gi-gtk-3.0.24: Gtk bindings

CopyrightWill Thompson Iñaki García Etxebarria and Jonas Platte
LicenseLGPL-2.1
MaintainerIñaki García Etxebarria (garetxe@gmail.com)
Safe HaskellNone
LanguageHaskell2010

GI.Gtk.Objects.TreeModelSort

Contents

Description

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

C code

{
  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 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

C code

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);
}
Synopsis

Exported types

class GObject o => IsTreeModelSort o Source #

Type class for types which can be safely cast to TreeModelSort, for instance with toTreeModelSort.

toTreeModelSort :: (MonadIO m, IsTreeModelSort o) => o -> m TreeModelSort Source #

Cast to TreeModelSort, for types for which this is known to be safe. For general casts, use castTo.

Methods

clearCache

treeModelSortClearCache Source #

Arguments

:: (HasCallStack, MonadIO m, IsTreeModelSort a) 
=> a

treeModelSort: A TreeModelSort

-> m () 

This function should almost never be called. It clears the treeModelSort of any cached iterators that haven’t been reffed with treeModelRefNode. 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.

convertChildIterToIter

treeModelSortConvertChildIterToIter Source #

Arguments

:: (HasCallStack, MonadIO m, IsTreeModelSort a) 
=> a

treeModelSort: A TreeModelSort

-> TreeIter

childIter: A valid TreeIter pointing to a row on the child model

-> m (Bool, TreeIter)

Returns: True, if sortIter was set, i.e. if sortIter is a valid iterator pointer to a visible row in the child model.

Sets sortIter to point to the row in treeModelSort that corresponds to the row pointed at by childIter. If sortIter was not set, False is returned. Note: a boolean is only returned since 2.14.

convertChildPathToPath

treeModelSortConvertChildPathToPath Source #

Arguments

:: (HasCallStack, MonadIO m, IsTreeModelSort a) 
=> a

treeModelSort: A TreeModelSort

-> TreePath

childPath: A TreePath to convert

-> m (Maybe TreePath)

Returns: A newly allocated TreePath, or Nothing

Converts childPath to a path relative to treeModelSort. That is, childPath points to a path in the child model. The returned path will point to the same row in the sorted model. If childPath isn’t a valid path on the child model, then Nothing is returned.

convertIterToChildIter

treeModelSortConvertIterToChildIter Source #

Arguments

:: (HasCallStack, MonadIO m, IsTreeModelSort a) 
=> a

treeModelSort: A TreeModelSort

-> TreeIter

sortedIter: A valid TreeIter pointing to a row on treeModelSort.

-> m TreeIter 

Sets childIter to point to the row pointed to by sortedIter.

convertPathToChildPath

treeModelSortConvertPathToChildPath Source #

Arguments

:: (HasCallStack, MonadIO m, IsTreeModelSort a) 
=> a

treeModelSort: A TreeModelSort

-> TreePath

sortedPath: A TreePath to convert

-> m (Maybe TreePath)

Returns: A newly allocated TreePath, or Nothing

Converts sortedPath to a path on the child model of treeModelSort. That is, sortedPath points to a location in treeModelSort. The returned path will point to the same location in the model not being sorted. If sortedPath does not point to a location in the child model, Nothing is returned.

getModel

treeModelSortGetModel Source #

Arguments

:: (HasCallStack, MonadIO m, IsTreeModelSort a) 
=> a

treeModel: a TreeModelSort

-> m TreeModel

Returns: the "child model" being sorted

Returns the model the TreeModelSort is sorting.

iterIsValid

treeModelSortIterIsValid Source #

Arguments

:: (HasCallStack, MonadIO m, IsTreeModelSort a) 
=> a

treeModelSort: A TreeModelSort.

-> TreeIter

iter: A TreeIter.

-> m Bool

Returns: True if the iter is valid, False if the iter is invalid.

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

Checks if the given iter is a valid iter for this TreeModelSort.

Since: 2.2

resetDefaultSortFunc

treeModelSortResetDefaultSortFunc Source #

Arguments

:: (HasCallStack, MonadIO m, IsTreeModelSort a) 
=> a

treeModelSort: A TreeModelSort

-> m () 

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 TreeModelSort is in “unsorted” state.

Properties

model

No description available in the introspection data.

constructTreeModelSortModel :: (IsTreeModelSort o, IsTreeModel a) => a -> IO (GValueConstruct o) Source #

Construct a GValueConstruct with valid value for the “model” property. This is rarely needed directly, but it is used by new.

getTreeModelSortModel :: (MonadIO m, IsTreeModelSort o) => o -> m TreeModel Source #

Get the value of the “model” property. When overloading is enabled, this is equivalent to

get treeModelSort #model