code: @Override public void updatePosition(float verticalDragOffset) {
      ViewHelper.setPivotX(getView(), getView().getWidth() - getMarginRight());
      ViewHelper.setPivotY(getView(), getView().getHeight() - getMarginBottom());
    }
docs: Uses Nineoldandroids to change the position of the view.
  
  @param verticalDragOffset used to calculate the new position.