gtk2/gtk/gtktreemodelsort.c

/* gtktreemodelsort.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.
 */


/* NOTE: There is a potential for confusion in this code as to whether an iter,
 * path or value refers to the GtkTreeModelSort model, or the child model being
 * sorted.  As a convention, variables referencing the child model will have an
 * s_ prefix before them (ie. s_iter, s_value, s_path);
 */

#include "gtktreemodelsort.h"
#include "gtktreesortable.h"
#include "gtksignal.h"
#include "gtktreedatalist.h"
#include <string.h>



typedef struct _SortElt SortElt;
struct _SortElt
{
  GtkTreeIter iter;
  SortElt *parent;
  GArray *children;
  gint ref;
  gint offset;
};

typedef struct _SortData SortData;
struct _SortData
{
  GtkTreeModel *model;
  gint sort_col;
  GValueCompareFunc func;
};


#define get_array(e,t) ((GArray *)((e)->parent?(e)->parent->children:GTK_TREE_MODEL_SORT(t)->root))


static void         gtk_tree_model_sort_init            (GtkTreeModelSort      *tree_model_sort);
static void         gtk_tree_model_sort_class_init      (GtkTreeModelSortClass *tree_model_sort_class);
static void         gtk_tree_model_sort_tree_model_init (GtkTreeModelIface     *iface);
static void         gtk_tree_model_sort_tree_sortable_init (GtkTreeSortableIface   *iface);
static void         gtk_tree_model_sort_finalize        (GObject               *object);
static void         gtk_tree_model_sort_range_changed   (GtkTreeModel          *model,
							 GtkTreePath           *start_path,
							 GtkTreeIter           *start_iter,
							 GtkTreePath           *end_path,
							 GtkTreeIter           *end_iter,
							 gpointer               data);
static void         gtk_tree_model_sort_inserted        (GtkTreeModel          *model,
							 GtkTreePath           *path,
							 GtkTreeIter           *iter,
							 gpointer               data);
static void         gtk_tree_model_sort_has_child_toggled   (GtkTreeModel          *model,
							     GtkTreePath           *path,
							     GtkTreeIter           *iter,
							     gpointer               data);
static void         gtk_tree_model_sort_deleted         (GtkTreeModel          *model,
							 GtkTreePath           *path,
							 gpointer               data);
static gint         gtk_tree_model_sort_get_n_columns   (GtkTreeModel          *tree_model);
static GType        gtk_tree_model_sort_get_column_type (GtkTreeModel          *tree_model,
							 gint                   index);
static gboolean     gtk_tree_model_sort_get_iter        (GtkTreeModel          *tree_model,
							 GtkTreeIter           *iter,
							 GtkTreePath           *path);
static GtkTreePath *gtk_tree_model_sort_get_path        (GtkTreeModel          *tree_model,
							 GtkTreeIter           *iter);
static void         gtk_tree_model_sort_get_value       (GtkTreeModel          *tree_model,
							 GtkTreeIter           *iter,
							 gint                   column,
							 GValue                *value);
static gboolean     gtk_tree_model_sort_iter_next       (GtkTreeModel          *tree_model,
							 GtkTreeIter           *iter);
static gboolean     gtk_tree_model_sort_iter_children   (GtkTreeModel          *tree_model,
							 GtkTreeIter           *iter,
							 GtkTreeIter           *parent);
static gboolean     gtk_tree_model_sort_iter_has_child  (GtkTreeModel          *tree_model,
							 GtkTreeIter           *iter);
static gint         gtk_tree_model_sort_iter_n_children (GtkTreeModel          *tree_model,
							 GtkTreeIter           *iter);
static gboolean     gtk_tree_model_sort_iter_nth_child  (GtkTreeModel          *tree_model,
							 GtkTreeIter           *iter,
							 GtkTreeIter           *parent,
							 gint                   n);
static gboolean     gtk_tree_model_sort_iter_parent     (GtkTreeModel          *tree_model,
							 GtkTreeIter           *iter,
							 GtkTreeIter           *child);
static void         gtk_tree_model_sort_ref_node        (GtkTreeModel          *tree_model,
							 GtkTreeIter           *iter);
static void         gtk_tree_model_sort_unref_node      (GtkTreeModel          *tree_model,
							 GtkTreeIter           *iter);

/* sortable */
static gboolean gtk_tree_model_sort_get_sort_column_id (GtkTreeSortable        *sortable,
							gint                   *sort_column_id,
							GtkTreeSortOrder       *order);
static void     gtk_tree_model_sort_set_sort_column_id (GtkTreeSortable        *sortable,
							gint                    sort_column_id,
							GtkTreeSortOrder        order);
static void     gtk_tree_model_sort_set_sort_func      (GtkTreeSortable        *sortable,
							gint                    sort_column_id,
							GtkTreeIterCompareFunc  func,
							gpointer                data,
							GtkDestroyNotify        destroy);

