mirrored_repositories/dungeon-paper-app/lib/app/widgets
// 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 'package:dungeon_paper/app/themes/themes.dart';
import 'package:dungeon_paper/core/platform_helper.dart';
import 'package:dungeon_paper/core/utils/math_utils.dart';
import 'package:flutter/material.dart';

const Duration _kExpand = Duration(milliseconds: 200);

const defaultPadding = EdgeInsets.symmetric(horizontal: 8);

/// A single-line [ListTile] with an expansion arrow icon that expands or collapses
/// the tile to reveal or hide the [children].
///
/// This widget is typically used with [ListView] to create an
/// "expand / collapse" list entry. When used with scrolling widgets like
/// [ListView], a unique [PageStorageKey] must be specified to enable the
/// [CustomExpansionTile] to save and restore its expanded state when it is scrolled
/// in and out of view.
///
/// This class overrides the [ListTileThemeData.iconColor] and [ListTileThemeData.textColor]
/// theme properties for its [ListTile]. These colors animate between values when
/// the tile is expanded and collapsed: between [iconColor], [collapsedIconColor] and
/// between [textColor] and [collapsedTextColor].
///
/// The expansion arrow icon is shown on the right by default in left-to-right languages
/// (i.e. the trailing edge). This can be changed using [controlAffinity]. This maps
/// to the [leading] and [trailing] properties of [CustomExpansionTile].
///
/// {@tool dartpad}
/// This example demonstrates different configurations of ExpansionTile.
///
/// ** See code in examples/api/lib/material/expansion_tile/expansion_tile.0.dart **
/// {@end-tool}
///
/// See also:
///
///  * [ListTile], useful for creating expansion tile [children] when the
///    expansion tile represents a sublist.
///  * The "Expand and collapse" section of
///    <https://material.io/components/lists#types>
class CustomExpansionTile extends StatefulWidget {
  /// Creates a single-line [ListTile] with an expansion arrow icon that expands or collapses
  /// the tile to reveal or hide the [children]. The [initiallyExpanded] property must
  /// be non-null.
  CustomExpansionTile({
    super.key,
    this.expandable = true,
    this.title,
    this.titleBuilder,
    this.subtitle,
    this.onExpansionChanged,
    List<Widget> children = const [],
    this.leading = const <Widget>[],
    this.trailing = const <Widget>[],
    this.visualDensity = VisualDensity.compact,
    this.initiallyExpanded = false,
    this.maintainState = false,
    this.tilePadding = defaultPadding,
    this.childrenPadding = defaultPadding,
    this.expandedCrossAxisAlignment = CrossAxisAlignment.stretch,
    this.expandedAlignment,
    this.backgroundColor,
    this.collapsedBackgroundColor,
    this.textColor,
    this.collapsedTextColor,
    this.iconColor,
    this.collapsedIconColor,
    this.controlAffinity,
    this.icon,
    this.minIconWidth = 20,
    this.reorderablePadding = false,
    this.controller,
  })  :
        assert(
          expandedCrossAxisAlignment != CrossAxisAlignment.baseline,
          'CrossAxisAlignment.baseline is not supported since the expanded children '
          'are aligned in a column, not a row. Try to use another constant.',
        ),
        assert(title != null || titleBuilder != null),
        itemBuilder = ((BuildContext context, int index) => children[index]),
        itemCount = children.length;

  const CustomExpansionTile.builder({
    super.key,
    this.expandable = true,
    this.title,
    this.titleBuilder,
    this.subtitle,
    this.onExpansionChanged,
    required this.itemBuilder,
    required this.itemCount,
    this.leading = const <Widget>[],
    this.trailing = const <Widget>[],
    this.visualDensity,
    this.initiallyExpanded = false,
    this.maintainState = false,
    this.tilePadding,
    this.expandedCrossAxisAlignment,
    this.expandedAlignment,
    this.childrenPadding,
    this.backgroundColor,
    this.collapsedBackgroundColor,
    this.textColor,
    this.collapsedTextColor,
    this.iconColor,
    this.collapsedIconColor,
    this.controlAffinity,
    this.icon,
    this.minIconWidth = 20,
    this.reorderablePadding = false,
    this.controller,
  })  :
        assert(
          expandedCrossAxisAlignment != CrossAxisAlignment.baseline,
          'CrossAxisAlignment.baseline is not supported since the expanded children '
          'are aligned in a column, not a row. Try to use another constant.',
        ),
        assert(title != null || titleBuilder != null);

  /// CUSTOM - is expansion even enabled?
  final bool expandable;
  final Widget Function(BuildContext context, int index) itemBuilder;
  final int itemCount;

  /// A widget to display before the title.
  ///
  /// Typically a [CircleAvatar] widget.
  ///
  /// Note that depending on the value of [controlAffinity], the [leading] widget
  /// may replace the rotating expansion arrow icon.
  final List<Widget> leading;

