toggle_buttons.dart

// 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 'button.dart';
import 'color_scheme.dart';
import 'constants.dart';
import 'debug.dart';
import 'material_state.dart';
import 'theme.dart';
import 'theme_data.dart';
import 'toggle_buttons_theme.dart';

/// A set of toggle buttons.
///
/// The list of [children] are laid out along [direction]. The state of each button
/// is controlled by [isSelected], which is a list of bools that determine
/// if a button is in an unselected or selected state. They are both
/// correlated by their index in the list. The length of [isSelected] has to
/// match the length of the [children] list.
///
/// {@youtube 560 315 https://www.youtube.com/watch?v=kVEguaQWGAY}
///
/// ## Customizing toggle buttons
/// Each toggle's behavior can be configured by the [onPressed] callback, which
/// can update the [isSelected] list however it wants to.
///
/// {@animation 700 150 https://flutter.github.io/assets-for-api-docs/assets/material/toggle_buttons_simple.mp4}
///
/// Here is an implementation that allows for multiple buttons to be
/// simultaneously selected, while requiring none of the buttons to be
/// selected.
/// ```dart
/// ToggleButtons(
///   children: <Widget>[
///     Icon(Icons.ac_unit),
///     Icon(Icons.call),
///     Icon(Icons.cake),
///   ],
///   onPressed: (int index) {
///     setState(() {
///       isSelected[index] = !isSelected[index];
///     });
///   },
///   isSelected: isSelected,
/// ),
/// ```
///
/// {@animation 700 150 https://flutter.github.io/assets-for-api-docs/assets/material/toggle_buttons_required_mutually_exclusive.mp4}
///
/// Here is an implementation that requires mutually exclusive selection
/// while requiring at least one selection. Note that this assumes that
/// [isSelected] was properly initialized with one selection.
/// ```dart
/// ToggleButtons(
///   children: <Widget>[
///     Icon(Icons.ac_unit),
///     Icon(Icons.call),
///     Icon(Icons.cake),
///   ],
///   onPressed: (int index) {
///     setState(() {
///       for (int buttonIndex = 0; buttonIndex < isSelected.length; buttonIndex++) {
///         if (buttonIndex == index) {
///           isSelected[buttonIndex] = true;
///         } else {
///           isSelected[buttonIndex] = false;
///         }
///       }
///     });
///   },
///   isSelected: isSelected,
/// ),
/// ```
///
/// {@animation 700 150 https://flutter.github.io/assets-for-api-docs/assets/material/toggle_buttons_mutually_exclusive.mp4}
///
/// Here is an implementation that requires mutually exclusive selection,
/// but allows for none of the buttons to be selected.
/// ```dart
/// ToggleButtons(
///   children: <Widget>[
///     Icon(Icons.ac_unit),
///     Icon(Icons.call),
///     Icon(Icons.cake),
///   ],
///   onPressed: (int index) {
///     setState(() {
///       for (int buttonIndex = 0; buttonIndex < isSelected.length; buttonIndex++) {
///         if (buttonIndex == index) {
///           isSelected[buttonIndex] = !isSelected[buttonIndex];
///         } else {
///           isSelected[buttonIndex] = false;
///         }
///       }
///     });
///   },
///   isSelected: isSelected,
/// ),
/// ```
///
/// {@animation 700 150 https://flutter.github.io/assets-for-api-docs/assets/material/toggle_buttons_required.mp4}
///
/// Here is an implementation that allows for multiple buttons to be
/// simultaneously selected, while requiring at least one selection. Note
/// that this assumes that [isSelected] was properly initialized with one
/// selection.
/// ```dart
/// ToggleButtons(
///   children: <Widget>[
///     Icon(Icons.ac_unit),
///     Icon(Icons.call),
///     Icon(Icons.cake),
///   ],
///   onPressed: (int index) {
///     int count = 0;
///     isSelected.forEach((bool val) {
///       if (val) count++;
///     });
///
///     if (isSelected[index] && count < 2)
///       return;
///
///     setState(() {
///       isSelected[index] = !isSelected[index];
///     });
///   },
///   isSelected: isSelected,
/// ),
/// ```
///
/// ## ToggleButton Borders
/// The toggle buttons, by default, have a solid, 1 logical pixel border
/// surrounding itself and separating each button. The toggle button borders'
/// color, width, and corner radii are configurable.
///
/// The [selectedBorderColor] determines the border's color when the button is
/// selected, while [disabledBorderColor] determines the border's color when
/// the button is disabled. [borderColor] is used when the button is enabled.
///
/// To remove the border, set [renderBorder] to false. Setting [borderWidth] to
/// 0.0 results in a hairline border. For more information on hairline borders,
/// see [BorderSide.width].
///
/// See also:
///
///  * <https://material.io/design/components/buttons.html#toggle-button>
class ToggleButtons extends StatelessWidget {
  /// Creates a set of toggle buttons.
  ///
  /// It displays its widgets provided in a [List] of [children] along [direction].
  /// The state of each button is controlled by [isSelected], which is a list
  /// of bools that determine if a button is in an active, disabled, or
  /// selected state. They are both correlated by their index in the list.
  /// The length of [isSelected] has to match the length of the [children]
  /// list.
  ///
  /// Both [children] and [isSelected] properties arguments are required.
  ///
  /// [isSelected] values must be non-null. [focusNodes] must be null or a
  /// list of non-null nodes. [renderBorder] and [direction] must not be null.
  /// If [direction] is [Axis.vertical], [verticalDirection] must not be null.
  const ToggleButtons({
    Key? key,
    required this.children,
    required this.isSelected,
    this.onPressed,
    this.mouseCursor,
    this.tapTargetSize,
    this.textStyle,
    this.constraints,
    this.color,
    this.selectedColor,
    this.disabledColor,
    this.fillColor,
    this.focusColor,
    this.highlightColor,
    this.hoverColor,
    this.splashColor,
    this.focusNodes,
    this.renderBorder = true,
    this.borderColor,
    this.selectedBorderColor,
    this.disabledBorderColor,
    this.borderRadius,
    this.borderWidth,
    this.direction = Axis.horizontal,
    this.verticalDirection = VerticalDirection.down,
  }) :
    assert(children != null),
    assert(isSelected != null),
    assert(children.length == isSelected.length),
    assert(direction != null),
    assert(direction == Axis.horizontal || verticalDirection != null),
    super(key: key);

  static const double _defaultBorderWidth = 1.0;

  /// The toggle button widgets.
  ///
  /// These are typically [Icon] or [Text] widgets. The boolean selection
  /// state of each widget is defined by the corresponding [isSelected]
  /// list item.
  ///
  /// The length of children has to match the length of [isSelected]. If
  /// [focusNodes] is not null, the length of children has to also match
  /// the length of [focusNodes].
  final List<Widget> children;

  /// The corresponding selection state of each toggle button.
  ///
  /// Each value in this list represents the selection state of the [children]
  /// widget at the same index.
  ///
  /// The length of [isSelected] has to match the length of [children].
  final List<bool> isSelected;

  /// The callback that is called when a button is tapped.
  ///
  /// The index parameter of the callback is the index of the button that is
  /// tapped or otherwise activated.
  ///
  /// When the callback is null, all toggle buttons will be disabled.
  final void Function(int index)? onPressed;

  /// {@macro flutter.material.RawMaterialButton.mouseCursor}
  final MouseCursor? mouseCursor;

  /// Configures the minimum size of the area within which the buttons may
  /// be pressed.
  ///
  /// If the [tapTargetSize] is larger than [constraints], the buttons will
  /// include a transparent margin that responds to taps.
  ///
  /// Defaults to [ThemeData.materialTapTargetSize].
  final MaterialTapTargetSize? tapTargetSize;

