title: Is there a simple way to add a border to Kivy Buttons
body: <p>I am using <code>python-2.7</code> and <code>kivy</code>. Can someone tell me that how to add a different colour border to kivy button. </p>
  
  <h1>test.py</h1>
  
  <pre><code>from kivy.uix.screenmanager import Screen
  from kivy.app import App
  from kivy.core.window import Window
  
  Window.clearcolor = (0.5, 0.5, 0.5, 1)
  Window.size = (300, 100)
  
  
  class User(Screen):
      pass
  
  
  class Test(App):
  
      def build(self):
          return self.root
  
  
  if __name__ == '__main__':
      Test().run()
  </code></pre>
  
  <h1>test.py</h1>
  
  <pre><code>User:
      BoxLayout:
  
          Button:
              background_normal: ''
              text: 'Ok'
  </code></pre>