Gtk.TreeModel

g GObject.GInterface GObject.GInterface Gtk.TreeModel Gtk.TreeModel GObject.GInterface->Gtk.TreeModel

Implementations:
 Gtk.ListStore, Gtk.TreeModelFilter, Gtk.TreeModelSort, Gtk.TreeStore

Methods

  filter_new (root)
  foreach (func, *user_data)
  get (treeiter, *columns)
  get_column_type (index_)
  get_flags ()
  get_iter (path)
  get_iter_first ()
  get_iter_from_string (path_string)
  get_n_columns ()
  get_path (iter)
  get_string_from_iter (iter)
  get_value (iter, column)
  iter_children (parent)
  iter_has_child (iter)
  iter_n_children (iter)
  iter_next (iter)
  iter_nth_child (parent, n)
  iter_parent (child)
  iter_previous (iter)
  ref_node (iter)
  row_changed (path, iter)
  row_deleted (path)
  row_has_child_toggled (path, iter)
  row_inserted (path, iter)
  rows_reordered (path, iter, new_order)
  set_row (treeiter, row)
  sort_new_with_model ()
  unref_node (iter)

Virtual Methods

  do_get_column_type (index_)
  do_get_flags ()
  do_get_iter (path)
  do_get_n_columns ()
  do_get_path (iter)
  do_get_value (iter, column)
  do_iter_children (parent)
  do_iter_has_child (iter)
  do_iter_n_children (iter)
  do_iter_next (iter)
  do_iter_nth_child (parent, n)
  do_iter_parent (child)
  do_iter_previous (iter)
  do_ref_node (iter)
  do_row_changed (path, iter)
  do_row_deleted (path)
  do_row_has_child_toggled (path, iter)
  do_row_inserted (path, iter)
  do_unref_node (iter)

Properties

None

Signals

Name Short Description
row-changed This signal is emitted when a row in the model has changed.
row-deleted This signal is emitted when a row has been deleted.
row-has-child-toggled This signal is emitted when a row has gotten the first child row or lost its last child row.
row-inserted This signal is emitted when a new row has been inserted in the model.
rows-reordered This signal is emitted when the children of a node in the Gtk.TreeModel have been reordered.

Fields

None

Class Details

class Gtk.TreeModel
Bases:GObject.GInterface
Structure:Gtk.TreeModelIface

Note

Implements __len__, __bool__, __nonzero__, __iter__, __getitem__, __setitem__ and __delitem__.

Iterating over a Gtk.TreeModel yields Gtk.TreeModelRow instances.

__getitem__ returns a Gtk.TreeModelRow.

The Gtk.TreeModel interface defines a generic tree interface for use by the Gtk.TreeView widget. It is an abstract interface, and is designed to be usable with any appropriate data structure. The programmer just has to implement this interface on their own data type for it to be viewable by a Gtk.TreeView widget.

The model is represented as a hierarchical tree of strongly-typed, columned data. In other words, the model can be seen as a tree where every node has different values depending on which column is being queried. The type of data found in a column is determined by using the GObject.GType system (ie. GObject.TYPE_INT, #GTK_TYPE_BUTTON, GObject.TYPE_POINTER, etc). The types are homogeneous per column across all nodes. It is important to note that this interface only provides a way of examining a model and observing changes. The implementation of each individual model decides how and if changes are made.

In order to make life simpler for programmers who do not need to write their own specialized model, two generic models are provided — the Gtk.TreeStore and the Gtk.ListStore. To use these, the developer simply pushes data into these models as necessary. These models provide the data structure as well as all appropriate tree interfaces. As a result, implementing drag and drop, sorting, and storing data is trivial. For the vast majority of trees and lists, these two models are sufficient.

Models are accessed on a node/column level of granularity. One can query for the value of a model at a certain node and a certain column on that node. There are two structures used to reference a particular node in a model. They are the Gtk.TreePath-struct and the Gtk.TreeIter-struct (“iter” is short for iterator). Most of the interface consists of operations on a Gtk.TreeIter-struct.

