title: Kivy ScrollView is not able to scroll
body: <p>This is the .py file:</p>
  <pre><code>from kivy.app import App
  from kivy.uix.button import Button
  from kivy.uix.scrollview import ScrollView
  from kivy.uix.stacklayout import StackLayout
  
  
  class Stack(StackLayout):
      def __init__(self,**kwargs):
          super().__init__(**kwargs)
          for i in range(0,100):
              b1 = Button(text=str(i+1),size_hint=(.1,.1))
              self.add_widget(b1)
  
  class ScrollView(ScrollView):
      pass
  
  class GameApp(App):
      def build(self):
          return Stack()
      
  GameApp().run()
  </code></pre>
  <p>And this is the .kV file:</p>
  <pre><code>&lt;ScrollView&gt;:
          Stack:
                  size_hint:1,None
                  height:4000
  </code></pre>
  <p>In the output I am getting the buttons but I am unable to scroll.</p>