with this program; if not, write to the Free Software 
//	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
 
/////////////////////////////////////////////////////////////////////////// 
// 
//	For those of you who say this looks familiar... it should.  This is 
//	the same linked-list style that the Amiga Exec uses, with dummy head 
//	and tail nodes.  It's really a very convienent way to implement 
//	doubly-linked lists. 
// 
 
#include "list.h" 
 
List::List() { 
	Init(); 
} 
 
void List::Init() { 
	head.next = tail.prev = 0; 
	head.prev = &tail; 
	tail.next = &head; 
} 
 
ListNode *List::RemoveHead() { 
	if (head.prev->prev) { 
		ListNode *t = head.prev; 
 
		head.prev->Remove(); 
		return t; 
	} 
 
	return 0; 
} 
 
ListNode *List::RemoveTail() { 
	if (tail.next->next) { 
		ListNode *t = tail.next; 
 
		tail.next->Remove(); 
		return t; 
	} 
 
	return 0; 
} 
 
void List::Take(List &from) { 
	if (from.IsEmpty()) 
		return; 
 
	head.prev = from.head.prev; 
	tail.next = from.tail.next; 
	head.prev->next = &head; 
	tail.next->prev = &tail; 
 
	from.Init(); 
}