code: @Override
      public int viewToModel(float x, float y, Shape a, Position.Bias[] bias)
      {
          if (view != null)
          {
              int retValue = view.viewToModel(x, y, a, bias);
              return retValue;
          }
          return -1;
      }
docs: Provides a mapping from the view coordinate space to the logical
  coordinate space of the model.
  
  @param x
  x coordinate of the view location to convert
  @param y
  y coordinate of the view location to convert
  @param a
  the allocated region to render into
  @return the location within the model that best represents the given
  point in the view