/* The GIMP -- an image manipulation program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * 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.
 */

#include "config.h"

#include <glib-object.h>

#include "libgimpcolor/gimpcolor.h"

#include "core-types.h"

#include "gimp.h"
#include "gimpchannel.h"
#include "gimpimage.h"
#include "gimpimage-qmask.h"
#include "gimpimage-undo.h"
#include "gimpimage-undo-push.h"
#include "gimplayer.h"
#include "gimplayer-floating-sel.h"
#include "gimpselection.h"

#include "gimp-intl.h"


/*  public functions  */

void
gimp_image_set_qmask_state (GimpImage *gimage,
                            gboolean   qmask_state)
{
  GimpChannel *selection;
  GimpChannel *mask;

  g_return_if_fail (GIMP_IS_IMAGE (gimage));

  if (qmask_state == gimage->qmask_state)
    return;

  /*  set image->qmask_state early so we can return early when
   *  being called recursively
   */
  gimage->qmask_state = qmask_state ? TRUE : FALSE;

  selection = gimp_image_get_mask (gimage);
  mask      = gimp_image_get_qmask (gimage);

  if (qmask_state)
    {
      if (! mask)
        {
          gimp_image_undo_group_start (gimage, GIMP_UNDO_GROUP_IMAGE_QMASK,
                                       _("Enable QuickMask"));

          if (gimp_channel_is_empty (selection))
            {
              /* if no selection */

              GimpLayer *floating_sel = gimp_image_floating_sel (gimage);

              if (floating_sel)
                floating_sel_to_layer (floating_sel);

              mask = gimp_channel_new (gimage,
                                       gimage->width,
                                       gimage->height,
                                       GIMP_IMAGE_QMASK_NAME,
                                       &gimage->qmask_color);

              /* Clear the mask */
              gimp_channel_clear (mask, NULL, FALSE);
            }
          else
            {
              /* if selection */

              mask = GIMP_CHANNEL (gimp_item_duplicate (GIMP_ITEM (selection),
                                                        GIMP_TYPE_CHANNEL,
                                                        FALSE));

              /* Clear the selection */
              gimp_channel_clear (selection, NULL, TRUE);

              gimp_channel_set_color (mask, &gimage->qmask_color, FALSE);
              gimp_item_rename (GIMP_ITEM (mask), GIMP_IMAGE_QMASK_NAME);
            }

          if (gimage->qmask_inverted)
            gimp_channel_invert (mask, FALSE);

          gimp_image_add_channel (gimage, mask, 0);

          gimp_image_undo_group_end (gimage);
        }
    }
  else
    {
      if (mask)
        {
          GimpLayer *floating_sel = gimp_image_floating_sel (gimage);

          gimp_image_undo_group_start (gimage, GIMP_UNDO_GROUP_IMAGE_QMASK,
                                       _("Disable QuickMask"));

          if (gimage->qmask_inverted)
            gimp_channel_invert (mask, TRUE);

          if (floating_sel && floating_sel->fs.drawable == GIMP_DRAWABLE (mask))
            floating_sel_anchor (floating_sel);

          gimp_selection_load (gimp_image_get_mask (gimage), mask);
          gimp_image_remove_channel (gimage, mask);

          gimp_image_undo_group_end (gimage);
        }
    }

  gimp_image_qmask_changed (gimage);
}

gboolean
gimp_image_get_qmask_state (const GimpImage *gimage)
{
  g_return_val_if_fail (GIMP_IS_IMAGE (gimage), FALSE);

  return gimage->qmask_state;
}

GimpChannel *
gimp_image_get_qmask (const GimpImage *gimage)
{
  g_return_val_if_fail (GIMP_IS_IMAGE (gimage), NULL);

  return gimp_image_get_channel_by_name (gimage, GIMP_IMAGE_QMASK_NAME);
}

void
gimp_image_qmask_invert (GimpImage *gimage)
{
  g_return_if_fail (GIMP_IS_IMAGE (gimage));

  if (gimage->qmask_state)
    {
      GimpChannel *qmask = gimp_image_get_qmask (gimage);

      if (qmask)
        {
          gimp_channel_invert (qmask, TRUE);

          gimp_drawable_update (GIMP_DRAWABLE (qmask),
                                0, 0,
                                GIMP_ITEM (qmask)->width,
                                GIMP_ITEM (qmask)->height);
        }
    }

  gimage->qmask_inverted = ! gimage->qmask_inverted;
}