floating_action_button.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 'floating_action_button_theme.dart';
import 'material_state.dart';
import 'scaffold.dart';
import 'text_theme.dart';
import 'theme.dart';
import 'theme_data.dart';
import 'tooltip.dart';

class _DefaultHeroTag {
  const _DefaultHeroTag();
  @override
  String toString() => '<default FloatingActionButton tag>';
}

enum _FloatingActionButtonType {
  regular,
  small,
  large,
  extended,
}

/// A Material Design floating action button.
///
/// A floating action button is a circular icon button that hovers over content
/// to promote a primary action in the application. Floating action buttons are
/// most commonly used in the [Scaffold.floatingActionButton] field.
///
/// {@youtube 560 315 https://www.youtube.com/watch?v=2uaoEDOgk_I}
///
/// Use at most a single floating action button per screen. Floating action
/// buttons should be used for positive actions such as "create", "share", or
/// "navigate". (If more than one floating action button is used within a
/// [Route], then make sure that each button has a unique [heroTag], otherwise
/// an exception will be thrown.)
///
/// If the [onPressed] callback is null, then the button will be disabled and
/// will not react to touch. It is highly discouraged to disable a floating
/// action button as there is no indication to the user that the button is
/// disabled. Consider changing the [backgroundColor] if disabling the floating
/// action button.
///
/// {@tool dartpad}
/// This example shows how to display a [FloatingActionButton] in a
/// [Scaffold], with a pink [backgroundColor] and a thumbs up [Icon].
///
/// ![](https://flutter.github.io/assets-for-api-docs/assets/material/floating_action_button.png)
///
/// ** See code in examples/api/lib/material/floating_action_button/floating_action_button.0.dart **
/// {@end-tool}
///
/// {@tool dartpad}
/// This example shows how to make an extended [FloatingActionButton] in a
/// [Scaffold], with a pink [backgroundColor], a thumbs up [Icon] and a
/// [Text] label that reads "Approve".
///
/// ![](https://flutter.github.io/assets-for-api-docs/assets/material/floating_action_button_label.png)
///
/// ** See code in examples/api/lib/material/floating_action_button/floating_action_button.1.dart **
/// {@end-tool}
///
/// Material Design 3 introduced new types of floating action buttons.
/// {@tool dartpad}
/// This sample shows the creation of [FloatingActionButton] widget in the typical location in a Scaffold,
/// as described in: https://m3.material.io/components/floating-action-button/overview
///
/// ** See code in examples/api/lib/material/floating_action_button/floating_action_button.2.dart **
/// {@end-tool}
///
/// {@tool dartpad}
/// This sample shows the creation of all the variants of [FloatingActionButton] widget as
/// described in: https://m3.material.io/components/floating-action-button/overview
///
/// ** See code in examples/api/lib/material/floating_action_button/floating_action_button.3.dart **
/// {@end-tool}
///
/// See also:
///
///  * [Scaffold], in which floating action buttons typically live.
///  * [ElevatedButton], a filled button whose material elevates when pressed.
///  * <https://material.io/design/components/buttons-floating-action-button.html>
///  * <https://m3.material.io/components/floating-action-button>
class FloatingActionButton extends StatelessWidget {
  /// Creates a circular floating action button.
  ///
  /// The [mini] and [clipBehavior] arguments must not be null. Additionally,
  /// [elevation], [highlightElevation], and [disabledElevation] (if specified)
  /// must be non-negative.
  const FloatingActionButton({
    super.key,
    this.child,
    this.tooltip,
    this.foregroundColor,
    this.backgroundColor,
    this.focusColor,
    this.hoverColor,
    this.splashColor,
    this.heroTag = const _DefaultHeroTag(),
    this.elevation,
    this.focusElevation,
    this.hoverElevation,
    this.highlightElevation,
    this.disabledElevation,
    required this.onPressed,
    this.mouseCursor,
    this.mini = false,
    this.shape,
    this.clipBehavior = Clip.none,
    this.focusNode,
    this.autofocus = false,
    this.materialTapTargetSize,
    this.isExtended = false,
    this.enableFeedback,
  }) : assert(elevation == null || elevation >= 0.0),
       assert(focusElevation == null || focusElevation >= 0.0),
       assert(hoverElevation == null || hoverElevation >= 0.0),
       assert(highlightElevation == null || highlightElevation >= 0.0),
       assert(disabledElevation == null || disabledElevation >= 0.0),
       assert(mini != null),
       assert(clipBehavior != null),
       assert(isExtended != null),
       assert(autofocus != null),
       _floatingActionButtonType = mini ? _FloatingActionButtonType.small : _FloatingActionButtonType.regular,
       _extendedLabel = null,
       extendedIconLabelSpacing = null,
       extendedPadding = null,
       extendedTextStyle = null;

