Look at https://www.youtube.com/watch?v=RxqZ_2fz-ZI
My speculation: you did not structure correctly your application.
Look at video 4 and 5 and you will understand how to structure.
a) python file creation with import at the top. so call it application.py and include
import gi
#
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk as gtk, Gdk as gdk, GLib, GObject as gobject
gobject.threads_init()
import string  # not used for now
import os  # not used for now
from datetime import datetime, timedelta
import time
import threading..
b) class GUI (called "foo" in the video) hereunder called GUIclass
c) several def linked to the glade file within that class
d) init with import of the glade file
e) main
see few extracts below. look at few applications done with glade / pygtk on github.
class GUIclass:
    #
def exit_action(self, widget, data=None):
 self.exitdialog.show()
def exit_confirmed(self, widget, data=None):
 self.exitdialog.hide()
 game_not_cancelled = False
 ...
 gtk.main_quit()
 return True
def exit_aborted(self, widget, data=None):
    self.exitdialog.hide()
def watch_stop_yes(self, widget, data=None):
#
def deactivate_event_mode(self, widget, data=None):
   ...
def __init__(self):
    ...
    number_of_period = 2
    watch_stop_default = True
    add_time_seconds = 0
    #
    # define all relations between labels and entries and combobox and spinbutton and python variables
    builder = gtk.Builder()
    builder.add_from_file("/home/family/glade/scoreboard_uwr_180815.glade")
    #
    # load all windows
    self.controlwindow = builder.get_object("scoreboard_control_window")
    self.viewwindow = builder.get_object("scoreboard_view_window")
    self.logdialog = builder.get_object("scoreboard_log_dialog")
    self.logoffdialog = builder.get_object("scoreboard_logoff_confirm")
    self.logcanceldialog = builder.get_object("scoreboard_logcancel_confirm")
    self.resetdialog = builder.get_object("scoreboard_resetconfirm")
    self.exitdialog = builder.get_object("scoreboard_exitconfirm")
    #
    # declaration of all data from the "scoreboard_control_window"
    self.spinbutton_points_team_left = builder.get_object("spinbutton_points_team_left")
    self.spinbutton_points_team_right = builder.get_object("spinbutton_points_team_right")
    self.spinbutton_timeout_left = builder.get_object("spinbutton_timeout_left")
    self.spinbutton_timeout_right = builder.get_object("spinbutton_timeout_right")
    self.spinbutton_period_time = builder.get_object("spinbutton_period_time")
    self.spinbutton_period = builder.get_object("spinbutton_period")
    self.spinbutton_break_time = builder.get_object("spinbutton_break_time")
    self.spinbutton_penalty_duration = builder.get_object("spinbutton_penalty_duration")
    self.spinbutton_timeout = builder.get_object("spinbutton_timeout")
    self.spinbutton_time_penalty = builder.get_object("spinbutton_time_penalty")
    self.spinbutton_add_time = builder.get_object("spinbutton_add_time")
    self.spinbutton_warning_timepenalty = builder.get_object("spinbutton_warning_timepenalty")
    self.spinbutton_warning_break_timeout = builder.get_object("spinbutton_warning_break_timeout")
    #
    self.togglebutton_start_stop_game = builder.get_object("togglebutton_start_stop_game")
    #        self.comboboxtext_watch_stop = builder.get_object("comboboxtext_watch_stop")
    self.entry_tournament_name = builder.get_object("entry_tournament_name")
    self.entry_tournament_contact = builder.get_object("entry_tournament_contact")
    self.entry_team_blue_name = builder.get_object("entry_team_blue_name")
    self.entry_team_white_name = builder.get_object("entry_team_white_name")
    self.entry_name_penalty_player_1_left = builder.get_object("entry_name_penalty_player_1_left")
    self.entry_name_penalty_player_2_left = builder.get_object("entry_name_penalty_player_2_left")
    self.entry_name_penalty_player_3_left = builder.get_object("entry_name_penalty_player_3_left")
    self.entry_name_penalty_player_1_right = builder.get_object("entry_name_penalty_player_1_right")
    self.entry_name_penalty_player_2_right = builder.get_object("entry_name_penalty_player_2_right")
    self.entry_name_penalty_player_3_right = builder.get_object("entry_name_penalty_player_3_right")
    # define here further entries
    #
