# Copyright 2018 Open Source Robotics Foundation, Inc.
#
# 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.
"""Module for UnlessCondition class."""
from typing import Text
from .if_condition import IfCondition
from ..launch_context import LaunchContext
from ..some_substitutions_type import SomeSubstitutionsType
[docs]
class UnlessCondition(IfCondition):
"""
Encapsulates an if condition to be evaluated when launching.
Exactly the same as :py:class:`IfCondition` except it returns true if the
condition expression evaluates to false.
"""
[docs]
def __init__(self, predicate_expression: SomeSubstitutionsType) -> None:
super().__init__(predicate_expression)
def _predicate_func(self, context: LaunchContext) -> bool:
return not super()._predicate_func(context)
[docs]
def describe(self) -> Text:
"""Return a description of this Condition."""
return self.__repr__()