Column sizing in Flutter DataGrid (SfDataGrid)

9 Sep 202124 minutes to read

SfDataGrid allows to set the column widths based on certain logic using SfDataGrid.columnWidthMode or GridColumn.columnWidthMode property. Below are the list of predefined column sizing options available.

Mode Description
ColumnWidthMode.auto Calculates the width of column based on GridColumn.columName and DataGridCell.value properties. So, the header and cell contents are not truncated.
ColumnWidthMode.fitByCellValue Calculates the width of column based on DataGridCell.value property. So, the cell contents are not truncated.
ColumnWidthMode.fitByColumnName Calculates the width of column based on GridColumn.columName property. So, the header contents are not truncated.
ColumnWidthMode.lastColumnFill Applies default Column width to all the columns except last column which is visible and the remaining width from total width of SfDataGrid is set to last column.
ColumnWidthMode.fill Divides the total width equally for columns.
ColumnWidthMode.none No sizing. Default column width or defined width set to column.

NOTE
ColumnWidthMode will not work when the column width defined explicitly. columnWidthMode calculates column width based on miniumWidth and maximumWidth properties.

The following example shows how to set the width equally for column based on the view port size.

@override
Widget build(BuildContext context) {
  return Scaffold(
      body: SfDataGrid(
          source: _employeeDataSource,
          columnWidthMode: ColumnWidthMode.fill,
          columns: <GridColumn>[
        GridColumn(
            columnName: 'id',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'ID',
                  overflow: TextOverflow.ellipsis,
                ))),
        GridColumn(
            columnName: 'name',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'Name',
                  overflow: TextOverflow.ellipsis,
                ))),
        GridColumn(
            columnName: 'designation',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'Designation',
                  overflow: TextOverflow.ellipsis,
                ))),
        GridColumn(
            columnName: 'city',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'city',
                  overflow: TextOverflow.ellipsis,
                ))),
        GridColumn(
            columnName: 'salary',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'Salary',
                  overflow: TextOverflow.ellipsis,
                )))
      ]));
}

NOTE
The GridColumn.columnWidthMode takes higher priority than the SfDataGrid.columnWidthMode.

columns filled based on view port size in flutter datagrid

Consider all the rows to calculate the autofit size

By default, the autofit calculation is performed for only visible rows. You can use the SfDataGrid.columnWidthCalculationRange property as ColumnWidthCalculationRange.allRows to perform the autofit calculation for all the available rows.

@override
Widget build(BuildContext context) {
  return SfDataGrid(
      source: _employeeDataSource,
      columnWidthMode: ColumnWidthMode.auto,
      columnWidthCalculationRange: ColumnWidthCalculationRange.allRows,
      columns: <GridColumn>[
        GridColumn(
            columnName: 'ID',
            label: Container(
                padding: EdgeInsets.all(16.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'ID',
                  softWrap: false,
                ))),
        GridColumn(
            columnName: 'Name',
            label: Container(
                padding: EdgeInsets.all(16.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'Name',
                  softWrap: false,
                ))),
        GridColumn(
            columnName: 'Designation',
            label: Container(
                padding: EdgeInsets.all(16.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'Designation',
                  softWrap: false,
                ))),
        GridColumn(
            columnName: 'Salary',
            label: Container(
                padding: EdgeInsets.all(16.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'Salary',
                  softWrap: false,
                )))
      ]);
}

Change the padding value for autofit calculation

By default, the EdgeInsets.all(16.0) is added with the auto width or height value. You can change the padding for specific columns by using the GridColumn.autoFitPadding property.

NOTE
GridColumn.autoFitPadding is applicable for header cell also.

