Review PDFFastShutter code

[mrakitin]

profile_collection/startup/15-optics.py

Lines 55 to 89 in b06e317

	class PDFFastShutter(Device):
	cmd = Cpt(EpicsSignal, 'Cmd', kind='omitted')
	status = Cpt(EpicsSignal, 'Sts', kind='omitted')
	def __init__(self, *args, **kwargs):
	super().__init__(*args, **kwargs)
	self.st = None
	# TODO: ask CJ to change it downstream to only accept the 'Open' or 'Close' strings (no numbers please!).
	self.setmap = {'Open': 0, 'Close': 1,
	1: 0, 0: 1} # MR: this is an inversed logic on the xpdacq side
	self.readmap = {0: 'Open', 1: 'Close'}
	def set(self, val):
	def check_if_done(value, old_value, **kwargs):
	if ((val in ['Open', 1] and value == 0) or
	(val in ['Close', 0] and value == 1)):
	if self.st is not None:
	self.st._finished()
	self.st = None
	return True
	return False
	self.cmd.set(self.setmap[val])
	status = SubscriptionStatus(self.status, check_if_done)
	return status
	def get(self):
	return self.readmap[self.cmd.get()]
	def read(self):
	d = super().read()
	d[self.name] = {'value': self.get(), 'timestamp': time.time()}
	return d
	def stop(self, success=False):
	return self.set('Close')

@tacaswell writes:

it looks like self._st is never not None

[mrakitin]

@awalter-bnl pointed out that the shutter re-work in NSLS-II/nslsii#52 will handle the states better.