Source Code for Module smach.sequence

 1   
 2  import threading 
 3  from contextlib import contextmanager 
 4   
 5  import smach 
 6   
 7  __all__ = ['Sequence'] 
 8   
 9 -class Sequence(smach.state_machine.StateMachine): 
10      """Sequence Container 
11   
12      This container inherits functionality from L{smach.StateMachine} and adds 
13      some auto-generated transitions that create a sequence of states from the 
14      order in which said states are added to the container. 
15      """ 
16 -    def __init__(self, 
17              outcomes, 
18              connector_outcome): 
19          """Constructor. 
20   
21          @type outcomes: list of string 
22          @param outcomes: The potential outcomes of this container. 
23   
24          @type connector_outcome: string 
25          @param connector_outcome: The outcome used to connect states in the 
26          sequence. 
27          """ 
28          smach.state_machine.StateMachine.__init__(self, outcomes) 
29   
30          self._last_added_seq_label = None 
31          self._connector_outcome = connector_outcome 
32   
33      ### Construction Methods 
34      @staticmethod 
35 -    def add(label, state, transitions = None, remapping = None): 
36          """Add a state to the sequence. 
37          Each state added will receive an additional transition from it to the 
38          state which is added after it. The transition will follow the outcome 
39          specified at construction of this container. 
40           
41          @type label: string 
42          @param label: The label of the state being added. 
43           
44          @param state: An instance of a class implementing the L{State} interface. 
45           
46          @param transitions: A dictionary mapping state outcomes to other state 
47          labels. If one of these transitions follows the connector outcome 
48          specified in the constructor, the provided transition will override 
49          the automatically generated connector transition. 
50          """ 
51          # Get currently opened container 
52          self = Sequence._currently_opened_container() 
53   
54          if transitions is None: 
55              transitions = {} 
56   
57          # Perform sequence linking 
58          if self._last_added_seq_label is not None: 
59              #print self._transitions[self._last_added_seq_label] 
60   
61              last_label = self._last_added_seq_label 
62              # Check if the connector outcome has been overriden 
63              if self._connector_outcome not in self._transitions[last_label]\ 
64                      or self._transitions[last_label][self._connector_outcome] is None: 
65                  self._transitions[last_label][self._connector_outcome] = label 
66              try: 
67                  self.check_state_spec(last_label, self._states[last_label], self._transitions[last_label]) 
68              except: 
69                  smach.logerr("Attempting to construct smach state sequence failed.") 
70   
71              #print self._transitions[self._last_added_seq_label] 
72   
73          # Store the last added state label 
74          self._last_added_seq_label = label 
75   
76          return smach.StateMachine.add(label, state, transitions, remapping) 
77