Class ListItemCollection

UserList --+
           |
          ListItemCollection

ListItemCollection (items=None) -> ListItemCollection

An collection class for ListItem objects.

The ListItemCollection wraps a list object and limits it to the
abstract ListItem class type, so that it is guaranteed, that the
collection only contains a specific object type.

It adds a notification slot 'list_changed', to which a method or
function can be connected either by assigning the attribute directly
or using the set_list_changed() method. The slot'ed callback will be
invoked, whenever the list contents change. The signature of the
function or method to connect has to get one argument, which will be
the ListItemCollection.

class Example:
    ...

    def list_callback (self, collection):
        ...

collection.list_changed = object_example.list_callback
collection.set_list_changed (object_example.list_callback)

The ListItemCollection also adds a notification slot 'item_changed',
to which a method or function can be connected using (again) the
attribute directly or the set_item_changed() method. The callback
will be invoked, whenever a ListItem of the collection changes and
calls the callback. The signature of the function or method to
connect has to get one argument, which will be the ListItem, which
invoked it.

class Example:
    ...

    def item_callback (self, item):
        ...

collection.item_changed = object_example.item_callback
collection.set_item_changed (object_example.item_callback)

The ListItemCollection does support the usual list operations such as
appending, insertion and removal using indices, slicing,the count()
and len() methods and the list iterator.

Attributes:
length       - Amount of the items attached to the ListItemCollection.
list_changed - Slot to connect a method to, which will be called whenever
               the contents of the ListItemCollection change.
item_changed - Slot to connect a method to, which will be called whenever
               an item of the ListItemCollection changes.