import 'dart:math' as math;

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

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

/// Column configuration for a [MyDataTable].
///
/// One column configuration must be provided for each column to
/// display in the table. The list of [MyDataColumn] objects is passed
/// as the `columns` argument to the [new MyDataTable] constructor.
@immutable
class MyDataColumn {
  /// Creates the configuration for a column of a [MyDataTable].
  ///
  /// The [label] argument must not be null.
  const MyDataColumn({
    @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.
  ///
  /// 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 [MyDataTable.sortColumnIndex] and [MyDataTable.sortAscending].
  final MyDataColumnSortCallback onSort;

  bool get _debugInteractive => onSort != null;
}

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

  /// Creates the configuration for a row of a [MyDataTable], deriving
  /// the key from a row index.
  ///
  /// The [cells] argument must not be null.
  MyDataRow.byIndex({
    int index,
    this.selected = false,
    this.onSelectChanged,
    @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.
  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<MyDataCell> cells;

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

/// The data for a cell of a [MyDataTable].
///
/// One list of [MyDataCell] objects must be provided for each [MyDataRow]
/// in the [MyDataTable], in the [new MyDataRow] constructor's `cells`
/// argument.
@immutable
class MyDataCell {
  /// Creates an object to hold the data for a cell in a [MyDataTable].
  ///
  /// 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 MyDataCell(
    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 final MyDataCell empty =
      MyDataCell(Container(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.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
  /// [MyDataRow.onSelectChanged] is provided).
  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
/// [PaginatedMyDataTable] which automatically splits the data into
/// multiple pages.
///
/// {@tool snippet --template=stateless_widget_scaffold}
///
/// This sample shows how to display a [MyDataTable] with three columns: name, age, and
/// role. The columns are defined by three [MyDataColumn] objects. The table
/// contains three rows of data for three example users, the data for which
/// is defined by three [MyDataRow] objects.
///
/// ![](https://flutter.github.io/assets-for-api-docs/assets/material/data_table.png)
///
/// ```dart
/// Widget build(BuildContext context) {
///   return MyDataTable(
///     columns: const <MyDataColumn>[
///       MyDataColumn(
///         label: Text(
///           'Name',
///           style: TextStyle(fontStyle: FontStyle.italic),
///         ),
///       ),
///       MyDataColumn(
///         label: Text(
///           'Age',
///           style: TextStyle(fontStyle: FontStyle.italic),
///         ),
///       ),
///       MyDataColumn(
///         label: Text(
///           'Role',
///           style: TextStyle(fontStyle: FontStyle.italic),
///         ),
///       ),
///     ],
///     rows: const <MyDataRow>[
///       MyDataRow(
///         cells: <MyDataCell>[
///           MyDataCell(Text('Sarah')),
///           MyDataCell(Text('19')),
///           MyDataCell(Text('Student')),
///         ],
///       ),
///       MyDataRow(
///         cells: <MyDataCell>[
///           MyDataCell(Text('Janine')),
///           MyDataCell(Text('43')),
///           MyDataCell(Text('Professor')),
///         ],
///       ),
///       MyDataRow(
///         cells: <MyDataCell>[
///           MyDataCell(Text('William')),
///           MyDataCell(Text('27')),
///           MyDataCell(Text('Associate Professor')),
///         ],
///       ),
///     ],
///   );
/// }
/// ```
///
/// {@end-tool}
// TODO(ianh): Also suggest [ScrollingMyDataTable] once we have it.
///
/// See also:
///
///  * [MyDataColumn], which describes a column in the data table.
///  * [MyDataRow], which contains the data for a row in the data table.
///  * [MyDataCell], which contains the data for a single cell in the data table.
///  * [PaginatedMyDataTable], 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 MyDataTable extends StatelessWidget {
  /// Creates a widget describing a data table.
  ///
  /// The [columns] argument must be a list of as many [MyDataColumn]
  /// 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 [MyDataRow] 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 [MyDataRow] object in [rows] must have as many [MyDataCell]
  /// objects in the [MyDataRow.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.
  MyDataTable({
    Key key,
    @required this.columns,
    this.sortColumnIndex,
    this.sortAscending = true,
    this.onSelectAll,
    this.MyDataRowHeight = kMinInteractiveDimension,
    this.headingRowHeight = 56.0,
    this.horizontalMargin = 24.0,
    this.columnSpacing = 56.0,
    this.oddLine,
    this.evenLine,
    @required this.rows,
  })  : assert(columns != null),
        assert(columns.isNotEmpty),
        assert(sortColumnIndex == null ||
            (sortColumnIndex >= 0 && sortColumnIndex < columns.length)),
        assert(sortAscending != null),
        assert(MyDataRowHeight != null),
        assert(headingRowHeight != null),
        assert(horizontalMargin != null),
        assert(columnSpacing != null),
        assert(rows != null),
        assert(
            !rows.any((MyDataRow row) => row.cells.length != columns.length)),
        _onlyTextColumn = _initOnlyTextColumn(columns),
        super(key: key);

