Class

Gtk.TreeModelSort

Description [src]

class Gtk.TreeModelSort : GObject.Object {
  parent: GObject
}

A GtkTreeModel which makes an underlying tree model sortable

The GtkTreeModelSort is a model which implements the GtkTreeSortable interface. It does not hold any data itself, but rather is created with a child model and proxies its data. It has identical column types to this child model, and the changes in the child are propagated. The primary purpose of this model is to provide a way to sort a different model without modifying it. Note that the sort function used by GtkTreeModelSort is not guaranteed to be stable.

The use of this is best demonstrated through an example. In the following sample code we create two GtkTreeView widgets each with a view of the same data. As the model is wrapped here by a GtkTreeModelSort, the two GtkTreeViews can each sort their view of the data without affecting the other. By contrast, if we simply put the same model in each widget, then sorting the first would sort the second.

Using a GtkTreeModelSort

{
  GtkTreeView *tree_view1;
  GtkTreeView *tree_view2;
  GtkTreeModel *sort_model1;
  GtkTreeModel *sort_model2;
  GtkTreeModel *child_model;

  // get the child model
  child_model = get_my_model ();

  // Create the first tree
  sort_model1 = gtk_tree_model_sort_new_with_model (child_model);
  tree_view1 = gtk_tree_view_new_with_model (sort_model1);

  // Create the second tree
  sort_model2 = gtk_tree_model_sort_new_with_model (child_model);
  tree_view2 = gtk_tree_view_new_with_model (sort_model2);

  // Now we can sort the two models independently
  gtk_tree_sortable_set_sort_column_id (GTK_TREE_SORTABLE (sort_model1),
                                        COLUMN_1, GTK_SORT_ASCENDING);
  gtk_tree_sortable_set_sort_column_id (GTK_TREE_SORTABLE (sort_model2),
                                        COLUMN_1, GTK_SORT_DESCENDING);
}

To demonstrate how to access the underlying child model from the sort model, the next example will be a callback for the GtkTreeSelection GtkTreeSelection::changed signal. In this callback, we get a string from COLUMN_1 of the model. We then modify the string, find the same selected row on the child model, and change the row there.

Accessing the child model of in a selection changed callback

void
selection_changed (GtkTreeSelection *selection, gpointer data)
{
  GtkTreeModel *sort_model = NULL;
  GtkTreeModel *child_model;
  GtkTreeIter sort_iter;
  GtkTreeIter child_iter;
  char *some_data = NULL;
  char *modified_data;

  // Get the current selected row and the model.
  if (! gtk_tree_selection_get_selected (selection,
                                         &sort_model,
                                         &sort_iter))
    return;

  // Look up the current value on the selected row and get
  // a new value to change it to.
  gtk_tree_model_get (GTK_TREE_MODEL (sort_model), &sort_iter,
                      COLUMN_1, &some_data,
                      -1);

  modified_data = change_the_data (some_data);
  g_free (some_data);

  // Get an iterator on the child model, instead of the sort model.
  gtk_tree_model_sort_convert_iter_to_child_iter (GTK_TREE_MODEL_SORT (sort_model),
                                                  &child_iter,
                                                  &sort_iter);

  // Get the child model and change the value of the row. In this
  // example, the child model is a GtkListStore. It could be any other
  // type of model, though.
  child_model = gtk_tree_model_sort_get_model (GTK_TREE_MODEL_SORT (sort_model));
  gtk_list_store_set (GTK_LIST_STORE (child_model), &child_iter,
                      COLUMN_1, &modified_data,
                      -1);
  g_free (modified_data);
}

Hierarchy

hierarchy this GtkTreeModelSort implements_0 GtkTreeDragSource this--implements_0 implements_1 GtkTreeModel this--implements_1 implements_2 GtkTreeSortable this--implements_2 ancestor_0 GObject ancestor_0--this

Ancestors

  • GObject

Constructors

gtk_tree_model_sort_new_with_model

Creates a new GtkTreeModelSort, with child_model as the child model.

Instance methods

gtk_tree_model_sort_clear_cache

This function should almost never be called. It clears the tree_model_sort of any cached iterators that haven’t been reffed with gtk_tree_model_ref_node(). This might be useful if the child model being sorted is static (and doesn’t change often) and there has been a lot of unreffed access to nodes. As a side effect of this function, all unreffed iters will be invalid.

gtk_tree_model_sort_convert_child_iter_to_iter

Sets sort_iter to point to the row in tree_model_sort that corresponds to the row pointed at by child_iter. If sort_iter was not set, FALSE is returned. Note: a boolean is only returned since 2.14.

gtk_tree_model_sort_convert_child_path_to_path

Converts child_path to a path relative to tree_model_sort. That is, child_path points to a path in the child model. The returned path will point to the same row in the sorted model. If child_path isn’t a valid path on the child model, then NULL is returned.

gtk_tree_model_sort_convert_iter_to_child_iter

Sets child_iter to point to the row pointed to by sorted_iter.

gtk_tree_model_sort_convert_path_to_child_path

Converts sorted_path to a path on the child model of tree_model_sort. That is, sorted_path points to a location in tree_model_sort. The returned path will point to the same location in the model not being sorted. If sorted_path does not point to a location in the child model, NULL is returned.

gtk_tree_model_sort_get_model

Returns the model the GtkTreeModelSort is sorting.

gtk_tree_model_sort_iter_is_valid

This function is slow. Only use it for debugging and/or testing purposes.

gtk_tree_model_sort_reset_default_sort_func

This resets the default sort function to be in the “unsorted” state. That is, it is in the same order as the child model. It will re-sort the model to be in the same order as the child model only if the GtkTreeModelSort is in “unsorted” state.

Methods inherited from GtkTreeDragSource (3)
gtk_tree_drag_source_drag_data_delete

Asks the GtkTreeDragSource to delete the row at path, because it was moved somewhere else via drag-and-drop. Returns FALSE if the deletion fails because path no longer exists, or for some model-specific reason. Should robustly handle a path no longer found in the model!

gtk_tree_drag_source_drag_data_get

Asks the GtkTreeDragSource to return a GdkContentProvider representing the row at path. Should robustly handle a path no longer found in the model!

gtk_tree_drag_source_row_draggable

Asks the GtkTreeDragSource whether a particular row can be used as the source of a DND operation. If the source doesn’t implement this interface, the row is assumed draggable.

Methods inherited from GtkTreeModel (28)
Methods inherited from GtkTreeSortable (6)
gtk_tree_sortable_get_sort_column_id

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_has_default_sort_func

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.

gtk_tree_sortable_set_default_sort_func

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.

gtk_tree_sortable_set_sort_column_id

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. sort_column_id may either be a regular column id, or one of the following special values:

gtk_tree_sortable_set_sort_func

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_sort_column_changed

Emits a GtkTreeSortable::sort-column-changed signal on sortable.

Properties

Gtk.TreeModelSort:model
No description available.

Class structure

struct GtkTreeModelSortClass {
  GObjectClass parent_class;
  
}
Class members
parent_class
GObjectClass
  No description available.