priority_container.py

Go to the documentation of this file.

#!/usr/bin/env python
from flexbe_core.core.operatable_state_machine import OperatableStateMachine


class PriorityContainer(OperatableStateMachine):
    """
    A state machine that is always executed alone when becoming active.
    """

    active_container = None

    def __init__(self, conditions=dict(), *args, **kwargs):
        super(PriorityContainer, self).__init__(*args, **kwargs)
        self._parent_active_container = None

    def execute(self, *args, **kwargs):
        if (PriorityContainer.active_container is None
            or not all(p == PriorityContainer.active_container.split('/')[i]
                       for i, p in enumerate(self.path.split('/')))):
            self._parent_active_container = PriorityContainer.active_container
            PriorityContainer.active_container = self.path

        outcome = OperatableStateMachine.execute(self, *args, **kwargs)

        if outcome is not None:
            PriorityContainer.active_container = self._parent_active_container

        return outcome