src/lay/modules/table.js
function(hide){
      var othis = $(this)
      ,elemCell = othis.children(ELEM_CELL);
      
      if(hide){
        othis.find('.layui-table-grid-down').remove();
      } else if(elemCell.prop('scrollWidth') > elemCell.outerWidth()){
        if(elemCell.find('.'+ ELEM_GRID_DOWN)[0]) return;
        othis.append('<div class="'+ ELEM_GRID_DOWN +'"><i class="layui-icon layui-icon-down"></i></div>');
      }
    }
function(hide){
      var othis = $(this)
      ,elemCell = othis.children(ELEM_CELL);
      
      if(hide){
        othis.find('.layui-table-grid-down').remove();
      } else if(elemCell.prop('scrollWidth') > elemCell.outerWidth()){
        if(elemCell.find('.'+ ELEM_GRID_DOWN)[0]) return;
        othis.append('<div class="'+ ELEM_GRID_DOWN +'"><i class="layui-icon layui-icon-down"></i></div>');
      }
    }
单元格展开图标