Centering an object in Qiwi

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 think one of the predefined layouts might be the best choice. Here is what my code produces ...

For square layouts:

For wide layouts:

This is the right behavior, and it's great, but is there a better way? For example, I can imagine that it becomes erratic in the form of non-circular figures.

Here is my code:

#!/usr/bin/kivy import kivy kivy.require('1.7.2') from random import random from kivy.app import App from kivy.uix.widget import Widget from kivy.uix.gridlayout import GridLayout from kivy.uix.anchorlayout import AnchorLayout from kivy.uix.relativelayout import RelativeLayout from kivy.graphics import Color, Ellipse, Rectangle class MinimalApp(App): title = 'My App' def build(self): root = RootLayout() return(root) class RootLayout(AnchorLayout): pass class Circley(RelativeLayout): pass if __name__ == '__main__': MinimalApp().run() 

And HF:

 #:kivy 1.7.2 #:import kivy kivy <RootLayout>: anchor_x: 'center' # I think this /is/ centered anchor_y: 'center' canvas.before: Color: rgba: 0.4, 0.4, 0.4, 1 Rectangle: pos: self.pos size: self.size Circley: anchor_x: 'center' # this is /not/ centered. anchor_y: 'center' canvas.before: Color: rgba: 0.94, 0.94, 0.94, 1 Ellipse: size: min(self.size), min(self.size) pos: 0.5*self.size[0] - 0.5*min(self.size), 0.5*self.size[1] - 0.5*min(self.size) Label: text: unicode(self.size) # this is /not/ appearing color: 1,0,0,1 

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() 

Japan flag:

 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()