// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:math' as math;

import 'package:flutter/foundation.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';

import 'checkbox.dart';
import 'constants.dart';
import 'data_table_theme.dart';
import 'debug.dart';
import 'divider.dart';
import 'dropdown.dart';
import 'icons.dart';
import 'ink_well.dart';
import 'material.dart';
import 'material_state.dart';
import 'theme.dart';
import 'theme_data.dart';
import 'tooltip.dart';

/// Signature for [DataColumn.onSort] callback.
typedef DataColumnSortCallback = void Function(int columnIndex, bool ascending);

/// Column configuration for a [DataTable].
///
/// One column configuration must be provided for each column to
/// display in the table. The list of [DataColumn] objects is passed
/// as the `columns` argument to the [new DataTable] constructor.
@immutable
class DataColumn {
  /// Creates the configuration for a column of a [DataTable].
  ///
  /// The [label] argument must not be null.
  const DataColumn({
    required this.label,
    this.tooltip,
    this.numeric = false,
    this.onSort,
  }) : assert(label != null);

  /// The column heading.
  ///
  /// Typically, this will be a [Text] widget. It could also be an
  /// [Icon] (typically using size 18), or a [Row] with an icon and
  /// some text.
  ///
  /// By default, this widget will only occupy the minimal space. If you want
  /// it to take the entire remaining space, e.g. when you want to use [Center],
  /// you can wrap it with an [Expanded].
  ///
  /// The label should not include the sort indicator.
  final Widget label;

  /// The column heading's tooltip.
  ///
  /// This is a longer description of the column heading, for cases
  /// where the heading might have been abbreviated to keep the column
  /// width to a reasonable size.
  final String? tooltip;

  /// Whether this column represents numeric data or not.
  ///
  /// The contents of cells of columns containing numeric data are
  /// right-aligned.
  final bool numeric;

  /// Called when the user asks to sort the table using this column.
  ///
  /// If null, the column will not be considered sortable.
  ///
  /// See [DataTable.sortColumnIndex] and [DataTable.sortAscending].
  final DataColumnSortCallback? onSort;

  bool get _debugInteractive => onSort != null;
}

/// Row configuration and cell data for a [DataTable].
///
/// One row configuration must be provided for each row to
/// display in the table. The list of [DataRow] objects is passed
/// as the `rows` argument to the [new DataTable] constructor.
///
/// The data for this row of the table is provided in the [cells]
/// property of the [DataRow] object.
@immutable
class DataRow {
  /// Creates the configuration for a row of a [DataTable].
  ///
  /// The [cells] argument must not be null.
  const DataRow({
    this.key,
    this.selected = false,
    this.onSelectChanged,
    this.color,
    required this.cells,
  }) : assert(cells != null);

  /// Creates the configuration for a row of a [DataTable], deriving
  /// the key from a row index.
  ///
  /// The [cells] argument must not be null.
  DataRow.byIndex({
    int? index,
    this.selected = false,
    this.onSelectChanged,
    this.color,
    required this.cells,
  }) : assert(cells != null),
       key = ValueKey<int?>(index);

  /// A [Key] that uniquely identifies this row. This is used to
  /// ensure that if a row is added or removed, any stateful widgets
  /// related to this row (e.g. an in-progress checkbox animation)
  /// remain on the right row visually.
  ///
  /// If the table never changes once created, no key is necessary.
  final LocalKey? key;

  /// Called when the user selects or unselects a selectable row.
  ///
  /// If this is not null, then the row is selectable. The current
  /// selection state of the row is given by [selected].
  ///
  /// If any row is selectable, then the table's heading row will have
  /// a checkbox that can be checked to select all selectable rows
  /// (and which is checked if all the rows are selected), and each
  /// subsequent row will have a checkbox to toggle just that row.
  ///
  /// A row whose [onSelectChanged] callback is null is ignored for
  /// the purposes of determining the state of the "all" checkbox,
  /// and its checkbox is disabled.
  ///
  /// If a [DataCell] in the row has its [DataCell.onTap] callback defined,
  /// that callback behavior overrides the gesture behavior of the row for
  /// that particular cell.
  final ValueChanged<bool?>? onSelectChanged;

  /// Whether the row is selected.
  ///
  /// If [onSelectChanged] is non-null for any row in the table, then
  /// a checkbox is shown at the start of each row. If the row is
  /// selected (true), the checkbox will be checked and the row will
  /// be highlighted.
  ///
  /// Otherwise, the checkbox, if present, will not be checked.
  final bool selected;

  /// The data for this row.
  ///
  /// There must be exactly as many cells as there are columns in the
  /// table.
  final List<DataCell> cells;

  /// The color for the row.
  ///
  /// By default, the color is transparent unless selected. Selected rows has
  /// a grey translucent color.
  ///
  /// The effective color can depend on the [MaterialState] state, if the
  /// row is selected, pressed, hovered, focused, disabled or enabled. The
  /// color is painted as an overlay to the row. To make sure that the row's
  /// [InkWell] is visible (when pressed, hovered and focused), it is
  /// recommended to use a translucent color.
  ///
  /// ```dart
  /// DataRow(
  ///   color: MaterialStateProperty.resolveWith<Color>((Set<MaterialState> states) {
  ///     if (states.contains(MaterialState.selected))
  ///       return Theme.of(context).colorScheme.primary.withOpacity(0.08);
  ///     return null;  // Use the default value.
  ///   }),
  /// )
  /// ```
  ///
  /// See also:
  ///
  ///  * The Material Design specification for overlay colors and how they
  ///    match a component's state:
  ///    <https://material.io/design/interaction/states.html#anatomy>.
  final MaterialStateProperty<Color?>? color;

  bool get _debugInteractive => onSelectChanged != null || cells.any((DataCell cell) => cell._debugInteractive);
}

