/* -*- Mode: C; indent-tabs-mode:nil; c-basic-offset: 8-*- */

/*

 * This file is part of The Croco Library

 *

 * Copyright (C) 2002-2003 Dodji Seketeli <dodji@seketeli.org>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of version 2.1 of the 

 * GNU Lesser General Public

 * License as published by the Free Software Foundation.

 *

 * 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 Lesser General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307

 * USA

 */

/*

 *$Id: cr-cascade.c,v 1.7 2005/05/10 19:48:56 dodji Exp $

 */

#include <config.h>

#include <string.h>

#include "cr-cascade.h"

#define PRIVATE(a_this) ((a_this)->priv)

struct _CRCascadePriv {

 /**

	 *the 3 style sheets of the cascade:

	 *author, user, and useragent sheet.

	 *Intended to be addressed by

	 *sheets[ORIGIN_AUTHOR] or sheets[ORIGIN_USER]

	 *of sheets[ORIGIN_UA] ;

	 */

        CRStyleSheet *sheets[3];

        guint ref_count;

};

/**

 * cr_cascade_new:

 *@a_author_sheet: the author origin style sheet.  May be NULL.

 *@a_user_sheet: the user origin style sheet.  May be NULL.

 *@a_ua_sheet: the user agent origin style sheet.  May be NULL.

 *

 *Constructor of the #CRCascade class.

 *Note that all three parameters of this

 *method are ref counted and their refcount is increased.

 *Their refcount will be decreased at the destruction of

 *the instance of #CRCascade.

 *So the caller should not call their destructor. The caller

 *should call their ref/unref method instead if it wants

 *

 *Returns the newly built instance of CRCascade or NULL if

 *an error arose during constrution.

 */

CRCascade *

cr_cascade_new (CRStyleSheet * a_author_sheet,

                CRStyleSheet * a_user_sheet, CRStyleSheet * a_ua_sheet)

{

        CRCascade *result = NULL;

        result = g_try_malloc (sizeof (CRCascade));

        if (!result) {

                cr_utils_trace_info ("Out of memory");

                return NULL;

        }

        memset (result, 0, sizeof (CRCascade));

        PRIVATE (result) = g_try_malloc (sizeof (CRCascadePriv));

        if (!PRIVATE (result)) {

                cr_utils_trace_info ("Out of memory");

                return NULL;

        }

        memset (PRIVATE (result), 0, sizeof (CRCascadePriv));

        if (a_author_sheet) {

                cr_cascade_set_sheet (result, a_author_sheet, ORIGIN_AUTHOR);

        }

        if (a_user_sheet) {

                cr_cascade_set_sheet (result, a_user_sheet, ORIGIN_USER);

        }

        if (a_ua_sheet) {

                cr_cascade_set_sheet (result, a_ua_sheet, ORIGIN_UA);

        }

        return result;

}

/**

 * cr_cascade_get_sheet:

 *@a_this: the current instance of #CRCascade.

 *@a_origin: the origin of the style sheet as

 *defined in the css2 spec in chapter 6.4.

 *Gets a given origin sheet.

 *

 *Gets a sheet, part of the cascade.

 *Note that the returned stylesheet

 *is refcounted so if the caller wants

 *to manage it's lifecycle, it must use

 *cr_stylesheet_ref()/cr_stylesheet_unref() instead

 *of the cr_stylesheet_destroy() method.

 *Returns the style sheet, or NULL if it does not

 *exist.

 */

CRStyleSheet *

cr_cascade_get_sheet (CRCascade * a_this, enum CRStyleOrigin a_origin)

{

        g_return_val_if_fail (a_this

                              && a_origin >= ORIGIN_UA

                              && a_origin < NB_ORIGINS, NULL);

        return PRIVATE (a_this)->sheets[a_origin];

}

/**

 * cr_cascade_set_sheet:

 *@a_this: the current instance of #CRCascade.

 *@a_sheet: the stylesheet to set.

 *@a_origin: the origin of the stylesheet.

 *

 *Sets a stylesheet in the cascade

 *

 *Returns CR_OK upon successfull completion, an error

 *code otherwise.

 */

enum CRStatus

cr_cascade_set_sheet (CRCascade * a_this,

                      CRStyleSheet * a_sheet, enum CRStyleOrigin a_origin)

{

        g_return_val_if_fail (a_this

                              && a_sheet

                              && a_origin >= ORIGIN_UA

                              && a_origin < NB_ORIGINS, CR_BAD_PARAM_ERROR);

        if (PRIVATE (a_this)->sheets[a_origin])

                cr_stylesheet_unref (PRIVATE (a_this)->sheets[a_origin]);

        PRIVATE (a_this)->sheets[a_origin] = a_sheet;

        cr_stylesheet_ref (a_sheet);

        a_sheet->origin = a_origin;

        return CR_OK;

}

/**

 *cr_cascade_ref:

 *@a_this: the current instance of #CRCascade

 *

 *Increases the reference counter of the current instance

 *of #CRCascade.

 */

void

cr_cascade_ref (CRCascade * a_this)

{

        g_return_if_fail (a_this && PRIVATE (a_this));

        PRIVATE (a_this)->ref_count++;

}

/**

 * cr_cascade_unref:

 *@a_this: the current instance of 

 *#CRCascade.

 *

 *Decrements the reference counter associated

 *to this instance of #CRCascade. If the reference

 *counter reaches zero, the instance is destroyed 

 *using cr_cascade_destroy()

 */

void

cr_cascade_unref (CRCascade * a_this)

{

        g_return_if_fail (a_this && PRIVATE (a_this));

        if (PRIVATE (a_this)->ref_count)

                PRIVATE (a_this)->ref_count--;

        if (!PRIVATE (a_this)->ref_count) {

                cr_cascade_destroy (a_this);

        }

}

/**

 * cr_cascade_destroy:

 * @a_this: the current instance of #CRCascade

 *

 * Destructor of #CRCascade.

 */

void

cr_cascade_destroy (CRCascade * a_this)

{

        g_return_if_fail (a_this);

        if (PRIVATE (a_this)) {

                gulong i = 0;

                for (i = 0; PRIVATE (a_this)->sheets && i < NB_ORIGINS; i++) {

                        if (PRIVATE (a_this)->sheets[i]) {

                                if (cr_stylesheet_unref

                                    (PRIVATE (a_this)->sheets[i])

                                    == TRUE) {

                                        PRIVATE (a_this)->sheets[i] = NULL;

                                }

                        }

                }

                g_free (PRIVATE (a_this));

                PRIVATE (a_this) = NULL;

        }

        g_free (a_this);

}