    self.label_control_current_time = builder.get_object("label_control_current_time")
    self.eventbox_control_left = builder.get_object("eventbox_control_left")
    #        self.eventbox_blue_team = builder.get_object("eventbox_blue_team")
    self.label_control_team_name_left = builder.get_object("label_control_team_name_left")
    self.eventbox_control_right = builder.get_object("eventbox_control_right")
    self.label_control_team_name_right = builder.get_object("label_control_team_name_right")
    self.label_control_tournament_name = builder.get_object("label_control_tournament_name")
    self.label_control_tournament_contact = builder.get_object("label_control_tournament_contact")
    self.spinbutton_minutes_time_correction = builder.get_object("spinbutton_minutes_time_correction")
    self.spinbutton_seconds_time_correction = builder.get_object("spinbutton_seconds_time_correction")
    #        self.label_special_time_sequence = builder.get_object("label_special_time_sequence")
    #
    self.label_control_time_penalty_player_1_left = builder.get_object("label_control_time_penalty_player_1_left")
    self.label_control_time_penalty_player_2_left = builder.get_object("label_control_time_penalty_player_2_left")
    self.label_control_time_penalty_player_3_left = builder.get_object("label_control_time_penalty_player_3_left")
    self.label_control_time_penalty_player_1_right = builder.get_object("label_control_time_penalty_player_1_right")
    self.label_control_time_penalty_player_2_right = builder.get_object("label_control_time_penalty_player_2_right")
    self.label_control_time_penalty_player_3_right = builder.get_object("label_control_time_penalty_player_3_right")
    #
    #        self.label_timeout = builder.get_object("label_timeout")
    #        self.label_break = builder.get_object("label_break")
    #        self.label_penalty = builder.get_object("label_penalty")
    #
    self.spinbutton_points_team_left = builder.get_object("spinbutton_points_team_left")
    self.spinbutton_points_team_right = builder.get_object("spinbutton_points_team_right")
    self.eventbox_control_points_team_left = builder.get_object("eventbox_control_points_team_left")
    self.eventbox_control_points_team_right = builder.get_object("eventbox_control_points_team_right")
    self.label_control_points_team_left = builder.get_object("label_control_points_team_left")
    self.label_control_points_team_right = builder.get_object("label_control_points_team_right")
    self.label_control_special_time_sequence = builder.get_object("label_control_special_time_sequence")
    self.eventbox_control_team_name_left = builder.get_object("eventbox_control_team_name_left")
    self.eventbox_control_team_name_right = builder.get_object("eventbox_control_team_name_right")
    #
    # declaration of all data from the view window
    self.eventbox_view_team_color_left = builder.get_object("eventbox_view_team_color_left")
    self.eventbox_view_team_color_right = builder.get_object("eventbox_view_team_color_right")
    self.eventbox_view_points_team_left = builder.get_object("eventbox_view_points_team_left")
    self.eventbox_view_points_team_right = builder.get_object("eventbox_view_points_team_right")
    self.label_view_period = builder.get_object("label_view_period")
    self.label_view_current_time = builder.get_object("label_view_current_time")
    self.label_view_points_team_left = builder.get_object("label_view_points_team_left")
    self.label_view_timeout_left = builder.get_object("label_view_timeout_left")
    self.label_view_timeout_right = builder.get_object("label_view_timeout_right")
    self.label_view_points_team_right = builder.get_object("label_view_points_team_right")
    self.eventbox_view_team_color_left = builder.get_object("eventbox_view_team_color_left")
    self.eventbox_view_team_color_right = builder.get_object("eventbox_view_team_color_right")
    self.label_view_team_name_left = builder.get_object("label_view_team_name_left")
    self.label_view_team_name_right = builder.get_object("label_view_team_name_right")
    self.eventbox_view_team_name_left = builder.get_object("eventbox_view_team_name_left")
    self.eventbox_view_team_name_right = builder.get_object("eventbox_view_team_name_right")
    self.label_view_tournament_name = builder.get_object("label_view_tournament_name")