  /// The [TextStyle] to apply to any text in these toggle buttons.
  ///
  /// [TextStyle.color] will be ignored and substituted by [color],
  /// [selectedColor] or [disabledColor] depending on whether the buttons
  /// are active, selected, or disabled.
  final TextStyle? textStyle;

  /// Defines the button's size.
  ///
  /// Typically used to constrain the button's minimum size.
  ///
  /// If this property is null, then
  /// BoxConstraints(minWidth: 48.0, minHeight: 48.0) is be used.
  final BoxConstraints? constraints;

  /// The color for descendant [Text] and [Icon] widgets if the button is
  /// enabled and not selected.
  ///
  /// If [onPressed] is not null, this color will be used for values in
  /// [isSelected] that are false.
  ///
  /// If this property is null, then ToggleButtonTheme.of(context).color
  /// is used. If [ToggleButtonsThemeData.color] is also null, then
  /// Theme.of(context).colorScheme.onSurface is used.
  final Color? color;

  /// The color for descendant [Text] and [Icon] widgets if the button is
  /// selected.
  ///
  /// If [onPressed] is not null, this color will be used for values in
  /// [isSelected] that are true.
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).selectedColor is used. If
  /// [ToggleButtonsThemeData.selectedColor] is also null, then
  /// Theme.of(context).colorScheme.primary is used.
  final Color? selectedColor;

  /// The color for descendant [Text] and [Icon] widgets if the button is
  /// disabled.
  ///
  /// If [onPressed] is null, this color will be used.
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).disabledColor is used. If
  /// [ToggleButtonsThemeData.disabledColor] is also null, then
  /// Theme.of(context).colorScheme.onSurface.withOpacity(0.38) is used.
  final Color? disabledColor;

  /// The fill color for selected toggle buttons.
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).fillColor is used. If
  /// [ToggleButtonsThemeData.fillColor] is also null, then
  /// the fill color is null.
  ///
  /// If fillColor is a [MaterialStateProperty<Color>], then [MaterialStateProperty.resolve]
  /// is used for the following [MaterialState]s:
  ///
  ///  * [MaterialState.disabled]
  ///  * [MaterialState.selected]
  ///
  final Color? fillColor;

  /// The color to use for filling the button when the button has input focus.
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).focusColor is used. If
  /// [ToggleButtonsThemeData.focusColor] is also null, then
  /// Theme.of(context).focusColor is used.
  final Color? focusColor;

  /// The highlight color for the button's [InkWell].
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).highlightColor is used. If
  /// [ToggleButtonsThemeData.highlightColor] is also null, then
  /// Theme.of(context).highlightColor is used.
  final Color? highlightColor;

  /// The splash color for the button's [InkWell].
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).splashColor is used. If
  /// [ToggleButtonsThemeData.splashColor] is also null, then
  /// Theme.of(context).splashColor is used.
  final Color? splashColor;

  /// The color to use for filling the button when the button has a pointer
  /// hovering over it.
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).hoverColor is used. If
  /// [ToggleButtonsThemeData.hoverColor] is also null, then
  /// Theme.of(context).hoverColor is used.
  final Color? hoverColor;

  /// The list of [FocusNode]s, corresponding to each toggle button.
  ///
  /// Focus is used to determine which widget should be affected by keyboard
  /// events. The focus tree keeps track of which widget is currently focused
  /// on by the user.
  ///
  /// If not null, the length of focusNodes has to match the length of
  /// [children].
  ///
  /// See [FocusNode] for more information about how focus nodes are used.
  final List<FocusNode>? focusNodes;

  /// Whether or not to render a border around each toggle button.
  ///
  /// When true, a border with [borderWidth], [borderRadius] and the
  /// appropriate border color will render. Otherwise, no border will be
  /// rendered.
  final bool renderBorder;

  /// The border color to display when the toggle button is enabled and not
  /// selected.
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).borderColor is used. If
  /// [ToggleButtonsThemeData.borderColor] is also null, then
  /// Theme.of(context).colorScheme.onSurface is used.
  final Color? borderColor;

  /// The border color to display when the toggle button is selected.
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).selectedBorderColor is used. If
  /// [ToggleButtonsThemeData.selectedBorderColor] is also null, then
  /// Theme.of(context).colorScheme.primary is used.
  final Color? selectedBorderColor;

  /// The border color to display when the toggle button is disabled.
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).disabledBorderColor is used. If
  /// [ToggleButtonsThemeData.disabledBorderColor] is also null, then
  /// Theme.of(context).disabledBorderColor is used.
  final Color? disabledBorderColor;

  /// The width of the border surrounding each toggle button.
  ///
  /// This applies to both the greater surrounding border, as well as the
  /// borders rendered between toggle buttons.
  ///
  /// To render a hairline border (one physical pixel), set borderWidth to 0.0.
  /// See [BorderSide.width] for more details on hairline borders.
  ///
  /// To omit the border entirely, set [renderBorder] to false.
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).borderWidth is used. If
  /// [ToggleButtonsThemeData.borderWidth] is also null, then
  /// a width of 1.0 is used.
  final double? borderWidth;

  /// The radii of the border's corners.
  ///
  /// If this property is null, then
  /// ToggleButtonTheme.of(context).borderRadius is used. If
  /// [ToggleButtonsThemeData.borderRadius] is also null, then
  /// the buttons default to non-rounded borders.
  final BorderRadius? borderRadius;

  /// The direction along which the buttons are rendered.
  ///
  /// Defaults to [Axis.horizontal].
  final Axis direction;

  /// If [direction] is [Axis.vertical], this parameter determines whether to lay out
  /// the buttons starting from the first or last child from top to bottom.
  final VerticalDirection verticalDirection;

  // Determines if this is the first child that is being laid out
  // by the render object, _not_ the order of the children in its list.
  bool _isFirstButton(int index, int length, TextDirection textDirection) {
    return index == 0 && ((direction == Axis.horizontal && textDirection == TextDirection.ltr) ||
      (direction == Axis.vertical && verticalDirection == VerticalDirection.down))
      || index == length - 1 && ((direction == Axis.horizontal && textDirection == TextDirection.rtl) ||
      (direction == Axis.vertical && verticalDirection == VerticalDirection.up));
  }

  // Determines if this is the last child that is being laid out
  // by the render object, _not_ the order of the children in its list.
  bool _isLastButton(int index, int length, TextDirection textDirection) {
    return index == length - 1 && ((direction == Axis.horizontal && textDirection == TextDirection.ltr) ||
      (direction == Axis.vertical && verticalDirection == VerticalDirection.down))
      || index == 0 && ((direction == Axis.horizontal && textDirection == TextDirection.rtl) ||
      (direction == Axis.vertical && verticalDirection == VerticalDirection.up));
  }