  /// Creates a small circular floating action button.
  ///
  /// This constructor overrides the default size constraints of the floating
  /// action button.
  ///
  /// The [clipBehavior] and [autofocus] arguments must not be null.
  /// Additionally, [elevation], [focusElevation], [hoverElevation],
  /// [highlightElevation], and [disabledElevation] (if specified) must be
  /// non-negative.
  const FloatingActionButton.small({
    super.key,
    this.child,
    this.tooltip,
    this.foregroundColor,
    this.backgroundColor,
    this.focusColor,
    this.hoverColor,
    this.splashColor,
    this.heroTag = const _DefaultHeroTag(),
    this.elevation,
    this.focusElevation,
    this.hoverElevation,
    this.highlightElevation,
    this.disabledElevation,
    required this.onPressed,
    this.mouseCursor,
    this.shape,
    this.clipBehavior = Clip.none,
    this.focusNode,
    this.autofocus = false,
    this.materialTapTargetSize,
    this.enableFeedback,
  }) : assert(elevation == null || elevation >= 0.0),
       assert(focusElevation == null || focusElevation >= 0.0),
       assert(hoverElevation == null || hoverElevation >= 0.0),
       assert(highlightElevation == null || highlightElevation >= 0.0),
       assert(disabledElevation == null || disabledElevation >= 0.0),
       assert(clipBehavior != null),
       assert(autofocus != null),
       _floatingActionButtonType = _FloatingActionButtonType.small,
       mini = true,
       isExtended = false,
       _extendedLabel = null,
       extendedIconLabelSpacing = null,
       extendedPadding = null,
       extendedTextStyle = null;

  /// Creates a large circular floating action button.
  ///
  /// This constructor overrides the default size constraints of the floating
  /// action button.
  ///
  /// The [clipBehavior] and [autofocus] arguments must not be null.
  /// Additionally, [elevation], [focusElevation], [hoverElevation],
  /// [highlightElevation], and [disabledElevation] (if specified) must be
  /// non-negative.
  const FloatingActionButton.large({
    super.key,
    this.child,
    this.tooltip,
    this.foregroundColor,
    this.backgroundColor,
    this.focusColor,
    this.hoverColor,
    this.splashColor,
    this.heroTag = const _DefaultHeroTag(),
    this.elevation,
    this.focusElevation,
    this.hoverElevation,
    this.highlightElevation,
    this.disabledElevation,
    required this.onPressed,
    this.mouseCursor,
    this.shape,
    this.clipBehavior = Clip.none,
    this.focusNode,
    this.autofocus = false,
    this.materialTapTargetSize,
    this.enableFeedback,
  }) : assert(elevation == null || elevation >= 0.0),
       assert(focusElevation == null || focusElevation >= 0.0),
       assert(hoverElevation == null || hoverElevation >= 0.0),
       assert(highlightElevation == null || highlightElevation >= 0.0),
       assert(disabledElevation == null || disabledElevation >= 0.0),
       assert(clipBehavior != null),
       assert(autofocus != null),
       _floatingActionButtonType = _FloatingActionButtonType.large,
       mini = false,
       isExtended = false,
       _extendedLabel = null,
       extendedIconLabelSpacing = null,
       extendedPadding = null,
       extendedTextStyle = null;

