Kivy: inherit another dynamic classes values

Question

I have a dynamic classes like this:

<BLMother@BoxLayout>:
    orientation:"horizontal"
    padding: 10, 0
    spacing: 10

For some of my CustomBoxLayout, I would like to add a canvas:before. I could create a new dynamic classes which combine the values of both like this:

<BLChildren@BoxLayout>:
    orientation:"horizontal"
    padding: 10, 0
    spacing: 10
    canvas.before:
        Color:
            rgba: 1, 1, 1, 0.8
       Rectangle:
            size: self.size
            pos: self.x + self.width*0.025, self.y    

Is there a way BLChildren can inherit all the value from BLMother?

I use Kivy (1.10.1.dev0)

Answer 1

i don't know why you put pos = self.x + self.width*0.025, self.y but here you go:

-kv:

<BLMother@BoxLayout>:
   orientation:"horizontal"
   padding: 10, 0
   spacing: 10

<BLChildren@BLMother>:
   canvas.before:
      Color:
         rgba: 1, 1, 1, 0.8
      Rectangle:
         size: self.size
         pos: self.x , self.y

BLChildren:

-py:

from kivy.app import App


class TestApp(App):
   pass


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

Answer 2

Yes, the BLChildren can inherit all the value from BLMother. Please refer to the example below for details.

Example - Inheritance from BLMother

main.py

from kivy.app import App
from kivy.uix.floatlayout import FloatLayout


class RootWidget(FloatLayout):
    pass


class TestApp(App):
    title = "With Inheritance of BLMother"

    def build(self):
        return RootWidget()


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

test.kv

#:kivy 1.10.0

<BLMother@BoxLayout>:
    orientation:"horizontal"
    padding: 10, 0
    spacing: 10

<BLChildren@BoxLayout>:
    canvas.before:
        Color:
            rgba: 1, 1, 1, 0.8
        Rectangle:
            size: self.size
            pos: self.x + self.width*0.025, self.y
    BLMother:

<RootWidget>:
    BLChildren:

Output - Inheritance from BLMother