title: Kivy slider override on_touch_up
body: <p>I am trying to build my first kivy app and create a simple audio cutting tool. I am using the slider widget to show the position in a playing song (that works so far) but I would like to enable the user to move the slider to a desired position and play the song from that chosen position. </p>
  
  <p>Code I have so far:</p>
  
  <p>file main.py:</p>
  
  <p>automatic moving when the song is playing (callback of clock interval):</p>
  
  <pre><code>def my_callback(self, dt):
      if not self.loaded:
          pass
      else:
          if self.playing:
              self.position = self.song.get_pos()
              self.truePos_slider.value = 100 * self.position / self.duration
  </code></pre>
  
  <p>when user touches the slider and move it to another position this should happen:</p>
  
  <pre><code>def slider_move(self):
      if self.loaded:
          self.position = (self.truePos_slider.value/100) * self.duration
  </code></pre>
  
  <p>file layout.kv:</p>
  
  <pre><code>...
          BoxLayout:
              orientation: 'vertical'
              Slider:
                  id: truePos_slider
                  on_release: root.slider_move()
  ...
  </code></pre>
  
  <p>The problem is that the Slider from kivy doesn't have the on_release event as Button has. I think my problem is similar as described here:</p>
  
  <p><a href="https://stackoverflow.com/questions/32127576/kivy-slider-event-on-release/44620490#44620490">Kivy slider event on_release</a></p>
  
  <p>I actually like the solution from inclement, but I don't know where exactly should I put the code of MySliderSubclass with the override method in order to make my layout.kv file recognize it. Could you please help me?</p>
  
  <p>I am sorry if it's a stupid question, I am actually new to Python too...</p>