packages/flutter/lib/src/material/elevated_button.dart - external/github.com/flutter/flutter - Git at Google

 // 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 'dart:ui' show lerpDouble;

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

 import 'button_style.dart';
 import 'button_style_button.dart';
 import 'color_scheme.dart';
 import 'constants.dart';
 import 'elevated_button_theme.dart';
 import 'ink_ripple.dart';
 import 'ink_well.dart';
 import 'material_state.dart';
 import 'theme.dart';
 import 'theme_data.dart';

 /// A Material Design "elevated button".
 ///
 /// Use elevated buttons to add dimension to otherwise mostly flat
 /// layouts, e.g.  in long busy lists of content, or in wide
 /// spaces. Avoid using elevated buttons on already-elevated content
 /// such as dialogs or cards.
 ///
 /// An elevated button is a label [child] displayed on a [Material]
 /// widget whose [Material.elevation] increases when the button is
 /// pressed. The label's [Text] and [Icon] widgets are displayed in
 /// [style]'s [ButtonStyle.foregroundColor] and the button's filled
 /// background is the [ButtonStyle.backgroundColor].
 ///
 /// The elevated button's default style is defined by
 /// [defaultStyleOf].  The style of this elevated button can be
 /// overridden with its [style] parameter. The style of all elevated
 /// buttons in a subtree can be overridden with the
 /// [ElevatedButtonTheme], and the style of all of the elevated
 /// buttons in an app can be overridden with the [Theme]'s
 /// [ThemeData.elevatedButtonTheme] property.
 ///
 /// The static [styleFrom] method is a convenient way to create a
 /// elevated button [ButtonStyle] from simple values.
 ///
 /// If [onPressed] and [onLongPress] callbacks are null, then the
 /// button will be disabled.
 ///
 /// {@tool dartpad}
 /// This sample produces an enabled and a disabled ElevatedButton.
 ///
 /// ** See code in examples/api/lib/material/elevated_button/elevated_button.0.dart **
 /// {@end-tool}
 ///
 /// See also:
 ///
 ///  * [TextButton], a simple flat button without a shadow.
 ///  * [OutlinedButton], a [TextButton] with a border outline.
 ///  * <https://material.io/design/components/buttons.html>
 class ElevatedButton extends ButtonStyleButton {
   /// Create an ElevatedButton.
   ///
   /// The [autofocus] and [clipBehavior] arguments must not be null.
   const ElevatedButton({
     Key? key,
     required VoidCallback? onPressed,
     VoidCallback? onLongPress,
     ValueChanged<bool>? onHover,
     ValueChanged<bool>? onFocusChange,
     ButtonStyle? style,
     FocusNode? focusNode,
     bool autofocus = false,
     Clip clipBehavior = Clip.none,
     required Widget? child,
   }) : super(
     key: key,
     onPressed: onPressed,
     onLongPress: onLongPress,
     onHover: onHover,
     onFocusChange: onFocusChange,
     style: style,
     focusNode: focusNode,
     autofocus: autofocus,
     clipBehavior: clipBehavior,
     child: child,
   );

   /// Create an elevated button from a pair of widgets that serve as the button's
   /// [icon] and [label].
   ///
   /// The icon and label are arranged in a row and padded by 12 logical pixels
   /// at the start, and 16 at the end, with an 8 pixel gap in between.
   ///
   /// The [icon] and [label] arguments must not be null.
   factory ElevatedButton.icon({
     Key? key,
     required VoidCallback? onPressed,
     VoidCallback? onLongPress,
     ValueChanged<bool>? onHover,
     ValueChanged<bool>? onFocusChange,
     ButtonStyle? style,
     FocusNode? focusNode,
     bool? autofocus,
     Clip? clipBehavior,
     required Widget icon,
     required Widget label,
   }) = _ElevatedButtonWithIcon;

