Kivy.garden.progressspinner

Question

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我只使用绿色等颜色就可以了。但是，当我将其与自定义图像一起用于渐变效果时，无论我放入哪种图像，它似乎始终在内部显示黑线。

我没有触摸任何代码。我唯一要做的就是更改图像的来源。无论如何，有没有摆脱模糊的黑线？它们为什么出现？

'''
ProgressSpinner
===============
Android Lollipop style progress spinner.
'''

from kivy.lang import Builder
from kivy.core.image import Image as CoreImage
from kivy.properties import NumericProperty, ListProperty, BoundedNumericProperty, StringProperty, ObjectProperty
from kivy.animation import Animation
from kivy.clock import Clock
from kivy.properties import BooleanProperty
from kivy.uix.widget import Widget

Builder.load_string('''
<ProgressSpinnerBase>:
    _size: min(self.height, self.width)
    _rsize: self._size / 2.
    _stroke: max(0.1, self._rsize / 20. if self.stroke_width is None else self.stroke_width)
    _radius: self._rsize - self._stroke * 2.
<ProgressSpinner>:
    canvas:
        Color:
            rgba: self.color
        Line:
            circle:
                (self.center_x, self.center_y, self._radius,
                self._angle_center + self._angle_start,
                self._angle_center + self._angle_end)
            width: self._stroke
            cap: 'none'
<TextureProgressSpinner>:
    canvas:
        StencilPush
        Color:
            rgba: 1, 1, 1, 1
        Line:
            circle:
                (self.center_x, self.center_y, self._radius,
                self._angle_center + self._angle_start,
                self._angle_center + self._angle_end)
            width: self._stroke
            cap: 'none'
        StencilUse
        Color:
            rgba: self.color
        Rectangle:
            pos: self.center_x - self._rsize, self.center_y - self._rsize
            size: self._size, self._size
            texture: self.texture
        StencilUnUse
        Color:
            rgba: 1, 1, 1, 1
        Line:
            circle:
                (self.center_x, self.center_y, self._radius,
                self._angle_center + self._angle_start,
                self._angle_center + self._angle_end)
            width: self._stroke
            cap: 'none'
        StencilPop
<RotatingTextureProgressSpinner>:
    canvas:
        PushMatrix
        Rotate:
            angle: -self._angle_center
            origin: self.center

        StencilPush
        Color:
            rgba: 1, 1, 1, 1
        Line:
            circle:
                (self.center_x, self.center_y, self._radius,
                self._angle_start, self._angle_end)
            width: self._stroke
            cap: 'none'
        StencilUse
        Color:
            rgba: self.color
        Rectangle:
            pos: self.center_x - self._rsize, self.center_y - self._rsize
            size: self._size, self._size
            texture: self.texture
        StencilUnUse
        Color:
            rgba: 1, 1, 1, 1
        Line:
            circle:
                (self.center_x, self.center_y, self._radius,
                self._angle_start, self._angle_end)
            width: self._stroke
            cap: 'none'
        StencilPop

        PopMatrix
''')


class ProgressSpinnerBase(Widget):
    '''ProgressSpinnerBase - base class for progress spinner widgets
    '''

    color = ListProperty([1, 1, 1, 1])
    '''Color to render the spinner.
    :attr:`color` is a :class:`~kivy.properties.ListProperty` and defaults
    to [1, 1, 1, 1] (white, full opacity).
    '''

    speed = BoundedNumericProperty(1, min=0.1)
    '''Speed coefficient of the spinner. This value is multiplied by the
    base speed of 90 degrees per second.
    :attr:`speed` is a :class:`~kivy.properties.BoundedNumericProperty` and
    defaults to 1.
    '''

    stroke_length = BoundedNumericProperty(25., min=1, max=180)
    '''Base length of the stroke in degrees.
    :attr:`stroke_length` is a :class:`~kivy.properties.BoundedNumericProperty`
    and defaults to 25.
    '''

    stroke_width = NumericProperty(None, allownone=True)
    '''Width of the stroke in pixels. If set to None, the width will be
    calculated automatically as 1/20th of the radius.
    :attr:`stroke_width` is a :class:`~kivy.properties.NumericProperty` and
    defaults to None.
    '''

    auto_start = BooleanProperty(True)
    '''Whether to automatically start spinning.
    :attr:`auto_start` is a :class:`~kivy.properties.BooleanProperty` and
    defaults to True.
    '''

    # internal properties
    _angle_center = NumericProperty(0)
    _angle_start = NumericProperty()
    _angle_end = NumericProperty()
    _size = NumericProperty()
    _rsize = NumericProperty()
    _stroke = NumericProperty(1)
    _radius = NumericProperty(50)

    def __init__(self, **kwargs):
        super(ProgressSpinnerBase, self).__init__(**kwargs)
        self._state = 'wait1'
        self._next = None
        self._spinning = False

        if self.auto_start:
            self.start_spinning()

    def start_spinning(self, *args):
        '''Start spinning the progress spinner. Ignores all positional args
        for easy binding.
        '''
        if not self._spinning:
            self._state = 'wait1'
            self._next = None
            self._angle_center = 0.
            self._angle_start = 360.
            self._angle_end = 360. + self.stroke_length
            Clock.schedule_interval(self._update, 0)
            Clock.schedule_once(self._rotate, 0.3)
            self._spinning = True

    def stop_spinning(self, *args):
        '''Stop spinning the progress spinner. Ignores all positional args
        for easy binding.
        If you intend to keep the spinner around, you should stop it when
        not using it and restart it when needed again.
        '''
        if self._spinning:
            if self._next:
                if isinstance(self._next, Animation):
                    self._next.cancel(self)
                else:
                    self._next.cancel()
            Clock.unschedule(self._update)
            Clock.unschedule(self._rotate)
            self._angle_start = self._angle_end = 0
            self._spinning = False

    def _update(self, dt):
        angle_speed = 90. * self.speed
        self._angle_center += dt * angle_speed

        if self._angle_center > 360:
            self._angle_center -= 360.

