/* GIMP - The GNU 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 3 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, see <https://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <string.h>

#include <gegl.h>
#include <gtk/gtk.h>

#include "display-types.h"

#include "core/gimp.h"
#include "core/gimpimage.h"

#include "widgets/gimpwidgets-utils.h"

#include "gimpdisplay.h"
#include "gimpdisplayshell.h"
#include "gimpdisplayshell-icon.h"


#define GIMP_DISPLAY_UPDATE_ICON_TIMEOUT  1000

static gboolean   gimp_display_shell_icon_update_idle (gpointer data);


/*  public functions  */

void
gimp_display_shell_icon_update (GimpDisplayShell *shell)
{
  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));

  gimp_display_shell_icon_update_stop (shell);

  if (gimp_display_get_image (shell->display))
    shell->icon_idle_id = g_timeout_add_full (G_PRIORITY_LOW,
                                              GIMP_DISPLAY_UPDATE_ICON_TIMEOUT,
                                              gimp_display_shell_icon_update_idle,
                                              shell,
                                              NULL);
  else
    gimp_display_shell_icon_update_idle (shell);
}

void
gimp_display_shell_icon_update_stop (GimpDisplayShell *shell)
{
  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));

  if (shell->icon_idle_id)
    {
      g_source_remove (shell->icon_idle_id);
      shell->icon_idle_id = 0;
    }
}


/*  private functions  */

static gboolean
gimp_display_shell_icon_update_idle (gpointer data)
{
  GimpDisplayShell *shell = GIMP_DISPLAY_SHELL (data);
  GimpImage        *image = gimp_display_get_image (shell->display);
  GdkPixbuf        *icon  = NULL;

  shell->icon_idle_id = 0;

  if (image)
    {
      Gimp      *gimp = gimp_display_get_gimp (shell->display);
      GdkPixbuf *pixbuf;
      gint       width;
      gint       height;
      gdouble    factor = ((gdouble) gimp_image_get_height (image) /
                           (gdouble) gimp_image_get_width  (image));

      if (factor >= 1)
        {
          height = MAX (shell->icon_size, 1);
          width  = MAX (((gdouble) shell->icon_size) / factor, 1);
        }
      else
        {
          height = MAX (((gdouble) shell->icon_size) * factor, 1);
          width  = MAX (shell->icon_size, 1);
        }

      pixbuf = gimp_viewable_get_pixbuf (GIMP_VIEWABLE (image),
                                         gimp_get_user_context (gimp),
                                         width, height);

      icon = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8,
                             shell->icon_size, shell->icon_size);

      memset (gdk_pixbuf_get_pixels (icon), 0,
              gdk_pixbuf_get_height (icon) *
              gdk_pixbuf_get_rowstride (icon));

      gdk_pixbuf_copy_area (pixbuf, 0, 0, width, height,
                            icon,
                            0, shell->icon_size - height);

      pixbuf = gimp_widget_load_icon (GTK_WIDGET (shell), "gimp-wilber-outline",
                                      shell->icon_size_small);

      width  = gdk_pixbuf_get_width  (pixbuf);
      height = gdk_pixbuf_get_height (pixbuf);

      gdk_pixbuf_composite (pixbuf, icon,
                            shell->icon_size - width, 0,
                            width, height,
                            shell->icon_size - width, 0.0, 1.0, 1.0,
                            GDK_INTERP_NEAREST, 255);
      g_object_unref (pixbuf);
    }

  g_object_set (shell, "icon", icon, NULL);

  if (icon)
    g_object_unref (icon);

  return FALSE;
}