/// The data for a cell of a [DataTable].
///
/// One list of [DataCell] objects must be provided for each [DataRow]
/// in the [DataTable], in the new [DataRow] constructor's `cells`
/// argument.
@immutable
class DataCell {
  /// Creates an object to hold the data for a cell in a [DataTable].
  ///
  /// The first argument is the widget to show for the cell, typically
  /// a [Text] or [DropdownButton] widget; this becomes the [child]
  /// property and must not be null.
  ///
  /// If the cell has no data, then a [Text] widget with placeholder
  /// text should be provided instead, and then the [placeholder]
  /// argument should be set to true.
  const DataCell(
    this.child, {
    this.placeholder = false,
    this.showEditIcon = false,
    this.onTap,
  }) : assert(child != null);

  /// A cell that has no content and has zero width and height.
  static const DataCell empty = DataCell(SizedBox(width: 0.0, height: 0.0));

  /// The data for the row.
  ///
  /// Typically a [Text] widget or a [DropdownButton] widget.
  ///
  /// If the cell has no data, then a [Text] widget with placeholder
  /// text should be provided instead, and [placeholder] should be set
  /// to true.
  ///
  /// {@macro flutter.widgets.ProxyWidget.child}
  final Widget child;

  /// Whether the [child] is actually a placeholder.
  ///
  /// If this is true, the default text style for the cell is changed
  /// to be appropriate for placeholder text.
  final bool placeholder;

  /// Whether to show an edit icon at the end of the cell.
  ///
  /// This does not make the cell actually editable; the caller must
  /// implement editing behavior if desired (initiated from the
  /// [onTap] callback).
  ///
  /// If this is set, [onTap] should also be set, otherwise tapping
  /// the icon will have no effect.
  final bool showEditIcon;

  /// Called if the cell is tapped.
  ///
  /// If non-null, tapping the cell will call this callback. If
  /// null, tapping the cell will attempt to select the row (if
  /// [DataRow.onSelectChanged] is provided).
  ///
  /// To define a tap behavior for the entire row, see
  /// [DataRow.onSelectChanged].
  final VoidCallback? onTap;