    self.label_view_tournament_contact = builder.get_object("label_view_tournament_contact")
    self.label_view_specific_timesequence = builder.get_object("label_view_specific_timesequence")
    self.label_view_status_specific_timesequence = builder.get_object("label_view_status_specific_timesequence")
    self.label_view_special_time_sequence = builder.get_object("label_view_special_time_sequence")
    self.label_view_time_penalty_player_1_left = builder.get_object("label_view_time_penalty_player_1_left")
    self.label_view_time_penalty_player_2_left = builder.get_object("label_view_time_penalty_player_2_left")
    self.label_view_time_penalty_player_3_left = builder.get_object("label_view_time_penalty_player_3_left")
    self.label_view_time_penalty_player_1_right = builder.get_object("label_view_time_penalty_player_1_right")
    self.label_view_time_penalty_player_2_right = builder.get_object("label_view_time_penalty_player_2_right")
    self.label_view_time_penalty_player_3_right = builder.get_object("label_view_time_penalty_player_3_right")
    #
    self.label_view_name_penalty_player_1_left = builder.get_object("label_view_name_penalty_player_1_left")
    self.label_view_name_penalty_player_2_left = builder.get_object("label_view_name_penalty_player_2_left")
    self.label_view_name_penalty_player_3_left = builder.get_object("label_view_name_penalty_player_3_left")
    self.label_view_name_penalty_player_1_right = builder.get_object("label_view_name_penalty_player_1_right")
    self.label_view_name_penalty_player_2_right = builder.get_object("label_view_name_penalty_player_2_right")
    self.label_view_name_penalty_player_3_right = builder.get_object("label_view_name_penalty_player_3_right")
    #
    self.button_blue_starts_left = builder.get_object("button_blue_starts_left")
    self.button_blue_starts_right = builder.get_object("button_blue_starts_right")
    self.button_type_view_invertedcontrolview = builder.get_object("button_type_view_invertedcontrolview")
    self.button_type_view_copycontrolview = builder.get_object("button_type_view_copycontrolview")
    self.button_separate_game_view_off = builder.get_object("button_separate_game_view_off")
    self.button_separate_game_view_on = builder.get_object("button_separate_game_view_on")
    self.button_log_functionality_off = builder.get_object("button_log_functionality_off")
    self.button_log_functionality_on = builder.get_object("button_log_functionality_on")
    self.entry_log_filename = builder.get_object("entry_log_filename")
    self.button_nostop_watch = builder.get_object("button_nostop_watch")
    self.button_stop_watch = builder.get_object("button_stop_watch")
    self.button_activate_timepenalty_player_1_left = builder.get_object("button_activate_timepenalty_player_1_left")
    self.button_activate_timepenalty_player_2_left = builder.get_object("button_activate_timepenalty_player_2_left")
    self.button_activate_timepenalty_player_3_left = builder.get_object("button_activate_timepenalty_player_3_left")
    self.button_activate_timepenalty_player_1_right = builder.get_object(
        "button_activate_timepenalty_player_1_right")
    self.button_activate_timepenalty_player_2_right = builder.get_object(
        "button_activate_timepenalty_player_2_right")
    self.button_activate_timepenalty_player_3_right = builder.get_object(
        "button_activate_timepenalty_player_3_right")
    self.button_clear_timepenalty_player_1_left = builder.get_object("button_clear_timepenalty_player_1_left")
    self.button_clear_timepenalty_player_2_left = builder.get_object("button_clear_timepenalty_player_2_left")
    self.button_clear_timepenalty_player_3_left = builder.get_object("button_clear_timepenalty_player_3_left")
    self.button_clear_timepenalty_player_1_right = builder.get_object("button_clear_timepenalty_player_1_right")
    self.button_clear_timepenalty_player_2_right = builder.get_object("button_clear_timepenalty_player_2_right")
    self.button_clear_timepenalty_player_3_right = builder.get_object("button_clear_timepenalty_player_3_right")
    self.button_stop_special_time_sequence = builder.get_object("button_stop_special_time_sequence")
    self.button_start_special_time_sequence = builder.get_object("button_start_special_time_sequence")