  /// Creates a wider [StadiumBorder]-shaped floating action button with
  /// an optional [icon] and a [label].
  ///
  /// The [label], [autofocus], and [clipBehavior] arguments must not be null.
  /// Additionally, [elevation], [highlightElevation], and [disabledElevation]
  /// (if specified) must be non-negative.
  ///
  /// See also:
  ///  * <https://m3.material.io/components/extended-fab>
  const FloatingActionButton.extended({
    super.key,
    this.tooltip,
    this.foregroundColor,
    this.backgroundColor,
    this.focusColor,
    this.hoverColor,
    this.heroTag = const _DefaultHeroTag(),
    this.elevation,
    this.focusElevation,
    this.hoverElevation,
    this.splashColor,
    this.highlightElevation,
    this.disabledElevation,
    required this.onPressed,
    this.mouseCursor = SystemMouseCursors.click,
    this.shape,
    this.isExtended = true,
    this.materialTapTargetSize,
    this.clipBehavior = Clip.none,
    this.focusNode,
    this.autofocus = false,
    this.extendedIconLabelSpacing,
    this.extendedPadding,
    this.extendedTextStyle,
    Widget? icon,
    required Widget label,
    this.enableFeedback,
  }) : assert(elevation == null || elevation >= 0.0),
       assert(focusElevation == null || focusElevation >= 0.0),
       assert(hoverElevation == null || hoverElevation >= 0.0),
       assert(highlightElevation == null || highlightElevation >= 0.0),
       assert(disabledElevation == null || disabledElevation >= 0.0),
       assert(isExtended != null),
       assert(clipBehavior != null),
       assert(autofocus != null),
       mini = false,
       _floatingActionButtonType = _FloatingActionButtonType.extended,
       child = icon,
       _extendedLabel = label;

  /// The widget below this widget in the tree.
  ///
  /// Typically an [Icon].
  final Widget? child;

  /// Text that describes the action that will occur when the button is pressed.
  ///
  /// This text is displayed when the user long-presses on the button and is
  /// used for accessibility.
  final String? tooltip;

  /// The default foreground color for icons and text within the button.
  ///
  /// If this property is null, then the
  /// [FloatingActionButtonThemeData.foregroundColor] of
  /// [ThemeData.floatingActionButtonTheme] is used. If that property is also
  /// null, then the [ColorScheme.onSecondary] color of [ThemeData.colorScheme]
  /// is used.
  final Color? foregroundColor;

  /// The button's background color.
  ///
  /// If this property is null, then the
  /// [FloatingActionButtonThemeData.backgroundColor] of
  /// [ThemeData.floatingActionButtonTheme] is used. If that property is also
  /// null, then the [Theme]'s [ColorScheme.secondary] color is used.
  final Color? backgroundColor;

  /// The color to use for filling the button when the button has input focus.
  ///
  /// Defaults to [ThemeData.focusColor] for the current theme.
  final Color? focusColor;

  /// The color to use for filling the button when the button has a pointer
  /// hovering over it.
  ///
  /// Defaults to [ThemeData.hoverColor] for the current theme.
  final Color? hoverColor;

  /// The splash color for this [FloatingActionButton]'s [InkWell].
  ///
  /// If null, [FloatingActionButtonThemeData.splashColor] is used, if that is
  /// null, [ThemeData.splashColor] is used.
  final Color? splashColor;

  /// The tag to apply to the button's [Hero] widget.
  ///
  /// Defaults to a tag that matches other floating action buttons.
  ///
  /// Set this to null explicitly if you don't want the floating action button to
  /// have a hero tag.
  ///
  /// If this is not explicitly set, then there can only be one
  /// [FloatingActionButton] per route (that is, per screen), since otherwise
  /// there would be a tag conflict (multiple heroes on one route can't have the
  /// same tag). The Material Design specification recommends only using one
  /// floating action button per screen.
  final Object? heroTag;

  /// The callback that is called when the button is tapped or otherwise activated.
  ///
  /// If this is set to null, the button will be disabled.
  final VoidCallback? onPressed;

  /// {@macro flutter.material.RawMaterialButton.mouseCursor}
  ///
  /// If this property is null, [MaterialStateMouseCursor.clickable] will be used.
  final MouseCursor? mouseCursor;