A path is essentially a potential node. It is a location on a model that may or may not actually correspond to a node on a specific model. The Gtk.TreePath-struct can be converted into either an array of unsigned integers or a string. The string form is a list of numbers separated by a colon. Each number refers to the offset at that level. Thus, the path 0 refers to the root node and the path 2:4 refers to the fifth child of the third node.

By contrast, a Gtk.TreeIter-struct is a reference to a specific node on a specific model. It is a generic struct with an integer and three generic pointers. These are filled in by the model in a model-specific way. One can convert a path to an iterator by calling Gtk.TreeModel.get_iter(). These iterators are the primary way of accessing a model and are similar to the iterators used by Gtk.TextBuffer. They are generally statically allocated on the stack and only used for a short time. The model interface defines a set of operations using them for navigating the model.

It is expected that models fill in the iterator with private data. For example, the Gtk.ListStore model, which is internally a simple linked list, stores a list node in one of the pointers. The Gtk.TreeModelSort stores an array and an offset in two of the pointers. Additionally, there is an integer field. This field is generally filled with a unique stamp per model. This stamp is for catching errors resulting from using invalid iterators with a model.

The lifecycle of an iterator can be a little confusing at first. Iterators are expected to always be valid for as long as the model is unchanged (and doesn’t emit a signal). The model is considered to own all outstanding iterators and nothing needs to be done to free them from the user’s point of view. Additionally, some models guarantee that an iterator is valid for as long as the node it refers to is valid (most notably the Gtk.TreeStore and Gtk.ListStore). Although generally uninteresting, as one always has to allow for the case where iterators do not persist beyond a signal, some very important performance enhancements were made in the sort model. As a result, the Gtk.TreeModelFlags.ITERS_PERSIST flag was added to indicate this behavior.

To help show some common operation of a model, some examples are provided. The first example shows three ways of getting the iter at the location 3:2:5. While the first method shown is easier, the second is much more common, as you often get paths from callbacks.

Acquiring a Gtk.TreeIter-struct
// Three ways of getting the iter pointing to the location
GtkTreePath *path;
GtkTreeIter iter;
GtkTreeIter parent_iter;

// get the iterator from a string
gtk_tree_model_get_iter_from_string (model,
                                     &iter,
                                     "3:2:5");

// get the iterator from a path
path = gtk_tree_path_new_from_string ("3:2:5");
gtk_tree_model_get_iter (model, &iter, path);
gtk_tree_path_free (path);

// walk the tree to find the iterator
gtk_tree_model_iter_nth_child (model, &iter,
                               NULL, 3);
parent_iter = iter;
gtk_tree_model_iter_nth_child (model, &iter,
                               &parent_iter, 2);
parent_iter = iter;
gtk_tree_model_iter_nth_child (model, &iter,
                               &parent_iter, 5);

This second example shows a quick way of iterating through a list and getting a string and an integer from each row. The populate_model() function used below is not shown, as it is specific to the Gtk.ListStore. For information on how to write such a function, see the Gtk.ListStore documentation.

Reading data from a Gtk.TreeModel
enum
{
  STRING_COLUMN,
  INT_COLUMN,
  N_COLUMNS
};

...

GtkTreeModel *list_store;
GtkTreeIter iter;
gboolean valid;
gint row_count = 0;

// make a new list_store
list_store = gtk_list_store_new (N_COLUMNS,
                                 G_TYPE_STRING,
                                 G_TYPE_INT);

// Fill the list store with data
populate_model (list_store);

// Get the first iter in the list, check it is valid and walk
// through the list, reading each row.

valid = gtk_tree_model_get_iter_first (list_store,
                                       &iter);
while (valid)
 {
   gchar *str_data;
   gint   int_data;

   // Make sure you terminate calls to gtk_tree_model_get() with a “-1” value
   gtk_tree_model_get (list_store, &iter,
                       STRING_COLUMN, &str_data,
                       INT_COLUMN, &int_data,
                       -1);