/* Internal functions */
static gint         gtk_tree_model_sort_array_find_insert (GtkTreeModelSort *tree_model_sort,
							   GArray           *array,
							   GtkTreeIter      *iter,
							   gboolean          skip_sort_elt);
static GtkTreePath *gtk_tree_model_sort_convert_path_real (GtkTreeModelSort *tree_model_sort,
							   GtkTreePath      *child_path,
							   gboolean          build_children);
static void         gtk_tree_model_sort_build_level       (GtkTreeModelSort *tree_model_sort,
							   SortElt          *place);
static void         gtk_tree_model_sort_free_level        (GArray           *array);



GType
gtk_tree_model_sort_get_type (void)
{
  static GType tree_model_sort_type = 0;

  if (!tree_model_sort_type)
    {
      static const GTypeInfo tree_model_sort_info =
      {
        sizeof (GtkTreeModelSortClass),
	NULL,		/* base_init */
	NULL,		/* base_finalize */
        (GClassInitFunc) gtk_tree_model_sort_class_init,
	NULL,		/* class_finalize */
	NULL,		/* class_data */
        sizeof (GtkTreeModelSort),
	0,              /* n_preallocs */
        (GInstanceInitFunc) gtk_tree_model_sort_init
      };

      static const GInterfaceInfo tree_model_info =
      {
	(GInterfaceInitFunc) gtk_tree_model_sort_tree_model_init,
	NULL,
	NULL
      };

      static const GInterfaceInfo sortable_info =
      {
	(GInterfaceInitFunc) gtk_tree_model_sort_tree_sortable_init,
	NULL,
	NULL
      };

      tree_model_sort_type = g_type_register_static (G_TYPE_OBJECT, "GtkTreeModelSort", &tree_model_sort_info, 0);
      g_type_add_interface_static (tree_model_sort_type,
				   GTK_TYPE_TREE_MODEL,
				   &tree_model_info);

      g_type_add_interface_static (tree_model_sort_type,
				   GTK_TYPE_TREE_SORTABLE,
				   &sortable_info);
    }

  return tree_model_sort_type;
}

static void
gtk_tree_model_sort_class_init (GtkTreeModelSortClass *tree_model_sort_class)
{
  GObjectClass *object_class;

  object_class = (GObjectClass *) tree_model_sort_class;

  object_class->finalize = gtk_tree_model_sort_finalize;
}

static void
gtk_tree_model_sort_tree_model_init (GtkTreeModelIface *iface)
{
  iface->get_n_columns = gtk_tree_model_sort_get_n_columns;
  iface->get_column_type = gtk_tree_model_sort_get_column_type;
  iface->get_iter = gtk_tree_model_sort_get_iter;
  iface->get_path = gtk_tree_model_sort_get_path;
  iface->get_value = gtk_tree_model_sort_get_value;
  iface->iter_next = gtk_tree_model_sort_iter_next;
  iface->iter_children = gtk_tree_model_sort_iter_children;
  iface->iter_has_child = gtk_tree_model_sort_iter_has_child;
  iface->iter_n_children = gtk_tree_model_sort_iter_n_children;
  iface->iter_nth_child = gtk_tree_model_sort_iter_nth_child;
  iface->iter_parent = gtk_tree_model_sort_iter_parent;
  iface->ref_node = gtk_tree_model_sort_ref_node;
  iface->unref_node = gtk_tree_model_sort_unref_node;
}

static void
gtk_tree_model_sort_tree_sortable_init (GtkTreeSortableIface *iface)
{
  iface->get_sort_column_id = gtk_tree_model_sort_get_sort_column_id;
  iface->set_sort_column_id = gtk_tree_model_sort_set_sort_column_id;
  iface->set_sort_func = gtk_tree_model_sort_set_sort_func;
}

static void
gtk_tree_model_sort_init (GtkTreeModelSort *tree_model_sort)
{
  tree_model_sort->sort_column_id = -1;
  tree_model_sort->stamp = g_random_int ();
}

GtkTreeModel *
gtk_tree_model_sort_new (void)
{
  return GTK_TREE_MODEL (g_object_new (gtk_tree_model_sort_get_type (), NULL));
}

GtkTreeModel *
gtk_tree_model_sort_new_with_model (GtkTreeModel      *child_model)
{
  GtkTreeModel *retval;

  retval = gtk_tree_model_sort_new ();
  gtk_tree_model_sort_set_model (GTK_TREE_MODEL_SORT (retval), child_model);

  return retval;
}

/**
 * gtk_tree_model_sort_set_model:
 * @tree_model_sort: The #GtkTreeModelSort.
 * @child_model: A #GtkTreeModel, or NULL.
 * 
 * Sets the model of @tree_model_sort to be @model.  If @model is NULL, then the
 * old model is unset.
 **/
void
gtk_tree_model_sort_set_model (GtkTreeModelSort *tree_model_sort,
			       GtkTreeModel     *child_model)
{
  g_return_if_fail (tree_model_sort != NULL);
  g_return_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model_sort));

