Flutter PaginatedDataTable rowsPerPage

  import 'package:flutter/material.dart';

    class DemoTable extends StatelessWidget {
      @override
      Widget build(BuildContext context) {
        return _DemoTableBody();
      }
    }

    class _DemoTableBody extends StatefulWidget {
      @override
      __DemoTableBodyState createState() => __DemoTableBodyState();
    }

    class __DemoTableBodyState extends State<_DemoTableBody> {

      int _rowsPerPage = PaginatedDataTable.defaultRowsPerPage;

      // A Variable to hold the length of table based on the condition of comparing the actual data length with the PaginatedDataTable.defaultRowsPerPage

      int _rowsPerPage1 = PaginatedDataTable.defaultRowsPerPage;

      @override
      Widget build(BuildContext context) {

      //Obtain the data to be displayed from the Derived DataTableSource

        var dts = DTS(); 

        // dts.rowcount provides the actual data length, ForInstance, If we have 7 data stored in the DataTableSource Object, then we will get 12 as dts.rowCount

       var tableItemsCount = dts.rowCount; 

        // PaginatedDataTable.defaultRowsPerPage provides value as 10

        var defaultRowsPerPage = PaginatedDataTable.defaultRowsPerPage;

        // We are checking whether tablesItemCount is less than the defaultRowsPerPage which means we are actually checking the length of the data in DataTableSource with default PaginatedDataTable.defaultRowsPerPage i.e, 10

        var isRowCountLessDefaultRowsPerPage = tableItemsCount < defaultRowsPerPage;

        // Assigning rowsPerPage as 10 or acutal length of our data in stored in the DataTableSource Object

        _rowsPerPage =
            isRowCountLessDefaultRowsPerPage ? tableItemsCount : defaultRowsPerPage;
        return Scaffold(
          appBar: AppBar(
            title: Text("Demo Paginated Table"),
          ),
          body: SingleChildScrollView(
            child: PaginatedDataTable(
              header: Text('data with 7 rows per page'),
              // comparing the actual data length with the PaginatedDataTable.defaultRowsPerPage and then assigning it to _rowPerPage1 variable which then set using the setsState()
              onRowsPerPageChanged: isRowCountLessDefaultRowsPerPage // The source of problem!
                  ? null
                  : (rowCount) {
                      setState(() {
                        _rowsPerPage1 = rowCount;
                      });
                    },
              columns: <DataColumn>[
                DataColumn(label: Text('row')),
                DataColumn(label: Text('name')),
              ],
              source: dts,
              //Set Value for rowsPerPage based on comparing the actual data length with the PaginatedDataTable.defaultRowsPerPage 
              rowsPerPage:
                  isRowCountLessDefaultRowsPerPage ? _rowsPerPage : _rowsPerPage1,
            ),
          ),
        );
      }
    }

    class DTS extends DataTableSource {
      @override
      DataRow getRow(int index) {
        return DataRow.byIndex(
          index: index,
          cells: [
            DataCell(Text('row #$index')),
            DataCell(Text('name #$index')),
          ],
        );
      }

      @override
      int get rowCount => 9; // Manipulate this to which ever value you wish

      @override
      bool get isRowCountApproximate => false;

      @override
      int get selectedRowCount => 0;
    }

This error is caused by the values provided by flutter. rowsPerPage can only be 10, 20, 50 and 100.

snapshot source PaginatedDataTable

This is specified in the source PaginatedDataTable.