   // Do something with the data
   g_print ("Row %d: (%s,%d)\n",
            row_count, str_data, int_data);
   g_free (str_data);

   valid = gtk_tree_model_iter_next (list_store,
                                     &iter);
   row_count++;
 }

The Gtk.TreeModel interface contains two methods for reference counting: Gtk.TreeModel.ref_node() and Gtk.TreeModel.unref_node(). These two methods are optional to implement. The reference counting is meant as a way for views to let models know when nodes are being displayed. Gtk.TreeView will take a reference on a node when it is visible, which means the node is either in the toplevel or expanded. Being displayed does not mean that the node is currently directly visible to the user in the viewport. Based on this reference counting scheme a caching model, for example, can decide whether or not to cache a node based on the reference count. A file-system based model would not want to keep the entire file hierarchy in memory, but just the folders that are currently expanded in every current view.

When working with reference counting, the following rules must be taken into account:

  • Never take a reference on a node without owning a reference on its parent. This means that all parent nodes of a referenced node must be referenced as well.
  • Outstanding references on a deleted node are not released. This is not possible because the node has already been deleted by the time the row-deleted signal is received.
  • Models are not obligated to emit a signal on rows of which none of its siblings are referenced. To phrase this differently, signals are only required for levels in which nodes are referenced. For the root level however, signals must be emitted at all times (however the root level is always referenced when any view is attached).
filter_new(root)[source]
Parameters:root (Gtk.TreePath or None) – A Gtk.TreePath or None.
Returns:A new Gtk.TreeModel.
Return type:Gtk.TreeModel

Creates a new Gtk.TreeModel, with self as the child_model and root as the virtual root.

New in version 2.4.

foreach(func, *user_data)[source]
Parameters:

Calls func on each node in model in a depth-first fashion.

If func returns True, then the tree ceases to be walked, and Gtk.TreeModel.foreach() returns.

get(treeiter, *columns)[source]
Parameters:

Returns a tuple of all values specified by their indices in columns in the order the indices are contained in columns

Also see Gtk.TreeStore.get_value()

get_column_type(index_)[source]
Parameters:index (int) – the column index
Returns:the type of the column
Return type:GObject.GType

Returns the type of the column.

get_flags()[source]
Returns:the flags supported by this interface
Return type:Gtk.TreeModelFlags

Returns a set of flags supported by this interface.

The flags are a bitwise combination of Gtk.TreeModelFlags. The flags supported should not change during the lifetime of the self.

get_iter(path)[source]
Parameters:path (Gtk.TreePath) – the Gtk.TreePath-struct
Raises:ValueError if path doesn’t exist
Returns:a Gtk.TreeIter
Return type:Gtk.TreeIter

Returns an iterator pointing to path. If path does not exist ValueError is raised.

get_iter_first()[source]
Returns:Gtk.TreeIter or None if the tree is empty.
Return type:Gtk.TreeIter or None

Initializes iter with the first iterator in the tree (the one at the path “0”) and returns True. Returns False if the tree is empty.

get_iter_from_string(path_string)[source]
Parameters:path_string (str) – a string representation of a Gtk.TreePath-struct
Raises:ValueError if an iterator pointing to path_string does not exist.
Returns:a Gtk.TreeIter
Return type:Gtk.TreeIter

Returns a valid iterator pointing to path_string, if it exists. Otherwise raises ValueError

get_n_columns()[source]
Returns:the number of columns
Return type:int

Returns the number of columns supported by self.

get_path(iter)[source]
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct
Returns:a newly-created Gtk.TreePath-struct
Return type:Gtk.TreePath

Returns a newly-created Gtk.TreePath-struct referenced by iter.

This path should be freed with Gtk.TreePath.free().

get_string_from_iter(iter)[source]
Parameters:iter (Gtk.TreeIter) – a Gtk.TreeIter-struct
Returns:a newly-allocated string. Must be freed with GLib.free().
Return type:str

Generates a string representation of the iter.

This string is a “:” separated list of numbers. For example, “4:10:0:3” would be an acceptable return value for this string.

