GenericDiffractometer.py

#
#  Project: MXCuBE
#  https://github.com/mxcube.
#
#  This file is part of MXCuBE software.
#
#  MXCuBE is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  MXCuBE is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with MXCuBE.  If not, see <http://www.gnu.org/licenses/>.

"""
GenericDiffractometer
"""

import copy
import time
import gevent
import logging
import sample_centring
import math,numpy
import queue_model_objects_v1 as queue_model_objects

from HardwareRepository.TaskUtils import *
from HardwareRepository.BaseHardwareObjects import HardwareObject

__credits__ = ["MXCuBE colaboration"]

__version__ = "2.2."
__status__ = "Draft"


class DiffractometerState:
    """
    Enumeration of diffractometer states
    """
    Created      = 0
    Initializing = 1
    On           = 2
    Off          = 3
    Closed       = 4
    Open         = 5
    Ready        = 6
    Busy         = 7
    Moving       = 8
    Standby      = 9
    Running      = 10
    Started      = 11
    Stopped      = 12
    Paused       = 13
    Remote       = 14
    Reset        = 15
    Closing      = 16
    Disable      = 17
    Waiting      = 18
    Positioned   = 19
    Starting     = 20
    Loading      = 21
    Unknown      = 22
    Alarm        = 23
    Fault        = 24
    Invalid      = 25
    Offline      = 26

    STATE_DESC = {Created: "Created",
                  Initializing: "Initializing",
                  On: "On",
                  Off: "Off",
                  Closed: "Closed",
                  Open: "Open",
                  Ready: "Ready",
                  Busy: "Busy",
                  Moving: "Moving",
                  Standby: "Standby",
                  Running: "Running",
                  Started: "Started",
                  Stopped: "Stopped",
                  Paused: "Paused",
                  Remote: "Remote",
                  Reset: "Reset",
                  Closing : "Closing",
                  Disable: "Disable",
                  Waiting: "Waiting",
                  Positioned: " Positioned",
                  Starting: "Starting",
                  Loading: "Loading",
                  Unknown: "Unknown",
                  Alarm: "Alarm",
                  Fault: "Fault",
                  Invalid: "Invalid",
                  Offline: "Offline"}

    @staticmethod
    def tostring(state):
        return DiffractometerState.STATE_DESC.get(state, "Unknown")


class GenericDiffractometer(HardwareObject):
    """
    Abstract base class for diffractometers
    """

    CENTRING_MOTORS_NAME = ["phi",
                   "phiz",
                   "phiy",
                   "sampx",
                   "sampy",
                   "kappa",
                   "kappa_phi",
                   "beam_x",
                   "beam_y"]
    CHANNELS_NAME = ["CoaxCamScaleX",
                     "CoaxCamScaleY",
                     "State",
                     "CurrentPhase",
                     "TransferMode",
                     "SampleIsLoaded",
                     "HeadType"]
    COMMANDS_NAME = ["startSetPhase"
                    ]

    STATE_CHANGED_EVENT = "stateChanged"
    STATUS_CHANGED_EVENT = "statusChanged"
    MOTOR_POSITION_CHANGED_EVENT = "motorPositionChanged"
    MOTOR_STATUS_CHANGED_EVENT = "motorStatusChanged"

    HEAD_TYPE_MINIKAPPA = "MiniKappa"
    HEAD_TYPE_SMARTMAGNET = "SmartMagnet"
    HEAD_TYPE_PLATE = "Plate"
    HEAD_TYPE_PERMANENT = "Permanent"

    CENTRING_METHOD_MANUAL = "Manual 3-click"
    CENTRING_METHOD_AUTO = "Computer automatic"
    CENTRING_METHOD_MOVE_TO_BEAM = "Move to beam"

    PHASE_TRANSFER = "Transfer"
    PHASE_CENTRING = "Centring"
    PHASE_COLLECTION = "DataCollection"
    PHASE_BEAM = "BeamLocation"

    def __init__(self, name):
        HardwareObject.__init__(self, name)

        # Hardware objects ----------------------------------------------------
        self.motor_hwobj_dict = {}
        self.centring_motors_list = None
        self.front_light_switch = None
        self.back_light_switch = None
        self.camera_hwobj = None
        self.beam_info_hwobj = None
        self.sample_changer = None
        self.use_sc = False

