/* gtktreesortable.c
 * Copyright (C) 2000  Red Hat, Inc.,  Jonathan Blandford <jrb@redhat.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */


#include "gtktreesortable.h"
#include "gtksignal.h"

static void gtk_tree_sortable_base_init (gpointer g_class);

GtkType
gtk_tree_sortable_get_type (void)
{
  static GtkType tree_sortable_type = 0;

  if (! tree_sortable_type)
    {
      static const GTypeInfo tree_sortable_info =
      {
	sizeof (GtkTreeSortableIface), /* class_size */
	gtk_tree_sortable_base_init,   /* base_init */
	NULL,		/* base_finalize */
	NULL,
	NULL,		/* class_finalize */
	NULL,		/* class_data */
	0,
	0,
	NULL
      };
      tree_sortable_type = g_type_register_static (G_TYPE_INTERFACE, "GtkTreeSortable", &tree_sortable_info, 0);
      g_type_interface_add_prerequisite (tree_sortable_type, G_TYPE_OBJECT);
    }

  return tree_sortable_type;
}

static void
gtk_tree_sortable_base_init (gpointer g_class)
{
  static gboolean initialized = FALSE;

  if (! initialized)
    {
      g_signal_new ("sort_column_changed",
                    GTK_TYPE_TREE_SORTABLE,
                    G_SIGNAL_RUN_LAST,
                    G_STRUCT_OFFSET (GtkTreeSortableIface, sort_column_changed),
                    NULL, NULL,
                    gtk_marshal_VOID__VOID,
                    G_TYPE_NONE, 0);
      initialized = TRUE;
    }
}

/**
 * gtk_tree_sortable_sort_column_changed:
 * @sortable: A #GtkTreeSortable
 * 
 * Emits a GtkTreeSortable::sort_column_changed signal on 
 **/
void
gtk_tree_sortable_sort_column_changed (GtkTreeSortable *sortable)
{
  g_return_if_fail (GTK_IS_TREE_SORTABLE (sortable));

  g_signal_emit_by_name (G_OBJECT (sortable),
			 "sort_column_changed");
}

/**
 * gtk_tree_sortable_get_sort_column_id:
 * @sortable: A #GtkTreeSortable
 * @sort_column_id: The sort column id to be filled in
 * @order: The #GtkSortType to be filled in
 * 
 * Fills in @sort_column_id and @order with the current sort column and the
 * order, if applicable.  If the sort column is not set, then FALSE is returned,
 * and the values in @sort_column_id and @order are unchanged.
  * 
 * Return value: %TRUE, if the sort column has been set
 **/
gboolean
gtk_tree_sortable_get_sort_column_id (GtkTreeSortable  *sortable,
				      gint             *sort_column_id,
				      GtkSortType      *order)
{
  GtkTreeSortableIface *iface;

  g_return_val_if_fail (GTK_IS_TREE_SORTABLE (sortable), FALSE);

  iface = GTK_TREE_SORTABLE_GET_IFACE (sortable);

  g_return_val_if_fail (iface != NULL, FALSE);
  g_return_val_if_fail (iface->get_sort_column_id != NULL, FALSE);

  return (* iface->get_sort_column_id) (sortable, sort_column_id, order);
}

/**
 * gtk_tree_sortable_set_sort_column_id:
 * @sortable: A #GtkTreeSortable
 * @sort_column_id: the sort column id to set
 * @order: The sort order of the column
 * 
 * Sets the current sort column to be @sort_column_id.  The @sortable will
 * resort itself to reflect this change, after emitting a
 * GtkTreeSortable::sort_column_changed signal.  If @sort_column_id is -1, then
 * the default sort function will be used, if it is set.
 **/
void
gtk_tree_sortable_set_sort_column_id (GtkTreeSortable  *sortable,
				      gint              sort_column_id,
				      GtkSortType       order)
{
  GtkTreeSortableIface *iface;

  g_return_if_fail (GTK_IS_TREE_SORTABLE (sortable));

  iface = GTK_TREE_SORTABLE_GET_IFACE (sortable);

  g_return_if_fail (iface != NULL);
  g_return_if_fail (iface->set_sort_column_id != NULL);
  
  (* iface->set_sort_column_id) (sortable, sort_column_id, order);

}

/**
 * gtk_tree_sortable_set_sort_func:
 * @sortable: A #GtkTreeSortable
 * @sort_column_id: the sort column id to set the function for
 * @sort_func: The sorting function
 * @user_data: User data to pass to the sort func, or %NULL
 * @destroy: Destroy notifier of @user_data, or %NULL
 * 
 * Sets the comparison function used when sorting to be @sort_func.  If the
 * current sort column id of @sortable is the same as @sort_column_id, then the
 * model will sort.
 **/
void
gtk_tree_sortable_set_sort_func (GtkTreeSortable        *sortable,
				 gint                    sort_column_id,
				 GtkTreeIterCompareFunc  sort_func,
				 gpointer                user_data,
				 GtkDestroyNotify        destroy)
{
  GtkTreeSortableIface *iface;

  g_return_if_fail (GTK_IS_TREE_SORTABLE (sortable));

  iface = GTK_TREE_SORTABLE_GET_IFACE (sortable);

  g_return_if_fail (iface != NULL);
  g_return_if_fail (iface->set_sort_func != NULL);
  
  (* iface->set_sort_func) (sortable, sort_column_id, sort_func, user_data, destroy);
}

/**
 * gtk_tree_sortable_set_default_sort_func:
 * @sortable: A #GtkTreeSortable
 * @sort_func: The sorting function
 * @user_data: User data to pass to the sort func, or %NULL
 * @destroy: Destroy notifier of @user_data, or %NULL
 * 
 * Sets the default comparison function used when sorting to be @sort_func.  If
 * the current sort column id of @sortable is the same as @sort_column_id, then
 * the model will sort.
 **/
void
gtk_tree_sortable_set_default_sort_func (GtkTreeSortable        *sortable,
					 GtkTreeIterCompareFunc  sort_func,
					 gpointer                user_data,
					 GtkDestroyNotify        destroy)
{
  GtkTreeSortableIface *iface;

  g_return_if_fail (GTK_IS_TREE_SORTABLE (sortable));

  iface = GTK_TREE_SORTABLE_GET_IFACE (sortable);

  g_return_if_fail (iface != NULL);
  g_return_if_fail (iface->set_default_sort_func != NULL);
  
  (* iface->set_default_sort_func) (sortable, sort_func, user_data, destroy);
}

/**
 * gtk_tree_sortable_has_default_sort_func:
 * @sortable: A #GtkTreeSortable
 * 
 * Returns %TRUE if the model has a default sort function.  This is used
 * primarily by GtkTreeViewColumns in order to determine if a model can go back
 * to the default state, or not.
 * 
 * Return value: %TRUE, if the model has a default sort function
 **/
gboolean
gtk_tree_sortable_has_default_sort_func (GtkTreeSortable *sortable)
{
  GtkTreeSortableIface *iface;

  g_return_if_fail (GTK_IS_TREE_SORTABLE (sortable));

  iface = GTK_TREE_SORTABLE_GET_IFACE (sortable);

  g_return_if_fail (iface != NULL);
  g_return_if_fail (iface->has_default_sort_func != NULL);
  
  (* iface->has_default_sort_func) (sortable);
}