Decorators

Decorators are behaviours that manage a single child and provide common modifications to their underlying child behaviour (e.g. inverting the result). i.e. they provide a means for behaviours to wear different ‘hats’ depending on their context without a behaviour tree.

An example:

#!/usr/bin/env python

import py_trees.decorators
import py_trees.display

if __name__ == '__main__':

    root = py_trees.composites.Sequence(name="Life")
    timeout = py_trees.decorators.Timeout(
        name="Timeout",
        child=py_trees.behaviours.Success(name="Have a Beer!")
    )
    failure_is_success = py_trees.decorators.Inverter(
        name="Inverter",
        child=py_trees.behaviours.Success(name="Busy?")
        )
    root.add_children([failure_is_success, timeout])
    py_trees.display.render_dot_tree(root)

Decorators (Hats)

Decorators with very specific functionality:

• py_trees.decorators.Condition()
• py_trees.decorators.Inverter()
• py_trees.decorators.OneShot()
• py_trees.decorators.TimeOut()

And the X is Y family:

• py_trees.decorators.FailureIsRunning()
• py_trees.decorators.FailureIsSuccess()
• py_trees.decorators.RunningIsFailure()
• py_trees.decorators.RunningIsSuccess()
• py_trees.decorators.SuccessIsFailure()
• py_trees.decorators.SuccessIsRunning()