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              input_keys=[], 
20              output_keys=[]): 
21          """Constructor. 
22   
23          @type outcomes: list of string 
24          @param outcomes: The potential outcomes of this container. 
25   
26          @type connector_outcome: string 
27          @param connector_outcome: The outcome used to connect states in the 
28          sequence. 
29          """ 
30          smach.state_machine.StateMachine.__init__(self, outcomes, input_keys, output_keys) 
31   
32          self._last_added_seq_label = None 
33          self._connector_outcome = connector_outcome 
34   
35      ### Construction Methods 
36      @staticmethod 
37 -    def add(label, state, transitions = None, remapping = None): 
38          """Add a state to the sequence. 
39          Each state added will receive an additional transition from it to the 
40          state which is added after it. The transition will follow the outcome 
41          specified at construction of this container. 
42           
43          @type label: string 
44          @param label: The label of the state being added. 
45           
46          @param state: An instance of a class implementing the L{State} interface. 
47           
48          @param transitions: A dictionary mapping state outcomes to other state 
49          labels. If one of these transitions follows the connector outcome 
50          specified in the constructor, the provided transition will override 
51          the automatically generated connector transition. 
52          """ 
53          # Get currently opened container 
54          self = Sequence._currently_opened_container() 
55   
56          if transitions is None: 
57              transitions = {} 
58   
59          # Perform sequence linking 
60          if self._last_added_seq_label is not None: 
61              #print self._transitions[self._last_added_seq_label] 
62   
63              last_label = self._last_added_seq_label 
64              # Check if the connector outcome has been overriden 
65              if self._connector_outcome not in self._transitions[last_label]\ 
66                      or self._transitions[last_label][self._connector_outcome] is None: 
67                  self._transitions[last_label][self._connector_outcome] = label 
68              try: 
69                  self.check_state_spec(last_label, self._states[last_label], self._transitions[last_label]) 
70              except: 
71                  smach.logerr("Attempting to construct smach state sequence failed.") 
72   
73              #print self._transitions[self._last_added_seq_label] 
74   
75          # Store the last added state label 
76          self._last_added_seq_label = label 
77   
78          return smach.StateMachine.add(label, state, transitions, remapping) 
79