- redefine activate method

- for task introduced open() conext method

components/astirrer.py

@@ -1,5 +1,6 @@
 import abc
 from utils.value import AttributeChange
+from contextlib import contextmanager
 
 
 class AStirrer(AttributeChange):
@@ -11,7 +12,6 @@ class AStirrer(AttributeChange):
 		self.dutyCycle = 1
 		self.cycleCounter = 0
 		self.isOn = 1
-		self.is_active = False
 
 	def process(self):
 		isOn = self.isOn
@@ -51,14 +51,21 @@ class AStirrer(AttributeChange):
 	def on_set_speed(self, speed):
 		pass
 
+	@contextmanager
+	def open(self):
+		try:
+			self.activate(True)
+			yield None
+		finally:
+			self.activate(False)
+
+		return None
+
 	@abc.abstractmethod
-	def on_activate(self, enable):
+	def activate(self, enable):
 		pass
 
-	def activate(self, enable):
-		self.is_active = enable
-		self.on_activate(enable)
-
+	@abc.abstractmethod
 	def is_activated(self):
-		return self.is_active
+		pass