  /// The z-coordinate at which to place this button relative to its parent.
  ///
  /// This controls the size of the shadow below the floating action button.
  ///
  /// Defaults to 6, the appropriate elevation for floating action buttons. The
  /// value is always non-negative.
  ///
  /// See also:
  ///
  ///  * [highlightElevation], the elevation when the button is pressed.
  ///  * [disabledElevation], the elevation when the button is disabled.
  final double? elevation;

  /// The z-coordinate at which to place this button relative to its parent when
  /// the button has the input focus.
  ///
  /// This controls the size of the shadow below the floating action button.
  ///
  /// Defaults to 8, the appropriate elevation for floating action buttons
  /// while they have focus. The value is always non-negative.
  ///
  /// See also:
  ///
  ///  * [elevation], the default elevation.
  ///  * [highlightElevation], the elevation when the button is pressed.
  ///  * [disabledElevation], the elevation when the button is disabled.
  final double? focusElevation;

  /// The z-coordinate at which to place this button relative to its parent when
  /// the button is enabled and has a pointer hovering over it.
  ///
  /// This controls the size of the shadow below the floating action button.
  ///
  /// Defaults to 8, the appropriate elevation for floating action buttons while
  /// they have a pointer hovering over them. The value is always non-negative.
  ///
  /// See also:
  ///
  ///  * [elevation], the default elevation.
  ///  * [highlightElevation], the elevation when the button is pressed.
  ///  * [disabledElevation], the elevation when the button is disabled.
  final double? hoverElevation;

  /// The z-coordinate at which to place this button relative to its parent when
  /// the user is touching the button.
  ///
  /// This controls the size of the shadow below the floating action button.
  ///
  /// Defaults to 12, the appropriate elevation for floating action buttons
  /// while they are being touched. The value is always non-negative.
  ///
  /// See also:
  ///
  ///  * [elevation], the default elevation.
  final double? highlightElevation;

  /// The z-coordinate at which to place this button when the button is disabled
  /// ([onPressed] is null).
  ///
  /// This controls the size of the shadow below the floating action button.
  ///
  /// Defaults to the same value as [elevation]. Setting this to zero makes the
  /// floating action button work similar to an [ElevatedButton] but the titular
  /// "floating" effect is lost. The value is always non-negative.
  ///
  /// See also:
  ///
  ///  * [elevation], the default elevation.
  ///  * [highlightElevation], the elevation when the button is pressed.
  final double? disabledElevation;

  /// Controls the size of this button.
  ///
  /// By default, floating action buttons are non-mini and have a height and
  /// width of 56.0 logical pixels. Mini floating action buttons have a height
  /// and width of 40.0 logical pixels with a layout width and height of 48.0
  /// logical pixels. (The extra 4 pixels of padding on each side are added as a
  /// result of the floating action button having [MaterialTapTargetSize.padded]
  /// set on the underlying [RawMaterialButton.materialTapTargetSize].)
  final bool mini;

  /// The shape of the button's [Material].
  ///
  /// The button's highlight and splash are clipped to this shape. If the
  /// button has an elevation, then its drop shadow is defined by this
  /// shape as well.
  final ShapeBorder? shape;

  /// {@macro flutter.material.Material.clipBehavior}
  ///
  /// Defaults to [Clip.none], and must not be null.
  final Clip clipBehavior;

  /// True if this is an "extended" floating action button.
  ///
  /// Typically [extended] buttons have a [StadiumBorder] [shape]
  /// and have been created with the [FloatingActionButton.extended]
  /// constructor.
  ///
  /// The [Scaffold] animates the appearance of ordinary floating
  /// action buttons with scale and rotation transitions. Extended
  /// floating action buttons are scaled and faded in.
  final bool isExtended;

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

  /// {@macro flutter.widgets.Focus.autofocus}
  final bool autofocus;

  /// Configures the minimum size of the tap target.
  ///
  /// Defaults to [ThemeData.materialTapTargetSize].
  ///
  /// See also:
  ///
  ///  * [MaterialTapTargetSize], for a description of how this affects tap targets.
  final MaterialTapTargetSize? materialTapTargetSize;

