From 835da32571c08259fc81c89f711047a80bc16a5b Mon Sep 17 00:00:00 2001
From: "Wolfgang Draxinger (root@gar-ex-erdastep)"
 <Wolfgang.Draxinger@physik.uni-muenchen.de>
Date: Tue, 6 Dec 2011 19:38:31 +0100
Subject: things moved from scratchpad.py into their homes

---
 MotionControl/MotionStage.py | 115 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 MotionControl/MotionStage.py

(limited to 'MotionControl/MotionStage.py')

diff --git a/MotionControl/MotionStage.py b/MotionControl/MotionStage.py
new file mode 100644
index 0000000..937ce45
--- /dev/null
+++ b/MotionControl/MotionStage.py
@@ -0,0 +1,115 @@
+# -*- coding: utf-8 -*-
+
+class CycleAbort(Exception):
+	pass
+
+class MotionStage(object):
+	def __init__(self, axes, constraints = None):
+		import Queue
+
+		self.axes = axes
+		self.constraints = constraints
+
+		self.action_queue = Queue.Queue()
+		self.abort_action = NullAction()
+
+		self.onCycleStarted = Signal()
+		self.onCycleFinished = Signal()
+		self.onCycleAborted = Signal()
+
+		self.active = False
+		self.target = None
+
+	def __del__(self):
+		self.abort()
+
+	def __getattr__(self, name):
+		if name == 'position':
+			return [axis.position for axis in self.axes]
+
+	def update(self):
+		for axis in self.axes:
+			axis.update()
+
+	def set_target(self, target):
+		if isinstance(target, list):
+			if len(target) != len(self.axes):
+				raise ValueError
+			self.target = target
+		if isinstance(target, dict):
+			for k,v in target:
+				self.target[k] = v
+		if isinstance(target, tuple):
+			self.target[target[0]] = target[1]
+
+		speed = None
+		current_position = self.position
+		if not None in current_position:
+			delta = [abs(a-b) for a,b in zip(target, current_position)]
+			max_delta = max(delta)
+			speed = [float(d)/float(max_delta) for d in delta]
+		self.action_queue = Queue.Queue()
+		self.action_queue.put(GotoAbsolute(self.axes, self.target, speed))
+
+	def can_cycle_start(self):
+		if self.active:
+			return False
+		return True # FIXME: Add constraint tests here
+
+	def start_cycle(self):
+		import threading, weakref
+
+		if not self.can_cycle_start():
+			return False
+
+		self.current_action = None
+		self.active = True
+		self.worker_thread = threading.Thread(target = MotionControl.cycle_worker, name = "MotionControl.worker", args=(weakref.proxy(self),))
+		self.worker_thread.daemon =True
+		self.worker_thread.start()
+		self.onCycleStarted.send()
+
+	def abort(self):
+		self.active = False
+		self.worker_thread.join()
+
+	def __del__(self):
+		self.abort()
+
+	def cycle_worker(ref):
+		abort_action = ref.abort_action
+		try:
+			import time
+			while True:
+				if not ref.active:
+					raise CycleAbort()
+				ref.update()
+				if not ref.current_action or ref.current_action.ended():
+					if ref.action_queue.empty():
+						break
+					ref.current_action = ref.action_queue.get_nowait()
+
+				ref.current_action.execute()
+
+				while True:
+					if not ref.active:
+						raise CycleAbort()
+					ref.update()
+					if ref.current_action.ended():
+						break
+
+				ref.action_queue.task_done()
+
+			ref.onCycleFinished.send()
+		except CycleAbort:
+			ref.abort_action.execute()
+			ref.onCycleAborted.send()
+
+		finally:
+			try:
+				while not ref.action_queue.empty():
+					ref.action_queue.get_nowait()
+					ref.action_queue.task_done()
+			except:
+				pass
+			ref.active = False
-- 
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