  if (child_model)
    g_object_ref (G_OBJECT (child_model));

  if (tree_model_sort->child_model)
    {
      g_signal_handler_disconnect (G_OBJECT (tree_model_sort->child_model),
				   tree_model_sort->changed_id);
      g_signal_handler_disconnect (G_OBJECT (tree_model_sort->child_model),
				   tree_model_sort->inserted_id);
      g_signal_handler_disconnect (G_OBJECT (tree_model_sort->child_model),
				   tree_model_sort->has_child_toggled_id);
      g_signal_handler_disconnect (G_OBJECT (tree_model_sort->child_model),
				   tree_model_sort->deleted_id);

      g_object_unref (G_OBJECT (tree_model_sort->child_model));
    }

  if (tree_model_sort->root)
    {
      gtk_tree_model_sort_free_level (tree_model_sort->root);
      tree_model_sort->root;
    }

  if (tree_model_sort->sort_list)
    {
      _gtk_tree_data_list_header_free (tree_model_sort->sort_list);
      tree_model_sort->sort_list = NULL;
    }

  tree_model_sort->child_model = child_model;
  if (child_model)
    {
      GType *types;
      gint i, n_columns;

      tree_model_sort->changed_id =
	g_signal_connectc (child_model,
			   "range_changed",
			   G_CALLBACK (gtk_tree_model_sort_range_changed),
			   tree_model_sort,
			   FALSE);
      tree_model_sort->inserted_id = 
	g_signal_connectc (child_model,
			   "inserted",
			   G_CALLBACK (gtk_tree_model_sort_inserted),
			   tree_model_sort,
			   FALSE);
      tree_model_sort->has_child_toggled_id = 
	g_signal_connectc (child_model,
			   "has_child_toggled",
			   G_CALLBACK (gtk_tree_model_sort_has_child_toggled),
			   tree_model_sort,
			   FALSE);
      tree_model_sort->deleted_id =
	g_signal_connectc (child_model,
			   "deleted",
			   G_CALLBACK (gtk_tree_model_sort_deleted),
			   tree_model_sort,
			   FALSE);

      tree_model_sort->flags = gtk_tree_model_get_flags (child_model);
      n_columns = gtk_tree_model_get_n_columns (child_model);
      types = g_new (GType, n_columns);
      for (i = 0; i < n_columns; i++)
	types[i] = gtk_tree_model_get_column_type (child_model, i);
      tree_model_sort->sort_list = _gtk_tree_data_list_header_new (n_columns, types);
      g_free (types);
    }
}

/**
 * gtk_tree_model_sort_get_model:
 * @tree_model: a #GtkTreeModelSort
 * 
 * Returns the model the #GtkTreeModelSort is sorting.
 * 
 * Return value: the "child model" being sorted
 **/
GtkTreeModel*
gtk_tree_model_sort_get_model (GtkTreeModelSort  *tree_model)
{
  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model), NULL);

  return tree_model->child_model;
}

/**
 * gtk_tree_model_sort_convert_path:
 * @tree_model_sort: The #GtkTreeModelSort.
 * @child_path: A #GtkTreePath, relative to the child model.
 * 
 * Converts the @child_path to a new path, relative to the sorted position.  In other
 * words, the value found in the @tree_model_sort ->child_model at the @child_path, is
 * identical to that found in the @tree_model_sort and the return value.
 * 
 * Return value: A new path, or NULL if @child_path does not exist in @tree_model_sort
 * ->child_model.
 **/
GtkTreePath *
gtk_tree_model_sort_convert_path (GtkTreeModelSort *tree_model_sort,
				  GtkTreePath      *child_path)
{
  g_return_val_if_fail (tree_model_sort != NULL, NULL);
  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model_sort), NULL);
  g_return_val_if_fail (child_path != NULL, NULL);

  return gtk_tree_model_sort_convert_path_real (tree_model_sort, child_path, TRUE);
}

static void
gtk_tree_model_sort_finalize (GObject *object)
{
  GtkTreeModelSort *tree_model_sort = (GtkTreeModelSort *) object;

  if (tree_model_sort->root)
    gtk_tree_model_sort_free_level (tree_model_sort->root);

  if (tree_model_sort->child_model)
    {
      g_object_unref (G_OBJECT (tree_model_sort->child_model));
      tree_model_sort->child_model = NULL;
    }
  if (tree_model_sort->sort_list)
    {
      _gtk_tree_data_list_header_free (tree_model_sort->sort_list);
      tree_model_sort->sort_list = NULL;
    }
}

static void
gtk_tree_model_sort_range_changed (GtkTreeModel *s_model,
				   GtkTreePath  *s_start_path,
				   GtkTreeIter  *s_start_iter,
				   GtkTreePath  *s_end_path,
				   GtkTreeIter  *s_end_iter,
				   gpointer      data)
{
  GtkTreeModelSort *tree_model_sort = GTK_TREE_MODEL_SORT (data);
  GtkTreePath *path;
  GtkTreeIter iter;
  SortElt *elt;
  GArray *array;
  gboolean free_s_path = FALSE;
  gint index;

  g_return_if_fail (s_start_path != NULL || s_start_iter != NULL);

  if (s_start_path == NULL)
    {
      free_s_path = TRUE;
      s_start_path = gtk_tree_model_get_path (s_model, s_start_iter);
    }

  path = gtk_tree_model_sort_convert_path_real (tree_model_sort, s_start_path, FALSE);
  if (path == NULL)
    {
      if (free_s_path)
	gtk_tree_path_free (s_start_path);
      return;
    }

  gtk_tree_model_get_iter (GTK_TREE_MODEL (data), &iter, path);
  elt = (SortElt *) iter.user_data;
  array = get_array (elt, tree_model_sort);

  /* FIXME: as an optimization for when the column other then the one we're
   * sorting is changed, we can check the prev and next element to see if
   * they're different.
   */
  
  /* Now we need to resort things. */
  index = gtk_tree_model_sort_array_find_insert (tree_model_sort,
						 array,
						 (GtkTreeIter *) elt,
						 TRUE);

  gtk_tree_model_range_changed (GTK_TREE_MODEL (data), path, &iter, path, &iter);

  gtk_tree_path_free (path);
  if (free_s_path)
    gtk_tree_path_free (s_start_path);
}

/* FALSE if the value was inserted, TRUE otherwise */
static gboolean
gtk_tree_model_sort_insert_value (GtkTreeModelSort *sort,
				  GtkTreePath      *s_path,
				  GtkTreeIter      *s_iter)
{
  GtkTreePath *tmp_path;
  GArray *array;
  gint index;
  GtkTreeIter iter;
  SortElt elt;
  gint offset;
  gint j;
  SortElt *tmp_elt;
  offset = gtk_tree_path_get_indices (s_path)[gtk_tree_path_get_depth (s_path) - 1];

  elt.iter = *s_iter;
  elt.ref = 0;
  elt.children = NULL;
  elt.offset = offset;

  tmp_path = gtk_tree_path_copy (s_path);

  if (gtk_tree_path_up (tmp_path))
    {
      GtkTreePath *parent_path;

      parent_path = gtk_tree_model_sort_convert_path_real (sort, tmp_path, FALSE);
      if (parent_path == NULL)
	{
	  gtk_tree_path_free (tmp_path);
	  return FALSE;
	}
      gtk_tree_model_get_iter (GTK_TREE_MODEL (sort), &iter, parent_path);
      elt.parent = ((SortElt *) iter.user_data);
      array = ((SortElt *) iter.user_data)->children;
      gtk_tree_path_free (parent_path);
      if (array == NULL)
	{
	  gtk_tree_path_free (tmp_path);
	  return FALSE;
	}
    }
  else
    {
      if (sort->root == NULL)
	sort->root = g_array_sized_new (FALSE, FALSE, sizeof (SortElt), 1);
      array = sort->root;
      elt.parent = NULL;
    }
  gtk_tree_path_free (tmp_path);

  index = gtk_tree_model_sort_array_find_insert (sort, array, (GtkTreeIter *) &elt, FALSE);

  g_array_insert_vals (array, index, &elt, 1);

  /* update all the larger offsets */
  tmp_elt = (SortElt *) array->data;
  for (j = 0; j < array->len; j++, tmp_elt++)
	{
	  if ((tmp_elt->offset >= offset) &&
	      j != index)
	    tmp_elt->offset ++;
	}

  return TRUE;
}

static void
gtk_tree_model_sort_inserted (GtkTreeModel *s_model,
			      GtkTreePath  *s_path,
			      GtkTreeIter  *s_iter,
			      gpointer      data)
{
  GtkTreeModelSort *tree_model_sort = GTK_TREE_MODEL_SORT (data);
  GtkTreePath *path;
  GtkTreeIter iter;

  g_return_if_fail (s_path != NULL || s_iter != NULL);

  if (s_path == NULL)
    s_path = gtk_tree_model_get_path (s_model, s_iter);

  if (!(tree_model_sort->flags & GTK_TREE_MODEL_ITERS_PERSIST))
    {
      gtk_tree_model_sort_free_level ((GArray *) tree_model_sort->root);
      tree_model_sort->root = NULL;
    }
  else
    {
      GtkTreeIter real_s_iter;

      if (s_iter == NULL)
	gtk_tree_model_get_iter (s_model, &real_s_iter, s_path);
      else
	real_s_iter = (* s_iter);

      if (!gtk_tree_model_sort_insert_value (tree_model_sort, s_path, &real_s_iter))
	return;
    }

  path = gtk_tree_model_sort_convert_path_real (tree_model_sort, s_path, FALSE);
  if (path == NULL)
    return;