@override
Widget build(BuildContext context) {
  return SfDataGrid(
      source: _employeeDataSource,
      columnWidthMode: ColumnWidthMode.auto,
      columns: <GridColumn>[
        GridColumn(
            columnName: 'id',
            autoFitPadding: EdgeInsets.all(10.0),
            label: Container(
                padding: EdgeInsets.all(10.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'ID',
                  softWrap: false,
                ))),
        GridColumn(
            columnName: 'name',
            autoFitPadding: EdgeInsets.all(10.0),
            label: Container(
                padding: EdgeInsets.all(10.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'Name',
                  softWrap: false,
                ))),
        GridColumn(
            columnName: 'designation',
            autoFitPadding: EdgeInsets.all(10.0),
            label: Container(
                padding: EdgeInsets.all(10.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'Designation',
                  softWrap: false,
                ))),
        GridColumn(
            columnName: 'salary',
            autoFitPadding: EdgeInsets.all(10.0),
            label: Container(
                padding: EdgeInsets.all(10.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'Salary',
                  softWrap: false,
                )))
      ]);
}

class EmployeeDataSource extends DataGridSource {
  EmployeeDataSource({required List<Employee> employees}) {
    _employeeData = employees
        .map<DataGridRow>((e) => DataGridRow(cells: [
              DataGridCell<int>(columnName: 'ID', value: e.id),
              DataGridCell<String>(columnName: 'Name', value: e.name),
              DataGridCell<String>(
                  columnName: 'Designation', value: e.designation),
              DataGridCell<int>(columnName: 'Salary', value: e.salary),
            ]))
        .toList();
  }

  List<DataGridRow> _employeeData = [];

  @override
  List<DataGridRow> get rows => _employeeData;

  @override
  DataGridRowAdapter buildRow(DataGridRow row) {
    return DataGridRowAdapter(
        cells: row.getCells().map<Widget>((cell) {
      return Container(
        alignment: Alignment.center,
        // The autoFitPadding and the cell padding value should be same.
        padding: EdgeInsets.all(10.0),
        child: Text(cell.value.toString()),
      );
    }).toList());
  }
}

flutter datagrid shows customization of padding in autofit calculation

Autofit calculation based on different TextStyle

By default, the cell width is calculated based on the default text style. To calculate the cell width based on different TextStyle, just override the computeHeaderCellWidth method for header and computeCellWidth method for cell and return the super method with the required TextStyle.

final CustomColumnSizer _customColumnSizer = CustomColumnSizer();

@override
Widget build(BuildContext context) {
  return SfDataGrid(
      source: _employeeDataSource,
      columnSizer: _customColumnSizer,
      columnWidthMode: ColumnWidthMode.auto,
      columns: <GridColumn>[
        GridColumn(
            columnName: 'ID',
            autoFitPadding: EdgeInsets.all(12.0),
            label: Container(
                padding: EdgeInsets.all(12.0),
                alignment: Alignment.center,
                child: Text(
                  'ID',
                ))),
        GridColumn(
            columnName: 'Name',
            autoFitPadding: EdgeInsets.all(12.0),
            label: Container(
                padding: EdgeInsets.all(12.0),
                alignment: Alignment.center,
                child: Text(
                  'Name',
                  style: TextStyle(
                      fontWeight: FontWeight.bold, fontStyle: FontStyle.italic),
                ))),
        GridColumn(
            columnName: 'Designation',
            autoFitPadding: EdgeInsets.all(12.0),
            label: Container(
                padding: EdgeInsets.all(12.0),
                alignment: Alignment.center,
                child: Text(
                  'Designation',
                  overflow: TextOverflow.ellipsis,
                  style: TextStyle(
                      fontWeight: FontWeight.bold, fontStyle: FontStyle.italic),
                ))),
        GridColumn(
            columnName: 'Salary',
            autoFitPadding: EdgeInsets.all(12.0),
            label: Container(
                padding: EdgeInsets.all(12.0),
                alignment: Alignment.center,
                child: Text('Salary'))),
      ]);
}

class EmployeeDataSource extends DataGridSource {
  EmployeeDataSource({required List<Employee> employees}) {
    _employeeData = employees
        .map<DataGridRow>((e) => DataGridRow(cells: [
              DataGridCell<int>(columnName: 'ID', value: e.id),
              DataGridCell<String>(columnName: 'Name', value: e.name),
              DataGridCell<String>(
                  columnName: 'Designation', value: e.designation),
              DataGridCell<int>(columnName: 'Salary', value: e.salary),
            ]))
        .toList();
  }

  List<DataGridRow> _employeeData = [];

  @override
  List<DataGridRow> get rows => _employeeData;

