gistfile1.txt

from kivy.app import App
from kivy.uix.effectwidget import EffectWidget
from kivy.uix.image import Image
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.scatter import Scatter
from kivy.uix.button import Button
from kivy.uix.spinner import Spinner
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder
from kivy.properties import ObjectProperty

from kivy.uix.effectwidget import (MonochromeEffect,
                                   InvertEffect,
                                   ScanlinesEffect,
                                   ChannelMixEffect,
                                   ScanlinesEffect,
                                   FXAAEffect,
                                   PixelateEffect,
                                   HorizontalBlurEffect,
                                   VerticalBlurEffect)


class ComparisonWidget(EffectWidget):
    pass


class ComparisonWidget(EffectWidget):
    pass


class EffectSpinner(Spinner):
    pass


class SpinnerRow(BoxLayout):
    effectwidget = ObjectProperty()

    def update_effectwidget(self, *args):
        effects = []
        for child in self.children[::-1]:
            text = child.text
            if text == 'none':
                pass
            if text == 'fxaa':
                effects.append(FXAAEffect())
            if text == 'monochrome':
                effects.append(MonochromeEffect())
            if text == 'invert':
                effects.append(InvertEffect())
            if text == 'mix':
                effects.append(ChannelMixEffect())
            if text == 'flash':
                effects.append(FlashEffect())
            if text == 'blur_h':
                effects.append(HorizontalBlurEffect())
            if text == 'blur_v':
                effects.append(VerticalBlurEffect())
            if text == 'postprocessing':
                effects.append(ScanlinesEffect())
            if text == 'pixelate':
                effects.append(PixelateEffect())

        if self.effectwidget:
            self.effectwidget.effects = effects


example = Builder.load_string('''
#:import Vector kivy.vector.Vector
BoxLayout:
    orientation: 'vertical'
    BoxLayout:
        Button:
            text: 'Button on the left.'
    Carousel:
            ComparisonWidget:
                id: effect1
            ComparisonWidget:
                id: effect2
            Screen:
    SpinnerRow:
        effectwidget: effect1
        text: 'left effects'
    SpinnerRow:
        effectwidget: effect2
        text: 'right effects'


<ComparisonWidget>:
    Widget:
        canvas:
            Color:
                rgba: 1, 0, 0, 1
            Ellipse:
                pos: Vector(self.pos) + 0.5*Vector(self.size)
                size: 0.4*Vector(self.size)
            Color:
                rgba: 0, 1, 0.3, 1
            Ellipse:
                pos: Vector(self.pos) + 0.1*Vector(self.size)
                size: 0.6*Vector(self.size)
            Color:
                rgba: 0.5, 0.3, 0.8, 1
            Ellipse:
                pos: Vector(self.pos) + Vector([0, 0.6])*Vector(self.size)
                size: 0.4*Vector(self.size)
            Color:
                rgba: 1, 0.8, 0.1, 1
            Ellipse:
                pos: Vector(self.pos) + Vector([0.5, 0])*Vector(self.size)
                size: 0.4*Vector(self.size)
            Color:
                rgba: 0, 0, 0.8, 1
            Line:
                points:
                    [self.x, self.y,
                    self.x + self.width, self.y + 0.3*self.height,
                    self.x + 0.2*self.width, self.y + 0.1*self.height,
                    self.x + 0.85*self.width, self.y + 0.72*self.height,
                    self.x + 0.31*self.width, self.y + 0.6*self.height,
                    self.x, self.top]
                width: 1
            Color:
                rgba: 0, 0.9, 0.1, 1
            Line:
                points:
                    [self.x + self.width, self.y + self.height,
                    self.x + 0.35*self.width, self.y + 0.6*self.height,
                    self.x + 0.7*self.width, self.y + 0.15*self.height,
                    self.x + 0.2*self.width, self.y + 0.22*self.height,
                    self.x + 0.3*self.width, self.y + 0.92*self.height]
                width: 2

<SpinnerRow>:
    orientation: 'horizontal'
    size_hint_y: None
    height: dp(40)
    text: ''
    Label:
        text: root.text
    EffectSpinner:
        on_text: root.update_effectwidget()
    EffectSpinner:
        on_text: root.update_effectwidget()
    EffectSpinner:
        on_text: root.update_effectwidget()

<EffectSpinner>:
    text: 'none'
    values:
        ['none', 'fxaa', 'monochrome',
        'invert', 'mix',
        'blur_h', 'blur_v',
        'postprocessing', 'pixelate',]
''')


class EffectApp(App):
    def build(self):
        return example


EffectApp().run()