  bool get _debugInteractive => onTap != null;
}

/// A material design data table.
///
/// {@youtube 560 315 https://www.youtube.com/watch?v=ktTajqbhIcY}
///
/// Displaying data in a table is expensive, because to lay out the
/// table all the data must be measured twice, once to negotiate the
/// dimensions to use for each column, and once to actually lay out
/// the table given the results of the negotiation.
///
/// For this reason, if you have a lot of data (say, more than a dozen
/// rows with a dozen columns, though the precise limits depend on the
/// target device), it is suggested that you use a
/// [PaginatedDataTable] which automatically splits the data into
/// multiple pages.
///
/// {@tool dartpad --template=stateless_widget_scaffold}
///
/// This sample shows how to display a [DataTable] with three columns: name, age, and
/// role. The columns are defined by three [DataColumn] objects. The table
/// contains three rows of data for three example users, the data for which
/// is defined by three [DataRow] objects.
///
/// ![](https://flutter.github.io/assets-for-api-docs/assets/material/data_table.png)
///
/// ```dart
/// Widget build(BuildContext context) {
///   return DataTable(
///     columns: const <DataColumn>[
///       DataColumn(
///         label: Text(
///           'Name',
///           style: TextStyle(fontStyle: FontStyle.italic),
///         ),
///       ),
///       DataColumn(
///         label: Text(
///           'Age',
///           style: TextStyle(fontStyle: FontStyle.italic),
///         ),
///       ),
///       DataColumn(
///         label: Text(
///           'Role',
///           style: TextStyle(fontStyle: FontStyle.italic),
///         ),
///       ),
///     ],
///     rows: const <DataRow>[
///       DataRow(
///         cells: <DataCell>[
///           DataCell(Text('Sarah')),
///           DataCell(Text('19')),
///           DataCell(Text('Student')),
///         ],
///       ),
///       DataRow(
///         cells: <DataCell>[
///           DataCell(Text('Janine')),
///           DataCell(Text('43')),
///           DataCell(Text('Professor')),
///         ],
///       ),
///       DataRow(
///         cells: <DataCell>[
///           DataCell(Text('William')),
///           DataCell(Text('27')),
///           DataCell(Text('Associate Professor')),
///         ],
///       ),
///     ],
///   );
/// }
/// ```
///
/// {@end-tool}
///
///
/// {@tool dartpad --template=stateful_widget_scaffold}
///
/// This sample shows how to display a [DataTable] with alternate colors per
/// row, and a custom color for when the row is selected.
///
/// ```dart
/// static const int numItems = 10;
/// List<bool> selected = List<bool>.generate(numItems, (index) => false);
///
/// @override
/// Widget build(BuildContext context) {
///   return SizedBox(
///     width: double.infinity,
///     child: DataTable(
///       columns: const <DataColumn>[
///         DataColumn(
///           label: const Text('Number'),
///         ),
///       ],
///       rows: List<DataRow>.generate(
///         numItems,
///         (index) => DataRow(
///           color: MaterialStateProperty.resolveWith<Color?>((Set<MaterialState> states) {
///             // All rows will have the same selected color.
///             if (states.contains(MaterialState.selected))
///               return Theme.of(context).colorScheme.primary.withOpacity(0.08);
///             // Even rows will have a grey color.
///             if (index % 2 == 0)
///               return Colors.grey.withOpacity(0.3);
///             return null;  // Use default value for other states and odd rows.
///           }),
///           cells: [DataCell(Text('Row $index'))],
///           selected: selected[index],
///           onSelectChanged: (bool? value) {
///             setState(() {
///               selected[index] = value!;
///             });
///           },
///         ),
///       ),
///     ),
///   );
/// }
/// ```
/// {@end-tool}
///
/// [DataTable] can be sorted on the basis of any column in [columns] in
/// ascending or descending order. If [sortColumnIndex] is non-null, then the
/// table will be sorted by the values in the specified column. The boolean
/// [sortAscending] flag controls the sort order.
///
/// See also:
///
///  * [DataColumn], which describes a column in the data table.
///  * [DataRow], which contains the data for a row in the data table.
///  * [DataCell], which contains the data for a single cell in the data table.
///  * [PaginatedDataTable], which shows part of the data in a data table and
///    provides controls for paging through the remainder of the data.
///  * <https://material.io/design/components/data-tables.html>
class DataTable extends StatelessWidget {
  /// Creates a widget describing a data table.
  ///
  /// The [columns] argument must be a list of as many [DataColumn]
  /// objects as the table is to have columns, ignoring the leading
  /// checkbox column if any. The [columns] argument must have a
  /// length greater than zero and must not be null.
  ///
  /// The [rows] argument must be a list of as many [DataRow] objects
  /// as the table is to have rows, ignoring the leading heading row
  /// that contains the column headings (derived from the [columns]
  /// argument). There may be zero rows, but the rows argument must
  /// not be null.
  ///
  /// Each [DataRow] object in [rows] must have as many [DataCell]
  /// objects in the [DataRow.cells] list as the table has columns.
  ///
  /// If the table is sorted, the column that provides the current
  /// primary key should be specified by index in [sortColumnIndex], 0
  /// meaning the first column in [columns], 1 being the next one, and
  /// so forth.
  ///
  /// The actual sort order can be specified using [sortAscending]; if
  /// the sort order is ascending, this should be true (the default),
  /// otherwise it should be false.
  DataTable({
    Key? key,
    required this.columns,
    this.sortColumnIndex,
    this.sortAscending = true,
    this.onSelectAll,
    this.decoration,
    this.dataRowColor,
    this.dataRowHeight,
    this.dataTextStyle,
    this.headingRowColor,
    this.headingRowHeight,
    this.headingTextStyle,
    this.horizontalMargin,
    this.columnSpacing,
    this.showCheckboxColumn = true,
    this.showBottomBorder = false,
    this.dividerThickness,
    required this.rows,
  }) : assert(columns != null),
       assert(columns.isNotEmpty),
       assert(sortColumnIndex == null || (sortColumnIndex >= 0 && sortColumnIndex < columns.length)),
       assert(sortAscending != null),
       assert(showCheckboxColumn != null),
       assert(rows != null),
       assert(!rows.any((DataRow row) => row.cells.length != columns.length)),
       assert(dividerThickness == null || dividerThickness >= 0),
       _onlyTextColumn = _initOnlyTextColumn(columns),
       super(key: key);

  /// The configuration and labels for the columns in the table.
  final List<DataColumn> columns;

  /// The current primary sort key's column.
  ///
  /// If non-null, indicates that the indicated column is the column
  /// by which the data is sorted. The number must correspond to the
  /// index of the relevant column in [columns].
  ///
  /// Setting this will cause the relevant column to have a sort
  /// indicator displayed.
  ///
  /// When this is null, it implies that the table's sort order does
  /// not correspond to any of the columns.
  final int? sortColumnIndex;

  /// Whether the column mentioned in [sortColumnIndex], if any, is sorted
  /// in ascending order.
  ///
  /// If true, the order is ascending (meaning the rows with the
  /// smallest values for the current sort column are first in the
  /// table).
  ///
  /// If false, the order is descending (meaning the rows with the
  /// smallest values for the current sort column are last in the
  /// table).
  final bool sortAscending;

  /// Invoked when the user selects or unselects every row, using the
  /// checkbox in the heading row.
  ///
  /// If this is null, then the [DataRow.onSelectChanged] callback of
  /// every row in the table is invoked appropriately instead.
  ///
  /// To control whether a particular row is selectable or not, see
  /// [DataRow.onSelectChanged]. This callback is only relevant if any
  /// row is selectable.
  final ValueSetter<bool?>? onSelectAll;

  /// {@template flutter.material.dataTable.decoration}
  /// The background and border decoration for the table.
  /// {@endtemplate}
  ///
  /// If null, [DataTableThemeData.decoration] is used. By default there is no
  /// decoration.
  final Decoration? decoration;