  @override
  DataGridRowAdapter buildRow(DataGridRow row) {
    return DataGridRowAdapter(
        cells: row.getCells().map<Widget>((e) {
      return Container(
          alignment: Alignment.center,
          padding: EdgeInsets.all(12.0),
          child: Text(e.value.toString(),
              style: (e.columnName == 'Name' || e.columnName == 'Designation')
                  ? TextStyle(
                      fontWeight: FontWeight.bold, fontStyle: FontStyle.italic)
                  : null));
    }).toList());
  }
}

class CustomColumnSizer extends ColumnSizer {
  @override
  double computeHeaderCellWidth(GridColumn column, TextStyle style) {
    if (column.columnName == 'Name' || column.columnName == 'Designation') {
      style =
          TextStyle(fontWeight: FontWeight.bold, fontStyle: FontStyle.italic);
    }
    return super.computeHeaderCellWidth(column, style);
  }

  @override
  double computeCellWidth(GridColumn column, DataGridRow row, Object? cellValue,
      TextStyle textStyle) {
    if (column.columnName == 'Name' || column.columnName == 'Designation') {
      textStyle =
          TextStyle(fontWeight: FontWeight.bold, fontStyle: FontStyle.italic);
    }
    return super.computeCellWidth(column, row, cellValue, textStyle);
  }
}

NOTE
Download demo application from GitHub.

flutter datagrid shows autofit the columns based on different text style

Autofit calculation based on the formatted value

By default, the cell width is calculated based on the DataGridCell.value property. To autofit the cell width based on the displayed formatted value (i.e, DateFormat and NumberFormat), simply override the computeCellWidth method and return the super method with the required cellValue.

import 'package:intl/intl.dart';

final CustomColumnSizer _customColumnSizer = CustomColumnSizer();

@override
Widget build(BuildContext context) {
  return SfDataGrid(
      source: _employeeDataSource,
      columnSizer: _customColumnSizer,
      columnWidthMode: ColumnWidthMode.fitByCellValue,
      columns: <GridColumn>[
        GridColumn(
            columnName: 'ID',
            label: Container(
                padding: EdgeInsets.all(16.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'ID',
                  softWrap: false,
                ))),
        GridColumn(
            columnName: 'Name',
            label: Container(
                padding: EdgeInsets.all(16.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'Name',
                  softWrap: false,
                ))),
        GridColumn(
            columnName: 'DOB',
            label: Container(
                padding: EdgeInsets.all(16.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'DOB',
                  softWrap: false,
                ))),
        GridColumn(
            columnName: 'Salary',
            label: Container(
                padding: EdgeInsets.all(16.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'Salary',
                  softWrap: false,
                )))
      ]);
}

class EmployeeDataSource extends DataGridSource {
  EmployeeDataSource({required List<Employee> employees}) {
    _employeeData = employees
        .map<DataGridRow>((e) => DataGridRow(cells: [
              DataGridCell<int>(columnName: 'ID', value: e.id),
              DataGridCell<String>(columnName: 'Name', value: e.name),
              DataGridCell<DateTime>(columnName: 'DOB', value: e.dob),
              DataGridCell<int>(columnName: 'Salary', value: e.salary),
            ]))
        .toList();
  }

  List<DataGridRow> _employeeData = [];

  @override
  List<DataGridRow> get rows => _employeeData;

  @override
  DataGridRowAdapter buildRow(DataGridRow row) {
    return DataGridRowAdapter(
        cells: row.getCells().map<Widget>((e) {
      late String cellValue;
      if (e.columnName == 'DOB') {
        cellValue = DateFormat.yMMMMd('en_US').format(e.value);
      } else if (e.columnName == 'Salary') {
        cellValue =
            NumberFormat.simpleCurrency(decimalDigits: 0).format(e.value);
      } else {
        cellValue = e.value.toString();
      }

      return Container(
        alignment: Alignment.center,
        padding: EdgeInsets.all(16.0),
        child: Text(cellValue),
      );
    }).toList());
  }
}

class CustomColumnSizer extends ColumnSizer {
  @override
  double computeCellWidth(GridColumn column, DataGridRow row, Object? cellValue,
      TextStyle textStyle) {
    if (column.columnName == 'DOB') {
      cellValue = DateFormat.yMMMMd('en_US').format(cellValue as DateTime);
    } else if (column.columnName == 'Salary') {
      cellValue =
          NumberFormat.simpleCurrency(decimalDigits: 0).format(cellValue);
    }

    return super.computeCellWidth(column, row, cellValue, textStyle);
  }
}

NOTE
Download demo application from GitHub.

flutter datagrid shows autofit the columns based on formatted cell value

Fill remaining width for any column

While setting SfDataGrid.columnWidthMode as lastColumnFill remaining width is applied to last column. The remaining width to specific column can be applied by setting GridColumn.columnWidthMode property.

