如何在Kivy lang中使用touchripple.py？

Question

我正在尝试使用在kivy.uix.behaviors中找到的touchripple.py创建一个按钮。但是，我最终没有成功。任何人都可以使用Kivy lang展示带有按钮的触摸涟漪的简单示例吗？提前致谢。 现在，只有涟漪效应没有显示出来。请指教。谢谢。

在波纹示例2.py中：

from kivy.app import App
from kivy.uix.touchripple import TouchRippleBehavior
from kivy.uix.button import Button
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang import Builder
from kivy.properties import (StringProperty, NumericProperty, ObjectProperty,
ListProperty, DictProperty, BooleanProperty)

class RippleButton(TouchRippleBehavior, Button):
    isRippled = BooleanProperty(False)

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

    def on_touch_down(self, touch):
        collide_point = self.collide_point(touch.x, touch.y)
        if collide_point and not self.isRippled:
            self.isRippled = True
            self.ripple_show(touch)
        return super(RippleButton, self).on_touch_down(touch)

    def on_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()
        return super(RippleButton, self).on_touch_up(touch)

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

 class Login(Screen):
    pass

class MainScreen(Screen):
    pass

class ScreenManager(ScreenManager):
    pass

MainScreen = Builder.load_file("rippleexample2.kv")

class SimpleKivy4(App):
    def build(self):
        return MainScreen

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

在波纹示例2.kv中：

ScreenManager:
    Login:
    MainScreen:

<Login>:
    name:"login"
    RippleButton:
        text:'Login'
        font_size: 24
        on_release: app.root.current = "main"


<MainScreen>:
    name: "main"
    RippleButton:
        text: 'back'
        on_release: app.root.current = "login"

Answer 1

在仔细研究示例之后，我注意到他们在RippleButton中做了一些奇怪的事情。他们出于某些未知原因而停止了调度触摸事件。我已经修改了代码以继续进行分派（因此on_release现在应该可以工作了）。并且我添加了BooleanProperty来跟踪TouchRipple Behavior是否有效。

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


class RippleButton(TouchRippleBehavior, Button):
    isRippled = BooleanProperty(False)

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

    def on_touch_down(self, touch):
        collide_point = self.collide_point(touch.x, touch.y)
        if collide_point and not self.isRippled:
            self.isRippled = True
            self.ripple_show(touch)
        return super(RippleButton, self).on_touch_down(touch)

    def on_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()
        return super(RippleButton, self).on_touch_up(touch)

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

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

class TouchRippleApp(App):
    def build(self):
        return theRoot

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

Answer 2

下面是用于创建一个按钮的代码段，该按钮在交互时呈现触摸波纹动画：

摘要

class RippleButton(TouchRippleBehavior, Button):

    def on_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.
            return True
        return False

    def on_touch_up(self, touch):
        if touch.grab_current is self:
            touch.ungrab(self)
            self.ripple_fade()

            # defer on_release until ripple_fade has completed
            def defer_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.
            return True
        return False

示例

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


class RippleButton(TouchRippleBehavior, Button):

    def on_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.
            return True
        return False

    def on_touch_up(self, touch):
        if touch.grab_current is self:
            touch.ungrab(self)
            self.ripple_fade()

            # defer on_release until ripple_fade has completed
            def defer_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.
            return True
        return False

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


class Login(Screen):
    pass


class MainScreen(Screen):
    pass


class SimpleKivy4(App):
    def build(self):
        return Builder.load_file("main.kv")


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

main.kv

#:kivy 1.11.0

ScreenManager:
    Login:
    MainScreen:

<Login>:
    name:"login"
    RippleButton:
        text:'Login'
        font_size: 24
        on_release: root.manager.current = "main"


<MainScreen>:
    name: "main"
    RippleButton:
        text: 'back'
        on_release: root.manager.current = "login"

输出