#!/usr/bin/env python
#
# License: BSD
# https://raw.githubusercontent.com/stonier/py_trees/devel/LICENSE
#
##############################################################################
# Documentation
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"""
A library of fundamental behaviours for use.
"""
##############################################################################
# Imports
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from .common import Status
from .behaviour import Behaviour
from . import composites
from . import meta
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# Function Behaviours
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def success(self):
self.logger.debug("%s.update()" % self.__class__.__name__)
self.feedback_message = "success"
return Status.SUCCESS
def failure(self):
self.logger.debug("%s.update()" % self.__class__.__name__)
self.feedback_message = "failure"
return Status.FAILURE
def running(self):
self.logger.debug("%s.update()" % self.__class__.__name__)
self.feedback_message = "running"
return Status.RUNNING
Success = meta.create_behaviour_from_function(success)
"""
Do nothing but tick over with :data:`~py_trees.common.Status.SUCCESS`.
"""
Failure = meta.create_behaviour_from_function(failure)
"""
Do nothing but tick over with :data:`~py_trees.common.Status.FAILURE`.
"""
Running = meta.create_behaviour_from_function(running)
"""
Do nothing but tick over with :data:`~py_trees.common.Status.RUNNING`.
"""
##############################################################################
# Standalone Behaviours
##############################################################################
[docs]class Periodic(Behaviour):
"""
Simply periodically rotates it's status over the
:data:`~py_trees.common.Status.RUNNING`, :data:`~py_trees.common.Status.SUCCESS`,
:data:`~py_trees.common.Status.FAILURE` states.
That is, :data:`~py_trees.common.Status.RUNNING` for N ticks,
:data:`~py_trees.common.Status.SUCCESS` for N ticks,
:data:`~py_trees.common.Status.FAILURE` for N ticks...
Args:
name (:obj:`str`): name of the behaviour
n (:obj:`int`): period value (in ticks)
.. note:: It does not reset the count when initialising.
"""
def __init__(self, name, n):
super(Periodic, self).__init__(name)
self.count = 0
self.period = n
self.response = Status.RUNNING
[docs] def update(self):
self.count += 1
if self.count > self.period:
if self.response == Status.FAILURE:
self.feedback_message = "flip to running"
self.response = Status.RUNNING
elif self.response == Status.RUNNING:
self.feedback_message = "flip to success"
self.response = Status.SUCCESS
else:
self.feedback_message = "flip to failure"
self.response = Status.FAILURE
self.count = 0
else:
self.feedback_message = "constant"
return self.response
[docs]class SuccessEveryN(Behaviour):
"""
This behaviour updates it's status with :data:`~py_trees.common.Status.SUCCESS`
once every N ticks, :data:`~py_trees.common.Status.FAILURE` otherwise.
Args:
name (:obj:`str`): name of the behaviour
n (:obj:`int`): trigger success on every n'th tick
.. tip::
Use with decorators to change the status value as desired, e.g.
:meth:`py_trees.meta.failure_is_running`
"""
def __init__(self, name, n):
super(SuccessEveryN, self).__init__(name)
self.count = 0
self.every_n = n
[docs] def update(self):
self.count += 1
self.logger.debug("%s.update()][%s]" % (self.__class__.__name__, self.count))
if self.count % self.every_n == 0:
self.feedback_message = "now"
return Status.SUCCESS
else:
self.feedback_message = "not yet"
return Status.FAILURE
[docs]class Count(Behaviour):
"""
A counting behaviour that updates its status at each tick depending on
the value of the counter. The status will move through the states in order -
:data:`~py_trees.common.Status.FAILURE`, :data:`~py_trees.common.Status.RUNNING`,
:data:`~py_trees.common.Status.SUCCESS`.
This behaviour is useful for simple testing and demo scenarios.
Args:
name (:obj:`str`): name of the behaviour
fail_until (:obj:`int`): set status to :data:`~py_trees.common.Status.FAILURE` until the counter reaches this value
running_until (:obj:`int`): set status to :data:`~py_trees.common.Status.RUNNING` until the counter reaches this value
success_until (:obj:`int`): set status to :data:`~py_trees.common.Status.SUCCESS` until the counter reaches this value
reset (:obj:`bool`): whenever invalidated (usually by a sequence reinitialising, or higher priority interrupting)
Attributes:
count (:obj:`int`): a simple counter which increments every tick
"""
def __init__(self, name="Count", fail_until=3, running_until=5, success_until=6, reset=True, *args, **kwargs):
super(Count, self).__init__(name, *args, **kwargs)
self.count = 0
self.fail_until = fail_until
self.running_until = running_until
self.success_until = success_until
self.number_count_resets = 0
self.number_updated = 0
self.reset = reset
[docs] def terminate(self, new_status):
self.logger.debug("%s.terminate(%s->%s)" % (self.__class__.__name__, self.status, new_status))
# reset only if udpate got us into an invalid state
if new_status == Status.INVALID and self.reset:
self.count = 0
self.number_count_resets += 1
self.feedback_message = ""
[docs] def update(self):
self.number_updated += 1
self.count += 1
if self.count <= self.fail_until:
self.logger.debug("%s.update()[%s: failure]" % (self.__class__.__name__, self.count))
self.feedback_message = "failing"
return Status.FAILURE
elif self.count <= self.running_until:
self.logger.debug("%s.update()[%s: running]" % (self.__class__.__name__, self.count))
self.feedback_message = "running"
return Status.RUNNING
elif self.count <= self.success_until:
self.logger.debug("%s.update()[%s: success]" % (self.__class__.__name__, self.count))
self.feedback_message = "success"
return Status.SUCCESS
else:
self.logger.debug("%s.update()[%s: failure]" % (self.__class__.__name__, self.count))
self.feedback_message = "failing forever more"
return Status.FAILURE
def __repr__(self):
"""
Simple string representation of the object.
Returns:
:obj:`str`: string representation
"""
s = "%s\n" % self.name
s += " Status : %s\n" % self.status
s += " Count : %s\n" % self.count
s += " Resets : %s\n" % self.number_count_resets
s += " Updates: %s\n" % self.number_updated
return s
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# Composite Behaviours
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@meta.oneshot
class OneshotSequence(composites.Sequence):
"""
A sequence with a oneshot decorator applied to it.
"""
pass