  /// Whether detected gestures should provide acoustic and/or haptic feedback.
  ///
  /// For example, on Android a tap will produce a clicking sound and a
  /// long-press will produce a short vibration, when feedback is enabled.
  ///
  /// If null, [FloatingActionButtonThemeData.enableFeedback] is used.
  /// If both are null, then default value is true.
  ///
  /// See also:
  ///
  ///  * [Feedback] for providing platform-specific feedback to certain actions.
  final bool? enableFeedback;


  /// The spacing between the icon and the label for an extended
  /// [FloatingActionButton].
  ///
  /// If null, [FloatingActionButtonThemeData.extendedIconLabelSpacing] is used.
  /// If that is also null, the default is 8.0.
  final double? extendedIconLabelSpacing;

  /// The padding for an extended [FloatingActionButton]'s content.
  ///
  /// If null, [FloatingActionButtonThemeData.extendedPadding] is used. If that
  /// is also null, the default is
  /// `EdgeInsetsDirectional.only(start: 16.0, end: 20.0)` if an icon is
  /// provided, and `EdgeInsetsDirectional.only(start: 20.0, end: 20.0)` if not.
  final EdgeInsetsGeometry? extendedPadding;

  /// The text style for an extended [FloatingActionButton]'s label.
  ///
  /// If null, [FloatingActionButtonThemeData.extendedTextStyle] is used. If
  /// that is also null, then [TextTheme.labelLarge] with a letter spacing of 1.2
  /// is used.
  final TextStyle? extendedTextStyle;

  final _FloatingActionButtonType _floatingActionButtonType;

  final Widget? _extendedLabel;

  @override
  Widget build(BuildContext context) {
    final ThemeData theme = Theme.of(context);
    final FloatingActionButtonThemeData floatingActionButtonTheme = theme.floatingActionButtonTheme;
    final FloatingActionButtonThemeData defaults = theme.useMaterial3
      ? _FABDefaultsM3(context, _floatingActionButtonType, child != null)
      : _FABDefaultsM2(context, _floatingActionButtonType, child != null);

    final Color foregroundColor = this.foregroundColor
      ?? floatingActionButtonTheme.foregroundColor
      ?? defaults.foregroundColor!;
    final Color backgroundColor = this.backgroundColor
      ?? floatingActionButtonTheme.backgroundColor
      ?? defaults.backgroundColor!;
    final Color focusColor = this.focusColor
      ?? floatingActionButtonTheme.focusColor
      ?? defaults.focusColor!;
    final Color hoverColor = this.hoverColor
      ?? floatingActionButtonTheme.hoverColor
      ?? defaults.hoverColor!;
    final Color splashColor = this.splashColor
      ?? floatingActionButtonTheme.splashColor
      ?? defaults.splashColor!;
    final double elevation = this.elevation
      ?? floatingActionButtonTheme.elevation
      ?? defaults.elevation!;
    final double focusElevation = this.focusElevation
      ?? floatingActionButtonTheme.focusElevation
      ?? defaults.focusElevation!;
    final double hoverElevation = this.hoverElevation
      ?? floatingActionButtonTheme.hoverElevation
      ?? defaults.hoverElevation!;
    final double disabledElevation = this.disabledElevation
      ?? floatingActionButtonTheme.disabledElevation
      ?? defaults.disabledElevation
      ?? elevation;
    final double highlightElevation = this.highlightElevation
      ?? floatingActionButtonTheme.highlightElevation
      ?? defaults.highlightElevation!;
    final MaterialTapTargetSize materialTapTargetSize = this.materialTapTargetSize
      ?? theme.materialTapTargetSize;
    final bool enableFeedback = this.enableFeedback
      ?? floatingActionButtonTheme.enableFeedback
      ?? defaults.enableFeedback!;
    final double iconSize = floatingActionButtonTheme.iconSize
      ?? defaults.iconSize!;
    final TextStyle extendedTextStyle = (this.extendedTextStyle
      ?? floatingActionButtonTheme.extendedTextStyle
      ?? defaults.extendedTextStyle!).copyWith(color: foregroundColor);
    final ShapeBorder shape = this.shape
      ?? floatingActionButtonTheme.shape
      ?? defaults.shape!;