  BorderRadius _getEdgeBorderRadius(
    int index,
    int length,
    TextDirection textDirection,
    ToggleButtonsThemeData toggleButtonsTheme,
  ) {
    final BorderRadius resultingBorderRadius = borderRadius
      ?? toggleButtonsTheme.borderRadius
      ?? BorderRadius.zero;

    if (length == 1) {
      return resultingBorderRadius;
    } else if (direction == Axis.horizontal) {
      if (_isFirstButton(index, length, textDirection)) {
        return BorderRadius.only(
          topLeft: resultingBorderRadius.topLeft,
          bottomLeft: resultingBorderRadius.bottomLeft,
        );
      } else if (_isLastButton(index, length, textDirection)) {
        return BorderRadius.only(
          topRight: resultingBorderRadius.topRight,
          bottomRight: resultingBorderRadius.bottomRight,
        );
      }
    } else {
      if (_isFirstButton(index, length, textDirection)) {
        return BorderRadius.only(
          topLeft: resultingBorderRadius.topLeft,
          topRight: resultingBorderRadius.topRight,
        );
      } else if (_isLastButton(index, length, textDirection)) {
        return BorderRadius.only(
          bottomLeft: resultingBorderRadius.bottomLeft,
          bottomRight: resultingBorderRadius.bottomRight,
        );
      }
    }

    return BorderRadius.zero;
  }

  BorderRadius _getClipBorderRadius(
    int index,
    int length,
    TextDirection textDirection,
    ToggleButtonsThemeData toggleButtonsTheme,
  ) {
    final BorderRadius resultingBorderRadius = borderRadius
      ?? toggleButtonsTheme.borderRadius
      ?? BorderRadius.zero;
    final double resultingBorderWidth = borderWidth
      ?? toggleButtonsTheme.borderWidth
      ?? _defaultBorderWidth;

    if (length == 1) {
      return BorderRadius.only(
        topLeft: resultingBorderRadius.topLeft - Radius.circular(resultingBorderWidth / 2.0),
        bottomLeft: resultingBorderRadius.bottomLeft - Radius.circular(resultingBorderWidth / 2.0),
        topRight: resultingBorderRadius.topRight - Radius.circular(resultingBorderWidth / 2.0),
        bottomRight: resultingBorderRadius.bottomRight - Radius.circular(resultingBorderWidth / 2.0),
      );
    } else if (direction == Axis.horizontal) {
      if (_isFirstButton(index, length, textDirection)) {
        return BorderRadius.only(
          topLeft: resultingBorderRadius.topLeft - Radius.circular(resultingBorderWidth / 2.0),
          bottomLeft: resultingBorderRadius.bottomLeft - Radius.circular(resultingBorderWidth / 2.0),
        );
      } else if (_isLastButton(index, length, textDirection)) {
        return BorderRadius.only(
          topRight: resultingBorderRadius.topRight - Radius.circular(resultingBorderWidth / 2.0),
          bottomRight: resultingBorderRadius.bottomRight - Radius.circular(resultingBorderWidth / 2.0),
        );
      }
    } else {
      if (_isFirstButton(index, length, textDirection)) {
        return BorderRadius.only(
          topLeft: resultingBorderRadius.topLeft - Radius.circular(resultingBorderWidth / 2.0),
          topRight: resultingBorderRadius.topRight - Radius.circular(resultingBorderWidth / 2.0),
        );
      } else if (_isLastButton(index, length, textDirection)) {
        return BorderRadius.only(
          bottomLeft: resultingBorderRadius.bottomLeft - Radius.circular(resultingBorderWidth / 2.0),
          bottomRight: resultingBorderRadius.bottomRight - Radius.circular(resultingBorderWidth / 2.0),
        );
      }
    }
    return BorderRadius.zero;
  }

  BorderSide _getLeadingBorderSide(
    int index,
    ThemeData theme,
    ToggleButtonsThemeData toggleButtonsTheme,
  ) {
    if (!renderBorder)
      return BorderSide.none;

    final double resultingBorderWidth = borderWidth
      ?? toggleButtonsTheme.borderWidth
      ?? _defaultBorderWidth;
    if (onPressed != null && (isSelected[index] || (index != 0 && isSelected[index - 1]))) {
      return BorderSide(
        color: selectedBorderColor
          ?? toggleButtonsTheme.selectedBorderColor
          ?? theme.colorScheme.onSurface.withOpacity(0.12),
        width: resultingBorderWidth,
      );
    } else if (onPressed != null && !isSelected[index]) {
      return BorderSide(
        color: borderColor
          ?? toggleButtonsTheme.borderColor
          ?? theme.colorScheme.onSurface.withOpacity(0.12),
        width: resultingBorderWidth,
      );
    } else {
      return BorderSide(
        color: disabledBorderColor
          ?? toggleButtonsTheme.disabledBorderColor
          ?? theme.colorScheme.onSurface.withOpacity(0.12),
        width: resultingBorderWidth,
      );
    }
  }

  BorderSide _getBorderSide(
    int index,
    ThemeData theme,
    ToggleButtonsThemeData toggleButtonsTheme,
  ) {
    if (!renderBorder)
      return BorderSide.none;

    final double resultingBorderWidth = borderWidth
      ?? toggleButtonsTheme.borderWidth
      ?? _defaultBorderWidth;
    if (onPressed != null && isSelected[index]) {
      return BorderSide(
        color: selectedBorderColor
          ?? toggleButtonsTheme.selectedBorderColor
          ?? theme.colorScheme.onSurface.withOpacity(0.12),
        width: resultingBorderWidth,
      );
    } else if (onPressed != null && !isSelected[index]) {
      return BorderSide(
        color: borderColor
          ?? toggleButtonsTheme.borderColor
          ?? theme.colorScheme.onSurface.withOpacity(0.12),
        width: resultingBorderWidth,
      );
    } else {
      return BorderSide(
        color: disabledBorderColor
          ?? toggleButtonsTheme.disabledBorderColor
          ?? theme.colorScheme.onSurface.withOpacity(0.12),
        width: resultingBorderWidth,
      );
    }
  }

  BorderSide _getTrailingBorderSide(
    int index,
    ThemeData theme,
    ToggleButtonsThemeData toggleButtonsTheme,
  ) {
    if (!renderBorder)
      return BorderSide.none;

    if (index != children.length - 1)
      return BorderSide.none;

    final double resultingBorderWidth = borderWidth
      ?? toggleButtonsTheme.borderWidth
      ?? _defaultBorderWidth;
    if (onPressed != null && (isSelected[index])) {
      return BorderSide(
        color: selectedBorderColor
          ?? toggleButtonsTheme.selectedBorderColor
          ?? theme.colorScheme.onSurface.withOpacity(0.12),
        width: resultingBorderWidth,
      );
    } else if (onPressed != null && !isSelected[index]) {
      return BorderSide(
        color: borderColor
          ?? toggleButtonsTheme.borderColor
          ?? theme.colorScheme.onSurface.withOpacity(0.12),
        width: resultingBorderWidth,
      );
    } else {
      return BorderSide(
        color: disabledBorderColor
          ?? toggleButtonsTheme.disabledBorderColor
          ?? theme.colorScheme.onSurface.withOpacity(0.12),
        width: resultingBorderWidth,
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    assert(
      !isSelected.any((bool val) => val == null),
      'All elements of isSelected must be non-null.\n'
      'The current list of isSelected values is as follows:\n'
      '$isSelected',
    );
    assert(
      focusNodes == null || !focusNodes!.any((FocusNode val) => val == null),
      'All elements of focusNodes must be non-null.\n'
      'The current list of focus node values is as follows:\n'
      '$focusNodes',
    );
    assert(
      () {
        if (focusNodes != null)
          return focusNodes!.length == children.length;
        return true;
      }(),
      'focusNodes.length must match children.length.\n'
      'There are ${focusNodes!.length} focus nodes, while '
      'there are ${children.length} children.',
    );
    final ThemeData theme = Theme.of(context);
    final ToggleButtonsThemeData toggleButtonsTheme = ToggleButtonsTheme.of(context);
    final TextDirection textDirection = Directionality.of(context);

    final List<Widget> buttons = List<Widget>.generate(children.length, (int index) {
      final BorderRadius edgeBorderRadius = _getEdgeBorderRadius(index, children.length, textDirection, toggleButtonsTheme);
      final BorderRadius clipBorderRadius = _getClipBorderRadius(index, children.length, textDirection, toggleButtonsTheme);

      final BorderSide leadingBorderSide = _getLeadingBorderSide(index, theme, toggleButtonsTheme);
      final BorderSide borderSide = _getBorderSide(index, theme, toggleButtonsTheme);
      final BorderSide trailingBorderSide = _getTrailingBorderSide(index, theme, toggleButtonsTheme);