        # Channels and commands -----------------------------------------------
        self.channel_dict = {}
        self.used_channels_list = GenericDiffractometer.CHANNELS_NAME
        self.command_dict = {}
        self.used_commands_list = GenericDiffractometer.COMMANDS_NAME

	# flag for using sample_centring hwobj or not
	self.use_sample_centring = None 

        # Internal values -----------------------------------------------------
        self.ready_event = None
        self.head_type = GenericDiffractometer.HEAD_TYPE_MINIKAPPA
        self.phase_list = []
        self.grid_direction = None
        self.reversing_rotation = None

        self.beam_position = None
        self.zoom_centre = None
        self.pixels_per_mm_x = None
        self.pixels_per_mm_y = None
        self.image_width = None
        self.image_height = None

        self.current_state = None
        self.current_phase = None
        self.transfer_mode = None
        self.current_centring_procedure = None
        self.current_centring_method = None
        self.current_motor_positions = {}
        self.current_motor_states = {}

        self.fast_shutter_is_open = None
        self.centring_status = {"valid": False}
        self.centring_time = 0
        self.user_confirms_centring = None
        self.user_clicked_event = None
        self.omega_reference_par = None
        self.move_to_motors_positions_task = None
        self.move_to_motors_positions_procedure = None

        self.centring_methods = {
             GenericDiffractometer.CENTRING_METHOD_MANUAL: \
                 self.start_manual_centring,
             GenericDiffractometer.CENTRING_METHOD_AUTO: \
                 self.start_automatic_centring,
             GenericDiffractometer.CENTRING_METHOD_MOVE_TO_BEAM: \
                 self.start_move_to_beam}

        self.connect(self, 'equipmentReady', self.equipment_ready)
        self.connect(self, 'equipmentNotReady', self.equipment_not_ready)


    def init(self):
        # Internal values -----------------------------------------------------
        self.ready_event = gevent.event.Event()
        self.user_clicked_event = gevent.event.AsyncResult()
        self.user_confirms_centring = True

        # Hardware objects ----------------------------------------------------
        self.camera_hwobj = self.getObjectByRole("camera")
        if self.camera_hwobj is not None:
            self.image_height = self.camera_hwobj.getHeight()
            self.image_width = self.camera_hwobj.getWidth()
        else:
            logging.getLogger("HWR").debug("Diffractometer: " + \
                    "Camera hwobj is not defined")

        self.beam_info_hwobj = self.getObjectByRole("beam_info")
        if self.beam_info_hwobj is not None:
            self.beam_position = self.beam_info_hwobj.get_beam_position()
            self.connect(self.beam_info_hwobj, 
                         "beamPosChanged",
                         self.beam_position_changed)
        else:
            self.beam_position = [self.image_width / 2,
                                  self.image_height / 2]
            logging.getLogger("HWR").warning("Diffractometer: " +\
                    "BeamInfo hwobj is not defined")

        self.front_light_swtich = self.getObjectByRole('frontlightswtich')
        self.back_light_swtich = self.getObjectByRole('backlightswtich')

        # Channels -----------------------------------------------------------
        try:
           self.used_channels_list = eval(self.getProperty("used_channels"))
        except:
           pass # used the default value

        for channel_name in self.used_channels_list:
            self.channel_dict[channel_name] = self.getChannelObject(channel_name)
            if self.channel_dict[channel_name] is None:
                continue
            if channel_name == "TransferMode":
                self.connect(self.channel_dict["TransferMode"], "update", 
                             self.transfer_mode_changed)
            elif channel_name =="CurrentPhase":
                self.connect(self.channel_dict["CurrentPhase"], "update", 
                             self.current_phase_changed)
            elif channel_name =="HeadType":
                self.connect(self.channel_dict["HeadType"], "update",
                             self.head_type_changed)
            elif channel_name =="State":
                self.connect(self.channel_dict["State"], "update",
                             self.state_changed)

        # Commands -----------------------------------------------------------
        try:
            self.used_commands_list = eval(self.getProperty("used_commands"))
        except:
            pass # used the default value
        for command_name in self.used_commands_list:
            self.command_dict[command_name] = self.getCommandObject(command_name)

