title: Kivy using the StackLayout
body: <p>I want to use a StackLayout but it only display one button and not two as I expected. The code is:</p>
  
  <pre><code>from kivy.app import App
  from kivy.uix.boxlayout import BoxLayout
  from kivy.uix.label import  Label
  from kivy.lang import Builder
  from kivy.uix.textinput import TextInput
  from kivy.uix.stacklayout import StackLayout
  from kivy.uix.button import Button
  
  
  Builder.load_string("""
  
  &lt;ScreenUI&gt;:
      orientation: 'lr-bt'
      Button:
          text: 'Button 1'
      Button:
          text: 'Button 2'
  
  """)
  
  
  
  class ScreenUI(StackLayout):
      pass
  
  class WidgetApp(App): 
  
      def build(self):
          app = ScreenUI()
          return app
  
  if __name__ == '__main__':
      WidgetApp().run()
  </code></pre>
  
  <p>How do I use a StackLayout and add a List of Button?</p>
  
  <p>Update (to includes comments): To obtain the resize behaviour I used
      Builder.load_string("""</p>
  
  <pre><code>&lt;ScreenUI&gt;: 
      input1: input1
      button1: button1
  
      height: self.input1.height
      spacing: 5
      orientation: 'horizontal'
      id: layout1
      Label:
          text: 'Button 1'
          id: button1
          size: len(self.text) * root.input1.font_size, 2 * root.input1.font_size
          size_hint: None, None
      TextInput:
          id: input1
          text: 'Button 2'
          size: root.width - root.button1.width - root.spacing, 2 * self.font_size
          size_hint: None, None
  """)
  </code></pre>
  
  <p>Does a more elegant method exists?</p>