text: from kivy.app import App
  
  from kivy.uix.floatlayout import FloatLayout
  from kivy.graphics import Color, Ellipse, Line
  from kivy.gesture import Gesture, GestureDatabase
  
  from my_gestures import cross, circle, check, square
  
  
  def simplegesture(name, point_list):
      """
      A simple helper function
      """
      g = Gesture()
      g.add_stroke(point_list)
      g.normalize()
      g.name = name
      return g
  
  
  class GestureBoard(FloatLayout):
      """
      Our application main widget, derived from touchtracer example, use data
      constructed from touches to match symboles loaded from my_gestures.
  
      """
      def __init__(self, *args, **kwargs):
          super(GestureBoard, self).__init__()
          self.gdb = GestureDatabase()
  
          # add pre-recorded gestures to database
          self.gdb.add_gesture(cross)
          self.gdb.add_gesture(check)
          self.gdb.add_gesture(circle)
          self.gdb.add_gesture(square)
  
      def on_touch_down(self, touch):
          # start collecting points in touch.ud
          # create a line to display the points
          userdata = touch.ud
          with self.canvas:
              Color(1, 1, 0)
              d = 30.
              Ellipse(pos=(touch.x - d / 2, touch.y - d / 2), size=(d, d))
              userdata['line'] = Line(points=(touch.x, touch.y))
          return True
  
      def on_touch_move(self, touch):
          # store points of the touch movement
          try:
              touch.ud['line'].points += [touch.x, touch.y]
              return True
          except (KeyError) as e:
              pass
  
      def on_touch_up(self, touch):
          # touch is over, display informations, and check if it matches some
          # known gesture.
          g = simplegesture('', list(zip(touch.ud['line'].points[::2],
                                         touch.ud['line'].points[1::2])))
          # gestures to my_gestures.py
          print("gesture representation:", self.gdb.gesture_to_str(g))
  
          # print match scores between all known gestures
          print("cross:", g.get_score(cross))
          print("check:", g.get_score(check))
          print("circle:", g.get_score(circle))
          print("square:", g.get_score(square))
  
          # use database to find the more alike gesture, if any
          g2 = self.gdb.find(g, minscore=0.70)
  
          print(g2)
          if g2:
              if g2[1] == circle:
                  print("circle")
              if g2[1] == square:
                  print("square")
              if g2[1] == check:
                  print("check")
              if g2[1] == cross:
                  print("cross")
  
          # erase the lines on the screen, this is a bit quick&dirty, since we
          # can have another touch event on the way...
          self.canvas.clear()
  
  
  class DemoGesture(App):
      def build(self):
          return GestureBoard()
  
  if __name__ == '__main__':
      DemoGesture().run()
  