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

  final Decoration oddLine;
  final Decoration evenLine;

  /// 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 [MyDataRow.onSelectChanged] callback of
  /// every row in the table is invoked appropriately instead.
  ///
  /// To control whether a particular row is selectable or not, see
  /// [MyDataRow.onSelectChanged]. This callback is only relevant if any
  /// row is selectable.
  final ValueSetter<bool> onSelectAll;

  /// The height of each row (excluding the row that contains column headings).
  ///
  /// This value defaults to kMinInteractiveDimension to adhere to the Material
  /// Design specifications.
  final double MyDataRowHeight;

  /// The height of the heading row.
  ///
  /// This value defaults to 56.0 to adhere to the Material Design specifications.
  final double headingRowHeight;

  /// 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.
  ///
  /// This value defaults to 24.0 to adhere to the Material Design specifications.
  final double horizontalMargin;

  /// The horizontal margin between the contents of each data column.
  ///
  /// This value defaults to 56.0 to adhere to the Material Design specifications.
  final double columnSpacing;

  /// 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<MyDataRow> rows;

  // 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<MyDataColumn> columns) {
    int result;
    for (int index = 0; index < columns.length; index += 1) {
      final MyDataColumn column = columns[index];
      if (!column.numeric) {
        if (result != null) return null;
        result = index;
      }
    }
    return result;
  }

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

  static final LocalKey _headingRowKey = UniqueKey();

  void _handleSelectAll(bool checked) {
    if (onSelectAll != null) {
      onSelectAll(checked);
    } else {
      for (MyDataRow row in rows) {
        if ((row.onSelectChanged != null) && (row.selected != checked))
          row.onSelectChanged(checked);
      }
    }
  }

  static const double _sortArrowPadding = 2.0;
  static const double _headingFontSize = 12.0;
  static const Duration _sortArrowAnimationDuration =
      Duration(milliseconds: 150);
  static const Color _grey100Opacity =
      Color(0x0A000000); // Grey 100 as opacity instead of solid color
  static const Color _grey300Opacity =
      Color(0x1E000000); // Dark theme variant is just a guess.

  Widget _buildCheckbox({
    Color color,
    bool checked,
    VoidCallback onRowTap,
    ValueChanged<bool> onCheckboxChanged,
  }) {
    Widget contents = Semantics(
      container: true,
      child: Padding(
        padding: EdgeInsetsDirectional.only(
            start: horizontalMargin, end: horizontalMargin / 2.0),
        child: Center(
          child: Checkbox(
            activeColor: color,
            value: checked,
            onChanged: onCheckboxChanged,
          ),
        ),
      ),
    );
    if (onRowTap != null) {
      contents = TableRowInkWell(
        onTap: onRowTap,
        child: contents,
      );
    }
    return TableCell(
      verticalAlignment: TableCellVerticalAlignment.fill,
      child: contents,
    );
  }

