code: @Override
      public String filter(String value, String previousValue){
          if(previousValue != null && value.length() > previousValue.length())
              return value;
          return value.equals("0") || value.equals("0.0") ? "" : value;
      }
docs: The default filter removes the display of '0' or '0.0' if the user has erased the text. This is
  to prevent a number being shown when the user tries to erase it.
  @param value the value that is being filtered
  @param previousValue the previous value
  @return