    def _rotate(self, *args):
        if not self._spinning:
            return

        rotate_speed = 0.6 / self.speed
        wait_speed = 0.3 / self.speed
        if self._state == 'wait1':
            self._state = 'rotate1'
            self._next = Animation(_angle_end=self._angle_start + 360. - self.stroke_length, d=rotate_speed,
                                   t='in_quad')
            self._next.bind(on_complete=self._rotate)
            self._next.start(self)
        elif self._state == 'rotate1':
            self._state = 'wait2'
            self._next = Clock.schedule_once(self._rotate, wait_speed)
        elif self._state == 'wait2':
            self._state = 'rotate2'
            self._next = Animation(_angle_start=self._angle_end - self.stroke_length, d=rotate_speed, t='in_quad')
            self._next.bind(on_complete=self._rotate)
            self._next.start(self)
        elif self._state == 'rotate2':
            self._state = 'wait1'
            self._next = Clock.schedule_once(self._rotate, wait_speed)
            while self._angle_end > 720.:
                self._angle_start -= 360.
                self._angle_end -= 360.


class ProgressSpinner(ProgressSpinnerBase):
    '''ProgressSpinner class. Android Lollipop style progress spinner.
    '''
    pass


class TextureProgressSpinnerBase(ProgressSpinnerBase):
    texture = ObjectProperty()
    '''Texture to render for the spinner.
    :attr:`texture` is a :class:`~kivy.properties.ObjectProperty` and
    defaults to None.
    '''

    source = StringProperty('')
    '''Source image to render for the spinner.
    :attr:`source` is a :class:`~kivy.properties.StringProperty` and
    defaults to an empty string.
    '''

    def on_source(self, inst, value):
        if value:
            self.texture = CoreImage(value).texture


class TextureProgressSpinner(TextureProgressSpinnerBase):
    '''TextureProgressSpinner class.
    Same as ProgressSpinner, but with a texture/image instead of a solid color.
    '''
    pass


class RotatingTextureProgressSpinner(TextureProgressSpinnerBase):
    '''RotatingTextureProgressSpinner class.
    Same as TextureProgressSpinner, but the texture/image rotates along with
    the spinner.
    '''
    pass


if __name__ == '__main__':
    from kivy.app import App
    from kivy.graphics.texture import Texture
    from textwrap import dedent


    class TestApp(App):
        texture = ObjectProperty()

        def blittex(self, *args):
            rgbpixels = [(x, 0, y, 255) for x in range(256) for y in range(256)]
            pixels = b''.join((b''.join(map(bytearray, pix)) for pix in rgbpixels))
            self.texture = Texture.create(size=(256, 256))
            self.texture.blit_buffer(pixels, colorfmt='rgba', bufferfmt='ubyte')

        def build(self):
            Clock.schedule_once(self.blittex, -1)

            return Builder.load_string(dedent('''\
                <ProgressSpinnerBase>:
                    on_touch_down: self.stop_spinning() if self._spinning else self.start_spinning()
                <TTextureProgressSpinner@TextureProgressSpinner>:
                    texture: app.texture
                <TRotatingTextureProgressSpinner@RotatingTextureProgressSpinner>:
                    texture: app.texture

                <ITextureProgressSpinner@TextureProgressSpinner>:
                    source: 'demoimage.jpg'

                <IRotatingTextureProgressSpinner@RotatingTextureProgressSpinner>:
                    source: 'demoimage.jpg'
                BoxLayout:
                    BoxLayout:
                        orientation: 'vertical'

                        ProgressSpinner

                        TTextureProgressSpinner

                        TRotatingTextureProgressSpinner

                    BoxLayout:
                        orientation: 'vertical'

                        BoxLayout:
                            ProgressSpinner:
                                color: 0.3, 0.3, 1, 1
                                stroke_width: 1

                            ProgressSpinner:
                                speed: 0.5
                                color: 1, 0, 0, 1

                            ProgressSpinner:
                                speed: 2
                                color: 0, 1, 0, 1

                        BoxLayout:
                            TTextureProgressSpinner:
                                color: 1, 0, 0, 1

                            ITextureProgressSpinner:
                                stroke_width: 10

                            ITextureProgressSpinner:
                                stroke_length: 20

                        BoxLayout:
                            TRotatingTextureProgressSpinner:
                                color: 1, 0, 0, 1

                            IRotatingTextureProgressSpinner:
                                stroke_width: 10

                            IRotatingTextureProgressSpinner:
                                stroke_length: 20
            '''))


    TestApp().run()

上面的代码是来自progressspinner.py的代码