   /// A static convenience method that constructs an elevated button
   /// [ButtonStyle] given simple values.
   ///
   /// The [onPrimary], and [onSurface] colors are used to create a
   /// [MaterialStateProperty] [ButtonStyle.foregroundColor] value in the same
   /// way that [defaultStyleOf] uses the [ColorScheme] colors with the same
   /// names. Specify a value for [onPrimary] to specify the color of the
   /// button's text and icons as well as the overlay colors used to indicate the
   /// hover, focus, and pressed states. Use [primary] for the button's background
   /// fill color and [onSurface] to specify the button's disabled text, icon,
   /// and fill color.
   ///
   /// The button's elevations are defined relative to the [elevation]
   /// parameter. The disabled elevation is the same as the parameter
   /// value, [elevation] + 2 is used when the button is hovered
   /// or focused, and elevation + 6 is used when the button is pressed.
   ///
   /// Similarly, the [enabledMouseCursor] and [disabledMouseCursor]
   /// parameters are used to construct [ButtonStyle].mouseCursor.
   ///
   /// All of the other parameters are either used directly or used to
   /// create a [MaterialStateProperty] with a single value for all
   /// states.
   ///
   /// All parameters default to null, by default this method returns
   /// a [ButtonStyle] that doesn't override anything.
   ///
   /// For example, to override the default text and icon colors for a
   /// [ElevatedButton], as well as its overlay color, with all of the
   /// standard opacity adjustments for the pressed, focused, and
   /// hovered states, one could write:
   ///
   /// ```dart
   /// ElevatedButton(
   ///   style: ElevatedButton.styleFrom(primary: Colors.green),
   /// )
   /// ```
   static ButtonStyle styleFrom({
     Color? primary,
     Color? onPrimary,
     Color? onSurface,
     Color? shadowColor,
     double? elevation,
     TextStyle? textStyle,
     EdgeInsetsGeometry? padding,
     Size? minimumSize,
     Size? fixedSize,
     Size? maximumSize,
     BorderSide? side,
     OutlinedBorder? shape,
     MouseCursor? enabledMouseCursor,
     MouseCursor? disabledMouseCursor,
     VisualDensity? visualDensity,
     MaterialTapTargetSize? tapTargetSize,
     Duration? animationDuration,
     bool? enableFeedback,
     AlignmentGeometry? alignment,
     InteractiveInkFeatureFactory? splashFactory,
   }) {
     final MaterialStateProperty<Color?>? backgroundColor = (onSurface == null && primary == null)
       ? null
       : _ElevatedButtonDefaultBackground(primary, onSurface);
     final MaterialStateProperty<Color?>? foregroundColor = (onSurface == null && onPrimary == null)
       ? null
       : _ElevatedButtonDefaultForeground(onPrimary, onSurface);
     final MaterialStateProperty<Color?>? overlayColor = (onPrimary == null)
       ? null
       : _ElevatedButtonDefaultOverlay(onPrimary);
     final MaterialStateProperty<double>? elevationValue = (elevation == null)
       ? null
       : _ElevatedButtonDefaultElevation(elevation);
     final MaterialStateProperty<MouseCursor?>? mouseCursor = (enabledMouseCursor == null && disabledMouseCursor == null)
       ? null
       : _ElevatedButtonDefaultMouseCursor(enabledMouseCursor, disabledMouseCursor);

     return ButtonStyle(
       textStyle: MaterialStateProperty.all<TextStyle?>(textStyle),
       backgroundColor: backgroundColor,
       foregroundColor: foregroundColor,
       overlayColor: overlayColor,
       shadowColor: ButtonStyleButton.allOrNull<Color>(shadowColor),
       elevation: elevationValue,
       padding: ButtonStyleButton.allOrNull<EdgeInsetsGeometry>(padding),
       minimumSize: ButtonStyleButton.allOrNull<Size>(minimumSize),
       fixedSize: ButtonStyleButton.allOrNull<Size>(fixedSize),
       maximumSize: ButtonStyleButton.allOrNull<Size>(maximumSize),
       side: ButtonStyleButton.allOrNull<BorderSide>(side),
       shape: ButtonStyleButton.allOrNull<OutlinedBorder>(shape),
       mouseCursor: mouseCursor,
       visualDensity: visualDensity,
       tapTargetSize: tapTargetSize,
       animationDuration: animationDuration,
       enableFeedback: enableFeedback,
       alignment: alignment,
       splashFactory: splashFactory,
     );
   }

   /// Defines the button's default appearance.
   ///
   /// The button [child]'s [Text] and [Icon] widgets are rendered with
   /// the [ButtonStyle]'s foreground color. The button's [InkWell] adds
   /// the style's overlay color when the button is focused, hovered
   /// or pressed. The button's background color becomes its [Material]
   /// color.
   ///
   /// All of the ButtonStyle's defaults appear below. In this list
   /// "Theme.foo" is shorthand for `Theme.of(context).foo`. Color
   /// scheme values like "onSurface(0.38)" are shorthand for
   /// `onSurface.withOpacity(0.38)`. [MaterialStateProperty] valued
   /// properties that are not followed by a sublist have the same
   /// value for all states, otherwise the values are as specified for
   /// each state, and "others" means all other states.
   ///
   /// The `textScaleFactor` is the value of
   /// `MediaQuery.of(context).textScaleFactor` and the names of the
   /// EdgeInsets constructors and `EdgeInsetsGeometry.lerp` have been
   /// abbreviated for readability.
   ///
   /// The color of the [ButtonStyle.textStyle] is not used, the
   /// [ButtonStyle.foregroundColor] color is used instead.
   ///
   /// * `textStyle` - Theme.textTheme.button
   /// * `backgroundColor`
   ///   * disabled - Theme.colorScheme.onSurface(0.12)
   ///   * others - Theme.colorScheme.primary
   /// * `foregroundColor`
   ///   * disabled - Theme.colorScheme.onSurface(0.38)
   ///   * others - Theme.colorScheme.onPrimary
   /// * `overlayColor`
   ///   * hovered - Theme.colorScheme.onPrimary(0.08)
   ///   * focused or pressed - Theme.colorScheme.onPrimary(0.24)
   /// * `shadowColor` - Theme.shadowColor
   /// * `elevation`
   ///   * disabled - 0
   ///   * default - 2
   ///   * hovered or focused - 4
   ///   * pressed - 8
   /// * `padding`
   ///   * textScaleFactor <= 1 - horizontal(16)
   ///   * `1 < textScaleFactor <= 2` - lerp(horizontal(16), horizontal(8))
   ///   * `2 < textScaleFactor <= 3` - lerp(horizontal(8), horizontal(4))
   ///   * `3 < textScaleFactor` - horizontal(4)
   /// * `minimumSize` - Size(64, 36)
   /// * `fixedSize` - null
   /// * `maximumSize` - Size.infinite
   /// * `side` - null
   /// * `shape` - RoundedRectangleBorder(borderRadius: BorderRadius.circular(4))
   /// * `mouseCursor`
   ///   * disabled - SystemMouseCursors.forbidden
   ///   * others - SystemMouseCursors.click
   /// * `visualDensity` - theme.visualDensity
   /// * `tapTargetSize` - theme.materialTapTargetSize
   /// * `animationDuration` - kThemeChangeDuration
   /// * `enableFeedback` - true
   /// * `alignment` - Alignment.center
   /// * `splashFactory` - InkRipple.splashFactory
   ///
   /// The default padding values for the [ElevatedButton.icon] factory are slightly different:
   ///
   /// * `padding`
   ///   * `textScaleFactor <= 1` - start(12) end(16)
   ///   * `1 < textScaleFactor <= 2` - lerp(start(12) end(16), horizontal(8))
   ///   * `2 < textScaleFactor <= 3` - lerp(horizontal(8), horizontal(4))
   ///   * `3 < textScaleFactor` - horizontal(4)
   ///
   /// The default value for `side`, which defines the appearance of the button's
   /// outline, is null. That means that the outline is defined by the button
   /// shape's [OutlinedBorder.side]. Typically the default value of an
   /// [OutlinedBorder]'s side is [BorderSide.none], so an outline is not drawn.
   @override
   ButtonStyle defaultStyleOf(BuildContext context) {
     final ThemeData theme = Theme.of(context);
     final ColorScheme colorScheme = theme.colorScheme;

