def setParent(self, itemId, newParentId):
"""Sets the parent of an Item. The new parent item must exist and be
able to have children. (C{canHaveChildren(newParentId) == True}). It
is also possible to detach a node from the hierarchy (and thus make
it root) by setting the parent C{None}.
@param itemId:
the ID of the item to be set as the child of the Item
identified with newParentId.
@param newParentId:
the ID of the Item that's to be the new parent of the Item
identified with itemId.
@return: C{True} if the operation succeeded, C{False} if not
"""
# Checks that the item is in the container
if not self.containsId(itemId):
return False
# Gets the old parent
oldParentId = self._parent.get(itemId)
# Checks if no change is necessary
if ((newParentId is None and oldParentId is None)
or (newParentId is not None)
and (newParentId == oldParentId)):
return True
# Making root?
if newParentId is None:
# The itemId should become a root so we need to
# - Remove it from the old parent's children list
# - Add it as a root
# - Remove it from the item -> parent list (parent is null for
# roots)
# Removes from old parents children list
l = self._children.get(oldParentId)
if l is not None:
l.remove(itemId)
if len(l) > 0:
del self._children[oldParentId]
# Add to be a root
self._roots.append(itemId)
# Updates parent
del self._parent[itemId]
if self.hasFilters():
# Refilter the container if setParent is called when filters
# are applied. Changing parent can change what is included in
# the filtered version (if includeParentsWhenFiltering==true).
self.doFilterContainer(self.hasFilters())
self.fireItemSetChange()
return True
# We get here when the item should not become a root and we need to
# - Verify the new parent exists and can have children
# - Check that the new parent is not a child of the selected itemId
# - Updated the item -> parent mapping to point to the new parent
# - Remove the item from the roots list if it was a root
# - Remove the item from the old parent's children list if it was not a
# root
# Checks that the new parent exists in container and can have
# children
if ((not self.containsId(newParentId))
or (newParentId in self._noChildrenAllowed)):
return False
# Checks that setting parent doesn't result to a loop
o = newParentId
while o is not None and not (o == itemId):
o = self._parent.get(o)
if o is not None:
return False
# Updates parent
self._parent[itemId] = newParentId
pcl = self._children.get(newParentId)
if pcl is None:
# Create an empty list for holding children if one were not
# previously created
pcl = list()
self._children[newParentId] = pcl
pcl.append(itemId)
# Removes from old parent or root
if oldParentId is None:
self._roots.remove(itemId)
else:
l = self._children.get(oldParentId)
if l is not None:
l.remove(itemId)
if len(l) == 0:
del self._children[oldParentId]
if self.hasFilters():
# Refilter the container if setParent is called when filters
# are applied. Changing parent can change what is included in
# the filtered version (if includeParentsWhenFiltering==true).
self.doFilterContainer(self.hasFilters())
AbstractContainer.fireItemSetChange(self)
return True
def fireItemAdded(self, position, itemId, item):
if position >= 0:
event = ItemSetChangeEvent(self, position)
AbstractContainer.fireItemSetChange(self, event)
def fireItemAdded(self, position, itemId, item):
if position >= 0:
AbstractContainer.fireItemSetChange(self,
ItemSetChangeEvent(self, position))