def test_unbind(self):
"""Verify two binded traitlets can be unbinded."""
# Create two simple classes with Int traitlets.
class A(HasTraits):
value = Int()
a = A(value=9)
b = A(value=8)
# Conenct the two classes.
c = bind((a, 'value'), (b, 'value'))
a.value = 4
c.unbind()
# Change one of the values to make sure they stay in sync.
a.value = 5
self.assertNotEqual(a.value, b.value)
def test_connect_same(self):
"""Verify two traitlets of the same type can be bound together using bind."""
# Create two simple classes with Int traitlets.
class A(HasTraits):
value = Int()
a = A(value=9)
b = A(value=8)
# Conenct the two classes.
c = bind((a, 'value'), (b, 'value'))
# Make sure the values are the same at the point of binding.
self.assertEqual(a.value, b.value)
# Change one of the values to make sure they stay in sync.
a.value = 5
self.assertEqual(a.value, b.value)
b.value = 6
self.assertEqual(a.value, b.value)
def test_bind_different(self):
"""Verify two traitlets of different types can be bound together using bind."""
# Create two simple classes with Int traitlets.
class A(HasTraits):
value = Int()
class B(HasTraits):
count = Int()
a = A(value=9)
b = B(count=8)
# Conenct the two classes.
c = bind((a, 'value'), (b, 'count'))
# Make sure the values are the same at the point of binding.
self.assertEqual(a.value, b.count)
# Change one of the values to make sure they stay in sync.
a.value = 5
self.assertEqual(a.value, b.count)
b.count = 4
self.assertEqual(a.value, b.count)
def test_callbacks(self):
"""Verify two binded traitlets have their callbacks called once."""
# Create two simple classes with Int traitlets.
class A(HasTraits):
value = Int()
class B(HasTraits):
count = Int()
a = A(value=9)
b = B(count=8)
# Register callbacks that count.
callback_count = []
def a_callback(name, old, new):
callback_count.append('a')
a.on_trait_change(a_callback, 'value')
def b_callback(name, old, new):
callback_count.append('b')
b.on_trait_change(b_callback, 'count')
# Conenct the two classes.
c = bind((a, 'value'), (b, 'count'))
# Make sure b's count was set to a's value once.
self.assertEqual(''.join(callback_count), 'b')
del callback_count[:]
# Make sure a's value was set to b's count once.
b.count = 5
self.assertEqual(''.join(callback_count), 'ba')
del callback_count[:]
# Make sure b's count was set to a's value once.
a.value = 4
self.assertEqual(''.join(callback_count), 'ab')
del callback_count[:]
