我正在尝试重构the last code sample,以便 Button
实际上是它自己的一个带有 on_release
动作的类 . 但我的代码失败了 .
我想不仅重构它(根据我下面的尝试),但我还需要将 Button
的文本设置为"Clear"
from random import random
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.graphics import Color, Ellipse, Line
class MyPaintWidget(Widget):
def on_touch_down(self, touch):
userdata = touch.ud
userdata['color'] = c = (random(), 1, 1)
with self.canvas:
Color(*c, mode='hsv')
d = 30
Ellipse(pos=(touch.x - d/2, touch.y - d/2), size=(d, d))
userdata['line'] = Line(points=(touch.x, touch.y))
def on_touch_move(self, touch):
touch.ud['line'].points += [touch.x, touch.y]
class ClearButton(Button):
def __init__(self, paint_widget):
self.paint_widget=paint_widget
def on_release(self, button):
self.paint_widget.canvas.clear()
class MyPaintApp(App):
def build(self):
parent = Widget()
painter = MyPaintWidget()
clearbtn = ClearButton(painter)
parent.add_widget(painter)
parent.add_widget(clearbtn)
return parent
if __name__ == '__main__':
MyPaintApp().run()
1 回答
没有子类化,你可以这样做:
通过子类化,我更愿意使用Kv语言: