GtkTreeIterCompareFunc ()

gint
(*GtkTreeIterCompareFunc) (GtkTreeModel *model,
                           GtkTreeIter *a,
                           GtkTreeIter *b,
                           gpointer user_data);

A GtkTreeIterCompareFunc should return a negative integer, zero, or a positive integer if a sorts before b , a sorts with b , or a sorts after b respectively. If two iters compare as equal, their order in the sorted model is undefined. In order to ensure that the GtkTreeSortable behaves as expected, the GtkTreeIterCompareFunc must define a partial order on the model, i.e. it must be reflexive, antisymmetric and transitive.

For example, if model is a product catalogue, then a compare function for the “price” column could be one which returns price_of(@a) - price_of(@b).

GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID

#define GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID (-1)

The GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID can be used to make a GtkTreeSortable use the default sort function.

See also gtk_tree_sortable_set_sort_column_id()

GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID

#define GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID (-2)

The GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID can be used to make a GtkTreeSortable use no sorting.

See also gtk_tree_sortable_set_sort_column_id()

gtk_tree_sortable_sort_column_changed ()

void
gtk_tree_sortable_sort_column_changed (GtkTreeSortable *sortable);

Emits a “sort-column-changed” signal on sortable .

gtk_tree_sortable_get_sort_column_id ()

gboolean
gtk_tree_sortable_get_sort_column_id (GtkTreeSortable *sortable,
                                      gint *sort_column_id,
                                      GtkSortType *order);

Fills in sort_column_id and order with the current sort column and the order. It returns TRUE unless the sort_column_id is GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID or GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID.

gtk_tree_sortable_set_sort_column_id ()

void
gtk_tree_sortable_set_sort_column_id (GtkTreeSortable *sortable,
                                      gint sort_column_id,
                                      GtkSortType order);

Sets the current sort column to be sort_column_id . The sortable will resort itself to reflect this change, after emitting a “sort-column-changed” signal. sort_column_id may either be a regular column id, or one of the following special values:

gtk_tree_sortable_set_sort_func ()

void
gtk_tree_sortable_set_sort_func (GtkTreeSortable *sortable,
                                 gint sort_column_id,
                                 GtkTreeIterCompareFunc sort_func,
                                 gpointer user_data,
                                 GDestroyNotify destroy);

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 using this function.

gtk_tree_sortable_set_default_sort_func ()

void
gtk_tree_sortable_set_default_sort_func
                               (GtkTreeSortable *sortable,
                                GtkTreeIterCompareFunc sort_func,
                                gpointer user_data,
                                GDestroyNotify destroy);

Sets the default comparison function used when sorting to be sort_func . If the current sort column id of sortable is GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID, then the model will sort using this function.

If sort_func is NULL, then there will be no default comparison function. This means that once the model has been sorted, it can’t go back to the default state. In this case, when the current sort column id of sortable is GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID, the model will be unsorted.

gtk_tree_sortable_has_default_sort_func ()

gboolean
gtk_tree_sortable_has_default_sort_func
                               (GtkTreeSortable *sortable);

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.

GtkTreeSortable

typedef struct _GtkTreeSortable GtkTreeSortable;

struct GtkTreeSortableIface

struct GtkTreeSortableIface {
  /* signals */
  void     (* sort_column_changed)   (GtkTreeSortable        *sortable);

  /* virtual table */
  gboolean (* get_sort_column_id)    (GtkTreeSortable        *sortable,
				      gint                   *sort_column_id,
				      GtkSortType            *order);
  void     (* set_sort_column_id)    (GtkTreeSortable        *sortable,
				      gint                    sort_column_id,
				      GtkSortType             order);
  void     (* set_sort_func)         (GtkTreeSortable        *sortable,
				      gint                    sort_column_id,
				      GtkTreeIterCompareFunc  sort_func,
				      gpointer                user_data,
				      GDestroyNotify          destroy);
  void     (* set_default_sort_func) (GtkTreeSortable        *sortable,
				      GtkTreeIterCompareFunc  sort_func,
				      gpointer                user_data,
				      GDestroyNotify          destroy);
  gboolean (* has_default_sort_func) (GtkTreeSortable        *sortable);
};

The “sort-column-changed” signal

void
user_function (GtkTreeSortable *sortable,
               gpointer         user_data)

The ::sort-column-changed signal is emitted when the sort column or sort order of sortable is changed. The signal is emitted before the contents of sortable are resorted.

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