When nodes in a treegrid are rearranged by drag and drop:
This is done by:
dragModel.diDrag option.dropModel.diHelper specifies the displayed columns in the draggable helper.dragModel.isDraggable is implemented to exclude summary rows and root nodes.dropModel.isDroppable is implemented to exclude summary rows, ancestor rows of dropped rows and if dragged and dropped over rows are same.dropModel.drop moves the rows from old parent to new parent. You can override it to do custom action upon drop of rows.First of all mutiple row selection is turned on or checkbox selection is turned on.
Then dragModel.dragNodes method is implemented as in this example to return array of selected or checked rows.