Centering an object in Kivy

Question

I am trying to center a circle inside a layout. I\'m currently doing some padding calculations, but I\'m also looking for a better way. I imagine one of the predefined layouts

Answer 1

Snippet using FloatLayout, size_hint and pos_hint:

from kivy.app import App
from kivy.lang import Builder

kv = '''
FloatLayout:
    Widget:
        size: min(root.size), min(root.size)
        size_hint: None, None
        pos_hint: {'center_x': .5, 'center_y': .5}
        canvas:
            Color:
                rgb: 1, 0, 0
            Ellipse:    
                size: self.size
                pos: self.pos
'''
Builder.load_string(kv)

class MyApp(App):
    def build(self):
        return Builder.load_string(kv)

MyApp().run()

Flag of Japan:

from kivy.app import App
from kivy.lang import Builder

kv = '''
FloatLayout:
    canvas:
        Color:
            rgb: 1, 1, 1
        Rectangle:    
            size: self.size
            pos: self.pos   
    Widget:
        size: min(root.size)/2, min(root.size)/2
        size_hint: None, None
        pos_hint: {'center_x': .5, 'center_y': .5}
        canvas:
            Color:
                rgb: 1, 0, 0
            Ellipse:    
                size: self.size
                pos: self.pos
'''
Builder.load_string(kv)

class MyApp(App):
    def build(self):
        return Builder.load_string(kv)

MyApp().run()