        # Centring motors ----------------------------------------------------
        try:
           self.centring_motors_list = eval(self.getProperty("centring_motors"))
        except:
           self.centring_motors_list = GenericDiffractometer.CENTRING_MOTORS_NAME

        queue_model_objects.CentredPosition.\
            set_diffractometer_motor_names(*self.centring_motors_list)

        for motor_name in self.centring_motors_list:
            temp_motor_hwobj = self.getObjectByRole(motor_name)
            if temp_motor_hwobj is not None:
                logging.getLogger("HWR").debug("Diffractometer: Adding " + \
                  "%s motor to centring motors" % motor_name)

                self.motor_hwobj_dict[motor_name] = temp_motor_hwobj
                self.connect(temp_motor_hwobj, "stateChanged", 
                             self.motor_state_changed)     
                self.connect(temp_motor_hwobj, "positionChanged",
                             self.centring_motor_moved)

                if motor_name == "phi":
                    self.connect(temp_motor_hwobj, 
                                 "positionChanged", 
                                 self.emit_diffractometer_moved)
                elif motor_name == "zoom": 
                    self.connect(temp_motor_hwobj, 
                                 "predefinedPositionChanged", 
                                 self.zoom_motor_predefined_position_changed)
                    self.connect(temp_motor_hwobj, 
                                 "stateChanged",
                                 self.zoom_motor_state_changed)
            else:
                logging.getLogger("HWR").warning("Diffractometer: Motor " + \
                  "%s listed in the centring motor list, but not initalized" % motor_name)

        # sample changer -----------------------------------------------------
        self.sample_changer = self.getObjectByRole("samplechanger")
        if self.sample_changer is None :
            logging.getLogger("HWR").warning('Diffractometer: Sample Changer is not defined')
        else: 
            #By default use sample changer if it's defined and transfer_mode 
            # is set to SAMPLE_CHANGER. 
            # if not defined, set use_sc to True
            if self.transfer_mode is None or self.transfer_mode == "SAMPLE_CHANGER":
                self.use_sc = True

	try:
           self.use_sample_centring = self.getProperty("sample_centring")
	   if self.use_sample_centring:
		self.centring_phi=sample_centring.CentringMotor(\
                     self.motor_hwobj_dict['phi'], direction=-1)
	        self.centring_phiz=sample_centring.CentringMotor(\
                     self.motor_hwobj_dict['phiz'])
        	self.centring_phiy=sample_centring.CentringMotor(
                     self.motor_hwobj_dict['phiy'],direction=-1)
        	self.centring_sampx=sample_centring.CentringMotor(
                     self.motor_hwobj_dict['sampx'])
        	self.centring_sampy=sample_centring.CentringMotor(\
                      self.motor_hwobj_dict['sampy'])
        except:
           pass # used the default value

        # Other parameters ---------------------------------------------------
        try:
            self.zoom_centre = eval(self.getProperty("zoom_centre"))
        except:
            if self.image_width is not None and self.image_height is not None:
                self.zoom_centre = {'x': self.image_width / 2,'y' : self.image_height / 2}
                self.beam_position = [self.image_width / 2, self.image_height / 2]
                logging.getLogger("HWR").warning("Diffractometer: Zoom center is " +\
                       "not defined. Continuing with the middle: %s" % self.zoom_centre)
            else:
                logging.getLogger("HWR").warning("Diffractometer: " + \
                   "Neither zoom centre nor camera size iz defined")

        self.reversing_rotation = self.getProperty("reversing_rotation")
        try:
            # grid_direction describes how a grid is collected
            # 'fast' is collection direction and 'slow' describes
            # move to the next collection line 
            self.grid_direction = eval(self.getProperty("grid_direction"))
        except:
            self.grid_direction = {"fast": (0, 1),
                                   "slow": (1, 0),
                                   "omega_ref" : 0}
            logging.getLogger("HWR").warning("Diffractometer: Grid " + \
                "direction is not defined. Using default.")

        try:
            self.phase_list = eval(self.getProperty("phase_list"))
        except:
            self.phase_list = [GenericDiffractometer.PHASE_TRANSFER,
                               GenericDiffractometer.PHASE_CENTRING,
                               GenericDiffractometer.PHASE_COLLECTION,
                               GenericDiffractometer.PHASE_BEAM]

        #Compatibility
        #TODO remove this
        self.getCentringStatus = self.get_centring_status

        self.getPositions = self.get_positions
        self.moveMotors = self.move_motors
        self.isReady = self.is_ready

