TreeModelSort
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); } ]|
Constructors
Properties
Functions
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.
This signal is emitted when a row in the model has changed.
This signal is emitted when a row has been deleted.
This signal is emitted when a row has gotten the first child row or lost its last child row.
This signal is emitted when a new row has been inserted in the model.
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.
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.
Converts @child_path to a path relative to @tree_model_sort. That is,
Sets @child_iter to point to the row pointed to by @sorted_iter.
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.
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!
Asks the GtkTreeDragSource to return a GdkContentProvider representing the row at @path. Should robustly handle a @path no longer found in the model!
Calls @func on each node in model in a depth-first fashion.
Returns the type of the column.
Returns a set of flags supported by this interface.
Initializes @iter with the first iterator in the tree (the one at the path "0").
Sets @iter to a valid iterator pointing to @path_string, if it exists.
Returns the number of columns supported by @tree_model.
Generates a string representation of the iter.
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.
Sets @iter to point to the first child of @parent.
Returns true if @iter has children, false otherwise.
Checks if the given iter is a valid iter for this GtkTreeModelSort.
Returns the number of children that @iter has.
Sets @iter to be the child of @parent, using the given index.
Sets @iter to be the parent of @child.
Sets @iter to point to the previous node at the current level.
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.
Emits the ::row-changed signal on @tree_model.
Emits the ::row-deleted signal on @tree_model.
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.
Emits the ::row-has-child-toggled signal on @tree_model.
Emits the ::row-inserted signal on @tree_model.
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.
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:
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.
Emits a GtkTreeSortable::sort-column-changed signal on @sortable.