| 35 | |
| 36 | |
| 37 | class SyncCrazyflie: |
| 38 | |
| 39 | def __init__(self, link_uri, cf=None): |
| 40 | """ Create a synchronous Crazyflie instance with the specified |
| 41 | link_uri """ |
| 42 | |
| 43 | if cf: |
| 44 | self.cf = cf |
| 45 | else: |
| 46 | self.cf = Crazyflie() |
| 47 | |
| 48 | self._link_uri = link_uri |
| 49 | self._connect_event = None |
| 50 | self._disconnect_event = None |
| 51 | self._is_link_open = False |
| 52 | self._error_message = None |
| 53 | |
| 54 | def open_link(self): |
| 55 | if (self.is_link_open()): |
| 56 | raise Exception('Link already open') |
| 57 | |
| 58 | self._add_callbacks() |
| 59 | |
| 60 | print('Connecting to %s' % self._link_uri) |
| 61 | |
| 62 | self._connect_event = Event() |
| 63 | self.cf.open_link(self._link_uri) |
| 64 | self._connect_event.wait() |
| 65 | self._connect_event = None |
| 66 | |
| 67 | if not self._is_link_open: |
| 68 | self._remove_callbacks() |
| 69 | raise Exception(self._error_message) |
| 70 | |
| 71 | def __enter__(self): |
| 72 | self.open_link() |
| 73 | return self |
| 74 | |
| 75 | def close_link(self): |
| 76 | if (self.is_link_open()): |
| 77 | self._disconnect_event = Event() |
| 78 | self.cf.close_link() |
| 79 | self._disconnect_event.wait() |
| 80 | self._disconnect_event = None |
| 81 | |
| 82 | def __exit__(self, exc_type, exc_val, exc_tb): |
| 83 | self.close_link() |
| 84 | |
| 85 | def is_link_open(self): |
| 86 | return self._is_link_open |
| 87 | |
| 88 | def _connected(self, link_uri): |
| 89 | """ This callback is called form the Crazyflie API when a Crazyflie |
| 90 | has been connected and the TOCs have been downloaded.""" |
| 91 | print('Connected to %s' % link_uri) |
| 92 | self._is_link_open = True |
| 93 | if self._connect_event: |
| 94 | self._connect_event.set() |
no outgoing calls