    BoxConstraints sizeConstraints;
    Widget? resolvedChild = child != null ? IconTheme.merge(
      data: IconThemeData(size: iconSize),
      child: child!,
    ) : child;
    switch(_floatingActionButtonType) {
      case _FloatingActionButtonType.regular:
        sizeConstraints = floatingActionButtonTheme.sizeConstraints ?? defaults.sizeConstraints!;
        break;
      case _FloatingActionButtonType.small:
        sizeConstraints = floatingActionButtonTheme.smallSizeConstraints ?? defaults.smallSizeConstraints!;
        break;
      case _FloatingActionButtonType.large:
        sizeConstraints = floatingActionButtonTheme.largeSizeConstraints ?? defaults.largeSizeConstraints!;
        break;
      case _FloatingActionButtonType.extended:
        sizeConstraints = floatingActionButtonTheme.extendedSizeConstraints ?? defaults.extendedSizeConstraints!;
        final double iconLabelSpacing = extendedIconLabelSpacing ?? floatingActionButtonTheme.extendedIconLabelSpacing ?? 8.0;
        final EdgeInsetsGeometry padding = extendedPadding
            ?? floatingActionButtonTheme.extendedPadding
            ?? defaults.extendedPadding!;
        resolvedChild = _ChildOverflowBox(
          child: Padding(
            padding: padding,
            child: Row(
                mainAxisSize: MainAxisSize.min,
                children: <Widget>[
                  if (child != null)
                    child!,
                  if (child != null && isExtended)
                    SizedBox(width: iconLabelSpacing),
                  if (isExtended)
                    _extendedLabel!,
                ],
            ),
          ),
        );
        break;
    }

    Widget result = RawMaterialButton(
      onPressed: onPressed,
      mouseCursor: _EffectiveMouseCursor(mouseCursor, floatingActionButtonTheme.mouseCursor),
      elevation: elevation,
      focusElevation: focusElevation,
      hoverElevation: hoverElevation,
      highlightElevation: highlightElevation,
      disabledElevation: disabledElevation,
      constraints: sizeConstraints,
      materialTapTargetSize: materialTapTargetSize,
      fillColor: backgroundColor,
      focusColor: focusColor,
      hoverColor: hoverColor,
      splashColor: splashColor,
      textStyle: extendedTextStyle,
      shape: shape,
      clipBehavior: clipBehavior,
      focusNode: focusNode,
      autofocus: autofocus,
      enableFeedback: enableFeedback,
      child: resolvedChild,
    );

    if (tooltip != null) {
      result = Tooltip(
        message: tooltip,
        child: result,
      );
    }

    if (heroTag != null) {
      result = Hero(
        tag: heroTag!,
        child: result,
      );
    }

    return MergeSemantics(child: result);
  }

  @override
  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
    super.debugFillProperties(properties);
    properties.add(ObjectFlagProperty<VoidCallback>('onPressed', onPressed, ifNull: 'disabled'));
    properties.add(StringProperty('tooltip', tooltip, defaultValue: null));
    properties.add(ColorProperty('foregroundColor', foregroundColor, defaultValue: null));
    properties.add(ColorProperty('backgroundColor', backgroundColor, defaultValue: null));
    properties.add(ColorProperty('focusColor', focusColor, defaultValue: null));
    properties.add(ColorProperty('hoverColor', hoverColor, defaultValue: null));
    properties.add(ColorProperty('splashColor', splashColor, defaultValue: null));
    properties.add(ObjectFlagProperty<Object>('heroTag', heroTag, ifPresent: 'hero'));
    properties.add(DoubleProperty('elevation', elevation, defaultValue: null));
    properties.add(DoubleProperty('focusElevation', focusElevation, defaultValue: null));
    properties.add(DoubleProperty('hoverElevation', hoverElevation, defaultValue: null));
    properties.add(DoubleProperty('highlightElevation', highlightElevation, defaultValue: null));
    properties.add(DoubleProperty('disabledElevation', disabledElevation, defaultValue: null));
    properties.add(DiagnosticsProperty<ShapeBorder>('shape', shape, defaultValue: null));
    properties.add(DiagnosticsProperty<FocusNode>('focusNode', focusNode, defaultValue: null));
    properties.add(FlagProperty('isExtended', value: isExtended, ifTrue: 'extended'));
    properties.add(DiagnosticsProperty<MaterialTapTargetSize>('materialTapTargetSize', materialTapTargetSize, defaultValue: null));
  }
}