      return _ToggleButton(
        selected: isSelected[index],
        textStyle: textStyle,
        constraints: constraints,
        color: color,
        selectedColor: selectedColor,
        disabledColor: disabledColor,
        fillColor: fillColor,
        focusColor: focusColor ?? toggleButtonsTheme.focusColor,
        highlightColor: highlightColor ?? toggleButtonsTheme.highlightColor,
        hoverColor: hoverColor ?? toggleButtonsTheme.hoverColor,
        splashColor: splashColor ?? toggleButtonsTheme.splashColor,
        focusNode: focusNodes != null ? focusNodes![index] : null,
        onPressed: onPressed != null
          ? () {onPressed!(index);}
          : null,
        mouseCursor: mouseCursor,
        leadingBorderSide: leadingBorderSide,
        borderSide: borderSide,
        trailingBorderSide: trailingBorderSide,
        borderRadius: edgeBorderRadius,
        clipRadius: clipBorderRadius,
        isFirstButton: index == 0,
        isLastButton: index == children.length - 1,
        direction: direction,
        verticalDirection: verticalDirection,
        child: children[index],
      );
    });

    final Widget result = direction == Axis.horizontal
      ? IntrinsicHeight(
        child: Row(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: buttons,
        ),
      )
      : IntrinsicWidth(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          verticalDirection: verticalDirection,
          children: buttons,
        ),
      );

    final MaterialTapTargetSize resolvedTapTargetSize = tapTargetSize ?? theme.materialTapTargetSize;
    switch (resolvedTapTargetSize) {
      case MaterialTapTargetSize.padded:
        return _InputPadding(
          minSize: const Size(kMinInteractiveDimension, kMinInteractiveDimension),
          direction: direction,
          child: result,
        );
      case MaterialTapTargetSize.shrinkWrap:
        return result;
    }
  }

  @override
  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
    super.debugFillProperties(properties);
    properties.add(FlagProperty('disabled',
      value: onPressed == null,
      ifTrue: 'Buttons are disabled',
      ifFalse: 'Buttons are enabled',
    ));
    textStyle?.debugFillProperties(properties, prefix: 'textStyle.');
    properties.add(ColorProperty('color', color, defaultValue: null));
    properties.add(ColorProperty('selectedColor', selectedColor, defaultValue: null));
    properties.add(ColorProperty('disabledColor', disabledColor, defaultValue: null));
    properties.add(ColorProperty('fillColor', fillColor, defaultValue: null));
    properties.add(ColorProperty('focusColor', focusColor, defaultValue: null));
    properties.add(ColorProperty('highlightColor', highlightColor, defaultValue: null));
    properties.add(ColorProperty('hoverColor', hoverColor, defaultValue: null));
    properties.add(ColorProperty('splashColor', splashColor, defaultValue: null));
    properties.add(ColorProperty('borderColor', borderColor, defaultValue: null));
    properties.add(ColorProperty('selectedBorderColor', selectedBorderColor, defaultValue: null));
    properties.add(ColorProperty('disabledBorderColor', disabledBorderColor, defaultValue: null));
    properties.add(DiagnosticsProperty<BorderRadius>('borderRadius', borderRadius, defaultValue: null));
    properties.add(DoubleProperty('borderWidth', borderWidth, defaultValue: null));
    properties.add(DiagnosticsProperty<Axis>('direction', direction, defaultValue: Axis.horizontal));
    properties.add(DiagnosticsProperty<VerticalDirection>('verticalDirection', verticalDirection, defaultValue: VerticalDirection.down));
  }
}

/// An individual toggle button, otherwise known as a segmented button.
///
/// This button is used by [ToggleButtons] to implement a set of segmented controls.
class _ToggleButton extends StatelessWidget {
  /// Creates a toggle button based on [RawMaterialButton].
  ///
  /// This class adds some logic to distinguish between enabled, active, and
  /// disabled states, to determine the appropriate colors to use.
  ///
  /// It takes in a [shape] property to modify the borders of the button,
  /// which is used by [ToggleButtons] to customize borders based on the
  /// order in which this button appears in the list.
  const _ToggleButton({
    Key? key,
    this.selected = false,
    this.textStyle,
    this.constraints,
    this.color,
    this.selectedColor,
    this.disabledColor,
    required this.fillColor,
    required this.focusColor,
    required this.highlightColor,
    required this.hoverColor,
    required this.splashColor,
    this.focusNode,
    this.onPressed,
    this.mouseCursor,
    required this.leadingBorderSide,
    required this.borderSide,
    required this.trailingBorderSide,
    required this.borderRadius,
    required this.clipRadius,
    required this.isFirstButton,
    required this.isLastButton,
    required this.direction,
    required this.verticalDirection,
    required this.child,
  }) : super(key: key);

  /// Determines if the button is displayed as active/selected or enabled.
  final bool selected;

  /// The [TextStyle] to apply to any text that appears in this button.
  final TextStyle? textStyle;

  /// Defines the button's size.
  ///
  /// Typically used to constrain the button's minimum size.
  final BoxConstraints? constraints;

  /// The color for [Text] and [Icon] widgets if the button is enabled.
  ///
  /// If [selected] is false and [onPressed] is not null, this color will be used.
  final Color? color;

  /// The color for [Text] and [Icon] widgets if the button is selected.
  ///
  /// If [selected] is true and [onPressed] is not null, this color will be used.
  final Color? selectedColor;

  /// The color for [Text] and [Icon] widgets if the button is disabled.
  ///
  /// If [onPressed] is null, this color will be used.
  final Color? disabledColor;

  /// The color of the button's [Material].
  final Color? fillColor;

  /// The color for the button's [Material] when it has the input focus.
  final Color? focusColor;

  /// The color for the button's [Material] when a pointer is hovering over it.
  final Color? hoverColor;

  /// The highlight color for the button's [InkWell].
  final Color? highlightColor;

  /// The splash color for the button's [InkWell].
  final Color? splashColor;

  /// {@macro flutter.widgets.Focus.focusNode}
  final FocusNode? focusNode;

  /// Called when the button is tapped or otherwise activated.
  ///
  /// If this is null, the button will be disabled, see [enabled].
  final VoidCallback? onPressed;

  /// {@macro flutter.material.RawMaterialButton.mouseCursor}
  final MouseCursor? mouseCursor;

  /// The width and color of the button's leading side border.
  final BorderSide leadingBorderSide;

  /// If [direction] is [Axis.horizontal], this corresponds the width and color
  /// of the button's top and bottom side borders.
  ///
  /// If [direction] is [Axis.vertical], this corresponds the width and color
  /// of the button's left and right side borders.
  final BorderSide borderSide;

  /// The width and color of the button's trailing side border.
  final BorderSide trailingBorderSide;

  /// The border radii of each corner of the button.
  final BorderRadius borderRadius;

  /// The corner radii used to clip the button's contents.
  ///
  /// This is used to have the button's contents be properly clipped taking
  /// the [borderRadius] and the border's width into account.
  final BorderRadius clipRadius;

  /// Whether or not this toggle button is the first button in the list.
  final bool isFirstButton;

  /// Whether or not this toggle button is the last button in the list.
  final bool isLastButton;

  /// The direction along which the buttons are rendered.
  final Axis direction;

  /// If [direction] is [Axis.vertical], this property defines whether or not this button in its list
  /// of buttons is laid out starting from top to bottom or from bottom to top.
  final VerticalDirection verticalDirection;

  /// The button's label, which is usually an [Icon] or a [Text] widget.
  final Widget child;

  Color _resolveColor(Set<MaterialState> states, MaterialStateProperty<Color?> widgetColor,
  MaterialStateProperty<Color?> themeColor, MaterialStateProperty<Color> defaultColor) {
    return widgetColor.resolve(states)
      ?? themeColor.resolve(states)
      ?? defaultColor.resolve(states);
  }

