/* This file is an image processing operation for GEGL

 *

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

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 3 of the License, or (at your option) any later version.

 *

 * GEGL 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with GEGL; if not, see <http://www.gnu.org/licenses/>.

 *

 * Copyright 2006 Øyvind Kolås <pippin@gimp.org>

 */

#include "config.h"

#include <glib/gi18n-lib.h>

#ifdef GEGL_CHANT_PROPERTIES

gegl_chant_string(path, _("File"), "", _("a GeglBuffer on disk to open"))

#else

#define GEGL_CHANT_TYPE_SOURCE

#define GEGL_CHANT_C_FILE       "open-buffer.c"

#include "gegl-chant.h"

static void buffer_changed (GeglBuffer          *buffer,

                            const GeglRectangle *rect,

                            gpointer             userdata)

{

  gegl_operation_invalidate (GEGL_OPERATION (userdata), rect, FALSE);

}

static GeglBuffer *ensure_buffer (GeglOperation *operation)

{

  GeglChantO   *o = GEGL_CHANT_PROPERTIES (operation);

  GeglBuffer   *buffer = o->chant_data;

  if (buffer)

    return buffer;

  if (!buffer)

    {

      buffer = gegl_buffer_open (o->path);

      o->chant_data = buffer;

    }

  g_signal_connect (buffer, "changed",

                    G_CALLBACK(buffer_changed), operation);

  return buffer;

}

static GeglRectangle

get_bounding_box (GeglOperation *operation)

{

  GeglRectangle result = {0,0,0,0};

  GeglBuffer   *buffer = ensure_buffer (operation);

  result = *gegl_buffer_get_extent (GEGL_BUFFER (buffer));

  return result;

}

static GeglRectangle

get_cached_region (GeglOperation       *self,

                   const GeglRectangle *roi)

{

  return get_bounding_box (self);

}

static gboolean

process (GeglOperation         *operation,

         GeglOperationContext  *context,

         const gchar           *output_pad,

         const GeglRectangle   *result,

         gint                   level)

{

  GeglBuffer *buffer = ensure_buffer (operation);

  if (buffer)

    {

      g_object_ref (buffer); /* Add an extra reference, since

		              * gegl_operation_set_data is

		              * stealing one.

		              */

      /* override core behaviour, by resetting the buffer in the operation_context */

      gegl_operation_context_take_object (context, "output", G_OBJECT (buffer));

      return TRUE;

    }

  return FALSE;

}

static void

dispose (GObject *object)

{

  GeglChantO *o = GEGL_CHANT_PROPERTIES (object);

  GeglBuffer *buffer = o->chant_data;

  if (buffer)

    {

      g_object_unref (buffer);

      o->chant_data = NULL;

    }

  G_OBJECT_CLASS (gegl_chant_parent_class)->dispose (object);

}

static void

gegl_chant_class_init (GeglChantClass *klass)

{

  GeglOperationClass       *operation_class;

  operation_class = GEGL_OPERATION_CLASS (klass);

  G_OBJECT_CLASS (klass)->dispose = dispose;

  operation_class->process = process;

  operation_class->get_bounding_box = get_bounding_box;

  operation_class->get_cached_region = get_cached_region;

  gegl_operation_class_set_keys (operation_class,

    "name"       , "gegl:open-buffer",

    "categories" , "input",

    "description", _("A source that uses an on-disk GeglBuffer."),

    NULL);

  operation_class->no_cache = TRUE;

}

#endif