  gtk_tree_model_get_iter (GTK_TREE_MODEL (data), &iter, path);
  g_signal_emit_by_name (G_OBJECT (data), "inserted", path, &iter);
  gtk_tree_path_free (path);
}

static void
gtk_tree_model_sort_has_child_toggled (GtkTreeModel *s_model,
				       GtkTreePath  *s_path,
				       GtkTreeIter  *s_iter,
				       gpointer      data)
{
  GtkTreeModelSort *tree_model_sort = GTK_TREE_MODEL_SORT (data);
  GtkTreePath *path;
  GtkTreeIter iter;
  gboolean free_s_path = FALSE;

  g_return_if_fail (s_path != NULL || s_iter != NULL);

  if (!(tree_model_sort->flags & GTK_TREE_MODEL_ITERS_PERSIST))
    {
      gtk_tree_model_sort_free_level ((GArray *)tree_model_sort->root);
      tree_model_sort->root = NULL;
    }

  if (s_path == NULL)
    {
      s_path = gtk_tree_model_get_path (s_model, s_iter);
      free_s_path = TRUE;
    }

  path = gtk_tree_model_sort_convert_path_real (tree_model_sort, s_path, FALSE);
  if (path == NULL)
    return;
  gtk_tree_model_get_iter (GTK_TREE_MODEL (data), &iter, path);
  g_signal_emit_by_name (G_OBJECT (data),
			   "has_child_toggled",
			   path, &iter);
  gtk_tree_path_free (path);
  if (free_s_path)
    gtk_tree_path_free (s_path);
}

static void
gtk_tree_model_sort_deleted (GtkTreeModel *s_model,
			     GtkTreePath  *s_path,
			     gpointer      data)
{
  GtkTreeModelSort *tree_model_sort = GTK_TREE_MODEL_SORT (data);
  GtkTreePath *path;

  g_return_if_fail (s_path != NULL);
  path = gtk_tree_model_sort_convert_path (tree_model_sort, s_path);
  g_return_if_fail (path != NULL);

  if (!(tree_model_sort->flags & GTK_TREE_MODEL_ITERS_PERSIST))
    {
      gtk_tree_model_sort_free_level ((GArray *)tree_model_sort->root);
      tree_model_sort->root = NULL;
    }
  else
    {
      GArray *array;
      GtkTreeIter iter;
      SortElt *elt;
      gint offset;
      gint i;

      gtk_tree_model_get_iter (GTK_TREE_MODEL (tree_model_sort), &iter, path);
      elt = (SortElt *) iter.user_data;
      offset = elt->offset;
      array = get_array (elt, tree_model_sort);
      if (array->len == 1)
	{
	  if (((SortElt *)array->data)->parent == NULL)
	    tree_model_sort->root = NULL;
	  else
	    (((SortElt *)array->data)->parent)->children = NULL;
	  gtk_tree_model_sort_free_level (array);
	}
      else
	{
	  g_array_remove_index (array, elt - ((SortElt *) array->data));

	  for (i = 0; i < array->len; i++)
	    {
	      elt = & (g_array_index (array, SortElt, i));
	      if (elt->offset > offset)
		elt->offset--;
	    }
	}
    }

  tree_model_sort->stamp++;
  g_signal_emit_by_name (G_OBJECT (data), "deleted", path);
  gtk_tree_path_free (path);
}

static gint
gtk_tree_model_sort_get_n_columns (GtkTreeModel *tree_model)
{
  GtkTreeModelSort *tree_model_sort = (GtkTreeModelSort *) tree_model;

  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model), 0);

  if (tree_model_sort->child_model == 0)
    return 0;

  return gtk_tree_model_get_n_columns (GTK_TREE_MODEL_SORT (tree_model)->child_model);
}

static GType
gtk_tree_model_sort_get_column_type (GtkTreeModel *tree_model,
				     gint          index)
{
  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model), G_TYPE_INVALID);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->child_model != NULL, G_TYPE_INVALID);

  return gtk_tree_model_get_column_type (GTK_TREE_MODEL_SORT (tree_model)->child_model, index);
}

static gboolean
gtk_tree_model_sort_get_iter_helper (GtkTreeModelSort *tree_model_sort,
				     GArray       *array,
				     GtkTreeIter  *iter,
				     gint          depth,
				     GtkTreePath  *path)
{
  SortElt *elt;

  if (array == NULL)
    return FALSE;

  if (gtk_tree_path_get_indices (path)[depth] > array->len)
    return FALSE;

  elt = & (g_array_index (array, SortElt, gtk_tree_path_get_indices (path)[depth]));

  if (depth == gtk_tree_path_get_depth (path) - 1)
    {
      iter->stamp = tree_model_sort->stamp;
      iter->user_data = elt;
      return TRUE;
    }

  if (elt->children != NULL)
    return gtk_tree_model_sort_get_iter_helper (tree_model_sort,
						elt->children,
						iter,
						depth + 1,
						path);