  @override
  Widget build(BuildContext context) {
    assert(debugCheckHasMaterial(context));
    final Color currentColor;
    Color? currentFocusColor;
    Color? currentHoverColor;
    Color? currentSplashColor;
    final ThemeData theme = Theme.of(context);
    final ToggleButtonsThemeData toggleButtonsTheme = ToggleButtonsTheme.of(context);

    final Set<MaterialState> states = <MaterialState>{
        if (selected && onPressed != null) MaterialState.selected,
        if (onPressed == null) MaterialState.disabled,
    };

    final Color currentFillColor = _resolveColor(
      states,
      _ResolveFillColor(fillColor),
      _ResolveFillColor(toggleButtonsTheme.fillColor),
      _DefaultFillColor(theme.colorScheme),
    );

    if (onPressed != null && selected) {
      currentColor = selectedColor
        ?? toggleButtonsTheme.selectedColor
        ?? theme.colorScheme.primary;
      currentFocusColor = focusColor
        ?? toggleButtonsTheme.focusColor
        ?? theme.colorScheme.primary.withOpacity(0.12);
      currentHoverColor = hoverColor
        ?? toggleButtonsTheme.hoverColor
        ?? theme.colorScheme.primary.withOpacity(0.04);
      currentSplashColor = splashColor
        ?? toggleButtonsTheme.splashColor
        ?? theme.colorScheme.primary.withOpacity(0.16);
    } else if (onPressed != null && !selected) {
      currentColor = color
        ?? toggleButtonsTheme.color
        ?? theme.colorScheme.onSurface.withOpacity(0.87);
      currentFocusColor = focusColor
        ?? toggleButtonsTheme.focusColor
        ?? theme.colorScheme.onSurface.withOpacity(0.12);
      currentHoverColor = hoverColor
        ?? toggleButtonsTheme.hoverColor
        ?? theme.colorScheme.onSurface.withOpacity(0.04);
      currentSplashColor = splashColor
        ?? toggleButtonsTheme.splashColor
        ?? theme.colorScheme.onSurface.withOpacity(0.16);
    } else {
      currentColor = disabledColor
        ?? toggleButtonsTheme.disabledColor
        ?? theme.colorScheme.onSurface.withOpacity(0.38);
    }

    final TextStyle currentTextStyle = textStyle ?? toggleButtonsTheme.textStyle ?? theme.textTheme.bodyText2!;
    final BoxConstraints currentConstraints = constraints ?? toggleButtonsTheme.constraints ?? const BoxConstraints(minWidth: kMinInteractiveDimension, minHeight: kMinInteractiveDimension);

    final Widget result = ClipRRect(
      borderRadius: clipRadius,
      child: RawMaterialButton(
        textStyle: currentTextStyle.copyWith(
          color: currentColor,
        ),
        constraints: currentConstraints,
        elevation: 0.0,
        fillColor: currentFillColor,
        focusColor: currentFocusColor,
        focusElevation: 0,
        highlightColor: highlightColor ?? theme.colorScheme.surface.withOpacity(0.0),
        highlightElevation: 0.0,
        hoverColor: currentHoverColor,
        hoverElevation: 0,
        splashColor: currentSplashColor,
        focusNode: focusNode,
        materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
        onPressed: onPressed,
        mouseCursor: mouseCursor,
        child: child,
      ),
    );

    return _SelectToggleButton(
      key: key,
      leadingBorderSide: leadingBorderSide,
      borderSide: borderSide,
      trailingBorderSide: trailingBorderSide,
      borderRadius: borderRadius,
      isFirstButton: isFirstButton,
      isLastButton: isLastButton,
      direction: direction,
      verticalDirection: verticalDirection,
      child: result,
    );
  }

  @override
  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
    super.debugFillProperties(properties);
    properties.add(FlagProperty('selected',
      value: selected,
      ifTrue: 'Button is selected',
      ifFalse: 'Button is unselected',
    ));
  }
}

@immutable
class _ResolveFillColor extends MaterialStateProperty<Color?> with Diagnosticable {
  _ResolveFillColor(this.primary);

  final Color? primary;

  @override
  Color? resolve(Set<MaterialState> states) {
    if (primary is MaterialStateProperty<Color>) {
      return MaterialStateProperty.resolveAs<Color?>(primary, states);
    }
    return states.contains(MaterialState.selected) ? primary : null;
  }
}

@immutable
class _DefaultFillColor extends MaterialStateProperty<Color> with Diagnosticable {
  _DefaultFillColor(this.colorScheme);

  final ColorScheme colorScheme;

  @override
  Color resolve(Set<MaterialState> states) {
    if (states.contains(MaterialState.selected)) {
      return colorScheme.primary.withOpacity(0.12);
    }
    return colorScheme.surface.withOpacity(0.0);
  }
}

class _SelectToggleButton extends SingleChildRenderObjectWidget {
  const _SelectToggleButton({
    Key? key,
    required Widget child,
    required this.leadingBorderSide,
    required this.borderSide,
    required this.trailingBorderSide,
    required this.borderRadius,
    required this.isFirstButton,
    required this.isLastButton,
    required this.direction,
    required this.verticalDirection,
  }) : super(
    key: key,
    child: child,
  );

  // The width and color of the button's leading side border.
  final BorderSide leadingBorderSide;

  // The width and color of the side borders.
  //
  // If [direction] is [Axis.horizontal], this corresponds to the width and color
  // of the button's top and bottom side borders.
  //
  // If [direction] is [Axis.vertical], this corresponds to the width and color
  // of the button's left and right side borders.
  final BorderSide borderSide;

  // The width and color of the button's trailing side border.
  final BorderSide trailingBorderSide;

  // The border radii of each corner of the button.
  final BorderRadius borderRadius;

  // Whether or not this toggle button is the first button in the list.
  final bool isFirstButton;

  // Whether or not this toggle button is the last button in the list.
  final bool isLastButton;

  // The direction along which the buttons are rendered.
  final Axis direction;

  // If [direction] is [Axis.vertical], this property defines whether or not this button in its list
  // of buttons is laid out starting from top to bottom or from bottom to top.
  final VerticalDirection verticalDirection;

  @override
  _SelectToggleButtonRenderObject createRenderObject(BuildContext context) => _SelectToggleButtonRenderObject(
    leadingBorderSide,
    borderSide,
    trailingBorderSide,
    borderRadius,
    isFirstButton,
    isLastButton,
    direction,
    verticalDirection,
    Directionality.of(context),
  );

  @override
  void updateRenderObject(BuildContext context, _SelectToggleButtonRenderObject renderObject) {
    renderObject
      ..leadingBorderSide = leadingBorderSide
      ..borderSide  = borderSide
      ..trailingBorderSide = trailingBorderSide
      ..borderRadius = borderRadius
      ..isFirstButton = isFirstButton
      ..isLastButton = isLastButton
      ..direction = direction
      ..verticalDirection = verticalDirection
      ..textDirection = Directionality.of(context);
  }
}

class _SelectToggleButtonRenderObject extends RenderShiftedBox {
  _SelectToggleButtonRenderObject(
    this._leadingBorderSide,
    this._borderSide,
    this._trailingBorderSide,
    this._borderRadius,
    this._isFirstButton,
    this._isLastButton,
    this._direction,
    this._verticalDirection,
    this._textDirection, [
    RenderBox? child,
  ]) : super(child);

  Axis get direction => _direction;
  Axis _direction;
  set direction(Axis value) {
    if (_direction == value)
      return;
    _direction = value;
    markNeedsLayout();
  }

  VerticalDirection get verticalDirection => _verticalDirection;
  VerticalDirection _verticalDirection;
  set verticalDirection(VerticalDirection value) {
    if (_verticalDirection == value)
      return;
    _verticalDirection = value;
    markNeedsLayout();
  }