     final EdgeInsetsGeometry scaledPadding = ButtonStyleButton.scaledPadding(
       const EdgeInsets.symmetric(horizontal: 16),
       const EdgeInsets.symmetric(horizontal: 8),
       const EdgeInsets.symmetric(horizontal: 4),
       MediaQuery.maybeOf(context)?.textScaleFactor ?? 1,
     );

     return styleFrom(
       primary: colorScheme.primary,
       onPrimary: colorScheme.onPrimary,
       onSurface: colorScheme.onSurface,
       shadowColor: theme.shadowColor,
       elevation: 2,
       textStyle: theme.textTheme.button,
       padding: scaledPadding,
       minimumSize: const Size(64, 36),
       maximumSize: Size.infinite,
       shape: const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(4))),
       enabledMouseCursor: SystemMouseCursors.click,
       disabledMouseCursor: SystemMouseCursors.forbidden,
       visualDensity: theme.visualDensity,
       tapTargetSize: theme.materialTapTargetSize,
       animationDuration: kThemeChangeDuration,
       enableFeedback: true,
       alignment: Alignment.center,
       splashFactory: InkRipple.splashFactory,
     );
   }

   /// Returns the [ElevatedButtonThemeData.style] of the closest
   /// [ElevatedButtonTheme] ancestor.
   @override
   ButtonStyle? themeStyleOf(BuildContext context) {
     return ElevatedButtonTheme.of(context).style;
   }
 }

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

   final Color? primary;
   final Color? onSurface;

   @override
   Color? resolve(Set<MaterialState> states) {
     if (states.contains(MaterialState.disabled))
       return onSurface?.withOpacity(0.12);
     return primary;
   }
 }

 @immutable
 class _ElevatedButtonDefaultForeground extends MaterialStateProperty<Color?> with Diagnosticable {
   _ElevatedButtonDefaultForeground(this.onPrimary, this.onSurface);

   final Color? onPrimary;
   final Color? onSurface;

   @override
   Color? resolve(Set<MaterialState> states) {
     if (states.contains(MaterialState.disabled))
       return onSurface?.withOpacity(0.38);
     return onPrimary;
   }
 }

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

   final Color onPrimary;

   @override
   Color? resolve(Set<MaterialState> states) {
     if (states.contains(MaterialState.hovered))
       return onPrimary.withOpacity(0.08);
     if (states.contains(MaterialState.focused) || states.contains(MaterialState.pressed))
       return onPrimary.withOpacity(0.24);
     return null;
   }
 }

 @immutable
 class _ElevatedButtonDefaultElevation extends MaterialStateProperty<double> with Diagnosticable {
   _ElevatedButtonDefaultElevation(this.elevation);

   final double elevation;

   @override
   double resolve(Set<MaterialState> states) {
     if (states.contains(MaterialState.disabled))
       return 0;
     if (states.contains(MaterialState.hovered))
       return elevation + 2;
     if (states.contains(MaterialState.focused))
       return elevation + 2;
     if (states.contains(MaterialState.pressed))
       return elevation + 6;
     return elevation;
   }
 }

 @immutable
 class _ElevatedButtonDefaultMouseCursor extends MaterialStateProperty<MouseCursor?> with Diagnosticable {
   _ElevatedButtonDefaultMouseCursor(this.enabledCursor, this.disabledCursor);

   final MouseCursor? enabledCursor;
   final MouseCursor? disabledCursor;

