Source Code for Module asmach.util

  1   
  2  import roslib; roslib.load_manifest('smach') 
  3  import asmach as smach 
  4   
  5  import threading 
  6   
  7  import asmach as smach 
  8   
  9  __all__ = ['is_shutdown','set_shutdown_cb',\ 
 10          'cb_interface','has_smach_interface','CBInterface'] 
 11   
 12 -def is_shutdown(): 
 13      return False 
 14   
 15 -def set_shutdown_check(cb): 
 16      smach.is_shutdown = cb 
 17   
 18 -def has_smach_interface(obj): 
 19      """Returns True if the object has SMACH interface accessors.""" 
 20      return hasattr(obj,'get_registered_input_keys')\ 
 21              and hasattr(obj,'get_registered_output_keys')\ 
 22              and hasattr(obj,'get_registered_outcomes') 
 23   
 24  # Callback decorator for describing userdata 
 25 -class cb_interface(object): 
 26 -    def __init__(self, outcomes=[], input_keys=[], output_keys=[]): 
 27          self._outcomes = outcomes 
 28          self._input_keys = input_keys 
 29          self._output_keys = output_keys 
 30       
 31 -    def __call__(self, cb): 
 32          return CBInterface(cb, self._outcomes, self._input_keys, self._output_keys) 
 33 -class CBInterface(object): 
 34      """Decorator to describe the extension of a state's SMACH userdata and outcome interface. 
 35       
 36      Some SMACH states can be extended with the use of user callbacks. Since 
 37      the SMACH interface and SMACH userdata are strictly controlled, the ways in 
 38      which these callbacks interact with SMACH must be delcared. This decorator 
 39      allows this information to be attached to a given callback function. 
 40   
 41      If a callback adds a potential outcome to a state, suppose 'critical_failure', 
 42      then one could write this when defining the callback: 
 43   
 44      >>> import asmach as smach 
 45      >>> @smach.cb_interface(outcomes=['critical_failure']) 
 46      >>> def my_cb(x,y,z): 
 47      >>>     # User code 
 48      >>>     return 'critical_failure' 
 49   
 50      Suppose a state retrieves data that it passes into a callback. If the user 
 51      wants to take that data and put some of all of it into userdata, this 
 52      interface must be declared. In this case, the user could write: 
 53   
 54      >>> import asmach as smach 
 55      >>> @smach.cb_interface(output_keys=['processed_res']) 
 56      >>> def my_cb(ud, data): 
 57      >>>     ud.processed_res = data 
 58   
 59      """ 
 60 -    def __init__(self, cb, outcomes=[], input_keys=[], output_keys=[], io_keys=[]): 
 61          """Describe callback SMACH interface. 
 62   
 63          @type outcomes: array of strings 
 64          @param outcomes: Custom outcomes for this state. 
 65   
 66          @type input_keys: array of strings 
 67          @param input_keys: The userdata keys from which this state might read 
 68          at runtime.  
 69   
 70          @type output_keys: array of strings 
 71          @param output_keys: The userdata keys to which this state might write 
 72          at runtime. 
 73   
 74          @type io_keys: array of strings 
 75          @param io_keys: The userdata keys to which this state might write or 
 76          from which it might read at runtime. 
 77          """ 
 78   
 79          self._input_keys = set(input_keys) 
 80          self._input_keys.union(io_keys) 
 81   
 82          self._output_keys = set(output_keys) 
 83          self._output_keys.union(io_keys) 
 84   
 85          self._outcomes = outcomes 
 86   
 87          self._cb = cb 
 88   
 89 -    def __call__(self, *args, **kwargs): 
 90          return self._cb(*args, **kwargs) 
 91   
 92      ### SMACH Interface API 
 93 -    def get_registered_input_keys(self): 
 94          """Get a tuple of registered input keys.""" 
 95          return tuple(self._input_keys) 
 96 -    def get_registered_output_keys(self): 
 97          """Get a tuple of registered output keys.""" 
 98          return tuple(self._output_keys) 
 99 -    def get_registered_outcomes(self): 
100          """Get a list of registered outcomes. 
101          @rtype: tuple of string 
102          @return: Tuple of registered outcome strings. 
103          """ 
104          return tuple(self._outcomes) 
105