  /// {@template flutter.material.dataTable.dataRowColor}
  /// The background color for the data rows.
  ///
  /// The effective background color can be made to depend on the
  /// [MaterialState] state, i.e. if the row is selected, pressed, hovered,
  /// focused, disabled or enabled. The color is painted as an overlay to the
  /// row. To make sure that the row's [InkWell] is visible (when pressed,
  /// hovered and focused), it is recommended to use a translucent background
  /// color.
  /// {@endtemplate}
  ///
  /// If null, [DataTableThemeData.dataRowColor] is used. By default, the
  /// background color is transparent unless selected. Selected rows have a grey
  /// translucent color. To set a different color for individual rows, see
  /// [DataRow.color].
  ///
  /// {@template flutter.material.DataTable.dataRowColor}
  /// ```dart
  /// DataTable(
  ///   dataRowColor: MaterialStateProperty.resolveWith<Color>((Set<MaterialState> states) {
  ///     if (states.contains(MaterialState.selected))
  ///       return Theme.of(context).colorScheme.primary.withOpacity(0.08);
  ///     return null;  // Use the default value.
  ///   }),
  /// )
  /// ```
  ///
  /// See also:
  ///
  ///  * The Material Design specification for overlay colors and how they
  ///    match a component's state:
  ///    <https://material.io/design/interaction/states.html#anatomy>.
  /// {@endtemplate}
  final MaterialStateProperty<Color?>? dataRowColor;

  /// {@template flutter.material.dataTable.dataRowHeight}
  /// The height of each row (excluding the row that contains column headings).
  /// {@endtemplate}
  ///
  /// If null, [DataTableThemeData.dataRowHeight] is used. This value defaults
  /// to [kMinInteractiveDimension] to adhere to the Material Design
  /// specifications.
  final double? dataRowHeight;

  /// {@template flutter.material.dataTable.dataTextStyle}
  /// The text style for data rows.
  /// {@endtemplate}
  ///
  /// If null, [DataTableThemeData.dataTextStyle] is used. By default, the text
  /// style is [TextTheme.bodyText2].
  final TextStyle? dataTextStyle;

  /// {@template flutter.material.dataTable.headingRowColor}
  /// The background color for the heading row.
  ///
  /// The effective background color can be made to depend on the
  /// [MaterialState] state, i.e. if the row is pressed, hovered, focused when
  /// sorted. The color is painted as an overlay to the row. To make sure that
  /// the row's [InkWell] is visible (when pressed, hovered and focused), it is
  /// recommended to use a translucent color.
  /// {@endtemplate}
  ///
  /// If null, [DataTableThemeData.headingRowColor] is used.
  ///
  /// {@template flutter.material.DataTable.headingRowColor}
  /// ```dart
  /// DataTable(
  ///   headingRowColor: MaterialStateProperty.resolveWith<Color>((Set<MaterialState> states) {
  ///     if (states.contains(MaterialState.hovered))
  ///       return Theme.of(context).colorScheme.primary.withOpacity(0.08);
  ///     return null;  // Use the default value.
  ///   }),
  /// )
  /// ```
  ///
  /// See also:
  ///
  ///  * The Material Design specification for overlay colors and how they
  ///    match a component's state:
  ///    <https://material.io/design/interaction/states.html#anatomy>.
  /// {@endtemplate}
  final MaterialStateProperty<Color?>? headingRowColor;

  /// {@template flutter.material.dataTable.headingRowHeight}
  /// The height of the heading row.
  /// {@endtemplate}
  ///
  /// If null, [DataTableThemeData.headingRowHeight] is used. This value
  /// defaults to 56.0 to adhere to the Material Design specifications.
  final double? headingRowHeight;

  /// {@template flutter.material.dataTable.headingTextStyle}
  /// The text style for the heading row.
  /// {@endtemplate}
  ///
  /// If null, [DataTableThemeData.headingTextStyle] is used. By default, the
  /// text style is [TextTheme.subtitle2].
  final TextStyle? headingTextStyle;

  /// {@template flutter.material.dataTable.horizontalMargin}
  /// The horizontal margin between the edges of the table and the content
  /// in the first and last cells of each row.
  ///
  /// When a checkbox is displayed, it is also the margin between the checkbox
  /// the content in the first data column.
  /// {@endtemplate}
  ///
  /// If null, [DataTableThemeData.horizontalMargin] is used. This value
  /// defaults to 24.0 to adhere to the Material Design specifications.
  final double? horizontalMargin;

  /// {@template flutter.material.dataTable.columnSpacing}
  /// The horizontal margin between the contents of each data column.
  /// {@endtemplate}
  ///
  /// If null, [DataTableThemeData.columnSpacing] is used. This value defaults
  /// to 56.0 to adhere to the Material Design specifications.
  final double? columnSpacing;

  /// {@template flutter.material.dataTable.showCheckboxColumn}
  /// Whether the widget should display checkboxes for selectable rows.
  ///
  /// If true, a [Checkbox] will be placed at the beginning of each row that is
  /// selectable. However, if [DataRow.onSelectChanged] is not set for any row,
  /// checkboxes will not be placed, even if this value is true.
  ///
  /// If false, all rows will not display a [Checkbox].
  /// {@endtemplate}
  final bool showCheckboxColumn;

