Struct gtk::TreeModelSort

#[repr(transparent)]
pub struct TreeModelSort { /* private fields */ }

The TreeModelSort is a model which implements the TreeSortable 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 TreeModelSort is not guaranteed to be stable.

The use of this is best demonstrated through an example. In the following sample code we create two TreeView widgets each with a view of the same data. As the model is wrapped here by a TreeModelSort, 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 TreeModelSort

⚠️ The following code is in C ⚠️

{
  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 TreeSelection signal::TreeSelection::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

⚠️ The following code is in C ⚠️

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);
}

Implements

TreeModelSortExt, glib::ObjectExt, TreeDragSourceExt, TreeModelExt, TreeSortableExt, TreeSortableExtManual

Implementations

impl TreeModelSort

pub const NONE: Option<&'static TreeModelSort> = None

pub fn new(child_model: &impl IsA<TreeModel>) -> TreeModelSort

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

child_model

A TreeModel

Returns

A new TreeModelSort.

Trait Implementations

impl Clone for TreeModelSort

fn clone(&self) -> Self

Returns a copy of the value.

const fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TreeModelSort

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for TreeModelSort

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for TreeModelSort

fn hash<H>(&self, state: &mut H)where
    H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where
    H: Hasher,

Feeds a slice of this type into the given Hasher.

impl Ord for TreeModelSort

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

const fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

const fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

const fn clamp(self, min: Self, max: Self) -> Selfwhere
    Self: PartialOrd<Self>,

Restrict a value to a certain interval.

impl ParentClassIs for TreeModelSort

type Parent = Object

impl<OT: ObjectType> PartialEq<OT> for TreeModelSort

fn eq(&self, other: &OT) -> bool

This method tests for self and other values to be equal, and is used by ==.

const fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<OT: ObjectType> PartialOrd<OT> for TreeModelSort

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

const fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

const fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

const fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

const fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for TreeModelSort

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for TreeModelSort

impl IsA<TreeDragSource> for TreeModelSort

impl IsA<TreeModel> for TreeModelSort

impl IsA<TreeSortable> for TreeModelSort