text: import kivy
  
   
  from kivy.app import App
  from kivy.lang import Builder
  from kivy.uix.screenmanager import ScreenManager, Screen
  from kivy.config import Config
  from kivy.uix.behaviors import ButtonBehavior  
  from kivy.uix.image import Image
  
  
  Config.set('graphics', 'width', '400')
  Config.set('graphics', 'height', '791')
  
  # load file from kv file
  Builder.load_file('./kivycss.kv')
  # The Properties classes are used 
  # when you create an EventDispatcher. 
  from kivy.properties import NumericProperty
  from kivy.garden.graph import MeshLinePlot
    
  # BoxLayout arranges children in a vertical or horizontal box.  
  # or help to put the children at the desired location.  
    
  # he Clock object allows you to 
  # schedule a function call in the future 
  from kivy.clock import Clock 
  class ScreenHOME(Screen):
      pass
  
   
  class ScreenDATA(Screen):
      def update(self):
          # plot graph
          pass
      
  
  
  class ScreenREPAIR(Screen):
      number = NumericProperty()
      def start(self): 
            
          Clock.unschedule(self.increment_time)
          # increament tiem every num seconds now is one second for test purpose
          Clock.schedule_interval(self.increment_time, 1)
      def increment_time(self, interval): 
          self.number += 1
  
  
    
  
  
  # class ScreenButton(Button):
  #     screenmanager = ObjectProperty()
  #     def on_press(self, *args):
  #         super(ScreenButton, self).on_press(*args)
  #         self.screenmanager.current = 'whatever'
   
  # The ScreenManager controls moving between screens
  screen_manager = ScreenManager()
   
  # Add the screens to the manager and then supply a name
  # that is used to switch screens
  screen_manager.add_widget(ScreenHOME(name="screen_home"))
  screen_manager.add_widget(ScreenDATA(name="screen_data"))
  screen_manager.add_widget(ScreenREPAIR(name="screen_repair"))
   
  class KivyTut2App(App):
   
      def build(self):
          return screen_manager
      
   
  sample_app = KivyTut2App()
  sample_app.run()
  