StringProperty not displaying on Button CLick

[Dave McCormick]

Hi,

I am having trouble using StringProperties.  In the below python script if I un-comment  the Clock.schedule line in the "class cb(App):" the Kivy UI displays the counting number along with the same number counting in the terminal.

If I run the code as written using the "Start" button from the Kivy UI the counting number will show in the terminal but not in the UI. 

I also included the Kivy code.

Thank you in advance for any help,
Dave

#!/usr/bin/python
import sys
import glob
import serial
import time
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.config import Config
from kivy.clock import Clock
from kivy.properties import StringProperty
Config.set('graphics', 'width', '400')
Config.set('graphics', 'height', '150')

num  = 0
class Counter_Timer(BoxLayout):
    number = StringProperty()
    def count(self, dt):
        global num
        num = num + 1
        print num
        numSTR = str(num)
        self.number = numSTR

    def start_button(self):
        counter = Counter_Timer()
        Clock.schedule_interval(counter.count, 1.0)

class cb(App):
    def build(self):
        counter = Counter_Timer()
        # Clock.schedule_interval(counter.count, 1.0)

        return counter


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

Kivy Code.

# cb.kv
<Counter_Timer>:
    orientation: 'vertical'
    BoxLayout:
    Label:
        text: root.number + ' ticks'
        font_size: '24dp'
    Button:
        text: "Start"
        on_press: root.start_button()
    Button:
        text: "Stop"
       

[ZenCODE]

Interesting. This is an instancing issue. Try

class Counter_Timer(BoxLayout):
    number = StringProperty('')

    def count(self, dt):
        global num
        num = num + 1
        print num
        numSTR = str(num)
        self.number = numSTR

    def start_button(self):

        Clock.schedule_interval(self.count, 1.0)

The problem with your code is that in your 'start_button' function, you create a new instance of the Count_Timer and then display on it's label. But you can't see that instance. You want to change only the value on this instance you are working with...:-)

[Dave McCormick]

Thank you!!!!

It works and makes sense now.

Dave