@override
Widget build(BuildContext context) {
  return Scaffold(
      body: SfDataGrid(
          source: _employeeDataSource,
          columnWidthMode: ColumnWidthMode.lastColumnFill,
          columns: <GridColumn>[
        GridColumn(
            columnName: 'id',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'ID',
                  overflow: TextOverflow.ellipsis,
                ))),
        GridColumn(
            columnName: 'name',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'Name',
                  overflow: TextOverflow.ellipsis,
                ))),
        GridColumn(
            columnName: 'salary',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'Salary',
                  overflow: TextOverflow.ellipsis,
                ))),
        GridColumn(
            columnName: 'designation',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'Designation',
                  overflow: TextOverflow.ellipsis,
                )))
      ]));
}

The last column is filled in view in flutter datagrid

The below example shows Name column is set as lastColumnFill mode.

@override
Widget build(BuildContext context) {
  return Scaffold(
      body: SfDataGrid(
          source: _employeeDataSource,
          columns: <GridColumn>[
        GridColumn(
            columnName: 'id',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'ID',
                  overflow: TextOverflow.ellipsis,
                ))),
        GridColumn(
            columnName: 'name',
            columnWidthMode: ColumnWidthMode.lastColumnFill,
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'Name',
                  overflow: TextOverflow.ellipsis,
                ))),
        GridColumn(
            columnName: 'salary',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerRight,
                child: Text(
                  'Salary',
                  overflow: TextOverflow.ellipsis,
                ))),
        GridColumn(
            columnName: 'designation',
            label: Container(
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerLeft,
                child: Text(
                  'Designation',
                  overflow: TextOverflow.ellipsis,
                )))
      ]));
}

Name column is filled with remaining available space in flutter datagrid

Recalculating column widths when datasource is changed

By default, column widths are calculated based on the columnWidthMode property on initial loading of datagrid. When the datasource is changed for same datagrid at run time, datagrid does not recalculate the column widths. To recalculate the column widths at run time when datasource is changed or data is updated, you can override the shouldRecalculateColumnWidths method and return true.

Returning true may impact performance as the column widths are recalculated again (whenever the notifyListeners is called). If you are aware that column widths are going to be same whenever underlying data changes, return false from this method.

class EmployeeDataSource extends DataGridSource {
  EmployeeDataSource({required List<Employee> employees}) {
    dataGridRows = employees
        .map<DataGridRow>((dataGridRow) => DataGridRow(cells: [
              DataGridCell<int>(columnName: 'id', value: dataGridRow.id),
              DataGridCell<String>(columnName: 'name', value: dataGridRow.name),
              DataGridCell<String>(
                  columnName: 'designation', value: dataGridRow.designation),
              DataGridCell<int>(
                  columnName: 'salary', value: dataGridRow.salary),
            ]))
        .toList();
  }

  List<DataGridRow> dataGridRows = [];

  @override
  List<DataGridRow> get rows => dataGridRows;

  @override
  DataGridRowAdapter? buildRow(DataGridRow row) {
    return DataGridRowAdapter(
        cells: row.getCells().map<Widget>((dataGridCell) {
      return Container(
          alignment: (dataGridCell.columnName == 'id' ||
                  dataGridCell.columnName == 'salary')
              ? Alignment.centerRight
              : Alignment.centerLeft,
          padding: EdgeInsets.symmetric(horizontal: 16.0),
          child: Text(
            dataGridCell.value.toString(),
            overflow: TextOverflow.ellipsis,
          ));
    }).toList());
  }

  @override
  bool shouldRecalculateColumnWidths() {
    return true;
  }
}