  /// The primary content of the list item.
  ///
  /// Typically a [Text] widget.
  final Widget? title;

  final Widget Function(BuildContext context, Color color)? titleBuilder;

  final Widget? icon;

  final double minIconWidth;

  /// Additional content displayed below the title.
  ///
  /// Typically a [Text] widget.
  final Widget? subtitle;

  /// Called when the tile expands or collapses.
  ///
  /// When the tile starts expanding, this function is called with the value
  /// true. When the tile starts collapsing, this function is called with
  /// the value false.
  final ValueChanged<bool>? onExpansionChanged;

  /// The color to display behind the sublist when expanded.
  final Color? backgroundColor;

  /// When not null, defines the background color of tile when the sublist is collapsed.
  final Color? collapsedBackgroundColor;

  /// A widget to display after the title.
  ///
  /// Note that depending on the value of [controlAffinity], the [trailing] widget
  /// may replace the rotating expansion arrow icon.
  final List<Widget> trailing;

  /// Defines how compact the list tile's layout will be.
  ///
  /// {@macro flutter.material.themedata.visualDensity}
  ///
  /// See also:
  ///
  ///  * [ThemeData.visualDensity], which specifies the [visualDensity] for all
  ///    widgets within a [Theme].
  final VisualDensity? visualDensity;

  /// Specifies if the list tile is initially expanded (true) or collapsed (false, the default).
  final bool initiallyExpanded;

  /// Specifies whether the state of the children is maintained when the tile expands and collapses.
  ///
  /// When true, the children are kept in the tree while the tile is collapsed.
  /// When false (default), the children are removed from the tree when the tile is
  /// collapsed and recreated upon expansion.
  final bool maintainState;

  /// Specifies padding for the [ListTile].
  ///
  /// Analogous to [ListTile.contentPadding], this property defines the insets for
  /// the [leading], [title], [subtitle] and [trailing] widgets. It does not inset
  /// the expanded [children] widgets.
  ///
  /// When the value is null, the tile's padding is `EdgeInsets.symmetric(horizontal: 16.0)`.
  final EdgeInsetsGeometry? tilePadding;

  /// Specifies the alignment of [children], which are arranged in a column when
  /// the tile is expanded.
  ///
  /// The internals of the expanded tile make use of a [Column] widget for
  /// [children], and [Align] widget to align the column. The `expandedAlignment`
  /// parameter is passed directly into the [Align].
  ///
  /// Modifying this property controls the alignment of the column within the
  /// expanded tile, not the alignment of [children] widgets within the column.
  /// To align each child within [children], see [expandedCrossAxisAlignment].
  ///
  /// The width of the column is the width of the widest child widget in [children].
  ///
  /// When the value is null, the value of `expandedAlignment` is [Alignment.center].
  final Alignment? expandedAlignment;

  /// Specifies the alignment of each child within [children] when the tile is expanded.
  ///
  /// The internals of the expanded tile make use of a [Column] widget for
  /// [children], and the `crossAxisAlignment` parameter is passed directly into the [Column].
  ///
  /// Modifying this property controls the cross axis alignment of each child
  /// within its [Column]. Note that the width of the [Column] that houses
  /// [children] will be the same as the widest child widget in [children]. It is
  /// not necessarily the width of [Column] is equal to the width of expanded tile.
  ///
  /// To align the [Column] along the expanded tile, use the [expandedAlignment] property
  /// instead.
  ///
  /// When the value is null, the value of `expandedCrossAxisAlignment` is [CrossAxisAlignment.center].
  final CrossAxisAlignment? expandedCrossAxisAlignment;

  /// Specifies padding for [children].
  ///
  /// When the value is null, the value of `childrenPadding` is [EdgeInsets.zero].
  final EdgeInsetsGeometry? childrenPadding;

  /// The icon color of tile's expansion arrow icon when the sublist is expanded.
  ///
  /// Used to override to the [ListTileThemeData.iconColor].
  final Color? iconColor;

  /// The icon color of tile's expansion arrow icon when the sublist is collapsed.
  ///
  /// Used to override to the [ListTileThemeData.iconColor].
  final Color? collapsedIconColor;

  /// The color of the tile's titles when the sublist is expanded.
  ///
  /// Used to override to the [ListTileThemeData.textColor].
  final Color? textColor;

  /// The color of the tile's titles when the sublist is collapsed.
  ///
  /// Used to override to the [ListTileThemeData.textColor].
  final Color? collapsedTextColor;

  /// Typically used to force the expansion arrow icon to the tile's leading or trailing edge.
  ///
  /// By default, the value of `controlAffinity` is [ListTileControlAffinity.platform],
  /// which means that the expansion arrow icon will appear on the tile's trailing edge.
  final ListTileControlAffinity? controlAffinity;

  final bool reorderablePadding;
  
  final CustomExpansionTileController? controller;