New in version 2.2.

get_value(iter, column)[source]
Parameters:
Returns:

an empty GObject.Value to set

Return type:

value: GObject.Value

Initializes and sets value to that at column.

When done with value, GObject.Value.unset() needs to be called to free any allocated memory.

iter_children(parent)[source]
Parameters:parent (Gtk.TreeIter or None) – the Gtk.TreeIter-struct, or None
Returns:Gtk.TreeIter or None
Return type:Gtk.TreeIter or None

Sets iter to point to the first child of parent. If parent has no children, None is returned. If parent is None returns the first node, equivalent to Gtk.TreeModel.iter_first().

iter_has_child(iter)[source]
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct to test for children
Returns:True if iter has children
Return type:bool

Returns True if iter has children, False otherwise.

iter_n_children(iter)[source]
Parameters:iter (Gtk.TreeIter or None) – the Gtk.TreeIter-struct, or None
Returns:the number of children of iter
Return type:int

Returns the number of children that iter has.

As a special case, if iter is None, then the number of toplevel nodes is returned.

iter_next(iter)[source]
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct
Returns:a Gtk.TreeIter or None
Return type:Gtk.TreeIter or None

Returns an iterator pointing to the node following iter at the current level.

If there is no next iter, None is returned.

iter_nth_child(parent, n)[source]
Parameters:
Returns:

Gtk.TreeIter if parent has an n-th child otherwise None

Return type:

Gtk.TreeIter or None

Returns child iter of parent, using the given index.

The first index is 0. If n is too big, or parent has no children, None is returned. parent will remain a valid node after this function has been called. As a special case, if parent is None, then the n-th root node is set.

iter_parent(child)[source]
Parameters:child (Gtk.TreeIter) – the Gtk.TreeIter-struct
Returns:Gtk.TreeIter or None if child has a parent.
Return type:Gtk.TreeIter or :obj`None`

Returns iter of the parent of child.

If child is at the toplevel, and doesn’t have a parent, then None is returned. child will remain a valid node after this function has been called.

iter_previous(iter)[source]
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct
Returns:a Gtk.TreeIter or None
Return type:Gtk.TreeIter or None

Returns an iterator pointing to the previous node at the current level.

If there is no previous iter, None is returned.

New in version 3.0.

ref_node(iter)[source]
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct

Lets the tree ref the node.

This is an optional method for models to implement. To be more specific, models may ignore this call as it exists primarily for performance reasons.

This function is primarily meant as a way for views to let caching models know when nodes are being displayed (and hence, whether or not to cache that node). Being displayed means a node is in an expanded branch, regardless of whether the node is currently visible in the viewport. For example, a file-system based model would not want to keep the entire file-hierarchy in memory, just the sections that are currently being displayed by every current view.

A model should be expected to be able to get an iter independent of its reffed state.

row_changed(path, iter)[source]
Parameters:

Emits the Gtk.TreeModel ::row-changed signal on self.

row_deleted(path)[source]
Parameters:path (Gtk.TreePath) – a Gtk.TreePath-struct pointing to the previous location of the deleted row

Emits the Gtk.TreeModel ::row-deleted signal on self.

This should be called by models after a row has been removed. The location pointed to by path should be the location that the row previously was at. It may not be a valid location anymore.

Nodes that are deleted are not unreffed, this means that any outstanding references on the deleted node should not be released.

row_has_child_toggled(path, iter)[source]
Parameters:

Emits the Gtk.TreeModel ::row-has-child-toggled signal on self. This should be called by models after the child state of a node changes.

row_inserted(path, iter)[source]
Parameters:

Emits the Gtk.TreeModel ::row-inserted signal on self.

rows_reordered(path, iter, new_order)[source]
Parameters:
  • path (Gtk.TreePath) – a Gtk.TreePath-struct pointing to the tree node whose children have been reordered
  • iter (Gtk.TreeIter or None) – a valid Gtk.TreeIter-struct pointing to the node whose children have been reordered, or None if the depth of path is 0
  • new_order ([int]) – an array of integers mapping the current position of each child to its old position before the re-ordering, i.e. new_order [newpos] = oldpos

Emits the Gtk.TreeModel ::rows-reordered signal on self.

