title: Kivy anchor two widget at each side
body: <p>I'm trying to do a video on top of a graph, with two buttons controlling the graph. I'd like one button to be at the left of the window, the other one at the right, both on the same row, and my problem is placing the - and + buttons.
  I have the following kv file, the concerned buttons are the two Control class:</p>
  
  <pre><code>#:kivy 1.0.9
  
  &lt;Control&gt;
  
      canvas:
          Rectangle:
              size: 5, 5
              pos: self.pos
  
  
  
  &lt;VideoWidget&gt;:
      video_player: video_handler
      graph: graph_handler
      data_plus: ctr_plus_handler
      data_minus: ctr_minus_handler
  
      BoxLayout:
          orientation: 'vertical'
  
          VideoHandler:
              id: video_handler
              state: 'play'
              options: {'allow_stretch': True}
              size_hint: 1, 0.45
              on_touch_down: root.test()
              on_position: root.move()
  
          BoxLayout:
              size_hint: 1, 0.1
              orientation: 'horizontal'
  
              Control:
                  id: ctr_minus_handler
                  size_hint: 0.1, 1
  
                  pos_hint: {'left': 0.1}
  
  
              Control:
                  id: ctr_plus_handler
                  size_hint: 0.1, 1
                  pos_hint: {'right': 0.1}
  
  
  
          GraphWidget:
              id: graph_handler
              size_hint: 1, 0.45
  
  
  
  </code></pre>
  
  <p>But both Control are taking half the width of the row, whatever I change... Any ideas ?</p>