title: Python Kivy: ScrollView not scrollable within FloatLayout
body: <p>I have a FloatLayout based on Tech With Tim's Kivy tutorial application. The FloatLayout allows the window to be resized on any device since this app will be used on Android and iOS.
  I have figured out how to place the gridlayout and scrollview inside the floatlayout and position it where I want it to go, but I need to be able to scroll through the list of red items. (see picture)</p>
  <p>Right now, it responds to the scroll, but doesn't scroll all the way down the list and stop or stay at all. The list of item buttons also extends beyond the view and never compresses. Not sure if this is possible to fix, however.</p>
  <p><a href="https://i.stack.imgur.com/CV6W1.png" rel="nofollow noreferrer">Image of GUI</a></p>
  <p>Code:</p>
  <pre><code>class MainWindow(Screen):
  
      def sendData(self, data):
          pass
  
      def logOut(self):
          sm.current = &quot;login&quot;
  
      def on_enter(self):
          sundries = Sundry(join('Sundries.xlsx'))
          supplies = sundries.get_supplies()
          titleBtn = Button(text=supplies[0], size_hint=(0.4, 0.2), pos_hint={'x': 0,'y':0.8}, background_color=(0,0,255,1))
  
          root = ScrollView(size_hint=(0.4,0.8))
          layout = GridLayout(cols=1, spacing=1, size_hint=(0.8,0.7))
          # Make sure the height is such that there is something to scroll.
          for i in range(1, len(supplies), 1):
              btn = Button(text=supplies[i], size_hint_y=None, height=40,background_color=(255,0,0,1))
              layout.add_widget(btn)
  
          root.add_widget(layout)
          self.add_widget(root)
          self.add_widget(titleBtn)
  </code></pre>
  <p>Really appreciate your time if you can help me fix this :)</p>