  /// The data to show in each row (excluding the row that contains
  /// the column headings).
  ///
  /// Must be non-null, but may be empty.
  final List<DataRow> rows;

  /// {@template flutter.material.dataTable.dividerThickness}
  /// The width of the divider that appears between [TableRow]s.
  ///
  /// Must be greater than or equal to zero.
  /// {@endtemplate}
  ///
  /// If null, [DataTableThemeData.dividerThickness] is used. This value
  /// defaults to 1.0.
  final double? dividerThickness;

  /// Whether a border at the bottom of the table is displayed.
  ///
  /// By default, a border is not shown at the bottom to allow for a border
  /// around the table defined by [decoration].
  final bool showBottomBorder;

  // Set by the constructor to the index of the only Column that is
  // non-numeric, if there is exactly one, otherwise null.
  final int? _onlyTextColumn;
  static int? _initOnlyTextColumn(List<DataColumn> columns) {
    int? result;
    for (int index = 0; index < columns.length; index += 1) {
      final DataColumn column = columns[index];
      if (!column.numeric) {
        if (result != null)
          return null;
        result = index;
      }
    }
    return result;
  }

  bool get _debugInteractive {
    return columns.any((DataColumn column) => column._debugInteractive)
        || rows.any((DataRow row) => row._debugInteractive);
  }

  static final LocalKey _headingRowKey = UniqueKey();

  void _handleSelectAll(bool? checked, bool someChecked) {
    // If some checkboxes are checked, all checkboxes are selected. Otherwise,
    // use the new checked value but default to false if it's null.
    final bool effectiveChecked = someChecked || (checked ?? false);
    if (onSelectAll != null) {
      onSelectAll!(effectiveChecked);
    } else {
      for (final DataRow row in rows) {
        if (row.onSelectChanged != null && row.selected != effectiveChecked)
          row.onSelectChanged!(effectiveChecked);
      }
    }
  }

  /// The default height of the heading row.
  static const double _headingRowHeight = 56.0;

  /// The default horizontal margin between the edges of the table and the content
  /// in the first and last cells of each row.
  static const double _horizontalMargin = 24.0;

  /// The default horizontal margin between the contents of each data column.
  static const double _columnSpacing = 56.0;

  /// The default padding between the heading content and sort arrow.
  static const double _sortArrowPadding = 2.0;

  /// The default divider thickness.
  static const double _dividerThickness = 1.0;

  static const Duration _sortArrowAnimationDuration = Duration(milliseconds: 150);

  Widget _buildCheckbox({
    required BuildContext context,
    required bool? checked,
    required VoidCallback? onRowTap,
    required ValueChanged<bool?>? onCheckboxChanged,
    required MaterialStateProperty<Color?>? overlayColor,
    required bool tristate,
  }) {
    final ThemeData themeData = Theme.of(context);
    final double effectiveHorizontalMargin = horizontalMargin
      ?? themeData.dataTableTheme.horizontalMargin
      ?? _horizontalMargin;
    Widget contents = Semantics(
      container: true,
      child: Padding(
        padding: EdgeInsetsDirectional.only(
          start: effectiveHorizontalMargin,
          end: effectiveHorizontalMargin / 2.0,
        ),
        child: Center(
          child: Checkbox(
            // TODO(per): Remove when Checkbox has theme, https://github.com/flutter/flutter/issues/53420.
            activeColor: themeData.colorScheme.primary,
            checkColor: themeData.colorScheme.onPrimary,
            value: checked,
            onChanged: onCheckboxChanged,
            tristate: tristate,
          ),
        ),
      ),
    );
    if (onRowTap != null) {
      contents = TableRowInkWell(
        onTap: onRowTap,
        child: contents,
        overlayColor: overlayColor,
      );
    }
    return TableCell(
      verticalAlignment: TableCellVerticalAlignment.fill,
      child: contents,
    );
  }

  Widget _buildHeadingCell({
    required BuildContext context,
    required EdgeInsetsGeometry padding,
    required Widget label,
    required String? tooltip,
    required bool numeric,
    required VoidCallback? onSort,
    required bool sorted,
    required bool ascending,
    required MaterialStateProperty<Color?>? overlayColor,
  }) {
    final ThemeData themeData = Theme.of(context);
    label = Row(
      textDirection: numeric ? TextDirection.rtl : null,
      children: <Widget>[
        label,
        if (onSort != null)
          ...<Widget>[
            _SortArrow(
              visible: sorted,
              up: sorted ? ascending : null,
              duration: _sortArrowAnimationDuration,
            ),
            const SizedBox(width: _sortArrowPadding),
          ],
      ],
    );

    final TextStyle effectiveHeadingTextStyle = headingTextStyle
      ?? themeData.dataTableTheme.headingTextStyle
      ?? themeData.textTheme.subtitle2!;
    final double effectiveHeadingRowHeight = headingRowHeight
      ?? themeData.dataTableTheme.headingRowHeight
      ?? _headingRowHeight;
    label = Container(
      padding: padding,
      height: effectiveHeadingRowHeight,
      alignment: numeric ? Alignment.centerRight : AlignmentDirectional.centerStart,
      child: AnimatedDefaultTextStyle(
        style: effectiveHeadingTextStyle,
        softWrap: false,
        duration: _sortArrowAnimationDuration,
        child: label,
      ),
    );
    if (tooltip != null) {
      label = Tooltip(
        message: tooltip,
        child: label,
      );
    }