   # to make it compatibile
    def __getattr__(self, attr):
        if attr.startswith("__"):
            raise AttributeError(attr)
        else:
            if attr == "currentCentringProcedure":
                return self.current_centring_procedure
            if attr == "centringStatus" :
                return self.centring_status
            if attr == "imageClicked":
                return self.image_clicked
            if attr == "cancelCentringMethod":
                return self.cancel_centring_method
            if attr == "pixelsPerMmY":
                return self.pixels_per_mm_x
            if attr == "pixelsPerMmZ":
                return self.pixels_per_mm_y
            return HardwareObject.__getattr__(self,attr)

    def is_ready(self):
        """
        Detects if device is ready
        """
        return self.current_state == DiffractometerState.tostring(\
                    DiffractometerState.Ready)

    def wait_device_ready(self, timeout=10):
        """ Waits when diffractometer status is ready:

        :param timeout: timeout in second
        :type timeout: int
        """
        with gevent.Timeout(timeout, Exception("Timeout waiting for device ready")):
            while not self.is_ready():
                gevent.sleep(0.01)

    def execute_server_task(self, method, timeout=30, *args):
        """Method is used to execute commands and wait till
           diffractometer is in ready state

        :param method: method to be executed
        :type method: instance
        :param timeout: timeout in seconds
        :type timeout: seconds 
        """
        self.ready_event.clear()
        self.current_state = DiffractometerState.tostring(\
            DiffractometerState.Busy)
        task_id = method(*args)
        self.wait_device_ready(timeout)
        self.ready_event.set()

    def in_plate_mode(self):
        """Returns True if diffractometer in plate mod

        :returns: boolean
        """
        return self.head_type == GenericDiffractometer.HEAD_TYPE_PLATE

    def get_head_type(self):
        """Returns head type

        :returns: string
        """
        return self.head_type

    def use_sample_changer(self):
        """Returns True if sample changer is in use

        :returns: boolean
        """
        return False

    def set_use_sc(self, flag):
        """Sets use_sc flag, that indicates if sample changer is used

        :param flag: use sample changer flag
        :type flag: boolean
        """
        if flag:
            # check both transfer_mode and sample_Changer
            if self.sample_changer is None:
                logging.getLogger("HWR").error("Diffractometer: Sample " + \
                        "Changer is not available")
                return False

            if self.transfer_mode is None or self.channel_dict['TransferMode'].getValue() == "SAMPLE_CHANGER":
                # if transferMode is not defined, ignore the checkup
                self.use_sc = True
            else:
                logging.getLogger("HWR").error("Diffractometer: Set the " + \
                       "diffractometer TransferMode to SAMPLE_CHANGER first!!")
                return False
        else:
            self.use_sc = False
        return True

    def transfer_mode_changed(self, transfer_mode):
        """
        Descript. :
        """
        logging.getLogger("HWR").info("current_transfer_mode is set to %s" % transfer_mode)
        self.transfer_mode = transfer_mode
        if transfer_mode != "SAMPLE_CHANGER":
            self.use_sc = False
        self.emit('minidiffTransferModeChanged', (transfer_mode, ))

    def get_transfer_mode(self):
        """
        """
        return self.transfer_mode

    def get_current_phase(self):
        """
        Descript. :
        """
        return self.current_phase

    def get_grid_direction(self):
        """
        Descript. :
        """
        return self.grid_direction

    def get_available_centring_methods(self):
        """
        Descript. :
        """
        return self.centring_methods.keys()

    def get_current_centring_method(self):
        """
        Descript. :
        """
        return self.current_centring_method

    def is_reversing_rotation(self):
        """
        """
        return self.reversing_rotation == True

    def beam_position_changed(self, value):
        """
        Descript. :
        """
        self.beam_position = list(value)

    #def get_motor_positions(self):
    #    return

    #TODO rename to get_motor_positions
    def get_positions(self):
        """
        Descript. :
        """

        self.current_motor_positions["beam_x"] = (self.beam_position[0] - \
             self.zoom_centre['x'] )/self.pixels_per_mm_y
        self.current_motor_positions["beam_y"] = (self.beam_position[1] - \
             self.zoom_centre['y'] )/self.pixels_per_mm_x
        return self.current_motor_positions

    def get_omega_position(self):
        """
        Descript. :
        """
        return self.current_positions_dict.get("phi")

    def get_snapshot(self):
        if self.camera_hwobj:
            return self.camera_hwobj.get_snapshot()

    def save_snapshot(self, filename):
        """
        """
        if self.camera_hwobj:
            return self.camera_hwobj.save_snapshot(filename)

    def get_pixels_per_mm(self):
        """
        Returns tuple with pixels_per_mm_x and pixels_per_mm_y

