Kivy: increment/decrement for 1.8.0

colorchangeold.py

import kivy
kivy.require('1.8.0')

from kivy.app import App
from kivy.lang import Builder
from kivy.clock import Clock
from kivy.properties import NumericProperty

class TestApp(App):
    value = NumericProperty(0)

    def build(self):
        return Builder.load_string('''
BoxLayout:
    orientation: 'vertical'
    Label:
        text: str(app.value)

        canvas.before:
            Color:
                rgba: app.value / 64., (64 - app.value) / 64., 0, 1
            Rectangle:
                pos: self.pos
                size: self.size

    BoxLayout:
        Button:
            text: '-'
            on_press: app.minus()
            on_release: app.stopupdate()
        Button:
            text: '+'
            on_press: app.plus()
            on_release: app.stopupdate()
''')

    def _do_plus(self, dt):
        self.value += 1

    def _do_minus(self, dt):
        self.value -= 1

    def plus(self):
        self.event = self._do_plus
        Clock.schedule_interval(self._do_plus, 0.1)
        self._do_plus(None)

    def minus(self):
        self.event = self._do_minus
        Clock.schedule_interval(self._do_minus, 0.1)
        self._do_minus(None)

    def stopupdate(self):
        Clock.unschedule(self.event)

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