/*
 * Twin - A Tiny Window System
 * Copyright © 2004 Keith Packard <keithp@keithp.com>
 * All rights reserved.
 *
 * This Library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with the Twin Library; see the file COPYING.  If not,
 * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include "twinint.h"

void
_twin_queue_insert (twin_queue_t	**head,
		    twin_queue_proc_t	proc,
		    twin_queue_t	*new)
{
    twin_queue_t **prev, *q;

    for (prev = head; (q = *prev); prev = &q->next)
	if ((*proc) (new, q) == TWIN_AFTER)
	    break;
    new->next = *prev;
    new->order = 0;
    new->walking = TWIN_FALSE;
    new->deleted = TWIN_FALSE;
    *prev = new;
}

void
_twin_queue_remove (twin_queue_t	**head,
		    twin_queue_t	*old)
{
    twin_queue_t **prev, *q;

    for (prev = head; (q = *prev); prev = &q->next)
	if (q == old)
	{
	    *prev = q->next;
	    break;
	}
}

void
_twin_queue_reorder (twin_queue_t	**head,
                     twin_queue_proc_t   proc,
		     twin_queue_t	*elem)
{
    twin_queue_t **prev, *q;

    _twin_queue_remove(head, elem);

    for (prev = head; (q = *prev); prev = &q->next)
        if ((*proc) (elem, q) == TWIN_AFTER)
            break;
    elem->next = *prev;
    *prev = elem;
}

void
_twin_queue_delete (twin_queue_t	**head,
		    twin_queue_t	*old)
{
    _twin_queue_remove (head, old);
    old->deleted = TWIN_TRUE;
    if (!old->walking)
	free (old);
}

twin_queue_t *
_twin_queue_set_order (twin_queue_t	**head)
{
    twin_queue_t *first = *head;
    twin_queue_t *q;

    for (q = first; q; q = q->next)
    {
	q->order = q->next;
	q->walking = TWIN_TRUE;
    }
    return first;
}

void
_twin_queue_review_order (twin_queue_t	*first)
{
    twin_queue_t *q, *o;

    for (q = first; q; q = o)
    {
	o = q->order;
	q->order = 0;
	q->walking = TWIN_FALSE;
	if (q->deleted)
	    free (q);
    }
}