This should be called by models when their rows have been reordered.

New in version 3.10.

set_row(treeiter, row)
Parameters:

Sets all values of a row pointed to by treeiter from a list of values passes as row. The length of the row has to match the number of columns of the model. None in row means the value will be skipped and not set.

Also see Gtk.ListStore.set_value() and Gtk.TreeStore.set_value()

sort_new_with_model()[source]
Returns:A new Gtk.TreeModel.
Return type:Gtk.TreeModel

Creates a new Gtk.TreeModel, with self as the child model.

unref_node(iter)[source]
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct

Lets the tree unref the node.

This is an optional method for models to implement. To be more specific, models may ignore this call as it exists primarily for performance reasons. For more information on what this means, see Gtk.TreeModel.ref_node().

Please note that nodes that are deleted are not unreffed.

do_get_column_type(index_) virtual
Parameters:index (int) – the column index
Returns:the type of the column
Return type:GObject.GType

Returns the type of the column.

do_get_flags() virtual
Returns:the flags supported by this interface
Return type:Gtk.TreeModelFlags

Returns a set of flags supported by this interface.

The flags are a bitwise combination of Gtk.TreeModelFlags. The flags supported should not change during the lifetime of the tree_model.

do_get_iter(path) virtual
Parameters:path (Gtk.TreePath) – the Gtk.TreePath-struct
Returns:True, if iter was set
iter:the uninitialized Gtk.TreeIter-struct
Return type:(bool, iter: Gtk.TreeIter)

Sets iter to a valid iterator pointing to path. If path does not exist, iter is set to an invalid iterator and False is returned.

do_get_n_columns() virtual
Returns:the number of columns
Return type:int

Returns the number of columns supported by tree_model.

do_get_path(iter) virtual
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct
Returns:a newly-created Gtk.TreePath-struct
Return type:Gtk.TreePath

Returns a newly-created Gtk.TreePath-struct referenced by iter.

This path should be freed with Gtk.TreePath.free().

do_get_value(iter, column) virtual
Parameters:
Returns:

an empty GObject.Value to set

Return type:

value: GObject.Value

Initializes and sets value to that at column.

When done with value, GObject.Value.unset() needs to be called to free any allocated memory.

do_iter_children(parent) virtual
Parameters:parent (Gtk.TreeIter or None) – the Gtk.TreeIter-struct, or None
Returns:True, if iter has been set to the first child
iter:the new Gtk.TreeIter-struct to be set to the child
Return type:(bool, iter: Gtk.TreeIter)

Sets iter to point to the first child of parent.

If parent has no children, False is returned and iter is set to be invalid. parent will remain a valid node after this function has been called.

If parent is None returns the first node, equivalent to gtk_tree_model_get_iter_first (tree_model, iter);

do_iter_has_child(iter) virtual
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct to test for children
Returns:True if iter has children
Return type:bool

Returns True if iter has children, False otherwise.

do_iter_n_children(iter) virtual
Parameters:iter (Gtk.TreeIter or None) – the Gtk.TreeIter-struct, or None
Returns:the number of children of iter
Return type:int

Returns the number of children that iter has.

As a special case, if iter is None, then the number of toplevel nodes is returned.

do_iter_next(iter) virtual
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct
Returns:True if iter has been changed to the next node
Return type:bool

Sets iter to point to the node following it at the current level.

If there is no next iter, False is returned and iter is set to be invalid.

do_iter_nth_child(parent, n) virtual
Parameters:
Returns:

True, if parent has an n-th child

iter:the Gtk.TreeIter-struct to set to the nth child

Return type:

(bool, iter: Gtk.TreeIter)

Sets iter to be the child of parent, using the given index.

