How To Use Touchripple.py With Kivy Lang?

I'm trying to create a button using touchripple.py found in kivy.uix.behaviors. However, I ended up unsuccessful. Can anyone show an easy example of touchripple with buttons using

Solution 1:

Below is a snippet for creating a Button which renders the touch ripple animation on interaction:

Snippet

classRippleButton(TouchRippleBehavior, Button):

    defon_touch_down(self, touch):
        collide_point = self.collide_point(touch.x, touch.y)
        if collide_point:
            touch.grab(self)

            # The background_color (r, g, b, a) of button widget defaults to [1, 1, 1, 1]# where 'a' (alpha compositing or transparency) is 1 i.e. not transparent

            self.transparency = self.background_color[3]    # backup original transparency / alpha compositing
            self.background_color[3] = 0.5# set transparency to half (0.5)

            self.ripple_show(touch)

            # dispatch on_press event because we have consumed on_touch_down
            self.dispatch('on_press')

            # consumed touch down and don’t want it to propagate any further.returnTruereturnFalsedefon_touch_up(self, touch):
        if touch.grab_current is self:
            touch.ungrab(self)
            self.ripple_fade()

            # defer on_release until ripple_fade has completeddefdefer_release(dt):
                self.background_color[3] = self.transparency  # restore transparency / alpha compositing
                self.dispatch('on_release')

            Clock.schedule_once(defer_release, self.ripple_duration_out)

            # consumed touch up and don’t want it to propagate any further.returnTruereturnFalse

Example

main.py

from kivy.app import App
from kivy.uix.behaviors.touchripple import TouchRippleBehavior
from kivy.uix.button import Button
from kivy.uix.screenmanager import Screen
from kivy.lang import Builder
from kivy.clock import Clock


classRippleButton(TouchRippleBehavior, Button):

    defon_touch_down(self, touch):
        collide_point = self.collide_point(touch.x, touch.y)
        if collide_point:
            touch.grab(self)

            # The background_color (r, g, b, a) of button widget defaults to [1, 1, 1, 1]# where 'a' (alpha compositing or transparency) is 1 i.e. not transparent

            self.transparency = self.background_color[3]    # backup original transparency / alpha compositing
            self.background_color[3] = 0.5# set transparency to half (0.5)

            self.ripple_show(touch)

            # dispatch on_press event because we have consumed on_touch_down
            self.dispatch('on_press')

            # consumed touch down and don’t want it to propagate any further.returnTruereturnFalsedefon_touch_up(self, touch):
        if touch.grab_current is self:
            touch.ungrab(self)
            self.ripple_fade()

            # defer on_release until ripple_fade has completeddefdefer_release(dt):
                self.background_color[3] = self.transparency  # restore transparency / alpha compositing
                self.dispatch('on_release')

            Clock.schedule_once(defer_release, self.ripple_duration_out)

            # consumed touch up and don’t want it to propagate any further.returnTruereturnFalsedefdoit(self, *args):
        print('in doit')


classLogin(Screen):
    passclassMainScreen(Screen):
    passclassSimpleKivy4(App):
    defbuild(self):
        return Builder.load_file("main.kv")


if __name__ == "__main__":
    SimpleKivy4().run()

main.kv

#:kivy 1.11.0ScreenManager:Login:MainScreen:<Login>:name:"login"RippleButton:text:'Login'font_size:24on_release:root.manager.current="main"<MainScreen>:name:"main"RippleButton:text:'back'on_release:root.manager.current="login"

Output

Solution 2:

After looking a bit closer at the example, I noticed that they are doing some odd things in the RippleButton. They were stopping the dispatching of the touch events for some unknown reason. I have modified the code to continue the dispatching (so now the on_release should work). And I have added a BooleanProperty to keep track of whether the TouchRipple Behavior is in effect.

from kivy.app import App
from kivy.lang import Builder
from kivy.properties import BooleanProperty
from kivy.uix.behaviors import TouchRippleBehavior
from kivy.uix.button import Button


classRippleButton(TouchRippleBehavior, Button):
    isRippled = BooleanProperty(False)

    def__init__(self, **kwargs):
        super(RippleButton, self).__init__(**kwargs)

    defon_touch_down(self, touch):
        collide_point = self.collide_point(touch.x, touch.y)
        if collide_point andnot self.isRippled:
            self.isRippled = True
            self.ripple_show(touch)
        returnsuper(RippleButton, self).on_touch_down(touch)

    defon_touch_up(self, touch):
        collide_point = self.collide_point(touch.x, touch.y)
        if collide_point and self.isRippled:
            self.isRippled = False
            self.ripple_fade()
        returnsuper(RippleButton, self).on_touch_up(touch)

    defdoit(self, *args):
        print('in doit')

theRoot = Builder.load_string('''
RippleButton:
    text: 'Click Here'
    on_release: self.doit()
''')

classTouchRippleApp(App):
    defbuild(self):
        return theRoot

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