  if (gtk_tree_model_iter_has_child (tree_model_sort->child_model,
				     &(elt->iter)))

    gtk_tree_model_sort_build_level (tree_model_sort, elt);

  return gtk_tree_model_sort_get_iter_helper (tree_model_sort,
					      elt->children,
					      iter,
					      depth + 1,
					      path);
}

static gboolean
gtk_tree_model_sort_get_iter (GtkTreeModel *tree_model,
			      GtkTreeIter  *iter,
			      GtkTreePath  *path)
{
  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model), FALSE);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->child_model != NULL, FALSE);

  if (GTK_TREE_MODEL_SORT (tree_model)->root == NULL)
    gtk_tree_model_sort_build_level (GTK_TREE_MODEL_SORT (tree_model), NULL);

  return gtk_tree_model_sort_get_iter_helper (GTK_TREE_MODEL_SORT (tree_model),
					      GTK_TREE_MODEL_SORT (tree_model)->root,
					      iter, 0, path);
}

static GtkTreePath *
gtk_tree_model_sort_get_path (GtkTreeModel *tree_model,
			      GtkTreeIter  *iter)
{
  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model), NULL);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->child_model != NULL, NULL);

  return gtk_tree_model_get_path (GTK_TREE_MODEL_SORT (tree_model)->child_model, iter);
}

static void
gtk_tree_model_sort_get_value (GtkTreeModel *tree_model,
			       GtkTreeIter  *iter,
			       gint          column,
			       GValue        *value)
{
  SortElt *elt;

  g_return_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model));
  g_return_if_fail (GTK_TREE_MODEL_SORT (tree_model)->child_model != NULL);
  g_return_if_fail (GTK_TREE_MODEL_SORT (tree_model)->stamp == iter->stamp);

  elt = iter->user_data;

  gtk_tree_model_get_value (GTK_TREE_MODEL_SORT (tree_model)->child_model, (GtkTreeIter *)elt, column, value);
}

static gboolean
gtk_tree_model_sort_iter_next (GtkTreeModel *tree_model,
			       GtkTreeIter  *iter)
{
  GArray *array;
  SortElt *elt;

  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model), FALSE);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->child_model != NULL, FALSE);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->stamp == iter->stamp, FALSE);

  elt = iter->user_data;
  array = get_array (elt, tree_model);

  if (elt - ((SortElt*) array->data) >=  array->len - 1)
    {
      iter->stamp = 0;
      return FALSE;
    }
  iter->user_data = elt + 1;
  return TRUE;
}

static gboolean
gtk_tree_model_sort_iter_children (GtkTreeModel *tree_model,
				   GtkTreeIter  *iter,
				   GtkTreeIter  *parent)
{
  SortElt *elt;

  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model), FALSE);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->child_model != NULL, FALSE);

  if (parent)
    g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->stamp == parent->stamp, FALSE);

  if (parent)
    elt = parent->user_data;
  else
    elt = (SortElt *) ((GArray *)GTK_TREE_MODEL_SORT (tree_model)->root)->data;

  if (elt == NULL)
    return FALSE;

  if (elt->children == NULL &&
      gtk_tree_model_iter_has_child (GTK_TREE_MODEL_SORT (tree_model)->child_model, (GtkTreeIter *)elt))
    gtk_tree_model_sort_build_level (GTK_TREE_MODEL_SORT (tree_model), elt);

  if (elt->children == NULL)
    return FALSE;

  iter->stamp = GTK_TREE_MODEL_SORT (tree_model)->stamp;
  iter->user_data = elt->children->data;

  return TRUE;
}

static gboolean
gtk_tree_model_sort_iter_has_child (GtkTreeModel *tree_model,
				    GtkTreeIter  *iter)
{
  SortElt *elt;

  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model), FALSE);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->child_model != NULL, FALSE);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->stamp == iter->stamp, FALSE);

  elt = iter->user_data;
  if (elt->children)
    return TRUE;

  return gtk_tree_model_iter_has_child (GTK_TREE_MODEL_SORT (tree_model)->child_model, (GtkTreeIter *) elt);
}

static gint
gtk_tree_model_sort_iter_n_children (GtkTreeModel *tree_model,
				     GtkTreeIter  *iter)
{
  SortElt *elt;

  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model), 0);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->child_model != NULL, 0);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->stamp == iter->stamp, 0);

  elt = iter->user_data;
  if (elt->children)
    return elt->children->len;

  return gtk_tree_model_iter_n_children (GTK_TREE_MODEL_SORT (tree_model)->child_model, (GtkTreeIter *) elt);
}


static gboolean
gtk_tree_model_sort_iter_nth_child (GtkTreeModel *tree_model,
				    GtkTreeIter  *iter,
				    GtkTreeIter  *parent,
				    gint          n)
{
  SortElt *elt;