        :returns: list with two floats
        """
        return (self.pixels_per_mm_x, self.pixels_per_mm_y)

    def get_phase_list(self):
        """
        Returns list of available phases

        :returns: list with str
        """
        return self.phase_list

    def set_phase(self, phase_name, timeout=None):
        """
        """
        raise NotImplementedError

    def start_centring_method(self, method, sample_info=None, wait=False):
        """
        """

        if self.current_centring_method is not None:
            logging.getLogger("HWR").error("Diffractometer: already in centring method %s" %
                                     self.current_centring_method)
            return
        curr_time = time.strftime("%Y-%m-%d %H:%M:%S")
        self.centring_status = {"valid": False,
                                "startTime": curr_time,
                                "angleLimit": None}
        self.emit_centring_started(method)

        try:
            centring_method = self.centring_methods[method]
        except KeyError as diag:
            logging.getLogger("HWR").error("Diffractometer: unknown centring method (%s)" % str(diag))
            self.emit_centring_failed()
        else:
            try:
                centring_method(sample_info, wait_result=wait)
            except:
                logging.getLogger("HWR").exception("Diffractometer: problem while centring")
                self.emit_centring_failed()

    def cancel_centring_method(self, reject=False):
        """
        """

        if self.current_centring_procedure is not None:
            try:
                self.current_centring_procedure.kill()
            except:
                logging.getLogger("HWR").exception("Diffractometer: problem aborting the centring method")
            try:
                #TODO... do we need this at all?
                #fun = self.cancel_centring_methods[self.current_centring_method]
                pass
            except KeyError as diag:
                self.emit_centring_failed()
            else:
                try:
                    fun()
                except:
                    self.emit_centring_failed()
        else:
            self.emit_centring_failed()
        self.emit_progress_message("")
        if reject:
            self.reject_centring()

    def start_manual_centring(self, sample_info=None, wait_result=None):
        """
        """
        self.emit_progress_message("Manual 3 click centring...")
	if self.use_sample_centring:
            self.current_centring_procedure = \
                 sample_centring.start({"phi": self.centring_phi,
                                        "phiy": self.centring_phiy,
                                        "sampx": self.centring_sampx,
                                        "sampy": self.centring_sampy,
                                        "phiz": self.centring_phiz },
                                        self.pixels_per_mm_x,
                                        self.pixels_per_mm_y,
                                        self.beam_position[0],
                                        self.beam_position[1])
	else:
            self.current_centring_procedure = gevent.spawn(self.manual_centring)
        self.current_centring_procedure.link(self.centring_done)

    def start_automatic_centring(self, sample_info=None, loop_only=False, wait_result=None):
        """
        """
        self.emit_progress_message("Automatic centring...")
	if self.use_sample_centring:
            self.current_centring_procedure = \
                 sample_centring.start_auto(self.camera_hwobj,
                                            {"phi": self.centring_phi,
                                             "phiy": self.centring_phiy,
                                             "sampx": self.centring_sampx,
                                             "sampy": self.centring_sampy,
                                             "phiz": self.centring_phiz },
                                             self.pixels_per_mm_x,
                                             self.pixels_per_mm_y,
                                             self.beam_position[0],
                                             self.beam_position[1],
                                             msg_cb = self.emit_progress_message,
                                             new_point_cb=lambda point: self.emit("newAutomaticCentringPoint", point))
	else:
            self.current_centring_procedure = gevent.spawn(self.automatic_centring)
        self.current_centring_procedure.link(self.centring_done)

        if wait_result:
            self.ready_event.wait()
            self.ready_event.clear()

    def start_move_to_beam(self, coord_x=None, coord_y=None, omega=None, wait_result=None):
        """
        Descript. :
        """
        try:
            self.emit_progress_message("Move to beam...")
            self.centring_time = time.time()
            curr_time = time.strftime("%Y-%m-%d %H:%M:%S")
            self.centring_status = {"valid": True,
                                    "startTime": curr_time,
                                    "endTime": curr_time}
            if (coord_x is None and
                coord_y is None):
                coord_x = self.beam_position[0]
                coord_y = self.beam_position[1]