    // TODO(dkwingsmt): Only wrap Inkwell if onSort != null. Blocked by
    // https://github.com/flutter/flutter/issues/51152
    label = InkWell(
      onTap: onSort,
      overlayColor: overlayColor,
      child: label,
    );
    return label;
  }

  Widget _buildDataCell({
    required BuildContext context,
    required EdgeInsetsGeometry padding,
    required Widget label,
    required bool numeric,
    required bool placeholder,
    required bool showEditIcon,
    required VoidCallback? onTap,
    required VoidCallback? onSelectChanged,
    required MaterialStateProperty<Color?>? overlayColor,
  }) {
    final ThemeData themeData = Theme.of(context);
    if (showEditIcon) {
      const Widget icon = Icon(Icons.edit, size: 18.0);
      label = Expanded(child: label);
      label = Row(
        textDirection: numeric ? TextDirection.rtl : null,
        children: <Widget>[ label, icon ],
      );
    }

    final TextStyle effectiveDataTextStyle = dataTextStyle
      ?? themeData.dataTableTheme.dataTextStyle
      ?? themeData.textTheme.bodyText2!;
    final double effectiveDataRowHeight = dataRowHeight
      ?? themeData.dataTableTheme.dataRowHeight
      ?? kMinInteractiveDimension;
    label = Container(
      padding: padding,
      height: effectiveDataRowHeight,
      alignment: numeric ? Alignment.centerRight : AlignmentDirectional.centerStart,
      child: DefaultTextStyle(
        style: effectiveDataTextStyle.copyWith(
          color: placeholder ? effectiveDataTextStyle.color!.withOpacity(0.6) : null,
        ),
        child: DropdownButtonHideUnderline(child: label),
      ),
    );
    if (onTap != null) {
      label = InkWell(
        onTap: onTap,
        child: label,
        overlayColor: overlayColor,
      );
    } else if (onSelectChanged != null) {
      label = TableRowInkWell(
        onTap: onSelectChanged,
        child: label,
        overlayColor: overlayColor,
      );
    }
    return label;
  }

  @override
  Widget build(BuildContext context) {
    assert(!_debugInteractive || debugCheckHasMaterial(context));

    final ThemeData theme = Theme.of(context);
    final MaterialStateProperty<Color?>? effectiveHeadingRowColor = headingRowColor
      ?? theme.dataTableTheme.headingRowColor;
    final MaterialStateProperty<Color?>? effectiveDataRowColor = dataRowColor
      ?? theme.dataTableTheme.dataRowColor;
    final MaterialStateProperty<Color?> defaultRowColor = MaterialStateProperty.resolveWith(
      (Set<MaterialState> states) {
        if (states.contains(MaterialState.selected))
          return theme.colorScheme.primary.withOpacity(0.08);
        return null;
      },
    );
    final bool anyRowSelectable = rows.any((DataRow row) => row.onSelectChanged != null);
    final bool displayCheckboxColumn = showCheckboxColumn && anyRowSelectable;
    final Iterable<DataRow> rowsWithCheckbox = displayCheckboxColumn ?
      rows.where((DataRow row) => row.onSelectChanged != null) : <DataRow>[];
    final Iterable<DataRow> rowsChecked = rowsWithCheckbox.where((DataRow row) => row.selected);
    final bool allChecked = displayCheckboxColumn && rowsChecked.length == rowsWithCheckbox.length;
    final bool anyChecked = displayCheckboxColumn && rowsChecked.isNotEmpty;
    final bool someChecked = anyChecked && !allChecked;
    final double effectiveHorizontalMargin = horizontalMargin
      ?? theme.dataTableTheme.horizontalMargin
      ?? _horizontalMargin;
    final double effectiveColumnSpacing = columnSpacing
      ?? theme.dataTableTheme.columnSpacing
      ?? _columnSpacing;

    final List<TableColumnWidth> tableColumns = List<TableColumnWidth>.filled(columns.length + (displayCheckboxColumn ? 1 : 0), const _NullTableColumnWidth());
    final List<TableRow> tableRows = List<TableRow>.generate(
      rows.length + 1, // the +1 is for the header row
      (int index) {
        final bool isSelected = index > 0 && rows[index - 1].selected;
        final bool isDisabled = index > 0 && anyRowSelectable && rows[index - 1].onSelectChanged == null;
        final Set<MaterialState> states = <MaterialState>{
          if (isSelected)
            MaterialState.selected,
          if (isDisabled)
            MaterialState.disabled,
        };
        final Color? resolvedDataRowColor = index > 0 ? (rows[index - 1].color ?? effectiveDataRowColor)?.resolve(states) : null;
        final Color? resolvedHeadingRowColor = effectiveHeadingRowColor?.resolve(<MaterialState>{});
        final Color? rowColor = index > 0 ? resolvedDataRowColor : resolvedHeadingRowColor;
        final BorderSide borderSide = Divider.createBorderSide(
          context,
          width: dividerThickness
            ?? theme.dataTableTheme.dividerThickness
            ?? _dividerThickness,
        );
        final Border? border = showBottomBorder
          ? Border(bottom: borderSide)
          : index == 0 ? null : Border(top: borderSide);
        return TableRow(
          key: index == 0 ? _headingRowKey : rows[index - 1].key,
          decoration: BoxDecoration(
            border: border,
            color: rowColor ?? defaultRowColor.resolve(states),
          ),
          children: List<Widget>.filled(tableColumns.length, const _NullWidget()),
        );
      },
    );