   @override
   MouseCursor? resolve(Set<MaterialState> states) {
     if (states.contains(MaterialState.disabled))
       return disabledCursor;
     return enabledCursor;
   }
 }

 class _ElevatedButtonWithIcon extends ElevatedButton {
   _ElevatedButtonWithIcon({
     Key? key,
     required VoidCallback? onPressed,
     VoidCallback? onLongPress,
     ValueChanged<bool>? onHover,
     ValueChanged<bool>? onFocusChange,
     ButtonStyle? style,
     FocusNode? focusNode,
     bool? autofocus,
     Clip? clipBehavior,
     required Widget icon,
     required Widget label,
   }) : assert(icon != null),
        assert(label != null),
        super(
          key: key,
          onPressed: onPressed,
          onLongPress: onLongPress,
          onHover: onHover,
          onFocusChange: onFocusChange,
          style: style,
          focusNode: focusNode,
          autofocus: autofocus ?? false,
          clipBehavior: clipBehavior ?? Clip.none,
          child: _ElevatedButtonWithIconChild(icon: icon, label: label),
       );

   @override
   ButtonStyle defaultStyleOf(BuildContext context) {
     final EdgeInsetsGeometry scaledPadding = ButtonStyleButton.scaledPadding(
       const EdgeInsetsDirectional.fromSTEB(12, 0, 16, 0),
       const EdgeInsets.symmetric(horizontal: 8),
       const EdgeInsetsDirectional.fromSTEB(8, 0, 4, 0),
       MediaQuery.maybeOf(context)?.textScaleFactor ?? 1,
     );
     return super.defaultStyleOf(context).copyWith(
       padding: MaterialStateProperty.all<EdgeInsetsGeometry>(scaledPadding),
     );
   }
 }

 class _ElevatedButtonWithIconChild extends StatelessWidget {
   const _ElevatedButtonWithIconChild({ Key? key, required this.label, required this.icon }) : super(key: key);

   final Widget label;
   final Widget icon;

   @override
   Widget build(BuildContext context) {
     final double scale = MediaQuery.maybeOf(context)?.textScaleFactor ?? 1;
     final double gap = scale <= 1 ? 8 : lerpDouble(8, 4, math.min(scale - 1, 1))!;
     return Row(
       mainAxisSize: MainAxisSize.min,
       children: <Widget>[icon, SizedBox(width: gap), Flexible(child: label)],
     );
   }
 }
	// 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 'dart:ui' show lerpDouble;

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

	import 'button_style.dart';
	import 'button_style_button.dart';
	import 'color_scheme.dart';
	import 'constants.dart';
	import 'elevated_button_theme.dart';
	import 'ink_ripple.dart';
	import 'ink_well.dart';
	import 'material_state.dart';
	import 'theme.dart';
	import 'theme_data.dart';

	/// A Material Design "elevated button".
	///
	/// Use elevated buttons to add dimension to otherwise mostly flat
	/// layouts, e.g. in long busy lists of content, or in wide
	/// spaces. Avoid using elevated buttons on already-elevated content
	/// such as dialogs or cards.
	///
	/// An elevated button is a label [child] displayed on a [Material]
	/// widget whose [Material.elevation] increases when the button is
	/// pressed. The label's [Text] and [Icon] widgets are displayed in
	/// [style]'s [ButtonStyle.foregroundColor] and the button's filled
	/// background is the [ButtonStyle.backgroundColor].
	///
	/// The elevated button's default style is defined by
	/// [defaultStyleOf]. The style of this elevated button can be
	/// overridden with its [style] parameter. The style of all elevated
	/// buttons in a subtree can be overridden with the
	/// [ElevatedButtonTheme], and the style of all of the elevated
	/// buttons in an app can be overridden with the [Theme]'s
	/// [ThemeData.elevatedButtonTheme] property.
	///
	/// The static [styleFrom] method is a convenient way to create a
	/// elevated button [ButtonStyle] from simple values.
	///
	/// If [onPressed] and [onLongPress] callbacks are null, then the
	/// button will be disabled.
	///
	/// {@tool dartpad}
	/// This sample produces an enabled and a disabled ElevatedButton.
	///
	/// See code in examples/api/lib/material/elevated_button/elevated_button.0.dart
	/// {@end-tool}
	///
	/// See also:
	///
	/// * [TextButton], a simple flat button without a shadow.
	/// * [OutlinedButton], a [TextButton] with a border outline.
	/// * <https://material.io/design/components/buttons.html>
	class ElevatedButton extends ButtonStyleButton {
	/// Create an ElevatedButton.
	///
	/// The [autofocus] and [clipBehavior] arguments must not be null.
	const ElevatedButton({
	Key? key,
	required VoidCallback? onPressed,
	VoidCallback? onLongPress,
	ValueChanged<bool>? onHover,
	ValueChanged<bool>? onFocusChange,
	ButtonStyle? style,
	FocusNode? focusNode,
	bool autofocus = false,
	Clip clipBehavior = Clip.none,
	required Widget? child,
	}) : super(
	key: key,
	onPressed: onPressed,
	onLongPress: onLongPress,
	onHover: onHover,
	onFocusChange: onFocusChange,
	style: style,
	focusNode: focusNode,
	autofocus: autofocus,
	clipBehavior: clipBehavior,
	child: child,
	);

