AG-Grid でヘッダーの下にアクションエリアを表示する方法

import { AgGridReact } from "ag-grid-react";
import { useCallback, useMemo } from "react";

import type {
  ColDef,
  IsFullWidthRowParams,
  RowHeightParams,
  RowSelectedEvent,
} from "ag-grid-community";

type Data = { id: number; name: string };

// 表示するコンポーネント
const FullWidthCell = ({ api }: IsFullWidthRowParams) => {
  const length = useMemo(() => api.getSelectedRows().length, [api]);
  const selectedIds = useMemo(
    () => api.getSelectedRows().map((v) => v.id),
    [api]
  );

  return (
    <div
      style={{
        borderBottom: `1px solid #eee`,
        width: "100%",
        height: "100%",
        paddingLeft: 24,
      }}
    >
      {length}件を選択中。 {selectedIds.join(",")}
    </div>
  );
};

export const DataGrid = (): JSX.Element => {
  const rowData: Array<Data> = [
    { id: 1, name: "Item 1" },
    { id: 2, name: "Item 2" },
    { id: 3, name: "Item 3" },
    { id: 4, name: "Item 4" },
    { id: 5, name: "Item 5" },
  ];

  const columnDefs: ColDef<Data>[] = [
    {
      field: "check",
      headerCheckboxSelection: true,
      checkboxSelection: true,
    },
    { field: "id" },
    { field: "name" },
  ];

  // 上部に固定
  const isFullWidthRow = useCallback(
    (params: IsFullWidthRowParams) => params.rowNode.rowPinned === "top",
    []
  );

  // 高さを固定
  const getRowHeight = useCallback(
    (params: RowHeightParams) => (params.node.rowPinned ? 40 : undefined),
    []
  );

  // 選択時に有効を切り替え
  const onRowSelected = useCallback((event: RowSelectedEvent) => {
    event.api.setPinnedTopRowData(
      event.api.getSelectedRows().length > 0 ? [true] : undefined
    );
  }, []);

  return (
    <AgGridReact<Data>
      rowData={rowData}
      columnDefs={columnDefs}
      fullWidthCellRenderer={FullWidthCell}
      isFullWidthRow={isFullWidthRow}
      getRowHeight={getRowHeight}
      onRowSelected={onRowSelected}
      domLayout="autoHeight"
      rowSelection="multiple"
      rowMultiSelectWithClick
    />
  );
};