/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*-

   nautilus-background.c: Object for the background of a widget.
 
   Copyright (C) 2000 Eazel, Inc.
  
   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., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.
  
   Author: Darin Adler <darin@eazel.com>
*/

#include <config.h>
#include "nautilus-background-canvas-group.h"

#include <libgnomeui/gnome-canvas.h>
#include <libgnomeui/gnome-canvas-util.h>
#include <libart_lgpl/art_rgb_affine.h>
#include <libart_lgpl/art_rgb_rgba_affine.h>

#include "nautilus-background.h"
#include "nautilus-gdk-extensions.h"
#include "nautilus-gtk-macros.h"

#include <stdio.h>

static void nautilus_background_canvas_group_initialize_class (gpointer         klass);
static void nautilus_background_canvas_group_initialize       (gpointer         object,
															   gpointer         klass);

static void nautilus_background_canvas_group_update (GnomeCanvasItem	*item,
													 double				 affine[6],
													 ArtSVP				*clip_path,
													 gint				 flags);
													 
static void nautilus_background_canvas_group_draw	(GnomeCanvasItem	*item,
							       					 GdkDrawable		*drawable,
											         int				 x,
											         int				 y,
											         int				 width,
											         int				 height);
static void nautilus_background_canvas_group_render	(GnomeCanvasItem	*item,
													 GnomeCanvasBuf		*buffer);

NAUTILUS_DEFINE_CLASS_BOILERPLATE (NautilusBackgroundCanvasGroup, nautilus_background_canvas_group, GNOME_TYPE_CANVAS_GROUP)

static void
nautilus_background_canvas_group_initialize_class (gpointer klass)
{
	GNOME_CANVAS_ITEM_CLASS (klass)->update = nautilus_background_canvas_group_update;
	GNOME_CANVAS_ITEM_CLASS (klass)->draw = nautilus_background_canvas_group_draw;
	GNOME_CANVAS_ITEM_CLASS (klass)->render = nautilus_background_canvas_group_render;
}

static void
nautilus_background_canvas_group_initialize (gpointer object, gpointer klass)
{
}

static void
nautilus_background_canvas_group_update (GnomeCanvasItem	*item,
										 double				 affine[6],
										 ArtSVP				*clip_path,
										 gint				 flags)
{
	NautilusBackground *background = nautilus_get_widget_background (GTK_WIDGET (item->canvas));

	nautilus_background_pre_draw (background,
								  GTK_WIDGET (item->canvas)->allocation.width,
								  GTK_WIDGET (item->canvas)->allocation.height);

	NAUTILUS_CALL_PARENT_CLASS (GNOME_CANVAS_ITEM_CLASS, update, (item, affine, clip_path, flags));				     
}

static void
nautilus_background_canvas_group_draw (GnomeCanvasItem *item,
									   GdkDrawable *drawable,
									   int x,
									   int y,
									   int width,
									   int height)
{
	NautilusBackground *background;
	GdkGC *gc;

	/* Draw the background. */
	background = nautilus_get_widget_background (GTK_WIDGET (item->canvas));

	/* If GtkStyle handled it, then we don't want to bother doing
	 * any additional work. It would be way slow to draw again.
	 */
	if (nautilus_background_is_too_complex_for_gtk_style (background)) {
		/* Create a new gc each time.
		 * If this is a speed problem, we can create one and keep it around,
		 * but it's a bit more complicated to ensure that it's always compatible
		 * with whatever drawable is passed in.
		 */
		gc = gdk_gc_new (drawable);

		/* FIXME bugzilla.eazel.com 2280:
		 * It shouldn't be necessary to call nautilus_background_pre_draw here.
		 * However, nautilus_background_canvas_group_update (who should be the one
		 * spot we call nautilus_background_pre_draw from) doesn't seemed to get
		 * called prior to all drawing.
		 */
		nautilus_background_pre_draw (background,
									  GTK_WIDGET (item->canvas)->allocation.width,
									  GTK_WIDGET (item->canvas)->allocation.height);

		nautilus_background_draw (background, drawable, gc, x, y, width, height);

		gdk_gc_unref (gc);
	}

	/* Call through to the GnomeCanvasGroup implementation, which
	 * will draw all the canvas items.
	 */
	NAUTILUS_CALL_PARENT_CLASS (GNOME_CANVAS_ITEM_CLASS, draw, (item, drawable, x, y, width, height));				     
}


/* draw the background for the anti-aliased canvas case */
static void
nautilus_background_canvas_group_render (GnomeCanvasItem *item, GnomeCanvasBuf *buffer)
{
	NautilusBackground *background;
			
	background = nautilus_get_widget_background (GTK_WIDGET (item->canvas));
	if (background != NULL) {
		/* FIXME bugzilla.eazel.com 2280:
		 * It shouldn't be necessary to call nautilus_background_pre_draw here.
		 * However, nautilus_background_canvas_group_update (who should be the one
		 * spot we call nautilus_background_pre_draw from) doesn't seemed to get
		 * called prior to all drawing.
		 */
		nautilus_background_pre_draw (background,
									  GTK_WIDGET (item->canvas)->allocation.width,
									  GTK_WIDGET (item->canvas)->allocation.height);

		nautilus_background_draw_aa (background, buffer);
	}
	
	/* Call through to the GnomeCanvasGroup implementation, which will draw all
	 * the canvas items.
	 */
	NAUTILUS_CALL_PARENT_CLASS (GNOME_CANVAS_ITEM_CLASS, render, (item, buffer));
}