the whole thing

main.py

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.graphics import Color, Ellipse, Line
from kivy.graphics.instructions import Callback
from kivy.uix.boxlayout import BoxLayout
from kivy.core.window import Window
from kivy.interactive import InteractiveLauncher
from kivy.properties import NumericProperty
from kivy.event import EventDispatcher


import random

framePoints = [150, 250, 750, 250, 750, 600, 150, 600, 150, 250]
CIRCLEPOSITIONS = ([200,300],[350,300],[500,300],[650,300],[200,400],[350,400],[500,400],[650,400],[200,500],[350,500],[500,500],[650,500])
CIRCLESIZE = 80

RED = (0.3,0.3,0.3)
BLUE = (.6, .8, .6)
WHITE = (1,1,1)

NTRIALS = 12

itemGroups = {'YN': [[['T','TICK'],['T','POCK'],['Z','TICK'],['Z','POCK'],['M','TICK'],['M','POCK']],[['T','TICK'],['T','POCK'],['Z','TICK'],['Z','POCK'],['M','TICK'],['M','POCK']]]}


class Circles:

    def __init__(self, posx, posy, color):
        self.x = posx
        self.y = posy
        self.col = color


class Configuration:

    def __init__(self, nred = 6, nblue = 6):
        self.nred = nred
        self.nblue = nblue
        self.circles = []
        self.setupConf()

    def setupConf(self):

        circlePosz = list(CIRCLEPOSITIONS)

        for i in range(0,self.nred):
            coord = circlePosz.pop(0)
            self.circles.append(Circles(coord[0],coord[1],RED))

        for i in range(0,self.nblue):
            coord = circlePosz.pop(0)
            self.circles.append(Circles(coord[0],coord[1],BLUE))

class Trials:

    def __init__(self):
        self.setup = None
        self.question = None
        self.ans = None
        self.time = None

    def evaluate (self, answer):
        return True


   

class Session:

    def __init__(self, tyype, number):
        self.tyype = tyype
        self.number = number
        self.trials = []
        self.makeSession()

    def makeSession(self):

        for group in itemGroups[self.tyype]:

            random.shuffle(group)
            for tr in group:

                if tr[0] == 'T': nred = 12
                if tr[0] == 'Z': nred = 0
                if tr[0] == 'M': nred = random.randint(4,8)

                thisTrial = Trials()
                thisTrial.setup = Configuration(nred,12-nred)
                thisTrial.question = tr[1]
                self.trials.append(thisTrial)	






# if self.tyype == 'YN':

# if self.tyype == 'COMPARISON':



class EventHandler(Widget):
    trialDisplayed = NumericProperty(0)
  
    def __init__(self, **kwargs):
        super(EventHandler, self).__init__(**kwargs)
        Window.bind(on_key_down=self.on_key)
           
    def on_key(self, keycode, *args):
#        print args[2]
        if args[2] in ['m','z']:
            self.trialDisplayed += 1
            print self.trialDisplayed
            

events = EventHandler()



class DisplayWidget(Widget):
  
  
    def __init__(self, frame, trials, **kwargs):
        super(DisplayWidget, self).__init__(**kwargs)
        self.trials = trials
        self.frame = frame
# Window.clearcolor = (0.1, 0.1, 0.1, 1.)
        self.update_drawing()

    def update_drawing(self):
        self.canvas.clear()
        with self.canvas:
        
            Color(*WHITE)
            Line(points=self.frame, width=2.5)
            
            self.ntrial = events.trialDisplayed
            events.bind(trialDisplayed=self.callcall)

# I want to redraw the circle after having changed self.ntrial 

                                                                
            for circle in self.trials[self.ntrial].setup.circles:
                Color(*circle.col)
                d = CIRCLESIZE
                Ellipse(pos=(circle.x , circle.y), size=(d, d))
                self.cb = Callback(self.my_callback)
                                

    def my_callback (self, instr):
        print 'called'
    
    def callcall (self, *args):
        self.ntrial = events.trialDisplayed
        self.update_drawing()


class TiktokApp(App):


    def build(self):	

        self.session = Session('YN',1)
        layout = BoxLayout(orientation='vertical')        
        display = DisplayWidget(frame=framePoints,trials=self.session.trials)
        text = Label(text=self.session.trials[0].question + ' cercles sont rouges')
        layout.add_widget(display)
        layout.add_widget(text)
              
        return layout

    		

    def build_config(self, config):
        config.setdefaults('graphics', {
            'width': '1280',
            'height': '1024'
        })
        

        



if __name__ == '__main__':
    TiktokApp().run()