circles.py

from random import choice, randint, random

from kivy.animation import Animation
from kivy.properties import ColorProperty, NumericProperty
from kivy.clock import Clock
from kivy.app import App
from kivy.lang import Builder
from kivy.factory import Factory as F


KV = '''
<Circles>:
    canvas:
        Color:
            rgba: self.color1
        Line:
            cap: 'square'
            width: self.width1
            circle:
                (
                self.center_x, self.center_y,
                self.radius1, self.start1, self.end1
                )
        Color:
            rgba: self.color2
        Line:
            width: self.width2
            cap: 'square'
            circle:
                (
                self.center_x, self.center_y,
                self.radius2, self.start2, self.end2
                )
        Color:
            rgba: self.color3
        Line:
            width: self.width3
            cap: 'square'
            circle:
                (
                self.center_x, self.center_y,
                self.radius3, self.start3, self.end3
                )
        Color:
            rgba: self.color4
        Line:
            width: self.width4
            cap: 'square'
            circle:
                (
                self.center_x, self.center_y,
                self.radius4, self.start4, self.end4
                )
FloatLayout:
'''

class Circles(F.Widget):
    color1 = ColorProperty()
    color2 = ColorProperty()
    color3 = ColorProperty()
    color4 = ColorProperty()

    radius1 = NumericProperty(0)
    radius2 = NumericProperty(0)
    radius3 = NumericProperty(0)
    radius4 = NumericProperty(0)

    width1 = NumericProperty(1)
    width2 = NumericProperty(1)
    width3 = NumericProperty(1)
    width4 = NumericProperty(1)

    start1 = NumericProperty()
    start2 = NumericProperty()
    start3 = NumericProperty()
    start4 = NumericProperty()

    end1 = NumericProperty()
    end2 = NumericProperty()
    end3 = NumericProperty()
    end4 = NumericProperty()

    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.delay = delay = random() * 10 + 5
        Clock.schedule_interval(self.animate, delay)
        self.color1=[random(), random(), random(), random() * .5 + .5]
        self.color2=[random(), random(), random(), random() * .5 + .5]
        self.color3=[random(), random(), random(), random() * .5 + .5]
        self.color4=[random(), random(), random(), random() * .5 + .5]

        self.radius1=randint(40, 100)
        self.radius2=randint(40, 100)
        self.radius3=randint(40, 100)
        self.radius4=randint(40, 100)

        self.width1=randint(1, 20)
        self.width2=randint(1, 20)
        self.width3=randint(1, 20)
        self.width4=randint(1, 20)

        self.start1=randint(0, 360)
        self.start2=randint(0, 360)
        self.start3=randint(0, 360)
        self.start4=randint(0, 360)

        self.end1=randint(0, 360)
        self.end2=randint(0, 360)
        self.end3=randint(0, 360)
        self.end4=randint(0, 360)
        self.animate()

    def animate(self, *dt):
        Animation(
            d=self.delay,
            t=choice(('out_quad', 'out_sine', 'linear')),

            color1=[random(), random(), random(), random() * .5 + .5],
            color2=[random(), random(), random(), random() * .5 + .5],
            color3=[random(), random(), random(), random() * .5 + .5],
            color4=[random(), random(), random(), random() * .5 + .5],

            radius1=randint(40, 100),
            radius2=randint(40, 100),
            radius3=randint(40, 100),
            radius4=randint(40, 100),

            width1=randint(1, 20),
            width2=randint(1, 20),
            width3=randint(1, 20),
            width4=randint(1, 20),

            start1=randint(0, 360),
            start2=randint(0, 360),
            start3=randint(0, 360),
            start4=randint(0, 360),

            end1=randint(0, 360),
            end2=randint(0, 360),
            end3=randint(0, 360),
            end4=randint(0, 360),
        ).start(self)


class Application(App):
    def build(self):
        root = Builder.load_string(KV)
        for i in range(30):
            root.add_widget(
                Circles(
                    pos_hint={'center': (random(), random())}
                )
            )
        return root


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