code: public static void setHotspotBounds(Drawable drawable, int left, int top, int right, int bottom) {
          if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
              //We don't want the full size rect, Lollipop ripple would be too big
              int size = (right - left) / 8;
              drawable.setHotspotBounds(left + size, top + size, right - size, bottom - size);
          } else {
              drawable.setBounds(left, top, right, bottom);
          }
      }
docs: As our DiscreteSeekBar implementation uses a circular drawable on API < 21
  we want to use the same method to set its bounds as the Ripple's hotspot bounds.
  
  @param drawable Drawable
  @param left     Left
  @param top      Top
  @param right    Right
  @param bottom   Bottom