  Widget _buildHeadingCell({
    BuildContext context,
    EdgeInsetsGeometry padding,
    Widget label,
    String tooltip,
    bool numeric,
    VoidCallback onSort,
    bool sorted,
    bool ascending,
  }) {
    if (onSort != null) {
      final Widget arrow = _SortArrow(
        visible: sorted,
        down: sorted ? ascending : null,
        duration: _sortArrowAnimationDuration,
      );
      const Widget arrowPadding = SizedBox(width: _sortArrowPadding);
      label = Row(
        textDirection: numeric ? TextDirection.rtl : null,
        children: <Widget>[label, arrowPadding, arrow],
      );
    }
    label = Container(
      padding: padding,
      height: headingRowHeight,
      alignment:
          numeric ? Alignment.centerRight : AlignmentDirectional.centerStart,
      child: AnimatedDefaultTextStyle(
        style: TextStyle(
          // TODO(ianh): font family should match Theme; see https://github.com/flutter/flutter/issues/3116
          fontWeight: FontWeight.w500,
          fontSize: _headingFontSize,
          height: math.min(1.0, headingRowHeight / _headingFontSize),
          color: (Theme.of(context).brightness == Brightness.light)
              ? ((onSort != null && sorted) ? Colors.black87 : Colors.black54)
              : ((onSort != null && sorted) ? Colors.white : Colors.white70),
        ),
        softWrap: false,
        duration: _sortArrowAnimationDuration,
        child: label,
      ),
    );
    if (tooltip != null) {
      label = Tooltip(
        message: tooltip,
        child: label,
      );
    }
    if (onSort != null) {
      label = InkWell(
        onTap: onSort,
        child: label,
      );
    }
    return label;
  }

  Widget _buildMyDataCell({
    BuildContext context,
    EdgeInsetsGeometry padding,
    Widget label,
    bool numeric,
    bool placeholder,
    bool showEditIcon,
    VoidCallback onTap,
    VoidCallback onSelectChanged,
  }) {
    final bool isLightTheme = Theme.of(context).brightness == Brightness.light;
    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],
      );
    }
    label = Container(
      padding: padding,
      height: MyDataRowHeight,
      alignment:
          numeric ? Alignment.centerRight : AlignmentDirectional.centerStart,
      child: DefaultTextStyle(
        style: TextStyle(
          // TODO(ianh): font family should be Roboto; see https://github.com/flutter/flutter/issues/3116
          fontSize: 13.0,
          color: isLightTheme
              ? (placeholder ? Colors.black38 : Colors.black87)
              : (placeholder ? Colors.white38 : Colors.white70),
        ),
        child: IconTheme.merge(
          data: IconThemeData(
            color: isLightTheme ? Colors.black54 : Colors.white70,
          ),
          child: DropdownButtonHideUnderline(child: label),
        ),
      ),
    );
    if (onTap != null) {
      label = InkWell(
        onTap: onTap,
        child: label,
      );
    } else if (onSelectChanged != null) {
      label = TableRowInkWell(
        onTap: onSelectChanged,
        child: label,
      );
    }
    return label;
  }

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

    final ThemeData theme = Theme.of(context);
    final BoxDecoration _kSelectedDecoration = BoxDecoration(
      border: Border(bottom: Divider.createBorderSide(context, width: 1.0)),
      // The backgroundColor has to be transparent so you can see the ink on the material
      color: (Theme.of(context).brightness == Brightness.light)
          ? _grey100Opacity
          : _grey300Opacity,
    );
    final BoxDecoration _kUnselectedDecoration = BoxDecoration(
      border: Border(bottom: Divider.createBorderSide(context, width: 1.0)),
    );

    final bool showCheckboxColumn = false;
    final bool allChecked = false;

    final List<TableColumnWidth> tableColumns =
        List<TableColumnWidth>(columns.length + (showCheckboxColumn ? 1 : 0));
    final List<TableRow> tableRows = List<TableRow>.generate(
      rows.length + 1, // the +1 is for the header row
      (int index) {
        return TableRow(
          key: index == 0 ? _headingRowKey : rows[index - 1].key,
          decoration: index > 0 && rows[index - 1].selected
              ? _kSelectedDecoration
              : index > 0 && index.isOdd && oddLine != null
                  ? oddLine
                  : index.isEven && evenLine != null
                      ? evenLine
                      : _kUnselectedDecoration,
          children: List<Widget>(tableColumns.length),
        );
      },
    );

