com.smartgwt.client.widgets.grid.events

## Interface HasGroupByHandlers

- All Superinterfaces:
    com.google.gwt.event.shared.HasHandlers
  All Known Implementing Classes:
    CalendarView, CubeGrid, DateGrid, EditTree, ListGrid, ListPalette, Menu, MenuPalette, PickListMenu, RecordEditor, SelectionTreeMenu, TableView, TreeGrid, TreePalette

      public interface HasGroupByHandlers
      extends com.google.gwt.event.shared.HasHandlers

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `com.google.gwt.event.shared.HandlerRegistration` | `addGroupByHandler(GroupByHandler handler)` Callback fired when the user attempts to group or ungroup the listGrid, or when `groupBy()` is called programmatically.

    - ### Methods inherited from interface com.google.gwt.event.shared.HasHandlers

      `fireEvent`

- - ### Method Detail

    - #### addGroupByHandler

          com.google.gwt.event.shared.HandlerRegistration addGroupByHandler(GroupByHandler handler)

      Callback fired when the user attempts to group or ungroup the listGrid, or when `groupBy()` is called programmatically. This event may be cancelled.

      This notification is fired before the `data` is updated to reflect the grouping. See also `ListGrid.groupByComplete()`.

      Note that this method is not called when the data is regrouped, either `programmatically`, or in response to new data arriving from the server, and such regrouping can't be canceled - instead use callback `ListGrid.regroup()`.

      Parameters:
        `handler` - the groupBy handler
      Returns:
        `HandlerRegistration` used to remove this handler