  // The width and color of the button's leading side border.
  BorderSide get leadingBorderSide => _leadingBorderSide;
  BorderSide _leadingBorderSide;
  set leadingBorderSide(BorderSide value) {
    if (_leadingBorderSide == value)
      return;
    _leadingBorderSide = value;
    markNeedsLayout();
  }

  // The width and color of the button's top and bottom side borders.
  BorderSide get borderSide  => _borderSide;
  BorderSide _borderSide;
  set borderSide(BorderSide value) {
    if (_borderSide == value)
      return;
    _borderSide = value;
    markNeedsLayout();
  }

  // The width and color of the button's trailing side border.
  BorderSide get trailingBorderSide => _trailingBorderSide;
  BorderSide _trailingBorderSide;
  set trailingBorderSide(BorderSide value) {
    if (_trailingBorderSide == value)
      return;
    _trailingBorderSide = value;
    markNeedsLayout();
  }

  // The border radii of each corner of the button.
  BorderRadius get borderRadius => _borderRadius;
  BorderRadius _borderRadius;
  set borderRadius(BorderRadius value) {
    if (_borderRadius == value)
      return;
    _borderRadius = value;
    markNeedsLayout();
  }

  // Whether or not this toggle button is the first button in the list.
  bool get isFirstButton => _isFirstButton;
  bool _isFirstButton;
  set isFirstButton(bool value) {
    if (_isFirstButton == value)
      return;
    _isFirstButton = value;
    markNeedsLayout();
  }

  // Whether or not this toggle button is the last button in the list.
  bool get isLastButton => _isLastButton;
  bool _isLastButton;
  set isLastButton(bool value) {
    if (_isLastButton == value)
      return;
    _isLastButton = value;
    markNeedsLayout();
  }

  // The direction in which text flows for this application.
  TextDirection get textDirection => _textDirection;
  TextDirection _textDirection;
  set textDirection(TextDirection value) {
    if (_textDirection == value)
      return;
    _textDirection = value;
    markNeedsLayout();
  }

  static double _maxHeight(RenderBox? box, double width) {
    return box == null ? 0.0 : box.getMaxIntrinsicHeight(width);
  }

  static double _minHeight(RenderBox? box, double width) {
    return box == null ? 0.0 : box.getMinIntrinsicHeight(width);
  }

  static double _minWidth(RenderBox? box, double height) {
    return box == null ? 0.0 : box.getMinIntrinsicWidth(height);
  }

  static double _maxWidth(RenderBox? box, double height) {
    return box == null ? 0.0 : box.getMaxIntrinsicWidth(height);
  }

  @override
  double computeDistanceToActualBaseline(TextBaseline baseline) {
    // The baseline of this widget is the baseline of its child
    return direction == Axis.horizontal
      ? child!.computeDistanceToActualBaseline(baseline)! + borderSide.width
      : child!.computeDistanceToActualBaseline(baseline)! + leadingBorderSide.width;
  }

  @override
  double computeMaxIntrinsicHeight(double width) {
    return direction == Axis.horizontal
      ? borderSide.width * 2.0 + _maxHeight(child, width)
      : leadingBorderSide.width + _maxHeight(child, width) + trailingBorderSide.width;
  }

  @override
  double computeMinIntrinsicHeight(double width) {
    return direction == Axis.horizontal
        ? borderSide.width * 2.0 + _minHeight(child, width)
        : leadingBorderSide.width + _maxHeight(child, width) + trailingBorderSide.width;
  }

  @override
  double computeMaxIntrinsicWidth(double height) {
    return direction == Axis.horizontal
      ? leadingBorderSide.width + _maxWidth(child, height) + trailingBorderSide.width
      : borderSide.width * 2.0 + _maxWidth(child, height);
  }

  @override
  double computeMinIntrinsicWidth(double height) {
    return direction == Axis.horizontal
      ? leadingBorderSide.width + _minWidth(child, height) + trailingBorderSide.width
      : borderSide.width * 2.0 + _minWidth(child, height);
  }

  @override
  Size computeDryLayout(BoxConstraints constraints) {
    return _computeSize(
      constraints: constraints,
      layoutChild: ChildLayoutHelper.dryLayoutChild,
    );
  }

  @override
  void performLayout() {
    size = _computeSize(
      constraints: constraints,
      layoutChild: ChildLayoutHelper.layoutChild,
    );
    if (child == null) {
      return;
    }
    final BoxParentData childParentData = child!.parentData! as BoxParentData;
    if (direction == Axis.horizontal) {
      switch (textDirection) {
        case TextDirection.ltr:
          childParentData.offset = Offset(leadingBorderSide.width, borderSide.width);
          break;
        case TextDirection.rtl:
          childParentData.offset = Offset(trailingBorderSide.width, borderSide.width);
          break;
      }
    } else {
      switch (verticalDirection) {
        case VerticalDirection.down:
          childParentData.offset = Offset(borderSide.width, leadingBorderSide.width);
          break;
        case VerticalDirection.up:
          childParentData.offset = Offset(borderSide.width, trailingBorderSide.width);
          break;
      }
    }
  }

  Size _computeSize({required BoxConstraints constraints, required ChildLayouter layoutChild}) {
    if (child == null) {
      if (direction == Axis.horizontal) {
        return constraints.constrain(Size(
          leadingBorderSide.width + trailingBorderSide.width,
          borderSide.width * 2.0,
        ));
      } else {
        return constraints.constrain(Size(
          borderSide.width * 2.0,
          leadingBorderSide.width + trailingBorderSide.width,
        ));
      }
    }

    final double leftConstraint;
    final double rightConstraint;
    final double topConstraint;
    final double bottomConstraint;

    // It does not matter what [textDirection] or [verticalDirection] is,
    // since deflating the size constraints horizontally/vertically
    // and the returned size accounts for the width of both sides.
    if (direction == Axis.horizontal) {
      rightConstraint = trailingBorderSide.width;
      leftConstraint = leadingBorderSide.width;
      topConstraint = borderSide.width;
      bottomConstraint = borderSide.width;
    } else {
      rightConstraint = borderSide.width;
      leftConstraint = borderSide.width;
      topConstraint = leadingBorderSide.width;
      bottomConstraint = trailingBorderSide.width;
    }
    final BoxConstraints innerConstraints = constraints.deflate(
      EdgeInsets.only(
        left: leftConstraint,
        top: topConstraint,
        right: rightConstraint,
        bottom: bottomConstraint,
      ),
    );
    final Size childSize = layoutChild(child!, innerConstraints);

    return constraints.constrain(Size(
      leftConstraint + childSize.width + rightConstraint,
      topConstraint + childSize.height + bottomConstraint,
    ));
  }