    int rowIndex;

    int displayColumnIndex = 0;
    if (displayCheckboxColumn) {
      tableColumns[0] = FixedColumnWidth(effectiveHorizontalMargin + Checkbox.width + effectiveHorizontalMargin / 2.0);
      tableRows[0].children![0] = _buildCheckbox(
        context: context,
        checked: someChecked ? null : allChecked,
        onRowTap: null,
        onCheckboxChanged: (bool? checked) => _handleSelectAll(checked, someChecked),
        overlayColor: null,
        tristate: true,
      );
      rowIndex = 1;
      for (final DataRow row in rows) {
        tableRows[rowIndex].children![0] = _buildCheckbox(
          context: context,
          checked: row.selected,
          onRowTap: () => row.onSelectChanged != null ? row.onSelectChanged!(!row.selected) : null ,
          onCheckboxChanged: row.onSelectChanged,
          overlayColor: row.color ?? effectiveDataRowColor,
          tristate: false,
        );
        rowIndex += 1;
      }
      displayColumnIndex += 1;
    }

    for (int dataColumnIndex = 0; dataColumnIndex < columns.length; dataColumnIndex += 1) {
      final DataColumn column = columns[dataColumnIndex];

      final double paddingStart;
      if (dataColumnIndex == 0 && displayCheckboxColumn) {
        paddingStart = effectiveHorizontalMargin / 2.0;
      } else if (dataColumnIndex == 0 && !displayCheckboxColumn) {
        paddingStart = effectiveHorizontalMargin;
      } else {
        paddingStart = effectiveColumnSpacing / 2.0;
      }

      final double paddingEnd;
      if (dataColumnIndex == columns.length - 1) {
        paddingEnd = effectiveHorizontalMargin;
      } else {
        paddingEnd = effectiveColumnSpacing / 2.0;
      }

      final EdgeInsetsDirectional padding = EdgeInsetsDirectional.only(
        start: paddingStart,
        end: paddingEnd,
      );
      if (dataColumnIndex == _onlyTextColumn) {
        tableColumns[displayColumnIndex] = const IntrinsicColumnWidth(flex: 1.0);
      } else {
        tableColumns[displayColumnIndex] = const IntrinsicColumnWidth();
      }
      tableRows[0].children![displayColumnIndex] = _buildHeadingCell(
        context: context,
        padding: padding,
        label: column.label,
        tooltip: column.tooltip,
        numeric: column.numeric,
        onSort: column.onSort != null ? () => column.onSort!(dataColumnIndex, sortColumnIndex != dataColumnIndex || !sortAscending) : null,
        sorted: dataColumnIndex == sortColumnIndex,
        ascending: sortAscending,
        overlayColor: effectiveHeadingRowColor,
      );
      rowIndex = 1;
      for (final DataRow row in rows) {
        final DataCell cell = row.cells[dataColumnIndex];
        tableRows[rowIndex].children![displayColumnIndex] = _buildDataCell(
          context: context,
          padding: padding,
          label: cell.child,
          numeric: column.numeric,
          placeholder: cell.placeholder,
          showEditIcon: cell.showEditIcon,
          onTap: cell.onTap,
          onSelectChanged: () => row.onSelectChanged != null ? row.onSelectChanged!(!row.selected) : null,
          overlayColor: row.color ?? effectiveDataRowColor,
        );
        rowIndex += 1;
      }
      displayColumnIndex += 1;
    }

    return Container(
      decoration: decoration ?? theme.dataTableTheme.decoration,
      child: Material(
        type: MaterialType.transparency,
        child: Table(
          columnWidths: tableColumns.asMap(),
          children: tableRows,
        ),
      ),
    );
  }
}

/// A rectangular area of a Material that responds to touch but clips
/// its ink splashes to the current table row of the nearest table.
///
/// Must have an ancestor [Material] widget in which to cause ink
/// reactions and an ancestor [Table] widget to establish a row.
///
/// The [TableRowInkWell] must be in the same coordinate space (modulo
/// translations) as the [Table]. If it's rotated or scaled or
/// otherwise transformed, it will not be able to describe the
/// rectangle of the row in its own coordinate system as a [Rect], and
/// thus the splash will not occur. (In general, this is easy to
/// achieve: just put the [TableRowInkWell] as the direct child of the
/// [Table], and put the other contents of the cell inside it.)
///
/// See also:
///
///  * [DataTable], which makes use of [TableRowInkWell] when
///    [DataRow.onSelectChanged] is defined and [DataCell.onTap]
///    is not.
class TableRowInkWell extends InkResponse {
  /// Creates an ink well for a table row.
  const TableRowInkWell({
    Key? key,
    Widget? child,
    GestureTapCallback? onTap,
    GestureTapCallback? onDoubleTap,
    GestureLongPressCallback? onLongPress,
    ValueChanged<bool>? onHighlightChanged,
    MaterialStateProperty<Color?>? overlayColor,
  }) : super(
    key: key,
    child: child,
    onTap: onTap,
    onDoubleTap: onDoubleTap,
    onLongPress: onLongPress,
    onHighlightChanged: onHighlightChanged,
    containedInkWell: true,
    highlightShape: BoxShape.rectangle,
    overlayColor: overlayColor,
  );