    int rowIndex;

    int displayColumnIndex = 0;
    if (showCheckboxColumn) {
      tableColumns[0] = FixedColumnWidth(
          horizontalMargin + Checkbox.width + horizontalMargin / 2.0);
      tableRows[0].children[0] = _buildCheckbox(
        color: theme.accentColor,
        checked: allChecked,
        onCheckboxChanged: _handleSelectAll,
      );
      rowIndex = 1;
      for (MyDataRow row in rows) {
        tableRows[rowIndex].children[0] = _buildCheckbox(
          color: theme.accentColor,
          checked: row.selected,
          onRowTap: () => row.onSelectChanged != null
              ? row.onSelectChanged(!row.selected)
              : null,
          onCheckboxChanged: row.onSelectChanged,
        );
        rowIndex += 1;
      }
      displayColumnIndex += 1;
    }

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

      double paddingStart;
      if (MyDataColumnIndex == 0 && showCheckboxColumn) {
        paddingStart = horizontalMargin / 2.0;
      } else if (MyDataColumnIndex == 0 && !showCheckboxColumn) {
        paddingStart = horizontalMargin;
      } else {
        paddingStart = columnSpacing / 2.0;
      }

      double paddingEnd;
      if (MyDataColumnIndex == columns.length - 1) {
        paddingEnd = horizontalMargin;
      } else {
        paddingEnd = columnSpacing / 2.0;
      }

      final EdgeInsetsDirectional padding = EdgeInsetsDirectional.only(
        start: paddingStart,
        end: paddingEnd,
      );
      if (MyDataColumnIndex == _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(MyDataColumnIndex,
                sortColumnIndex != MyDataColumnIndex || !sortAscending)
            : null,
        sorted: MyDataColumnIndex == sortColumnIndex,
        ascending: sortAscending,
      );
      rowIndex = 1;
      for (MyDataRow row in rows) {
        final MyDataCell cell = row.cells[MyDataColumnIndex];
        tableRows[rowIndex].children[displayColumnIndex] = _buildMyDataCell(
          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,
        );
        rowIndex += 1;
      }
      displayColumnIndex += 1;
    }

    return 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.)
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,
  }) : super(
          key: key,
          child: child,
          onTap: onTap,
          onDoubleTap: onDoubleTap,
          onLongPress: onLongPress,
          onHighlightChanged: onHighlightChanged,
          containedInkWell: true,
          highlightShape: BoxShape.rectangle,
        );

  @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) {
        final RenderObject parentBox = table as RenderObject;
        parentBox.applyPaintTransform(cell, transform);
        assert(table == cell.parent);
        cell = parentBox;
        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,
    this.visible,
    this.down,
    this.duration,
  }) : super(key: key);

  final bool visible;

  final bool down;

  final Duration duration;

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

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

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

  bool _down;

  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.down ? 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 newDown = widget.down ?? _down;
    if (oldWidget.visible != widget.visible) {
      if (widget.visible &&
          (_opacityController.status == AnimationStatus.dismissed)) {
        _orientationController.stop();
        _orientationController.value = 0.0;
        _orientationOffset = newDown ? 0.0 : math.pi;
        skipArrow = true;
      }
      if (widget.visible) {
        _opacityController.forward();
      } else {
        _opacityController.reverse();
      }
    }
    if ((_down != newDown) && !skipArrow) {
      if (_orientationController.status == AnimationStatus.dismissed) {
        _orientationController.forward();
      } else {
        _orientationController.reverse();
      }
    }
    _down = newDown;
  }

  @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: Icon(
          Icons.arrow_downward,
          size: _arrowIconSize,
          color: (Theme.of(context).brightness == Brightness.light)
              ? Colors.black87
              : Colors.white70,
        ),
      ),
    );
  }
}
