#!/usr/bin/env python
#
# License: BSD
# https://raw.githubusercontent.com/splintered-reality/py_trees/devel/LICENSE
#
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# Documentation
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"""Time related behaviours."""
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# Imports
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import time
from . import behaviour, common
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# Behaviours
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[docs]class Timer(behaviour.Behaviour):
"""
A simple, blocking timer behaviour running off python time.time().
This behaviour is :py:data:`~py_trees.common.Status.RUNNING` until the timer
runs out, at which point it is :data:`~py_trees.common.Status.SUCCESS`. This can be
used in a wide variety of situations - pause, duration, timeout depending on how
it is wired into the tree (e.g. pause in a sequence, duration/timeout in
a parallel).
The timer gets reset either upon entry (:meth:`~py_trees.behaviour.Behaviour.initialise`)
if it hasn't already been set and gets cleared when it either runs out, or the behaviour is
interrupted by a higher priority or parent cancelling it.
Args:
name: name of the behaviour
duration: length of time to run (in seconds)
Raises:
TypeError: if the provided duration is not a real number
.. note::
This succeeds the first time the behaviour is ticked **after** the expected
finishing time.
.. tip::
Use the :func:`~py_trees.decorators.RunningIsFailure` decorator if you need
:data:`~py_trees.common.Status.FAILURE` until the timer finishes.
"""
[docs] def __init__(self, name: str = "Timer", duration: float = 5.0):
super(Timer, self).__init__(name)
if not isinstance(duration, float):
raise TypeError(
"Timer: duration should be int or float, but you passed in {}".format(
type(duration)
)
)
self.duration: float = duration
self.finish_time: float = 0.0
self.feedback_message: str = "duration set to '{0}'s".format(self.duration)
[docs] def initialise(self) -> None:
"""Store the expected finishing time."""
self.logger.debug("%s.initialise()" % self.__class__.__name__)
self.finish_time = time.time() + self.duration
self.feedback_message = "configured to fire in '{0}' seconds".format(
self.duration
)
[docs] def update(self) -> common.Status:
"""
Check the timer and update the behaviour result accordingly.
Returns:
:data:`~py_trees.common.Status.RUNNING` until timer expires, then
:data:`~py_trees.common.Status.SUCCESS`.
"""
self.logger.debug("%s.update()" % self.__class__.__name__)
current_time = time.time()
if current_time > self.finish_time:
self.feedback_message = "timer ran out [{0}]".format(self.duration)
return common.Status.SUCCESS
else:
# do not show the time, it causes the tree to be 'changed' every tick
# and we don't want to spam visualisations with almost meaningless updates
self.feedback_message = (
"still running" # (%s)" % (self.finish_time - current_time)
)
return common.Status.RUNNING