# Copyright 2017 SrMouraSilva
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from pluginsmanager.observer.update_type import UpdateType
[docs]class ObservableList(object):
"""
Detects changes in list.
In append, in remove and in setter, the `observer` is callable with changes
details
Based in https://www.pythonsheets.com/notes/python-basic.html#emulating-a-list
"""
[docs] def __init__(self, lista=None):
self.real_list = lista if lista is not None else []
self.observer = lambda *args, **kwargs: ...
[docs] def __str__(self):
"""
See :meth:`list.__repr__()` method
"""
return repr(self.real_list)
[docs] def __repr__(self):
"""
See :meth:`list.__repr__()` method
"""
return repr(self.real_list)
[docs] def append(self, item):
"""
See :meth:`list.append()` method
Calls observer ``self.observer(UpdateType.CREATED, item, index)`` where
**index** is *item position*
"""
self.real_list.append(item)
self.observer(UpdateType.CREATED, item, len(self.real_list) - 1)
[docs] def remove(self, item):
"""
See :meth:`list.remove()` method
Calls observer ``self.observer(UpdateType.DELETED, item, index)`` where
**index** is *item position*
"""
index = self.index(item)
self.real_list.remove(item)
self.observer(UpdateType.DELETED, item, index)
[docs] def index(self, x):
"""
See :meth:`list.index()` method
"""
return self.real_list.index(x)
[docs] def insert(self, index, x):
"""
See :meth:`list.insert()` method
Calls observer ``self.observer(UpdateType.CREATED, item, index)``
"""
self.real_list.insert(index, x)
self.observer(UpdateType.CREATED, x, index)
[docs] def pop(self, index=None):
"""
See :meth:`list.pop()` method
Remove the item at the given position in the list, and return it. If no index is specified,
a.pop() removes and returns the last item in the list.
:param int index: element index that will be removed
:return: item removed
"""
if index is None:
index = len(self.real_list) - 1
item = self[index]
del self[index]
return item
[docs] def __len__(self):
"""
See :meth:`list.__len__()` method
"""
return len(self.real_list)
[docs] def __getitem__(self, index):
"""
See :meth:`list.__getitem__()` method
"""
return self.real_list[index]
[docs] def __setitem__(self, index, val):
"""
See :meth:`list.__setitem__()` method
Calls observer ``self.observer(UpdateType.UPDATED, item, index)``
if ``val != self[index]``
"""
if val == self[index]:
return
old = self.real_list[index]
self.real_list[index] = val
self.observer(UpdateType.UPDATED, val, index, old=old)
[docs] def __delitem__(self, sliced):
"""
See :meth:`list.__delitem__()` method
Calls observer ``self.observer(UpdateType.DELETED, item, index)``
where **item** is `self[index]`
"""
item = self.real_list[sliced]
del self.real_list[sliced]
self.observer(UpdateType.DELETED, item, sliced)
[docs] def __contains__(self, item):
"""
See :meth:`list.__contains__()` method
"""
return item in self.real_list
[docs] def __iter__(self):
"""
See :meth:`list.__iter__()` method
"""
return iter(self.real_list)
[docs] def move(self, item, new_position):
"""
Moves a item list to new position
Calls observer ``self.observer(UpdateType.DELETED, item, index)``
and observer ``self.observer(UpdateType.CREATED, item, index)``
if ``val != self[index]``
:param item: Item that will be moved to new_position
:param new_position: Item's new position
"""
if item == self[new_position]:
return
self.remove(item)
self.insert(new_position, item)