@Override
 protected void onAttachedToWindow() {
   super.onAttachedToWindow();
   seekBar.setOnSeekArcChangeListener(presenter);
   if (!isInEditMode()) presenter.takeView(this);
   subscribeClicks();
 }
 @Override
 protected void onDetachedFromWindow() {
   super.onDetachedFromWindow();
   unsubscribeClicks();
   presenter.dropView(this);
   seekBar.setOnSeekArcChangeListener(null);
   destroyVisualizer();
 }