  @override
  void paint(PaintingContext context, Offset offset) {
    super.paint(context, offset);
    final Offset bottomRight = size.bottomRight(offset);
    final Rect outer = Rect.fromLTRB(offset.dx, offset.dy, bottomRight.dx, bottomRight.dy);
    final Rect center = outer.deflate(borderSide.width / 2.0);
    const double sweepAngle = math.pi / 2.0;
    final RRect rrect = RRect.fromRectAndCorners(
      center,
      topLeft: (borderRadius.topLeft.x * borderRadius.topLeft.y != 0.0) ? borderRadius.topLeft : Radius.zero,
      topRight: (borderRadius.topRight.x * borderRadius.topRight.y != 0.0) ? borderRadius.topRight : Radius.zero,
      bottomLeft: (borderRadius.bottomLeft.x * borderRadius.bottomLeft.y != 0.0) ? borderRadius.bottomLeft : Radius.zero,
      bottomRight: (borderRadius.bottomRight.x * borderRadius.bottomRight.y != 0.0) ? borderRadius.bottomRight : Radius.zero,
    ).scaleRadii();

    final Rect tlCorner = Rect.fromLTWH(
      rrect.left,
      rrect.top,
      rrect.tlRadiusX * 2.0,
      rrect.tlRadiusY * 2.0,
    );
    final Rect blCorner = Rect.fromLTWH(
      rrect.left,
      rrect.bottom - (rrect.blRadiusY * 2.0),
      rrect.blRadiusX * 2.0,
      rrect.blRadiusY * 2.0,
    );
    final Rect trCorner = Rect.fromLTWH(
      rrect.right - (rrect.trRadiusX * 2),
      rrect.top,
      rrect.trRadiusX * 2,
      rrect.trRadiusY * 2,
    );
    final Rect brCorner = Rect.fromLTWH(
      rrect.right - (rrect.brRadiusX * 2),
      rrect.bottom - (rrect.brRadiusY * 2),
      rrect.brRadiusX * 2,
      rrect.brRadiusY * 2,
    );

    final Paint leadingPaint = leadingBorderSide.toPaint();
    // Only one button.
    if (isFirstButton && isLastButton) {
      final Path leadingPath = Path();
      final double startX = (rrect.brRadiusX == 0.0) ? outer.right : rrect.right - rrect.brRadiusX;
      leadingPath..moveTo(startX, rrect.bottom)
        ..lineTo(rrect.left + rrect.blRadiusX, rrect.bottom)
        ..addArc(blCorner, math.pi / 2.0, sweepAngle)
        ..lineTo(rrect.left, rrect.top + rrect.tlRadiusY)
        ..addArc(tlCorner, math.pi, sweepAngle)
        ..lineTo(rrect.right - rrect.trRadiusX, rrect.top)
        ..addArc(trCorner, math.pi * 3.0 / 2.0, sweepAngle)
        ..lineTo(rrect.right, rrect.bottom - rrect.brRadiusY)
        ..addArc(brCorner, 0, sweepAngle);
      context.canvas.drawPath(leadingPath, leadingPaint);
      return;
    }

    if (direction == Axis.horizontal) {
      switch (textDirection) {
        case TextDirection.ltr:
          if (isLastButton) {
            final Path leftPath = Path();
            leftPath..moveTo(rrect.left, rrect.bottom + leadingBorderSide.width / 2)
              ..lineTo(rrect.left, rrect.top - leadingBorderSide.width / 2);
            context.canvas.drawPath(leftPath, leadingPaint);

            final Paint endingPaint = trailingBorderSide.toPaint();
            final Path endingPath = Path();
            endingPath..moveTo(rrect.left + borderSide.width / 2.0, rrect.top)
              ..lineTo(rrect.right - rrect.trRadiusX, rrect.top)
              ..addArc(trCorner, math.pi * 3.0 / 2.0, sweepAngle)
              ..lineTo(rrect.right, rrect.bottom - rrect.brRadiusY)
              ..addArc(brCorner, 0, sweepAngle)
              ..lineTo(rrect.left + borderSide.width / 2.0, rrect.bottom);
            context.canvas.drawPath(endingPath, endingPaint);
          } else if (isFirstButton) {
            final Path leadingPath = Path();
            leadingPath..moveTo(outer.right, rrect.bottom)
              ..lineTo(rrect.left + rrect.blRadiusX, rrect.bottom)
              ..addArc(blCorner, math.pi / 2.0, sweepAngle)
              ..lineTo(rrect.left, rrect.top + rrect.tlRadiusY)
              ..addArc(tlCorner, math.pi, sweepAngle)
              ..lineTo(outer.right, rrect.top);
            context.canvas.drawPath(leadingPath, leadingPaint);
          } else {
            final Path leadingPath = Path();
            leadingPath..moveTo(rrect.left, rrect.bottom + leadingBorderSide.width / 2)
              ..lineTo(rrect.left, rrect.top - leadingBorderSide.width / 2);
            context.canvas.drawPath(leadingPath, leadingPaint);

            final Paint horizontalPaint = borderSide.toPaint();
            final Path horizontalPaths = Path();
            horizontalPaths..moveTo(rrect.left + borderSide.width / 2.0, rrect.top)
              ..lineTo(outer.right - rrect.trRadiusX, rrect.top)
              ..moveTo(rrect.left + borderSide.width / 2.0 + rrect.tlRadiusX, rrect.bottom)
              ..lineTo(outer.right - rrect.trRadiusX, rrect.bottom);
            context.canvas.drawPath(horizontalPaths, horizontalPaint);
          }
          break;
        case TextDirection.rtl:
          if (isLastButton) {
            final Path leadingPath = Path();
            leadingPath..moveTo(rrect.right, rrect.bottom + leadingBorderSide.width / 2)
              ..lineTo(rrect.right, rrect.top - leadingBorderSide.width / 2);
            context.canvas.drawPath(leadingPath, leadingPaint);

            final Paint endingPaint = trailingBorderSide.toPaint();
            final Path endingPath = Path();
            endingPath..moveTo(rrect.right - borderSide.width / 2.0, rrect.top)
              ..lineTo(rrect.left + rrect.tlRadiusX, rrect.top)
              ..addArc(tlCorner, math.pi * 3.0 / 2.0, -sweepAngle)
              ..lineTo(rrect.left, rrect.bottom - rrect.blRadiusY)
              ..addArc(blCorner, math.pi, -sweepAngle)
              ..lineTo(rrect.right - borderSide.width / 2.0, rrect.bottom);
            context.canvas.drawPath(endingPath, endingPaint);
          } else if (isFirstButton) {
            final Path leadingPath = Path();
            leadingPath..moveTo(outer.left, rrect.bottom)
              ..lineTo(rrect.right - rrect.brRadiusX, rrect.bottom)
              ..addArc(brCorner, math.pi / 2.0, -sweepAngle)
              ..lineTo(rrect.right, rrect.top + rrect.trRadiusY)
              ..addArc(trCorner, 0, -sweepAngle)
              ..lineTo(outer.left, rrect.top);
            context.canvas.drawPath(leadingPath, leadingPaint);
          } else {
            final Path leadingPath = Path();
            leadingPath..moveTo(rrect.right, rrect.bottom + leadingBorderSide.width / 2)
              ..lineTo(rrect.right, rrect.top - leadingBorderSide.width / 2);
            context.canvas.drawPath(leadingPath, leadingPaint);

            final Paint horizontalPaint = borderSide.toPaint();
            final Path horizontalPaths = Path();
            horizontalPaths..moveTo(rrect.right - borderSide.width / 2.0, rrect.top)
              ..lineTo(outer.left - rrect.tlRadiusX, rrect.top)
              ..moveTo(rrect.right - borderSide.width / 2.0 + rrect.trRadiusX, rrect.bottom)
              ..lineTo(outer.left - rrect.tlRadiusX, rrect.bottom);
            context.canvas.drawPath(horizontalPaths, horizontalPaint);
          }
          break;
      }
    } else {
      switch (verticalDirection) {
        case VerticalDirection.down:
          if (isLastButton) {
            final Path topPath = Path();
            topPath..moveTo(outer.left, outer.top + leadingBorderSide.width / 2)
              ..lineTo(outer.right, outer.top + leadingBorderSide.width / 2);
            context.canvas.drawPath(topPath, leadingPaint);

