gtk.GenericTreeModel

gtk.GenericTreeModel
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gtk.GenericTreeModel — a TreeView model that helps create tree models in Python

Synopsis

class gtk.GenericTreeModel(gobject.GObject, gtk.TreeModel):
    gtk.GenericTreeModel()
    def invalidate_iters()
    def iter_is_valid(iter)
    def get_user_data(iter)
    def create_tree_iter(user_data)

Ancestry

+-- gobject.GObject
  +-- gtk.GenericTreeModel (implements gtk.TreeModel)

Properties

"leak-references" Read-Write If True, creating a gtk.TreeIter will bump the reference count of the object used as the internal row reference. This may cause a memory leak but will prevent problems with objects being destroyed while still in use in a gtk.TreeIter. Set this to False only if the model saves the objects used in tree iters.

Description

The gtk.GenericTreeModel helps in the creation of gtk.TreeView tree models in Python. The gtk.GenericTreeModel is subclassed to provide a new tree model that provides the tree model behavior using methods with predefined names that are called by the gtk.GenericTreeModel methods as required to provide the various tree model operations. The methods that need to be defined by the programmer in Python are:

def on_get_flags(self)
def on_get_n_columns(self)
def on_get_column_type(self, index)
def on_get_iter(self, path)
def on_get_path(self, rowref)
def on_get_value(self, rowref, column)
def on_iter_next(self, rowref)
def on_iter_children(self, parent)
def on_iter_has_child(self, rowref)
def on_iter_n_children(self, rowref)
def on_iter_nth_child(self, parent, n)
def on_iter_parent(self, child)

See the gtk.TreeModel description for details of the above methods.

In PyGTK 2.4 and above the invalidate_iters() and iter_is_valid() methods are available to help manage the gtk.TreeIter objects and their Python object references. These are particularly useful when the "leak-references" property is set to False.

The tree models derived from gtk.GenericTreeModel are protected from problems with out of date gtk.TreeIter objects because gtk.TreeIter objects are automatically checked for validity with the tree model.

If a custom tree model doesn't support persistent iters (i.e. gtk.TREE_MODEL_ITERS_PERSIST is not set in the return from the gtk.TreeModel.get_flags() method), it can call the invalidate_iters() method to invalidate all its outstanding gtk.TreeIter objects when it changes the model (e.g. after inserting a new row). The tree model can also dispose of any Python objects that it passed references to gtk.TreeIter objects after calling the invalidate_iters() method.

Applications can use the iter_is_valid() method to determine if a gtk.TreeIter is still valid for the custom tree model.

Constructor

    gtk.GenericTreeModel()

Returns :

a new gtk.GenericTreeModel object

Creates a new gtk.GenericTreeModel object

Methods

gtk.GenericTreeModel.invalidate_iters

    def invalidate_iters()

Note

This method is available in PyGTK 2.4 and above.

The invalidate_iters() method invalidates all the gtk.TreeIter objects for the custom tree model.

gtk.GenericTreeModel.iter_is_valid

    def iter_is_valid(iter)

`iter` :	a `gtk.TreeIter`
Returns :	`True` if `iter` is valid for the tree model; otherwise, `False` is returned.

Note

This method is available in PyGTK 2.4 and above.

The iter_is_valid() method returns True if the gtk.TreeIter specified by iter is valid for the custom tree model.

gtk.GenericTreeModel.get_user_data

    def get_user_data(iter)

`iter` :	a `gtk.TreeIter` created by this tree model.
Returns :	Python object reference that is wrapped by this `gtk.TreeIter`.

Warning

This method should be treated as protected. It should only be used by derived classes.

gtk.GenericTreeModel transparently wraps arbitrary Python objects to instances of gtk.TreeIter. E.g. you return anything from on_get_iter and the model wraps the value, so get_iter method returns a gtk.TreeIter. This method allows to retrieve the Python object used to construct given iterator.

gtk.GenericTreeModel.create_tree_iter

    def create_tree_iter(user_data)

`user_data` :	a Python object, the same you would return from e.g. `on_get_iter`.
Returns :	a `gtk.TreeIter`.

Warning

This method should be treated as protected. It should only be used by derived classes.

gtk.GenericTreeModel transparently wraps arbitrary Python objects to instances of gtk.TreeIter. E.g. you return anything from on_get_iter and the model wraps the value, so get_iter method returns a gtk.TreeIter. This method allows you to perform this wrapping explicitly, not just from a predefined set of methods.

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