            motors = self.get_centred_point_from_coord(\
                  coord_x, coord_y, return_by_names=True)
            if omega is not None:
                motors["phi"] = omega

            self.centring_status["motors"] = motors
            self.centring_status["valid"] = True
            self.centring_status["angleLimit"] = True
            self.emit_progress_message("")
            self.accept_centring()
            self.current_centring_method = None
            self.current_centring_procedure = None
        except:
            logging.exception("Diffractometer: Could not complete 2D centring")

    def centring_done(self, centring_procedure):
        """
        Descript. :
        """
        try:
            motor_pos = centring_procedure.get()
            if isinstance(motor_pos, gevent.GreenletExit):
                raise motor_pos
        except:
            logging.exception("Could not complete centring")
            self.emit_centring_failed()
        else:
            self.emit_progress_message("Moving sample to centred position...")
            self.emit_centring_moving()
            try:
                self.move_to_motors_positions(motor_pos)
            except:
                logging.exception("Could not move to centred position")
                self.emit_centring_failed()
            else:
                #if 3 click centring move -180
                if not self.in_plate_mode():
                    self.motor_hwobj_dict['phi'].syncMoveRelative(-180)
            self.centring_time = time.time()
            self.emit_centring_successful()
            self.emit_progress_message("")
            self.ready_event.set()

    def manual_centring(self):
        """
        """
        raise NotImplementedError

    def automatic_centring(self):
        """
        """
        raise NotImplementedError

    def centring_motor_moved(self, pos):
        """
        """
        if time.time() - self.centring_time > 1.0:
            self.invalidate_centring()
        self.emit_diffractometer_moved()

    def invalidate_centring(self):
        """
        """
        if self.current_centring_procedure is None and self.centring_status["valid"]:
            self.centring_status={"valid":False}
            self.emit_progress_message("")
            self.emit('centringInvalid', ())

    def emit_diffractometer_moved(self, *args):
        """
        """
        self.emit("diffractometerMoved", ())

    def motor_positions_to_screen(self, centred_positions_dict):
        """
        """
        if self.use_sample_centring:
            self.update_zoom_calibration()
            if None in (self.pixels_per_mm_x, self.pixels_per_mm_y):
                return 0, 0
            phi_angle = math.radians(self.centring_phi.direction * \
                    self.centring_phi.getPosition())
            sampx = self.centring_sampx.direction * \
                    (centred_positions_dict["sampx"] - \
                     self.centring_sampx.getPosition())
            sampy = self.centring_sampy.direction * \
                    (centred_positions_dict["sampy"] - \
                     self.centring_sampy.getPosition())
            phiy = self.centring_phiy.direction * \
                   (centred_positions_dict["phiy"] - \
                    self.centring_phiy.getPosition())
            phiz = self.centring_phiz.direction * \
                   (centred_positions_dict["phiz"] - \
                    self.centring_phiz.getPosition())
            rot_matrix = numpy.matrix([math.cos(phi_angle), - \
                   math.sin(phi_angle), math.sin(phi_angle), \
                   math.cos(phi_angle)])
            rot_matrix.shape = (2, 2)
            inv_rot_matrix = numpy.array(rot_matrix.I)
            dx, dy = numpy.dot(numpy.array([sampx, sampy]), \
                   inv_rot_matrix)*self.pixels_per_mm_x

            x = (phiy * self.pixels_per_mm_x) + self.beam_position[0]
            y = dy + (phiz * self.pixels_per_mm_y) + self.beam_position[1]

            return x, y
        else:
            raise NotImplementedError

    def move_to_centred_position(self, centred_position):
        """
        """
        self.move_motors(centred_position)

    def move_to_motors_positions(self, motors_positions, wait = False):
        """
        """
        self.emit_progress_message("Moving to motors positions...")
        self.move_to_motors_positions_procedure = gevent.spawn(\
             self.move_motors, motors_positions)
        self.move_to_motors_positions_procedure.link(self.move_motors_done)
  
    def move_motors(self, motor_positions, timeout=15):
        """
        Moves diffractometer motors to the requested positions