The first index is 0. If n is too big, or parent has no children, iter is set to an invalid iterator and False is returned. parent will remain a valid node after this function has been called. As a special case, if parent is None, then the n-th root node is set.

do_iter_parent(child) virtual
Parameters:child (Gtk.TreeIter) – the Gtk.TreeIter-struct
Returns:True, if iter is set to the parent of child
iter:the new Gtk.TreeIter-struct to set to the parent
Return type:(bool, iter: Gtk.TreeIter)

Sets iter to be the parent of child.

If child is at the toplevel, and doesn’t have a parent, then iter is set to an invalid iterator and False is returned. child will remain a valid node after this function has been called.

iter will be initialized before the lookup is performed, so child and iter cannot point to the same memory location.

do_iter_previous(iter) virtual
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct
Returns:True if iter has been changed to the previous node
Return type:bool

Sets iter to point to the previous node at the current level.

If there is no previous iter, False is returned and iter is set to be invalid.

New in version 3.0.

do_ref_node(iter) virtual
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct

Lets the tree ref the node.

This is an optional method for models to implement. To be more specific, models may ignore this call as it exists primarily for performance reasons.

This function is primarily meant as a way for views to let caching models know when nodes are being displayed (and hence, whether or not to cache that node). Being displayed means a node is in an expanded branch, regardless of whether the node is currently visible in the viewport. For example, a file-system based model would not want to keep the entire file-hierarchy in memory, just the sections that are currently being displayed by every current view.

A model should be expected to be able to get an iter independent of its reffed state.

do_row_changed(path, iter) virtual
Parameters:

Emits the Gtk.TreeModel ::row-changed signal on tree_model.

do_row_deleted(path) virtual
Parameters:path (Gtk.TreePath) – a Gtk.TreePath-struct pointing to the previous location of the deleted row

Emits the Gtk.TreeModel ::row-deleted signal on tree_model.

This should be called by models after a row has been removed. The location pointed to by path should be the location that the row previously was at. It may not be a valid location anymore.

Nodes that are deleted are not unreffed, this means that any outstanding references on the deleted node should not be released.

do_row_has_child_toggled(path, iter) virtual
Parameters:

Emits the Gtk.TreeModel ::row-has-child-toggled signal on tree_model. This should be called by models after the child state of a node changes.

do_row_inserted(path, iter) virtual
Parameters:

Emits the Gtk.TreeModel ::row-inserted signal on tree_model.

do_unref_node(iter) virtual
Parameters:iter (Gtk.TreeIter) – the Gtk.TreeIter-struct

Lets the tree unref the node.

This is an optional method for models to implement. To be more specific, models may ignore this call as it exists primarily for performance reasons. For more information on what this means, see Gtk.TreeModel.ref_node().

Please note that nodes that are deleted are not unreffed.

Signal Details

Gtk.TreeModel.signals.row_changed(tree_model, path, iter)
Signal Name:

row-changed

Flags:

RUN_LAST

Parameters:

This signal is emitted when a row in the model has changed.

Gtk.TreeModel.signals.row_deleted(tree_model, path)
Signal Name:

row-deleted

Flags:

RUN_FIRST

Parameters:

This signal is emitted when a row has been deleted.

Note that no iterator is passed to the signal handler, since the row is already deleted.

This should be called by models after a row has been removed. The location pointed to by path should be the location that the row previously was at. It may not be a valid location anymore.

Gtk.TreeModel.signals.row_has_child_toggled(tree_model, path, iter)
Signal Name:

row-has-child-toggled

Flags:

RUN_LAST

Parameters:

This signal is emitted when a row has gotten the first child row or lost its last child row.

Gtk.TreeModel.signals.row_inserted(tree_model, path, iter)
Signal Name:

row-inserted

Flags:

RUN_FIRST

Parameters:

This signal is emitted when a new row has been inserted in the model.

Note that the row may still be empty at this point, since it is a common pattern to first insert an empty row, and then fill it with the desired values.

Gtk.TreeModel.signals.rows_reordered()
Signal Name:rows-reordered
Flags:RUN_FIRST

This signal is emitted when the children of a node in the Gtk.TreeModel have been reordered.

Note that this signal is not emitted when rows are reordered by DND, since this is implemented by removing and then reinserting the row.