html files: pygtk
|
||||
Synopsis
class gtk.GenericTreeModel( |
Properties
|
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are protected from problems with out of date gtk.TreeIter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)
| 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)
| 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)
| 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.