def __publish_attr_changes(self, attr_changes):
# Format: {fit: {item: {attr_ids}}}
fit_changes_regular = {}
# Format: {fit: {item: {attr_ids}}}
fit_changes_masked = {}
for item, attr_ids in attr_changes.items():
item_fit = item._fit
item_attr_overrides = item.attrs._override_callbacks
item_changes_regular = attr_ids.difference(item_attr_overrides)
item_changes_masked = attr_ids.intersection(item_attr_overrides)
if item_changes_regular:
fit_changes_regular.setdefault(item_fit,
{})[item] = item_changes_regular
if item_changes_masked:
fit_changes_masked.setdefault(item_fit,
{})[item] = item_changes_masked
# Format: {fit, [messages]}
fits_msgs = {}
for fit, attr_changes in fit_changes_regular.items():
msg = AttrsValueChanged(attr_changes)
fits_msgs.setdefault(fit, []).append(msg)
for fit, attr_changes in fit_changes_masked.items():
msg = AttrsValueChangedMasked(attr_changes)
fits_msgs.setdefault(fit, []).append(msg)
for fit, msgs in fits_msgs.items():
fit._publish_bulk(msgs)
def _override_value_may_change(self, attr_id):
"""Notify everyone that callback value may change.
When originator of callback knows that callback return value may (or
will) change for an attribute, it should invoke this method.
"""
self.__publish(AttrsValueChanged({self.__item: {attr_id}}))
def _set_override_callback(self, attr_id, callback):
"""Set override for the attribute in the form of callback."""
if self.__override_callbacks is None:
self.__override_callbacks = {}
# If the same callback is set, do nothing
if self.__override_callbacks.get(attr_id) == callback:
return
self.__override_callbacks[attr_id] = callback
# Exposed attribute value may change after setting/resetting override
self.__publish(AttrsValueChanged({self.__item: {attr_id}}))
def _del_override_callback(self, attr_id):
"""Remove override callback from attribute."""
overrides = self.__override_callbacks or {}
if attr_id not in overrides:
return
del overrides[attr_id]
# Set overrides map to None if there're none left to save some memory
if not overrides:
self.__override_callbacks = None
# Exposed attribute value may change after removing override
self.__publish(AttrsValueChanged({self.__item: {attr_id}}))