anchor.diff:        _scrollStep -= _visibleItemsWindowSize;
       }
   
  -    checkSetScrollStepRedraw(_scrollStep, _scrollListDiv);
  +    checkSetScrollStepRedraw(_scrollStep);
     }
   
     num getMinMarginLeft() =>
         (0 - _spanWidth * items.length + ref('itemsDiv').marginEdge.width);
   
  -  checkSetScrollStepRedraw(_scrollStep, _scrollListDiv){
  +  checkSetScrollStepRedraw(_scrollStep){
       if (_scrollStep > 0){
         _scrollStep = 0;
       }
  
positive.code:   get _visibleItemsWindowSize => ref('itemsDiv') != null ? ref('itemsDiv').marginEdge.width : null;
    get _spanWidth => ref('${items[0][VALUE]}') != null ? ref('${items[0][VALUE]}').marginEdge.width : null;
  
    get _shouldDrawRight => ref('round-list').style.marginLeft > getMinMarginLeft();
    get _shouldDrawLeft => ref('round-list').style.marginLeft < 0;
  
    var browserWindow;
  
    static const String VALUE = 'value';
    static const String TEXT = 'text';
  
negative.code:     var mostRightItem =  ((-_leftMargin + _visibleItemsWindowSize) / _spanWidth).round();
  
      if (selectedItemOrder < mostLeftItem || selectedItemOrder >= mostRightItem) {
        checkSetScrollStepRedraw(_scrollStep);
      }
      else {
        redraw();
  