    self.button_clearreset_special_time_sequence = builder.get_object("button_clearreset_special_time_sequence")
    self.button_special_time_sequence_none = builder.get_object("button_special_time_sequence_none")
    self.button_special_time_sequence_timeout = builder.get_object("button_special_time_sequence_timeout")
    self.button_special_time_sequence_break = builder.get_object("button_special_time_sequence_break")
    self.button_special_time_sequence_penalty = builder.get_object("button_special_time_sequence_penalty")
    #
    self.ChooserButton_read_file_settings = builder.get_object("ChooserButton_read_file_settings")
    #
    self.label_log_dialog_time = builder.get_object("label_log_dialog_time")
    self.entry_log_dialog_remark_referee = builder.get_object("entry_log_dialog_remark_referee")
    self.entry_log_dialog_remark_scripter = builder.get_object("entry_log_dialog_remark_scripter")
    ##################################
    #   INIT the matrix of all inputs
    #
    col = 14
    row = 10
    logdata_array = [[""] * col for _ in range(row)]
    #neutralarrayline = ["","","","","","","","","","","","","",""]
    #logdata_array = []
    #for i in range(9):
    #    logdata_array.append(neutralarrayline)
    self.entry_logarray = []
    for i in range(10):
        self.entry_logarray.append([])
        for j in range(14):
            self.entry_logarray[i].append([])
            stringglade = str('%(prefix)s%(line)02d_%(column)02d'%{'prefix': "ld", 'line': i, 'column': j})
            #print(stringglade)
            #"ld"+str(i)+"_"+str(j)
            self.entry_logarray[i][j] = builder.get_object(stringglade)
    ##################################
    #self.entry_log_dialog_remark_equipment = builder.get_object("entry_log_dialog_remark_equipment")
    self.entry_anytime_line1intolog = builder.get_object("entry_anytime_line1intolog")
    self.entry_anytime_line2intolog = builder.get_object("entry_anytime_line2intolog")
    self.eventbox_exitbutton = builder.get_object("eventbox_exitbutton")
    self.eventbox_resetbutton = builder.get_object("eventbox_resetbutton")
    self.button_exit_view_window = builder.get_object("button_exit_view_window")
    #
    # connect all signals to actions
    builder.connect_signals(self)
    thread_time_control.connect("update_timers", self.update_timer_labels)
    #
    #        GDK_Escape = 0xff1b
    buffer_time_start_special_time_sequence = datetime.now()
    #
    # datetime data useful for elapsed time calculation and later for log / protocol
    start_time_of_the_game = datetime.now()
    start_time_control_timepenalty_player1_left = datetime.now()
    start_time_control_timepenalty_player2_left = datetime.now()
    start_time_control_timepenalty_player3_left = datetime.now()
    start_time_control_timepenalty_player1_right = datetime.now()
    start_time_control_timepenalty_player2_right = datetime.now()
    start_time_control_timepenalty_player3_right = datetime.now()
    start_time_of_second_period = datetime.now()
    end_time_of_the_game = datetime.now()  # usefull for log / protocol
    # for running time calculation of the main time counting
    buffer_last_time_stop = datetime.now()
    buffer_last_time_stop_control_timepenalty_player1_left = datetime.now()
    buffer_last_time_stop_control_timepenalty_player2_left = datetime.now()
    buffer_last_time_stop_control_timepenalty_player3_left = datetime.now()
    buffer_last_time_stop_control_timepenalty_player1_right = datetime.now()
    buffer_last_time_stop_control_timepenalty_player2_right = datetime.now()
    buffer_last_time_stop_control_timepenalty_player3_right = datetime.now()
    buffer_last_time_start = datetime.now()
    buffer_last_time_start_control_timepenalty_player1_left = datetime.now()
    buffer_last_time_start_control_timepenalty_player2_left = datetime.now()
    buffer_last_time_start_control_timepenalty_player3_left = datetime.now()
    buffer_last_time_start_control_timepenalty_player1_right = datetime.now()
    buffer_last_time_start_control_timepenalty_player2_right = datetime.now()
    buffer_last_time_start_control_timepenalty_player3_right = datetime.now()
    #
    # SEVERAL global parameters and stopwatches to be defined
    #       FIRST for period time downcounting
    #       SECOND for special_time_sequence
