/*
 * 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"

static twin_queue_t    *head;

static twin_order_t
_twin_work_order (twin_queue_t *a, twin_queue_t *b)
{
    twin_work_t	*aw = (twin_work_t *) a;
    twin_work_t	*bw = (twin_work_t *) b;
    
    if (aw->priority < bw->priority)
	return TWIN_BEFORE;
    if (aw->priority > bw->priority)
	return TWIN_AFTER;
    return TWIN_AT;
}

static void
_twin_queue_work (twin_work_t   *work)
{
    _twin_queue_insert (&head, _twin_work_order, &work->queue);
}

void
_twin_run_work (void)
{
    twin_work_t	*work;
    twin_work_t	*first;
    
    first = (twin_work_t *) _twin_queue_set_order (&head);
    for (work = first; work; work = (twin_work_t *) work->queue.order)
	if (!(*work->proc) (work->closure))
	    _twin_queue_delete (&head, &work->queue);
    _twin_queue_review_order (&first->queue);
}

twin_work_t *
twin_set_work (twin_work_proc_t	work_proc,
		  int			priority,
		  void			*closure)
{
    twin_work_t	*work = malloc (sizeof (twin_work_t));

    if (!work)
	return 0;

    work->proc = work_proc;
    work->priority = priority;
    work->closure = closure;
    _twin_queue_work (work);
    return work;
}

void
twin_clear_work (twin_work_t *work)
{
    _twin_queue_delete (&head, &work->queue);
}