qtvcp issues

Traceback (most recent call last):
  File "/home/ilya/qt5-linuxcnc/lib/python/qtvcp/widgets/dialog_widget.py", line 245, in <lambda>
    STATUS.connect('load-file-request', lambda w: self.load_dialog())
  File "/home/ilya/qt5-linuxcnc/lib/python/qtvcp/widgets/dialog_widget.py", line 272, in load_dialog
    self.PREFS_.putpref('last_file_path', path, str, 'BOOK_KEEPING')
AttributeError: 'NoneType' object has no attribute 'putpref'

def test_button(self):
        name = self.w.sender().text()
        print name

    #######################
    # callbacks from form #
    #######################

........

###########################################
# **** instantiate functions section **** #
###########################################

X = Y = Z = Z_only = 0

def validation_qle(define): #delete invalid chars
    b = 0
    edited_text = ''
    chars = ['1','2','3','4','5','6','7','8','9','0','.']
    text = define.w.sender().text()
    if text != '':
        if text[0] == '.':
            text = '0.'
            define.w.sender().setText(text)
    for i in text:
        if i == '.':
            b += 1
        if i == '.' and b > 1:
            print 'more than one dot'
        elif i not in chars:
            print 'invalid simbol'
        else:
                edited_text += i
        define.w.sender().setText(edited_text)
        
def validation_qle_finished(define): #put zero in an empty line
    axis = define.w.sender().text()
    if axis == '':
        define.w.sender().setText('0')
        axis = 0
    axis = float(axis)
    return axis
        
def ok_for_mdi(define):
    define.stat.poll()
    return not define.stat.estop and define.stat.enabled and define.stat.homed and (define.stat.interp_state == linuxcnc.INTERP_IDLE)

###################################
# **** HANDLER CLASS SECTION **** #
###################################

class HandlerClass:

    ########################
    # **** INITIALIZE **** #
    ########################
    # widgets allows access to  widgets from the qtvcp files
    # at this point the widgets and hal pins are not instantiated
    def __init__(self, halcomp,widgets,paths):
        self.hal = halcomp
        self.lineEdit =  QtWidgets.QLineEdit()
        self.w = widgets
        self.stat = linuxcnc.stat()
        self.cmnd = linuxcnc.command()
        self.error = linuxcnc.error_channel()
        self.PATH = paths.CONFIGPATH
        self.IMAGE_PATH = paths.IMAGEDIR
        self.STYLE = Styles(widgets, paths)

    ##########################################
    # Special Functions called from QTSCREEN
    ##########################################

    # at this point:
    # the widgets are instantiated.
    # the HAL pins are built but HAL is not set ready
    def initialized__(self):
        # Give notify library a reference to the statusbar
        STATUS.forced_update()
        # set custom theme
        #self.STYLE.dark_style()
        #self.STYLE.bright_style()
        self.STYLE.gorelovskiy_style()
        KEYBIND.add_call('Key_F3','on_keycall_F3')
        KEYBIND.add_call('Key_F4','on_keycall_F4')
        KEYBIND.add_call('Key_F5','on_keycall_F5')

    def processed_key_event__(self,receiver,event,is_pressed,key,code,shift,cntrl):
        # when typing in MDI, we don't want keybinding to call functions
        # so we catch and process the events directly.
        # We do want ESC, F1 and F2 to call keybinding functions though
        if code not in(QtCore.Qt.Key_Escape,QtCore.Qt.Key_F1 ,QtCore.Qt.Key_F2,
                    QtCore.Qt.Key_F3,QtCore.Qt.Key_F5,QtCore.Qt.Key_F5):
            if isinstance(receiver, OFFVIEW_WIDGET) or isinstance(receiver, MDI_WIDGET):
                if is_pressed:
                    receiver.keyPressEvent(event)
                    event.accept()
                return True
            if isinstance(receiver,QtWidgets.QDialog):
                print 'dialog'
                return True
        try:
            KEYBIND.call(self,event,is_pressed,shift,cntrl)
            return True
        except Exception as e:
            #log.debug('Exception loading Macros:', exc_info=e)
            print 'Error in, or no function for: %s in handler file for-%s'%(KEYBIND.convert(event),key)
            if e:
                print e
            #print 'from %s'% receiver
            return False

    ########################
    # callbacks from STATUS #
    ########################


    #######################
    # callbacks from form #
    #######################
    def edited_z_only(self):
        validation_qle(self)    
    def edited_x(self):
        validation_qle(self)
    def edited_y(self):
        validation_qle(self)        
    def edited_z(self):
        validation_qle(self)

    def editingFinished_Z_only(self):
        global Z_only
        Z_only = validation_qle_finished(self)        
    def editingFinished_X(self):
        global X
        X = validation_qle_finished(self)        
    def editingFinished_Y(self):
        global Y
        Y = validation_qle_finished(self)        
    def editingFinished_Z(self):
        global Z
        Z = validation_qle_finished(self)
        
    def mdi_parking(self):
        if ok_for_mdi(self):            
            self.cmnd.mode(linuxcnc.MODE_MDI)
            self.cmnd.wait_complete() # wait until mode switch executed
            self.cmnd.mdi("G0 Z%f" % Z)
            self.cmnd.mdi("G0 X%f Y%f" % (X, Y))            
    def parking_Z_Button(self):
        if ok_for_mdi(self):            
            self.cmnd.mode(linuxcnc.MODE_MDI)
            self.cmnd.wait_complete() # wait until mode switch executed
            self.cmnd.mdi("G0 Z%f" % Z_only)

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