Kivy: How to change window size?

Question

I'm starting to write a program using kivy, but I have some problems understand how it deals with sizes.

For example:

import kivy
kivy.require('1.5.1')

from kivy.app import App
from kivy.uix.button import Button

class MyApp(App):
    def build(self): return Button(text='Some text')

MyApp().run()

The above program works, but it creates a huge window. Trying to set size=(100, 100) does not change anything. Setting size_hint=(None, None) will show a button with the correct size, but it is placed randomly inside a still huge window. Trying to set the size of MyApp does not change anything too.

How do I create a window with the same size of the button? It should be a simple enough task, but looking at the documentation and example I can't find anything about this.

Answer 1

There're currently two ways:

• Before the window is created:

  import kivy
  kivy.require('1.9.0')
  
  from kivy.config import Config
  Config.set('graphics', 'width', '200')
  Config.set('graphics', 'height', '200')
  

• Dynamically after the Window was created:

  from kivy.core.window import Window
  Window.size = (300, 100)
  

Answer 2

Use this:

from kivy.core.window import Window
Window.size = (300, 100)

If you use

from kivy.config import Config
Config.set('graphics', 'width', '200')
Config.set('graphics', 'height', '200')
Config.write()

this will lead to loss of default screen size! Default screen size is really useful.

Answer 3

I would comment on martin's answer, but I don't have the reputation. When setting the config file, be sure to "write" your changes:

from kivy.config import Config
Config.set('graphics', 'width', '200')
Config.set('graphics', 'height', '200')
Config.write()

It's exactly like committing info to a database, if you know anything about that.