什么是Dojo treegrid展开/折叠事件？

Question

我有一个非常大的treeGrid(一个节点中有~2000个元素).当我点击[+]展开它时似乎被冻结了.我想在点击后将鼠标光标状态更改为"等待",但是一旦展开就会改为"默认".假设我可以将它放在onRowClick或onOpen事件中但是什么是onComplete事件我可以重置光标？还有一种方法/属性来查看行是展开还是折叠？我想改变它的风格.

var layout = [
  {
    cells: [
      [
        { field: "userid", name: "User Id" },
        {
          field: "childItems",
          children: [
            { field: "unid", name: "unid" },
            { field: "username", name: "User Name" },
            { field: "budget", name: "Budget" }
          ],
          aggregate: "sum"
        }
      ]
    ]
  }
]

var jsonStore = new dojo.data.ItemFileWriteStore({ url: <...............>});

var grid = new dojox.grid.TreeGrid(
  {
    structure: layout,
    store: jsonStore,
    query: { type: 'userid' },
    queryOptions: { deep: true },
    rowSelector: true,
    openAtLevels: [false],
    autoWidth: true,
    autoHeight: true,
    onRowClick: function (evt) {
      var idx = evt.rowIndex,
        item = this.getItem(idx);

      // ??????
    }
  },
  dojo.byId("treeGrid")
);