// This MaterialStateProperty is passed along to RawMaterialButton which
// resolves the property against MaterialState.pressed, MaterialState.hovered,
// MaterialState.focused, MaterialState.disabled.
class _EffectiveMouseCursor extends MaterialStateMouseCursor {
  const _EffectiveMouseCursor(this.widgetCursor, this.themeCursor);

  final MouseCursor? widgetCursor;
  final MaterialStateProperty<MouseCursor?>? themeCursor;

  @override
  MouseCursor resolve(Set<MaterialState> states) {
    return MaterialStateProperty.resolveAs<MouseCursor?>(widgetCursor, states)
      ?? themeCursor?.resolve(states)
      ?? MaterialStateMouseCursor.clickable.resolve(states);
  }

  @override
  String get debugDescription => 'MaterialStateMouseCursor(FloatActionButton)';
}

// This widget's size matches its child's size unless its constraints
// force it to be larger or smaller. The child is centered.
//
// Used to encapsulate extended FABs whose size is fixed, using Row
// and MainAxisSize.min, to be as wide as their label and icon.
class _ChildOverflowBox extends SingleChildRenderObjectWidget {
  const _ChildOverflowBox({
    super.child,
  });

  @override
  _RenderChildOverflowBox createRenderObject(BuildContext context) {
    return _RenderChildOverflowBox(
      textDirection: Directionality.of(context),
    );
  }

  @override
  void updateRenderObject(BuildContext context, _RenderChildOverflowBox renderObject) {
    renderObject.textDirection = Directionality.of(context);
  }
}

class _RenderChildOverflowBox extends RenderAligningShiftedBox {
  _RenderChildOverflowBox({
    super.textDirection,
  }) : super(alignment: Alignment.center);

  @override
  double computeMinIntrinsicWidth(double height) => 0.0;

  @override
  double computeMinIntrinsicHeight(double width) => 0.0;

  @override
  Size computeDryLayout(BoxConstraints constraints) {
    if (child != null) {
      final Size childSize = child!.getDryLayout(const BoxConstraints());
      return Size(
        math.max(constraints.minWidth, math.min(constraints.maxWidth, childSize.width)),
        math.max(constraints.minHeight, math.min(constraints.maxHeight, childSize.height)),
      );
    } else {
      return constraints.biggest;
    }
  }

  @override
  void performLayout() {
    final BoxConstraints constraints = this.constraints;
    if (child != null) {
      child!.layout(const BoxConstraints(), parentUsesSize: true);
      size = Size(
        math.max(constraints.minWidth, math.min(constraints.maxWidth, child!.size.width)),
        math.max(constraints.minHeight, math.min(constraints.maxHeight, child!.size.height)),
      );
      alignChild();
    } else {
      size = constraints.biggest;
    }
  }
}

// Hand coded defaults based on Material Design 2.
class _FABDefaultsM2 extends FloatingActionButtonThemeData {
  _FABDefaultsM2(BuildContext context, this.type, this.hasChild)
      : _theme = Theme.of(context),
        _colors = Theme.of(context).colorScheme,
        super(
          elevation: 6,
          focusElevation: 6,
          hoverElevation: 8,
          highlightElevation: 12,
          enableFeedback: true,
          sizeConstraints: const BoxConstraints.tightFor(
            width: 56.0,
            height: 56.0,
          ),
          smallSizeConstraints: const BoxConstraints.tightFor(
            width: 40.0,
            height: 40.0,
          ),
          largeSizeConstraints: const BoxConstraints.tightFor(
            width: 96.0,
            height: 96.0,
          ),
          extendedSizeConstraints: const BoxConstraints.tightFor(
            height: 48.0,
          ),
          extendedIconLabelSpacing: 8.0,
        );

  final _FloatingActionButtonType type;
  final bool hasChild;
  final ThemeData _theme;
  final ColorScheme _colors;

  bool get _isExtended => type == _FloatingActionButtonType.extended;
  bool get _isLarge => type == _FloatingActionButtonType.large;

