music_sampler/action.py

   1 from transitions.extensions import HierarchicalMachine as Machine
   2 from .helpers import debug_print, error_print
   3 from . import actions
   4
   5 class Action:
   6     STATES = [
   7         'initial',
   8         'loading',
   9         'failed',
  10         {
  11             'name': 'loaded',
  12             'children': ['running']
  13         }
  14     ]
  15
  16     TRANSITIONS = [
  17         {
  18             'trigger': 'load',
  19             'source': 'initial',
  20             'dest': 'loading'
  21         },
  22         {
  23             'trigger': 'fail',
  24             'source': 'loading',
  25             'dest': 'failed',
  26             'after': 'poll_loaded'
  27         },
  28         {
  29             'trigger': 'success',
  30             'source': 'loading',
  31             'dest': 'loaded',
  32             'after': 'poll_loaded'
  33         },
  34         {
  35             'trigger': 'run',
  36             'source': 'loaded',
  37             'dest': 'loaded_running',
  38             'after': 'finish_action',
  39             # if a child has no transitions, then it is bubbled to the parent,
  40             # and we don't want that. Not useful in that machine precisely.
  41             'conditions': ['is_loaded']
  42         },
  43         {
  44             'trigger': 'finish_action',
  45             'source': 'loaded_running',
  46             'dest': 'loaded'
  47         }
  48     ]
  49
  50     def __init__(self, action, key, **kwargs):
  51         Machine(model=self, states=self.STATES,
  52                 transitions=self.TRANSITIONS, initial='initial',
  53                 ignore_invalid_triggers=True, queued=True)
  54
  55         self.action = action
  56         self.key = key
  57         self.mapping = key.parent
  58         self.arguments = kwargs
  59         self.sleep_event = None
  60         self.waiting_music = None
  61
  62     def is_loaded_or_failed(self):
  63         return self.is_loaded(allow_substates=True) or self.is_failed()
  64
  65     def callback_music_loaded(self, success):
  66         if success:
  67             self.success()
  68         else:
  69             self.fail()
  70
  71     # Machine states / events
  72     def on_enter_loading(self):
  73         if hasattr(actions, self.action):
  74             if 'music' in self.arguments:
  75                 self.arguments['music'].subscribe_loaded(
  76                         self.callback_music_loaded)
  77             else:
  78                 self.success()
  79         else:
  80             error_print("Unknown action {}".format(self.action))
  81             self.fail()
  82
  83     def on_enter_loaded_running(self, key_start_time):
  84         debug_print(self.description())
  85         if hasattr(actions, self.action):
  86             getattr(actions, self.action).run(self,
  87                     key_start_time=key_start_time, **self.arguments)
  88
  89     def poll_loaded(self):
  90         self.key.callback_action_ready(self,
  91                 self.is_loaded(allow_substates=True))
  92
  93     # This one cannot be in the Machine state since it would be queued to run
  94     # *after* the wait is ended...
  95     def interrupt(self):
  96         if getattr(actions, self.action, None) and\
  97                 hasattr(getattr(actions, self.action), 'interrupt'):
  98             return getattr(getattr(actions, self.action), 'interrupt')(
  99                     self, **self.arguments)
 100
 101     # Helpers
 102     def music_list(self, music):
 103         if music is not None:
 104             return [music]
 105         else:
 106             return self.mapping.open_files.values()
 107
 108     def description(self):
 109         if hasattr(actions, self.action):
 110             return getattr(actions, self.action)\
 111                     .description(self, **self.arguments)
 112         else:
 113             return "unknown action {}".format(self.action)