    #       3 for the time penalty players left
    #       3 for the time penalty players right
    #
    ellapsed_period_time_seconds = 0
    buffer_last_started_ellapsed_period_time_seconds = 0
    period_time_in_second = 15 * 60
    period_time_in_second_orig = 15*60
    counter_seconds_board = 15 * 60
    warning_timepenalty = warning_default_timepenalty
    warning_break_timeout = warning_default_break_timeout
    #
    # diverse parameter of special_time_sequence
    timepenalty_maximum_seconds = 120
    penalty_maximum_seconds = 45
    timeout_maximum_seconds = 1 * 60
    break_maximum_seconds = 300
    ellapsed_special_time_sequence_seconds = 0
    counter_seconds_special_time_sequence = 0
    ellapsed_maximum_time_special_sequence_seconds = 300
    #
    ellapsed_time_penalty_player_1_left_seconds = 0
    buffer_last_started_ellapsed_time_penalty_player_1_left_seconds = 0
    counter_seconds_time_penalty_player_1_left = 0
    #
    ellapsed_time_penalty_player_2_left_seconds = 0
    buffer_last_started_ellapsed_time_penalty_player_2_left_seconds = 0
    counter_seconds_time_penalty_player_2_left = 0
    #
    ellapsed_time_penalty_player_3_left_seconds = 0
    buffer_last_started_ellapsed_time_penalty_player_3_left_seconds = 0
    counter_seconds_time_penalty_player_3_left = 0
    #
    ellapsed_time_penalty_player_1_right_seconds = 0
    buffer_last_started_ellapsed_time_penalty_player_1_right_seconds = 0
    counter_seconds_time_penalty_player_1_right = 0
    #
    ellapsed_time_penalty_player_2_right_seconds = 0
    buffer_last_started_ellapsed_time_penalty_player_2_right_seconds = 0
    counter_seconds_time_penalty_player_2_right = 0
    #
    ellapsed_time_penalty_player_3_right_seconds = 0
    buffer_last_started_ellapsed_time_penalty_player_3_right_seconds = 0
    counter_seconds_time_penalty_player_3_right = 0
    #
    activated_time_penalty_player_1_left_to_enter_or_delete = False
    activated_time_penalty_player_2_left_to_enter_or_delete = False
    activated_time_penalty_player_3_left_to_enter_or_delete = False
    activated_time_penalty_player_1_right_to_enter_or_delete = False
    activated_time_penalty_player_2_right_to_enter_or_delete = False
    activated_time_penalty_player_3_right_to_enter_or_delete = False
    #
    time_penalty_player_1_left_initialized = False
    time_penalty_player_1_right_initialized = False
    time_penalty_player_2_left_initialized = False
    time_penalty_player_2_right_initialized = False
    time_penalty_player_3_left_initialized = False
    time_penalty_player_3_right_initialized = False
    #
    # diverse helpfull match status or timing
    game_started = False
    action_start_time_of_the_game_is_ACTIVE = False  # toggle button start / stop of the overall timing
    running_period_time = False
    running_first_period_time = False
    running_second_period_time = False
    running_penalty = False
    running_timeout = False
    running_break = False
    stopped_special_time_sequence = False
    # basic setup of team name
    left_team_is_blue = True  # at application start
    #
    running_time_penalty_player_1_left = False
    running_time_penalty_player_2_left = False
    running_time_penalty_player_3_left = False
    running_time_penalty_player_1_right = False
    running_time_penalty_player_2_right = False
    running_time_penalty_player_3_right = False
    #
    # buffer for switching the results from right to left in the score viewer
    buffer_counter_minutes_time_penalty_player_1 = 0
    buffer_counter_seconds_time_penalty_player_1 = 0
    buffer_counter_minutes_time_penalty_player_2 = 0
    buffer_counter_seconds_time_penalty_player_2 = 0
    buffer_counter_minutes_time_penalty_player_3 = 0
    buffer_counter_seconds_time_penalty_player_3 = 0
    buffer_running_time_penalty_player_1_left = False
    buffer_running_time_penalty_player_2_left = False
    buffer_running_time_penalty_player_3_left = False
    buffer_points_team = 0
    ################################
    # right is white background (and black letter)
    self.eventbox_control_right.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 1, 1, 1))
    self.eventbox_view_team_color_right.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 1, 1, 1))
    # right point area white