  @override Color? get foregroundColor => _colors.onSecondary;
  @override Color? get backgroundColor => _colors.secondary;
  @override Color? get focusColor => _theme.focusColor;
  @override Color? get hoverColor => _theme.hoverColor;
  @override Color? get splashColor => _theme.splashColor;
  @override ShapeBorder? get shape => _isExtended ? const StadiumBorder() : const CircleBorder();
  @override double? get iconSize => _isLarge ? 36.0 : 24.0;

  @override EdgeInsetsGeometry? get extendedPadding => EdgeInsetsDirectional.only(start: hasChild && _isExtended ? 16.0 : 20.0, end: 20.0);
  @override TextStyle? get extendedTextStyle => _theme.textTheme.labelLarge!.copyWith(letterSpacing: 1.2);
}

// BEGIN GENERATED TOKEN PROPERTIES - FAB

// Do not edit by hand. The code between the "BEGIN GENERATED" and
// "END GENERATED" comments are generated from data in the Material
// Design token database by the script:
//   dev/tools/gen_defaults/bin/gen_defaults.dart.

// Token database version: v0_132

class _FABDefaultsM3 extends FloatingActionButtonThemeData {
  _FABDefaultsM3(this.context, this.type, this.hasChild)
    : super(
        elevation: 6.0,
        focusElevation: 6.0,
        hoverElevation: 8.0,
        highlightElevation: 6.0,
        enableFeedback: true,
        sizeConstraints: const BoxConstraints.tightFor(
          width: 56.0,
          height: 56.0,
        ),
        smallSizeConstraints: const BoxConstraints.tightFor(
          width: 40.0,
          height: 40.0,
        ),
        largeSizeConstraints: const BoxConstraints.tightFor(
          width: 96.0,
          height: 96.0,
        ),
        extendedSizeConstraints: const BoxConstraints.tightFor(
          height: 56.0,
        ),
        extendedIconLabelSpacing: 8.0,
      );

  final BuildContext context;
  final _FloatingActionButtonType type;
  final bool hasChild;
  late final ColorScheme _colors = Theme.of(context).colorScheme;
  late final TextTheme _textTheme = Theme.of(context).textTheme;

  bool get _isExtended => type == _FloatingActionButtonType.extended;

  @override Color? get foregroundColor => _colors.onPrimaryContainer;
  @override Color? get backgroundColor => _colors.primaryContainer;
  @override Color? get splashColor => _colors.onPrimaryContainer.withOpacity(0.12);
  @override Color? get focusColor => _colors.onPrimaryContainer.withOpacity(0.12);
  @override Color? get hoverColor => _colors.onPrimaryContainer.withOpacity(0.08);

  @override
  ShapeBorder? get shape {
    switch (type) {
      case _FloatingActionButtonType.regular:
       return const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(16.0)));
      case _FloatingActionButtonType.small:
       return const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(12.0)));
      case _FloatingActionButtonType.large:
       return const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(28.0)));
      case _FloatingActionButtonType.extended:
       return const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(16.0)));
     }
  }

  @override
  double? get iconSize {
    switch (type) {
      case _FloatingActionButtonType.regular: return 24.0;
      case _FloatingActionButtonType.small: return  24.0;
      case _FloatingActionButtonType.large: return 36.0;
      case _FloatingActionButtonType.extended: return 24.0;
    }
  }

  @override EdgeInsetsGeometry? get extendedPadding => EdgeInsetsDirectional.only(start: hasChild && _isExtended ? 16.0 : 20.0, end: 20.0);
  @override TextStyle? get extendedTextStyle => _textTheme.labelLarge;
}

// END GENERATED TOKEN PROPERTIES - FAB