            final Paint endingPaint = trailingBorderSide.toPaint();
            final Path endingPath = Path();
            endingPath..moveTo(rrect.left, rrect.top + leadingBorderSide.width / 2.0)
              ..lineTo(rrect.left, rrect.bottom - rrect.blRadiusY)
              ..addArc(blCorner, math.pi * 3.0, -sweepAngle)
              ..lineTo(rrect.right - rrect.blRadiusX, rrect.bottom)
              ..addArc(brCorner, math.pi / 2.0, -sweepAngle)
              ..lineTo(rrect.right, rrect.top + leadingBorderSide.width / 2.0);
            context.canvas.drawPath(endingPath, endingPaint);
          } else if (isFirstButton) {
            final Path leadingPath = Path();
            leadingPath..moveTo(rrect.left, outer.bottom)
              ..lineTo(rrect.left, rrect.top + rrect.tlRadiusX)
              ..addArc(tlCorner, math.pi, sweepAngle)
              ..lineTo(rrect.right - rrect.trRadiusX, rrect.top)
              ..addArc(trCorner, math.pi * 3.0 / 2.0, sweepAngle)
              ..lineTo(rrect.right, outer.bottom);
            context.canvas.drawPath(leadingPath, leadingPaint);
          } else {
            final Path topPath = Path();
            topPath..moveTo(outer.left, outer.top + leadingBorderSide.width / 2)
              ..lineTo(outer.right, outer.top + leadingBorderSide.width / 2);
            context.canvas.drawPath(topPath, leadingPaint);

            final Paint paint = borderSide.toPaint();
            final Path paths = Path(); // Left and right borders.
            paths..moveTo(rrect.left, outer.top + leadingBorderSide.width)
              ..lineTo(rrect.left, outer.bottom)
              ..moveTo(rrect.right, outer.top + leadingBorderSide.width)
              ..lineTo(rrect.right, outer.bottom);
            context.canvas.drawPath(paths, paint);
          }
          break;
        case VerticalDirection.up:
          if (isLastButton) {
            final Path bottomPath = Path();
            bottomPath..moveTo(outer.left, outer.bottom - leadingBorderSide.width / 2.0)
              ..lineTo(outer.right, outer.bottom - leadingBorderSide.width / 2.0);
            context.canvas.drawPath(bottomPath, leadingPaint);

            final Paint endingPaint = trailingBorderSide.toPaint();
            final Path endingPath = Path();
            endingPath..moveTo(rrect.left, rrect.bottom - leadingBorderSide.width / 2.0)
              ..lineTo(rrect.left, rrect.top + rrect.tlRadiusY)
              ..addArc(tlCorner, math.pi, sweepAngle)
              ..lineTo(rrect.right - rrect.trRadiusX, rrect.top)
              ..addArc(trCorner, math.pi * 3.0 / 2.0, sweepAngle)
              ..lineTo(rrect.right, rrect.bottom - leadingBorderSide.width / 2.0);
            context.canvas.drawPath(endingPath, endingPaint);
          } else if (isFirstButton) {
            final Path leadingPath = Path();
            leadingPath..moveTo(rrect.left, outer.top)
              ..lineTo(rrect.left, rrect.bottom - rrect.blRadiusY)
              ..addArc(blCorner, math.pi, -sweepAngle)
              ..lineTo(rrect.right - rrect.brRadiusX, rrect.bottom)
              ..addArc(brCorner, math.pi / 2.0, -sweepAngle)
              ..lineTo(rrect.right, outer.top);
            context.canvas.drawPath(leadingPath, leadingPaint);
          } else {
            final Path bottomPath = Path();
            bottomPath..moveTo(outer.left, outer.bottom - leadingBorderSide.width / 2.0)
              ..lineTo(outer.right, outer.bottom - leadingBorderSide.width / 2.0);
            context.canvas.drawPath(bottomPath, leadingPaint);

            final Paint paint = borderSide.toPaint();
            final Path paths = Path(); // Left and right borders.
            paths..moveTo(rrect.left, outer.top)
              ..lineTo(rrect.left, outer.bottom - leadingBorderSide.width)
              ..moveTo(rrect.right, outer.top)
              ..lineTo(rrect.right, outer.bottom - leadingBorderSide.width);
            context.canvas.drawPath(paths, paint);
          }
          break;
      }
    }
  }
}

/// A widget to pad the area around a [ToggleButtons]'s children.
///
/// This widget is based on a similar one used in [ButtonStyleButton] but it
/// only redirects taps along one axis to ensure the correct button is tapped
/// within the [ToggleButtons].
///
/// This ensures that a widget takes up at least as much space as the minSize
/// parameter to ensure adequate tap target size, while keeping the widget
/// visually smaller to the user.
class _InputPadding extends SingleChildRenderObjectWidget {
  const _InputPadding({
    Key? key,
    Widget? child,
    required this.minSize,
    required this.direction,
  }) : super(key: key, child: child);

  final Size minSize;
  final Axis direction;

  @override
  RenderObject createRenderObject(BuildContext context) {
    return _RenderInputPadding(minSize, direction);
  }

  @override
  void updateRenderObject(BuildContext context, covariant _RenderInputPadding renderObject) {
    renderObject.minSize = minSize;
    renderObject.direction = direction;
  }
}

class _RenderInputPadding extends RenderShiftedBox {
  _RenderInputPadding(this._minSize, this._direction, [RenderBox? child]) : super(child);

  Size get minSize => _minSize;
  Size _minSize;
  set minSize(Size value) {
    if (_minSize == value)
      return;
    _minSize = value;
    markNeedsLayout();
  }

  Axis get direction => _direction;
  Axis _direction;
  set direction(Axis value) {
    if (_direction == value)
      return;
    _direction = value;
    markNeedsLayout();
  }

  @override
  double computeMinIntrinsicWidth(double height) {
    if (child != null)
      return math.max(child!.getMinIntrinsicWidth(height), minSize.width);
    return 0.0;
  }

  @override
  double computeMinIntrinsicHeight(double width) {
    if (child != null)
      return math.max(child!.getMinIntrinsicHeight(width), minSize.height);
    return 0.0;
  }

  @override
  double computeMaxIntrinsicWidth(double height) {
    if (child != null)
      return math.max(child!.getMaxIntrinsicWidth(height), minSize.width);
    return 0.0;
  }

  @override
  double computeMaxIntrinsicHeight(double width) {
    if (child != null)
      return math.max(child!.getMaxIntrinsicHeight(width), minSize.height);
    return 0.0;
  }

  Size _computeSize({required BoxConstraints constraints, required ChildLayouter layoutChild}) {
    if (child != null) {
      final Size childSize = layoutChild(child!, constraints);
      final double height = math.max(childSize.width, minSize.width);
      final double width = math.max(childSize.height, minSize.height);
      return constraints.constrain(Size(height, width));
    }
    return Size.zero;
  }

  @override
  Size computeDryLayout(BoxConstraints constraints) {
    return _computeSize(
      constraints: constraints,
      layoutChild: ChildLayoutHelper.dryLayoutChild,
    );
  }

  @override
  void performLayout() {
    size = _computeSize(
      constraints: constraints,
      layoutChild: ChildLayoutHelper.layoutChild,
    );
    if (child != null) {
      final BoxParentData childParentData = child!.parentData! as BoxParentData;
      childParentData.offset = Alignment.center.alongOffset(size - child!.size as Offset);
    }
  }

  @override
  bool hitTest(BoxHitTestResult result, { required Offset position }) {
    // The super.hitTest() method also checks hitTestChildren(). We don't
    // want that in this case because we've padded around the children per
    // tapTargetSize.
    if (!size.contains(position)) {
      return false;
    }

    // Only adjust one axis to ensure the correct button is tapped.
    Offset center;
    if (direction == Axis.horizontal) {
      center = Offset(position.dx, child!.size.height / 2);
    } else {
      center = Offset(child!.size.width / 2, position.dy);
    }
    return result.addWithRawTransform(
      transform: MatrixUtils.forceToPoint(center),
      position: center,
      hitTest: (BoxHitTestResult result, Offset position) {
        assert(position == center);
        return child!.hitTest(result, position: center);
      },
    );
  }
}