#!/usr/bin/env python
#
# License: BSD
# https://raw.githubusercontent.com/splintered-reality/py_trees/devel/LICENSE
#
##############################################################################
# Documentation
##############################################################################
"""
.. argparse::
:module: py_trees.demos.stewardship
:func: command_line_argument_parser
:prog: py-trees-demo-tree-stewardship
.. graphviz:: dot/demo-tree-stewardship.dot
.. image:: images/tree_stewardship.gif
"""
##############################################################################
# Imports
##############################################################################
import argparse
import py_trees
import sys
import time
import py_trees.console as console
##############################################################################
# Classes
##############################################################################
def description():
content = "A demonstration of tree stewardship.\n\n"
content += "A slightly less trivial tree that uses a simple stdout pre-tick handler\n"
content += "and both the debug and snapshot visitors for logging and displaying\n"
content += "the state of the tree.\n"
content += "\n"
content += "EVENTS\n"
content += "\n"
content += " - 3 : sequence switches from running to success\n"
content += " - 4 : selector's first child flicks to success once only\n"
content += " - 8 : the fallback idler kicks in as everything else fails\n"
content += " - 14 : the first child kicks in again, aborting a running sequence behind it\n"
content += "\n"
if py_trees.console.has_colours:
banner_line = console.green + "*" * 79 + "\n" + console.reset
s = "\n"
s += banner_line
s += console.bold_white + "Trees".center(79) + "\n" + console.reset
s += banner_line
s += "\n"
s += content
s += "\n"
s += banner_line
else:
s = content
return s
def epilog():
if py_trees.console.has_colours:
return console.cyan + "And his noodly appendage reached forth to tickle the blessed...\n" + console.reset
else:
return None
def command_line_argument_parser():
parser = argparse.ArgumentParser(description=description(),
epilog=epilog(),
formatter_class=argparse.RawDescriptionHelpFormatter,
)
group = parser.add_mutually_exclusive_group()
group.add_argument('-r', '--render', action='store_true', help='render dot tree to file')
group.add_argument(
'--render-with-blackboard-variables',
action='store_true',
help='render dot tree to file with blackboard variables'
)
group.add_argument('-i', '--interactive', action='store_true', help='pause and wait for keypress at each tick')
return parser
def pre_tick_handler(behaviour_tree):
print("\n--------- Run %s ---------\n" % behaviour_tree.count)
[docs]class SuccessEveryN(py_trees.behaviours.SuccessEveryN):
[docs] def __init__(self):
super().__init__(name="EveryN", n=5)
self.blackboard = self.attach_blackboard_client(name=self.name)
self.blackboard.register_key("count", access=py_trees.common.Access.WRITE)
[docs] def update(self):
status = super().update()
self.blackboard.count = self.count
return status
[docs]class PeriodicSuccess(py_trees.behaviours.Periodic):
[docs] def __init__(self):
super().__init__(name="Periodic", n=3)
self.blackboard = self.attach_blackboard_client(name=self.name)
self.blackboard.register_key("period", access=py_trees.common.Access.WRITE)
[docs] def update(self):
status = super().update()
self.blackboard.period = self.period
return status
[docs]class Finisher(py_trees.behaviour.Behaviour):
[docs] def __init__(self):
super().__init__(name="Finisher")
self.blackboard = self.attach_blackboard_client(name=self.name)
self.blackboard.register_key("count", access=py_trees.common.Access.READ)
self.blackboard.register_key("period", access=py_trees.common.Access.READ)
[docs] def update(self):
print(console.green + "---------------------------" + console.reset)
print(console.bold + " Finisher" + console.reset)
print(console.green + " Count : {}".format(self.blackboard.count) + console.reset)
print(console.green + " Period: {}".format(self.blackboard.period) + console.reset)
print(console.green + "---------------------------" + console.reset)
return py_trees.common.Status.SUCCESS
def create_tree():
every_n_success = SuccessEveryN()
sequence = py_trees.composites.Sequence(name="Sequence")
guard = py_trees.behaviours.Success("Guard")
periodic_success = PeriodicSuccess()
finisher = Finisher()
sequence.add_child(guard)
sequence.add_child(periodic_success)
sequence.add_child(finisher)
idle = py_trees.behaviours.Success("Idle")
root = py_trees.composites.Selector(name="Demo Tree")
root.add_child(every_n_success)
root.add_child(sequence)
root.add_child(idle)
return root
##############################################################################
# Main
##############################################################################
[docs]def main():
"""
Entry point for the demo script.
"""
args = command_line_argument_parser().parse_args()
py_trees.logging.level = py_trees.logging.Level.DEBUG
tree = create_tree()
print(description())
####################
# Rendering
####################
if args.render:
py_trees.display.render_dot_tree(tree)
sys.exit()
if args.render_with_blackboard_variables:
py_trees.display.render_dot_tree(tree, with_blackboard_variables=True)
sys.exit()
####################
# Tree Stewardship
####################
py_trees.blackboard.Blackboard.enable_activity_stream(100)
behaviour_tree = py_trees.trees.BehaviourTree(tree)
behaviour_tree.add_pre_tick_handler(pre_tick_handler)
behaviour_tree.visitors.append(py_trees.visitors.DebugVisitor())
behaviour_tree.visitors.append(
py_trees.visitors.DisplaySnapshotVisitor(
display_blackboard=True,
display_activity_stream=True)
)
behaviour_tree.setup(timeout=15)
####################
# Tick Tock
####################
if args.interactive:
py_trees.console.read_single_keypress()
while True:
try:
behaviour_tree.tick()
if args.interactive:
py_trees.console.read_single_keypress()
else:
time.sleep(0.5)
except KeyboardInterrupt:
break
print("\n")