        :param motors_dict: dictionary with motor names or hwobj 
                            and target values.
        :type motors_dict: dict
        """
        for motor in motor_positions.keys():
            position = motor_positions[motor]
            if type(motor) in (str, unicode):
                motor_role = motor
                motor = self.motor_hwobj_dict.get(motor_role)
                del motor_positions[motor_role]
                if None in (motor, position):
                    continue
                motor_positions[motor] = position
            motor.move(position)
        self.wait_device_ready(timeout)

    def move_motors_done(self, move_motors_procedure):
        """
        Descript. :
        """
        self.move_to_motors_positions_procedure = None
        self.emit_progress_message("")

    def move_to_beam(self, x, y, omega=None):
        """
        Descript. : function to create a centring point based on all motors
                    positions.
        """
        try:
            pos = self.get_centred_point_from_coord(x, y, return_by_names=False)
            if omega is not None:
                pos["phiMotor"] = omega
            self.move_to_motors_positions(pos)
        except:
            logging.getLogger("HWR").exception("Diffractometer: could not center to beam, aborting")

    def image_clicked(self, x, y, xi=None, yi=None):
        """
        Descript. :
        """
	if self.use_sample_centring:
   	    sample_centring.user_click(x,y)
	else:
            self.user_clicked_event.set((x, y))

    def accept_centring(self):
        """
        Descript. :
        Arg.      " fully_centred_point. True if 3 click centring
                    else False
        """
        self.centring_status["valid"] = True
        self.centring_status["accepted"] = True
        self.emit('centringAccepted', (True, self.get_centring_status()))

    def reject_centring(self):
        """
        Descript. :
        """
        if self.current_centring_procedure:
            self.current_centring_procedure.kill()
        self.centring_status = {"valid":False}
        self.emit_progress_message("")
        self.emit('centringAccepted', (False, self.get_centring_status()))

    def emit_centring_started(self, method):
        """
        Descript. :
        """
        self.current_centring_method = method
        self.emit('centringStarted', (method, False))

    def emit_centring_moving(self):
        """
        Descript. :
        """
        self.emit('centringMoving', ())

    def emit_centring_failed(self):
        """
        Descript. :
        """
        self.centring_status = {"valid": False}
        method = self.current_centring_method
        self.current_centring_method = None
        self.current_centring_procedure = None
        self.emit('centringFailed', (method, self.get_centring_status()))

    def emit_centring_successful(self):
        """
        Descript. :
        """
        if self.current_centring_procedure is not None:
            curr_time = time.strftime("%Y-%m-%d %H:%M:%S")
            self.centring_status["endTime"] = curr_time

            motor_pos = self.current_centring_procedure.get()
            self.centring_status["motors"] = self.convert_from_obj_to_name(motor_pos)
            self.centring_status["method"] = self.current_centring_method
            self.centring_status["valid"] = True

            method = self.current_centring_method
            self.emit('centringSuccessful', (method, self.get_centring_status()))
            self.current_centring_method = None
            self.current_centring_procedure = None
        else:
            logging.getLogger("HWR").debug("Diffractometer: Trying to emit " + \
                "centringSuccessful outside of a centring")

    def emit_progress_message(self, msg = None):
        """
        Descript. :
        """
        self.emit('progressMessage', (msg,))

    def get_centring_status(self):
        """
        Descript. :
        """
        return copy.deepcopy(self.centring_status)

    def get_centred_point_from_coord(self):
        """
        """
        raise NotImplementedError

    def get_point_between_two_points(self, point_one, point_two, frame_num, frame_total):
        """
        Method returns a centring point between two centring points
        It is used to get a position on a helical line based on
        frame number and total frame number
        """
        new_point = {}
        point_one = point_one.as_dict()
        point_two = point_two.as_dict()
        for motor in point_one.keys():
            new_motor_pos = frame_num / float(frame_total) * abs(point_one[motor] - \
                  point_two[motor]) + point_one[motor]
            new_motor_pos += 0.5 * (point_two[motor] - point_one[motor]) / \
                  frame_total
            new_point[motor] = new_motor_pos
        return new_point

