loading.py

'''
'''
from kivy.app import App
from kivy.lang import Builder
from kivy.clock import Clock
import kivy.properties as P


KV = '''
#:import Animation kivy.animation.Animation

<Loading@Widget>:
    angle: (app.time * 360) % 360
    radius: self.width
    canvas:
        Color:
            rgba: rgba('#FF4444')
        Line:
            width: 9
            ellipse: self.x, self.y, self.radius or 0, self.radius or 0, self.angle or 0, (self.angle or 0) + 90
        Line:
            width: 9
            ellipse: self.x, self.y, self.radius or 0, self.radius or 0, (self.angle or 0) + 180, (self.angle or 0) + 180 + 90
        SmoothLine:
            width: 10
            ellipse: self.x, self.y, self.radius or 0, self.radius or 0, self.angle or 0, (self.angle or 0) + 90
        SmoothLine:
            width: 10
            ellipse: self.x, self.y, self.radius or 0, self.radius or 0, (self.angle or 0) + 180, (self.angle or 0) + 180 + 90

FloatLayout:
    Loading:
        id: loading
        size_hint: None, None
        pos_hint: {'center': (.5, .8)}
        opacity: 0
    ToggleButton:
        size_hint: None, None
        pos_hint: {'center': (.5, .3)}
        on_state:
            Animation.cancel_all(loading, 'opacity')
            Animation(opacity=1 if self.state == 'down' else 0).start(loading)
'''

class Application(App):
    time = P.NumericProperty()

    def build(self):
        Clock.schedule_interval(self.update_time, 0)
        return Builder.load_string(KV)

    def update_time(self, dt):
        self.time += dt

if __name__ == "__main__":
    Application().run()