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GtkTreeModelSort implements GtkTreeModel, GtkTreeSortable and GtkTreeDragSource.
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.
Example 19. Using a GtkTreeModelSort
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{ 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 "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.
Example 20. Accessing the child model of in a selection changed callback
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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); } |
GtkTreeModel *
gtk_tree_model_sort_new_with_model (GtkTreeModel *child_model);
Creates a new GtkTreeModel, with child_model
as the child model.
GtkTreeModel *
gtk_tree_model_sort_get_model (GtkTreeModelSort *tree_model);
Returns the model the GtkTreeModelSort is sorting.
GtkTreePath * gtk_tree_model_sort_convert_child_path_to_path (GtkTreeModelSort *tree_model_sort,GtkTreePath *child_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.
gboolean gtk_tree_model_sort_convert_child_iter_to_iter (GtkTreeModelSort *tree_model_sort,GtkTreeIter *sort_iter,GtkTreeIter *child_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.
tree_model_sort |
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sort_iter |
An uninitialized GtkTreeIter. |
[out] |
child_iter |
A valid GtkTreeIter pointing to a row on the child model |
TRUE, if sort_iter
was set, i.e. if sort_iter
is a
valid iterator pointer to a visible row in the child model.
GtkTreePath * gtk_tree_model_sort_convert_path_to_child_path (GtkTreeModelSort *tree_model_sort,GtkTreePath *sorted_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.
void gtk_tree_model_sort_convert_iter_to_child_iter (GtkTreeModelSort *tree_model_sort,GtkTreeIter *child_iter,GtkTreeIter *sorted_iter);
Sets child_iter
to point to the row pointed to by sorted_iter
.
tree_model_sort |
||
child_iter |
An uninitialized GtkTreeIter. |
[out] |
sorted_iter |
A valid GtkTreeIter pointing to a row on |
void
gtk_tree_model_sort_reset_default_sort_func
(GtkTreeModelSort *tree_model_sort);
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.
void
gtk_tree_model_sort_clear_cache (GtkTreeModelSort *tree_model_sort);
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.
gboolean gtk_tree_model_sort_iter_is_valid (GtkTreeModelSort *tree_model_sort,GtkTreeIter *iter);
This function is slow. Only use it for debugging and/or testing purposes.
Checks if the given iter is a valid iter for this GtkTreeModelSort.
Since: 2.2
“model” property“model” GtkTreeModel *
The model for the TreeModelSort to sort.
Flags: Read / Write / Construct Only