    def convert_from_obj_to_name(self, motor_pos):
        """
        """
        motors = {}
        for motor_role in self.centring_motors_list:
            motor_obj = self.getObjectByRole(motor_role)
            try:
               motors[motor_role] = motor_pos[motor_obj]
            except KeyError:
               if motor_obj:
                   motors[motor_role] = motor_obj.getPosition()
        motors["beam_x"] = (self.beam_position[0] - \
                            self.zoom_centre['x'] )/self.pixels_per_mm_y
        motors["beam_y"] = (self.beam_position[1] - \
                            self.zoom_centre['y'] )/self.pixels_per_mm_x
        return motors

    def visual_align(self, point_1, point_2):
        """
        Descript. :
        """
        return

    def move_omega_relative(self, relative_angle):
        """
        Descript. :
        """
        return

    def get_scan_limits(self, speed=None):
        """
        Gets scan limits. Necessary for example in the plate mode
        where osc range is limited
        """
        return

    def set_phase(self, phase, timeout=None):
        """Sets diffractometer to selected phase
           By default available phase is Centring, BeamLocation, 
           DataCollection, Transfer

        :param phase: phase
        :type phase: string
        :param timeout: timeout in sec
        :type timeout: int
        """
        if timeout:
            self.ready_event.clear()
            set_phase_task = gevent.spawn(self.execute_server_task,
                                          self.command_dict["startSetPhase"],
                                          timeout,
                                          phase)
            self.ready_event.wait()
            self.ready_event.clear()
        else:
            self.command_dict["startSetPhase"](phase)

    def update_zoom_calibration(self):
        """
        """
        self.pixels_per_mm_x = 1.0/self.channel_dict["CoaxCamScaleX"].getValue()
        self.pixels_per_mm_y = 1.0/self.channel_dict["CoaxCamScaleY"].getValue()
        self.emit("pixelsPerMmChanged", ((self.pixels_per_mm_x, self.pixels_per_mm_y)))

    def zoom_motor_state_changed(self, state):
        """
        """
        self.emit('zoomMotorStateChanged', (state, ))
        self.emit('minidiffStateChanged', (state,))

    def zoom_motor_predefined_position_changed(self, position_name, offset):
        """
        """
        self.update_zoom_calibration()
        self.emit('zoomMotorPredefinedPositionChanged', (position_name, offset, ))

    def equipment_ready(self):
        """
        """
        self.emit('minidiffReady', ())

    def equipment_not_ready(self):
        """
        """
        self.emit('minidiffNotReady', ())

    def state_changed(self, state):
        """ 
        """
        self.current_state = state
        self.emit("minidiffStateChanged", (self.current_state))

    def motor_state_changed(self, state):
        """
        Descript. :
        """
        self.emit('minidiffStateChanged', (state, ))

    def current_phase_changed(self, current_phase):
        """
        Descript. :
        """
        self.current_phase = current_phase
        #logging.getLogger("HWR").info("Current_phase_changed to %s" % current_phase)
        self.emit('minidiffPhaseChanged', (current_phase, ))

    def sample_is_loaded_changed(self, sample_is_loaded):
        """
        Descript. :
        """
        self.sample_is_loaded = sample_is_loaded
        #logging.getLogger("HWR").info("sample is loaded changed %s" % sample_is_loaded)
        self.emit('minidiffSampleIsLoadedChanged', (sample_is_loaded, ))

    def head_type_changed(self, head_type):
        """
        Descript. :
        """
        self.head_type = head_type
        #logging.getLogger("HWR").info("new head type is %s" % head_type)
        self.emit('minidiffHeadTypeChanged', (head_type, ))

        if "SampleIsLoaded" not in str(self.used_channels_list):
           return
        try:
           self.disconnect(self.channel_dict["SampleIsLoaded"], "update", 
                           self.sample_is_loaded_changed)
        except:
           pass

        if head_type == GenericDiffractometer.HEAD_TYPE_MINIKAPPA or \
           head_type == GenericDiffractometer.HEAD_TYPE_SMARTMAGNET:
           self.connect(self.channel_dict["SampleIsLoaded"], "update", 
                        self.sample_is_loaded_changed)
        else:
           logging.getLogger("HWR").info("Diffractometer: SmartMagnet " + \
               "is not available, only works for Minikappa and SmartMagnet head")

    def move_kappa_and_phi(self, kappa, kappa_phi):
        return

    def close_kappa(self):
        """
        Descript. :
        """
        return

    def get_osc_dynamic_limits(self):
        return (-10000, 10000)

    def zoom_in(self):
        return

    def zoom_out(self):
        return