  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model), FALSE);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->child_model != NULL, FALSE);
  if (parent)
    g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->stamp == parent->stamp, FALSE);

  elt = iter->user_data;


  if (elt->children == NULL)
    {
      if (gtk_tree_model_iter_has_child (GTK_TREE_MODEL_SORT (tree_model)->child_model, (GtkTreeIter *)elt))
	gtk_tree_model_sort_build_level (GTK_TREE_MODEL_SORT (tree_model), elt);
      else
	return FALSE;
    }

  if (elt->children == NULL)
    return FALSE;

  if (n >= elt->children->len)
    return FALSE;

  iter->stamp = GTK_TREE_MODEL_SORT (tree_model)->stamp;
  iter->user_data = &g_array_index (elt->children, SortElt, n);

  return TRUE;
}

static gboolean
gtk_tree_model_sort_iter_parent (GtkTreeModel *tree_model,
				 GtkTreeIter  *iter,
				 GtkTreeIter  *child)
{
  SortElt *elt;

  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (tree_model), FALSE);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->child_model != NULL, FALSE);
  g_return_val_if_fail (GTK_TREE_MODEL_SORT (tree_model)->stamp == child->stamp, FALSE);

  elt = iter->user_data;
  if (elt->parent)
    {
      iter->stamp = GTK_TREE_MODEL_SORT (tree_model)->stamp;
      iter->user_data = elt->parent;

      return TRUE;
    }
  return FALSE;
}

static void
gtk_tree_model_sort_ref_node (GtkTreeModel *tree_model,
			      GtkTreeIter  *iter)
{
}

static void
gtk_tree_model_sort_unref_node (GtkTreeModel *tree_model,
				GtkTreeIter  *iter)
{

 
}

static gboolean
gtk_tree_model_sort_get_sort_column_id (GtkTreeSortable  *sortable,
					gint             *sort_column_id,
					GtkTreeSortOrder *order)
{
  GtkTreeModelSort *tree_model_sort = (GtkTreeModelSort *) sortable;

  g_return_val_if_fail (sortable != NULL, FALSE);
  g_return_val_if_fail (GTK_IS_TREE_MODEL_SORT (sortable), FALSE);

  if (tree_model_sort->sort_column_id == -1)
    return FALSE;

  if (sort_column_id)
    *sort_column_id = tree_model_sort->sort_column_id;
  if (order)
    *order = tree_model_sort->order;

  return TRUE;
}

static void
gtk_tree_model_sort_set_sort_column_id (GtkTreeSortable  *sortable,
					 gint              sort_column_id,
					 GtkTreeSortOrder  order)
{
  GtkTreeModelSort *tree_model_sort = (GtkTreeModelSort *) sortable;
  GList *list;

  g_return_if_fail (sortable != NULL);
  g_return_if_fail (GTK_IS_TREE_MODEL_SORT (sortable));

  for (list = tree_model_sort->sort_list; list; list = list->next)
    {
      GtkTreeDataSortHeader *header = (GtkTreeDataSortHeader*) list->data;
      if (header->sort_column_id == sort_column_id)
	break;
    }
  g_return_if_fail (list != NULL);

  if ((tree_model_sort->sort_column_id == sort_column_id) &&
      (tree_model_sort->order == order))
    return;

  tree_model_sort->sort_column_id = sort_column_id;
  tree_model_sort->order = order;

  /*  if (tree_model_sort->sort_column_id >= 0)
      gtk_list_store_sort (tree_model_sort);*/

  gtk_tree_sortable_sort_column_changed (sortable);

}

static void
gtk_tree_model_sort_set_sort_func (GtkTreeSortable        *sortable,
				   gint                    sort_column_id,
				   GtkTreeIterCompareFunc  func,
				   gpointer                data,
				   GtkDestroyNotify        destroy)
{
  GtkTreeModelSort *tree_model_sort = (GtkTreeModelSort *) sortable;
  GtkTreeDataSortHeader *header = NULL;
  GList *list;

  g_return_if_fail (sortable != NULL);
  g_return_if_fail (GTK_IS_TREE_MODEL_SORT (sortable));
  g_return_if_fail (func != NULL);

  for (list = tree_model_sort->sort_list; list; list = list->next)
    {
      header = (GtkTreeDataSortHeader*) list->data;
      if (header->sort_column_id == sort_column_id)
	break;
    }

  if (header == NULL)
    {
      header = g_new0 (GtkTreeDataSortHeader, 1);
      header->sort_column_id = sort_column_id;
      tree_model_sort->sort_list = g_list_append (tree_model_sort->sort_list, header);
    }

  if (header->destroy)
    (* header->destroy) (header->data);

  header->func = func;
  header->data = data;
  header->destroy = destroy;
}

/* Internal functions */

static gint
gtk_tree_model_sort_array_find_insert (GtkTreeModelSort *tree_model_sort,
				       GArray           *array,
				       GtkTreeIter      *iter,
				       gboolean          skip_sort_elt)
{
  gint middle;
  gint cmp;
  GValueCompareFunc func;
  GValue value = {0, };
  GValue tmp_value = {0, };
  SortElt *tmp_elt;