  @override
  State<CustomExpansionTile> createState() => _CustomExpansionTileState();
}

class _CustomExpansionTileState extends State<CustomExpansionTile>
    with SingleTickerProviderStateMixin {
  static final Animatable<double> _easeOutTween =
      CurveTween(curve: Curves.easeOut);
  static final Animatable<double> _easeInTween =
      CurveTween(curve: Curves.easeIn);
  static final Animatable<double> _halfTween =
      Tween<double>(begin: 0.0, end: 0.5);

  final ColorTween _headerColorTween = ColorTween();
  final ColorTween _iconColorTween = ColorTween();
  final ColorTween _backgroundColorTween = ColorTween();

  late AnimationController _animationController;
  late Animation<double> _iconTurns;
  late Animation<double> _heightFactor;
  late Animation<Color?> _headerColor;
  late Animation<Color?> _iconColor;
  late CustomExpansionTileController _tileController;

  bool _isExpanded = false;

  @override
  void initState() {
    super.initState();
    _animationController = AnimationController(duration: _kExpand, vsync: this);
    _heightFactor = _animationController.drive(_easeInTween);
    _iconTurns = _animationController.drive(_halfTween.chain(_easeInTween));
    _headerColor = _animationController.drive(_headerColorTween.chain(_easeInTween));
    _iconColor = _animationController.drive(_iconColorTween.chain(_easeOutTween));

    _isExpanded = PageStorage.of(context).readState(context) as bool? ??
        widget.initiallyExpanded;
    if (_isExpanded) _animationController.value = 1.0;
    assert(widget.controller?._state == null);
    _tileController = widget.controller ?? CustomExpansionTileController();
    _tileController._state = this;
  }

  @override
  void dispose() {
    _animationController.dispose();
    super.dispose();
  }

  void _handleTap() {
    setState(() {
      _isExpanded = !_isExpanded;
      if (_isExpanded) {
        _animationController.forward();
      } else {
        _animationController.reverse().then<void>((void value) {
          if (!mounted) return;
          setState(() {
            // Rebuild without widget.children.
          });
        });
      }
      PageStorage.of(context).writeState(context, _isExpanded);
    });
    widget.onExpansionChanged?.call(_isExpanded);
  }

  // Platform or null affinity defaults to trailing.
  ListTileControlAffinity _effectiveAffinity(
      ListTileControlAffinity? affinity) {
    switch (affinity ?? ListTileControlAffinity.trailing) {
      case ListTileControlAffinity.leading:
        return ListTileControlAffinity.leading;
      case ListTileControlAffinity.trailing:
      case ListTileControlAffinity.platform:
        return ListTileControlAffinity.trailing;
    }
  }

  Widget? _buildIcon(BuildContext context) {
    return RotationTransition(
      turns: _iconTurns,
      child: const Icon(Icons.expand_more),
    );
  }

  Widget? _buildLeadingIcon(BuildContext context) {
    if (!widget.expandable || _effectiveAffinity(widget.controlAffinity) != ListTileControlAffinity.leading) return null;
    return _buildIcon(context);
  }

  Widget? _buildTrailingIcon(BuildContext context) {
    if (!widget.expandable || _effectiveAffinity(widget.controlAffinity) != ListTileControlAffinity.trailing) return null;
    if (widget.reorderablePadding && PlatformHelper.currentInteractionType == InteractionType.mouse) {
      return Padding(
        padding: const EdgeInsets.only(right: 24),
        child: _buildIcon(context),
      );
    }
    return _buildIcon(context);
  }

  Widget _buildChildren(BuildContext context, Widget? child) {
    return Wrap(
      children: <Widget>[
        ListTileTheme.merge(
          iconColor: _iconColor.value,
          textColor: _headerColor.value,
          horizontalTitleGap: 0,
          minLeadingWidth: 36,
          child: ListTile(
            shape: rRectShape,
            onTap: widget.expandable ? _handleTap : null,
            contentPadding: widget.tilePadding,
            leading: (widget.icon != null)
                ? Padding(
                    padding: const EdgeInsets.only(right: 8),
                    child: SizedBox(
                      width: widget.minIconWidth,
                      child: widget.icon!,
                    ),
                  )
                : _buildLeadingIcon(context),
            title: Row(
              children: [
                ...widget.leading,
                Expanded(
                  child: DefaultTextStyle(
                    style: Theme.of(context)
                        .textTheme
                        .titleMedium!
                        .copyWith(color: _headerColor.value),
                    child: widget.title ??
                        widget.titleBuilder!.call(
                          context,
                          _headerColor.value!,
                        ),
                  ),
                ),
                ...widget.trailing,
              ],
            ),
            subtitle: widget.subtitle,
            trailing: _buildTrailingIcon(context),
            visualDensity: widget.visualDensity,
          ),
        ),
        ClipRect(
          child: Align(
            alignment: widget.expandedAlignment ?? Alignment.center,
            heightFactor: _heightFactor.value,
            child: child,
          ),
        ),
      ],
      // ),
    );
  }

