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""" Used to track events in tests. """
# Enthought library imports.
from enthought.traits.api import HasTraits, List, Str, Tuple
class EventTracker(HasTraits):
""" Used to track traits events. """
# The traits events that have fired.
#
# This is a list of tuples in the form:-
#
# (obj, trait_name, old, new)
events = List(Tuple)
# The names of the traits events that have fired.
#
# This is useful if you just care about the order of the events, not the
# contents.
event_names = List(Str)
# The trait event subscriptions used by the tracker.
#
# This is a list of tuples in the form:-
#
# (obj, trait_name)
#
# Where 'obj' is the object to listen to, and 'trait_name' is the name of
# the trait to listen to, or None to listen for all trait events.
subscriptions = List(Tuple)
###########################################################################
# Private interface.
###########################################################################
#### Trait change handlers ################################################
def _subscriptions_changed(self, old, new):
""" Static trait change handler. """
map(self._remove_subscription, old)
map(self._add_subscription, new)
return
def _subscriptions_items_changed(self, event):
""" Static trait change handler. """
map(self._remove_subscription, event.removed)
map(self._add_subscription, event.added)
return
def _listener(self, obj, trait_name, old, new):
""" Dynamic trait change listener. """
self.events.append((obj, trait_name, old, new))
self.event_names.append(trait_name)
return
#### Methods ##############################################################
def _add_subscription(self, subscription):
""" Add a subscription. """
obj, trait_name = subscription
if trait_name is not None:
obj.on_trait_change(self._listener, trait_name)
else:
obj.on_trait_change(self._listener)
return
def _remove_subscription(self, subscription):
""" Remove a subscription. """
obj, trait_name = subscription
if trait_name is not None:
obj.on_trait_change(self._listener, trait_name, remove=True)
else:
obj.on_trait_change(self._listener, remove=True)
return
#### EOF ######################################################################
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