  func = NULL; //(GValueCompareFunc) gtk_tree_model_sort_get_func (tree_model_sort);

  g_return_val_if_fail (func != NULL, 0);

  gtk_tree_model_get_value (tree_model_sort->child_model, iter, tree_model_sort->sort_column_id, &value);

  for (middle = 0; middle < array->len; middle++)
    {
      tmp_elt = &(g_array_index (array, SortElt, middle));
      if (!skip_sort_elt &&
	  (SortElt *) iter == tmp_elt)
	  continue;
      gtk_tree_model_get_value (tree_model_sort->child_model,
				(GtkTreeIter *) tmp_elt,
				tree_model_sort->sort_column_id,
				&tmp_value);

      cmp = ((func) (&value, &tmp_value));
      g_value_unset (&tmp_value);

      if (cmp >= 0)
	break;
    }
  return middle;
}


static GtkTreePath *
gtk_tree_model_sort_convert_path_real (GtkTreeModelSort *tree_model_sort,
				       GtkTreePath      *child_path,
				       gboolean          build_children)
{
  GtkTreePath *retval;
  GArray *array;
  gint *indices;
  gint i = 0;

  if (tree_model_sort->root == NULL)
    {
      if (build_children)
	gtk_tree_model_sort_build_level (tree_model_sort, NULL);
      else
	return FALSE;
    }

  retval = gtk_tree_path_new ();
  array = (GArray *) tree_model_sort->root;
  indices = gtk_tree_path_get_indices (child_path);

  do
    {
      SortElt *elt;
      gboolean found = FALSE;
      gint j;

      if ((array->len < indices[i]) || (array == NULL))
	{
	  gtk_tree_path_free (retval);
	  return NULL;
	}

      elt = (SortElt *) array->data;
      for (j = 0; j < array->len; j++, elt++)
	{
	  if (elt->offset == indices[i])
	    {
	      found = TRUE;
	      break;
	    }
	}
      if (! found)
	{
	  gtk_tree_path_free (retval);
	  return NULL;
	}

      gtk_tree_path_prepend_index (retval, j);

      i++;

      if (i == gtk_tree_path_get_depth (child_path))
	break;

      if (elt->children == NULL)
	{
	  if (build_children)
	    {
	      gtk_tree_path_prepend_index (retval, j);
	      gtk_tree_model_sort_build_level (tree_model_sort, elt);
	    }
	  else
	    {
	      gtk_tree_path_free (retval);
	      return NULL;
	    }
	}
    }
  while (TRUE);

  return retval;
}
  
static void
gtk_tree_model_sort_build_level (GtkTreeModelSort *tree_model_sort,
				 SortElt          *place)
{
  gint n, i = 0;
  GArray *children;
  GtkTreeIter *parent_iter = NULL;
  GtkTreeIter iter;
  SortElt elt;
  SortData sort_data;

  if (place)
    parent_iter = & (place->iter);

      
  n = gtk_tree_model_iter_n_children (tree_model_sort->child_model, parent_iter);

  if (n == 0)
    return;

  children = g_array_sized_new (FALSE, FALSE, sizeof (SortElt), n);

  if (place)
    place->children = children;
  else
    tree_model_sort->root = children;

  gtk_tree_model_iter_children (tree_model_sort->child_model,
				&iter,
				parent_iter);

  do
    {
      elt.iter = iter;
      elt.parent = place;
      elt.children = NULL;
      elt.ref = 0;
      elt.offset = i;

      g_array_append_vals (children, &elt, 1);
      i++;
    }
  while (gtk_tree_model_iter_next (tree_model_sort->child_model, &iter));
}

static void
gtk_tree_model_sort_free_level (GArray *array)
{
  gint i;

  if (array == NULL)
    return;

  for (i = 0; i < array->len; i++)
    {
      SortElt *elt;

      elt = &g_array_index (array, SortElt, i);
      if (elt->children)
	gtk_tree_model_sort_free_level (array);
    }

  g_array_free (array, TRUE);
}

/* DEAD CODE */

#if 0
  /* FIXME: we can, as we are an array, do binary search to find the correct
   * location to insert the element.  However, I'd rather get it working.  The
   * below is quite wrong, but a step in the right direction.
   */
  low = 0;
  high = array->len;
  middle = (low + high)/2;

  /* Insert the value into the array */
  while (low != high)
    {
      gint cmp;
      tmp_elt = &(g_array_index (array, SortElt, middle));
      gtk_tree_model_get_value (sort->child_model,
				(GtkTreeIter *) tmp_elt,
				sort->sort_column_id,
				&tmp_value);

      cmp = ((func) (&tmp_value, &s_value));
      g_value_unset (&tmp_value);

      if (cmp < 0)
	high = middle;
      else if (cmp > 0)
	low = middle;
      else if (cmp == 0)
	break;
      middle = (low + high)/2;
    }
#endif