  @override
  void didChangeDependencies() {
    final ThemeData theme = Theme.of(context);
    final ColorScheme colorScheme = theme.colorScheme;
    _headerColorTween
      ..begin = widget.collapsedTextColor ?? theme.textTheme.titleMedium!.color
      ..end = widget.textColor ?? colorScheme.primary;
    _iconColorTween
      ..begin = widget.collapsedIconColor ?? theme.unselectedWidgetColor
      ..end = widget.iconColor ?? colorScheme.primary;
    _backgroundColorTween
      ..begin = widget.collapsedBackgroundColor
      ..end = widget.backgroundColor;
    super.didChangeDependencies();
  }

  @override
  Widget build(BuildContext context) {
    final bool closed = !_isExpanded && _animationController.isDismissed;
    final bool shouldRemoveChildren = closed && !widget.maintainState;

    final Widget result = Offstage(
      offstage: closed,
      child: TickerMode(
        enabled: !closed,
        child: Padding(
          padding: widget.childrenPadding ?? EdgeInsets.zero,
          child: Column(
            crossAxisAlignment:
                widget.expandedCrossAxisAlignment ?? CrossAxisAlignment.center,
            children: range(widget.itemCount)
                .map((x) => widget.itemBuilder(context, x))
                .toList(),
          ),
        ),
      ),
    );

    return AnimatedBuilder(
      animation: _animationController.view,
      builder: _buildChildren,
      child: shouldRemoveChildren ? null : result,
    );
  }
}

/// Enables control over a single [ExpansionTile]'s expanded/collapsed state.
///
/// It can be useful to expand or collapse an [ExpansionTile]
/// programatically, for example to reconfigure an existing expansion
/// tile based on a system event. To do so, create an [ExpansionTile]
/// with an [ExpansionTileController] that's owned by a stateful widget
/// or look up the tile's automatically created [ExpansionTileController]
/// with [ExpansionTileController.of]
///
/// The controller's [expand] and [collapse] methods cause the
/// the [ExpansionTile] to rebuild, so they may not be called from
/// a build method.
class CustomExpansionTileController {
  /// Create a controller to be used with [CustomExpansionTile.controller].
  CustomExpansionTileController();

  _CustomExpansionTileState? _state;

  /// Whether the [ExpansionTile] built with this controller is in expanded state.
  ///
  /// This property doesn't take the animation into account. It reports `true`
  /// even if the expansion animation is not completed.
  ///
  /// See also:
  ///
  ///  * [expand], which expands the [ExpansionTile].
  ///  * [collapse], which collapses the [ExpansionTile].
  ///  * [ExpansionTile.controller] to create an ExpansionTile with a controller.
  bool get isExpanded {
    assert(_state != null);
    return _state!._isExpanded;
  }

  /// Expands the [ExpansionTile] that was built with this controller;
  ///
  /// Normally the tile is expanded automatically when the user taps on the header.
  /// It is sometimes useful to trigger the expansion programmatically due
  /// to external changes.
  ///
  /// If the tile is already in the expanded state (see [isExpanded]), calling
  /// this method has no effect.
  ///
  /// Calling this method may cause the [ExpansionTile] to rebuild, so it may
  /// not be called from a build method.
  ///
  /// Calling this method will trigger an [ExpansionTile.onExpansionChanged] callback.
  ///
  /// See also:
  ///
  ///  * [collapse], which collapses the tile.
  ///  * [isExpanded] to check whether the tile is expanded.
  ///  * [ExpansionTile.controller] to create an ExpansionTile with a controller.
  void expand() {
    assert(_state != null);
    if (!isExpanded) {
      _state!._handleTap();
    }
  }

  /// Collapses the [ExpansionTile] that was built with this controller.
  ///
  /// Normally the tile is collapsed automatically when the user taps on the header.
  /// It can be useful sometimes to trigger the collapse programmatically due
  /// to some external changes.
  ///
  /// If the tile is already in the collapsed state (see [isExpanded]), calling
  /// this method has no effect.
  ///
  /// Calling this method may cause the [ExpansionTile] to rebuild, so it may
  /// not be called from a build method.
  ///
  /// Calling this method will trigger an [ExpansionTile.onExpansionChanged] callback.
  ///
  /// See also:
  ///
  ///  * [expand], which expands the tile.
  ///  * [isExpanded] to check whether the tile is expanded.
  ///  * [ExpansionTile.controller] to create an ExpansionTile with a controller.
  void collapse() {
    assert(_state != null);
    if (isExpanded) {
      _state!._handleTap();
    }
  }
}
