also create start, stop and wait function in task_producer

slic/core/adjustable/adjustable.py

@@ -6,13 +6,16 @@ from .convenience import SpecConvenience
 
 class Adjustable(BaseAdjustable, TaskProducer, SpecConvenience):
 
+    stop = None
+
     def __init__(self, ID, name=None, units=None, internal=False):
         self.ID = ID
         self.name = name or ID
         self.units = units
         self.internal = internal
 
-        self.set_target_value = self.task_producer(self.set_target_value)
+        self.set_target_value, _start, self.stop, self.wait =\
+            self.task_producer(self.set_target_value, stopper=self.stop)
 
 
     def tweak(self, delta, *args, **kwargs):

slic/core/task/tools.py

@@ -5,27 +5,35 @@ from .task import Task
 
 class TaskProducer:
 
+    #TODO: allow more than one current_task?
     current_task = None
 
+
     def task_producer(self, func, starter=None, stopper=None):
         @forwards_to(func, nfilled=1) # nfilled=1 to remove self
         @wraps(func)
         def wrapper(*args, hold=False, **kwargs):
             filled_func = lambda: func(*args, **kwargs)
             return self._as_task(filled_func, starter=starter, stopper=stopper, hold=hold)
-        return wrapper
+
+        def task_start():
+            if self.current_task:
+                return self.current_task.start()
+
+        def task_stop():
+            if self.current_task:
+                return self.current_task.stop()
+
+        def task_wait(self):
+            if self.current_task:
+                return self.current_task.wait()
+
+        return wrapper, task_start, task_stop, task_wait
+
 
     def _as_task(self, *args, **kwargs):
         self.current_task = task = Task(*args, **kwargs)
         return task
 
-    def wait(self):
-        if self.current_task:
-            return self.current_task.wait()
-
-    def stop(self):
-        if self.current_task:
-            return self.current_task.stop()
-