    self.eventbox_control_points_team_right.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 1, 1, 1))
    self.eventbox_view_points_team_right.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 1, 1, 1))
    self.eventbox_control_team_name_right.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 1, 1, 1))
    self.eventbox_view_team_name_right.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 1, 1, 1))
    # right letters of points black in white team
    self.label_control_points_team_right.override_color(gtk.StateFlags.NORMAL, gdk.RGBA(0, 0, 0, 1))
    self.label_view_points_team_right.override_color(gtk.StateFlags.NORMAL, gdk.RGBA(0, 0, 0, 1))
    self.label_control_team_name_right.override_color(gtk.StateFlags.NORMAL, gdk.RGBA(0, 0, 0, 1))
    self.label_view_team_name_right.override_color(gtk.StateFlags.NORMAL, gdk.RGBA(0, 0, 0, 1))
    #
    # left point area blue
    self.eventbox_control_left.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(0, 0, 1, 1))
    self.eventbox_view_team_color_left.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(0, 0, 1, 1))
    self.eventbox_control_points_team_left.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(0, 0, 1, 1))
    self.eventbox_view_points_team_left.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(0, 0, 1, 1))
    # left letters of points white in blue team
    self.label_control_points_team_left.override_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 1, 1, 1))
    self.label_view_points_team_left.override_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 1, 1, 1))
    self.eventbox_control_team_name_left.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(0, 0, 1, 1))
    self.eventbox_view_team_name_left.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(0, 0, 1, 1))
    self.label_control_team_name_left.override_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 1, 1, 1))
    self.label_view_team_name_left.override_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 1, 1, 1))
    #
    #
    self.entry_tournament_name.set_text("tournament")
    self.label_control_tournament_name.set_text("tournament")
    self.label_view_tournament_name.set_text("tournament")
    #
    self.entry_tournament_contact.set_text("Ms./Mr.")
    self.label_control_tournament_contact.set_text("Ms./Mr.")
    self.label_view_tournament_contact.set_text("Ms./Mr.")
    #
    self.entry_team_blue_name.set_text("TeamBLUE")
    self.label_control_team_name_left.set_text("TeamBLUE")
    self.label_view_team_name_left.set_text("Team BLUE")
    #
    self.entry_team_white_name.set_text("TeamWHITE")
    self.label_control_team_name_right.set_text("TeamWHITE")
    self.label_view_team_name_right.set_text("Team WHITE")
    #
    # make exit button for red
    self.eventbox_exitbutton.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 0, 0, 1))
    #
    # orange https://en.wikipedia.org/wiki/X11_color_names test rgb  100%  65%  0%
    self.eventbox_resetbutton.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 0.65, 0, 1))
    # make reset button for red
    # self.eventbox_resetbutton.override_background_color(gtk.StateFlags.NORMAL, gdk.RGBA(1, 0, 0, 1))
    self.label_control_special_time_sequence.set_text("none")
    #
    style_provider = gtk.CssProvider()
    ############################################################################################
    ############################################################################################
    #
    # modify that link below at a new installation
    #
    ############################################################################################
    css = open('/home/family/glade/scoreboard_uwr/scoreboard_gui_styles.css',
               'rb')  # rb needed for python 3 support
    ############################################################################################
    ############################################################################################
    css_data = css.read()
    css.close()
    style_provider.load_from_data(css_data)
    gtk.StyleContext.add_provider_for_screen(gdk.Screen.get_default(), style_provider,
                                             gtk.STYLE_PROVIDER_PRIORITY_APPLICATION)
if __name__ == "__main__":
    GUI = GUIclass()
    GUI.controlwindow.show()
    gtk.main()