  @override
  RectCallback getRectCallback(RenderBox referenceBox) {
    return () {
      RenderObject cell = referenceBox;
      AbstractNode? table = cell.parent;
      final Matrix4 transform = Matrix4.identity();
      while (table is RenderObject && table is! RenderTable) {
        table.applyPaintTransform(cell, transform);
        assert(table == cell.parent);
        cell = table;
        table = table.parent;
      }
      if (table is RenderTable) {
        final TableCellParentData cellParentData = cell.parentData! as TableCellParentData;
        assert(cellParentData.y != null);
        final Rect rect = table.getRowBox(cellParentData.y!);
        // The rect is in the table's coordinate space. We need to change it to the
        // TableRowInkWell's coordinate space.
        table.applyPaintTransform(cell, transform);
        final Offset? offset = MatrixUtils.getAsTranslation(transform);
        if (offset != null)
          return rect.shift(-offset);
      }
      return Rect.zero;
    };
  }

  @override
  bool debugCheckContext(BuildContext context) {
    assert(debugCheckHasTable(context));
    return super.debugCheckContext(context);
  }
}

class _SortArrow extends StatefulWidget {
  const _SortArrow({
    Key? key,
    required this.visible,
    required this.up,
    required this.duration,
  }) : super(key: key);

  final bool visible;

  final bool? up;

  final Duration duration;

  @override
  _SortArrowState createState() => _SortArrowState();
}

class _SortArrowState extends State<_SortArrow> with TickerProviderStateMixin {
  late AnimationController _opacityController;
  late Animation<double> _opacityAnimation;

  late AnimationController _orientationController;
  late Animation<double> _orientationAnimation;
  double _orientationOffset = 0.0;

  bool? _up;

  static final Animatable<double> _turnTween = Tween<double>(begin: 0.0, end: math.pi)
    .chain(CurveTween(curve: Curves.easeIn));

  @override
  void initState() {
    super.initState();
    _opacityAnimation = CurvedAnimation(
      parent: _opacityController = AnimationController(
        duration: widget.duration,
        vsync: this,
      ),
      curve: Curves.fastOutSlowIn,
    )
    ..addListener(_rebuild);
    _opacityController.value = widget.visible ? 1.0 : 0.0;
    _orientationController = AnimationController(
      duration: widget.duration,
      vsync: this,
    );
    _orientationAnimation = _orientationController.drive(_turnTween)
      ..addListener(_rebuild)
      ..addStatusListener(_resetOrientationAnimation);
    if (widget.visible)
      _orientationOffset = widget.up! ? 0.0 : math.pi;
  }

  void _rebuild() {
    setState(() {
      // The animations changed, so we need to rebuild.
    });
  }

  void _resetOrientationAnimation(AnimationStatus status) {
    if (status == AnimationStatus.completed) {
      assert(_orientationAnimation.value == math.pi);
      _orientationOffset += math.pi;
      _orientationController.value = 0.0; // TODO(ianh): This triggers a pointless rebuild.
    }
  }

  @override
  void didUpdateWidget(_SortArrow oldWidget) {
    super.didUpdateWidget(oldWidget);
    bool skipArrow = false;
    final bool? newUp = widget.up ?? _up;
    if (oldWidget.visible != widget.visible) {
      if (widget.visible && (_opacityController.status == AnimationStatus.dismissed)) {
        _orientationController.stop();
        _orientationController.value = 0.0;
        _orientationOffset = newUp! ? 0.0 : math.pi;
        skipArrow = true;
      }
      if (widget.visible) {
        _opacityController.forward();
      } else {
        _opacityController.reverse();
      }
    }
    if ((_up != newUp) && !skipArrow) {
      if (_orientationController.status == AnimationStatus.dismissed) {
        _orientationController.forward();
      } else {
        _orientationController.reverse();
      }
    }
    _up = newUp;
  }

  @override
  void dispose() {
    _opacityController.dispose();
    _orientationController.dispose();
    super.dispose();
  }

  static const double _arrowIconBaselineOffset = -1.5;
  static const double _arrowIconSize = 16.0;

  @override
  Widget build(BuildContext context) {
    return Opacity(
      opacity: _opacityAnimation.value,
      child: Transform(
        transform: Matrix4.rotationZ(_orientationOffset + _orientationAnimation.value)
                             ..setTranslationRaw(0.0, _arrowIconBaselineOffset, 0.0),
        alignment: Alignment.center,
        child: const Icon(
          Icons.arrow_upward,
          size: _arrowIconSize,
        ),
      ),
    );
  }
}

class _NullTableColumnWidth extends TableColumnWidth {
  const _NullTableColumnWidth();

  @override
  double maxIntrinsicWidth(Iterable<RenderBox> cells, double containerWidth) => throw UnimplementedError();

  @override
  double minIntrinsicWidth(Iterable<RenderBox> cells, double containerWidth) => throw UnimplementedError();
}

class _NullWidget extends Widget {
  const _NullWidget();

  @override
  Element createElement() => throw UnimplementedError();
}