	/// Create an elevated button from a pair of widgets that serve as the button's
	/// [icon] and [label].
	///
	/// The icon and label are arranged in a row and padded by 12 logical pixels
	/// at the start, and 16 at the end, with an 8 pixel gap in between.
	///
	/// The [icon] and [label] arguments must not be null.
	factory ElevatedButton.icon({
	Key? key,
	required VoidCallback? onPressed,
	VoidCallback? onLongPress,
	ValueChanged<bool>? onHover,
	ValueChanged<bool>? onFocusChange,
	ButtonStyle? style,
	FocusNode? focusNode,
	bool? autofocus,
	Clip? clipBehavior,
	required Widget icon,
	required Widget label,
	}) = _ElevatedButtonWithIcon;

	/// A static convenience method that constructs an elevated button
	/// [ButtonStyle] given simple values.
	///
	/// The [onPrimary], and [onSurface] colors are used to create a
	/// [MaterialStateProperty] [ButtonStyle.foregroundColor] value in the same
	/// way that [defaultStyleOf] uses the [ColorScheme] colors with the same
	/// names. Specify a value for [onPrimary] to specify the color of the
	/// button's text and icons as well as the overlay colors used to indicate the
	/// hover, focus, and pressed states. Use [primary] for the button's background
	/// fill color and [onSurface] to specify the button's disabled text, icon,
	/// and fill color.
	///
	/// The button's elevations are defined relative to the [elevation]
	/// parameter. The disabled elevation is the same as the parameter
	/// value, [elevation] + 2 is used when the button is hovered
	/// or focused, and elevation + 6 is used when the button is pressed.
	///
	/// Similarly, the [enabledMouseCursor] and [disabledMouseCursor]
	/// parameters are used to construct [ButtonStyle].mouseCursor.
	///
	/// All of the other parameters are either used directly or used to
	/// create a [MaterialStateProperty] with a single value for all
	/// states.
	///
	/// All parameters default to null, by default this method returns
	/// a [ButtonStyle] that doesn't override anything.
	///
	/// For example, to override the default text and icon colors for a
	/// [ElevatedButton], as well as its overlay color, with all of the
	/// standard opacity adjustments for the pressed, focused, and
	/// hovered states, one could write:
	///
	/// ```dart
	/// ElevatedButton(
	/// style: ElevatedButton.styleFrom(primary: Colors.green),
	/// )
	/// ```
	static ButtonStyle styleFrom({
	Color? primary,
	Color? onPrimary,
	Color? onSurface,
	Color? shadowColor,
	double? elevation,
	TextStyle? textStyle,
	EdgeInsetsGeometry? padding,
	Size? minimumSize,
	Size? fixedSize,
	Size? maximumSize,
	BorderSide? side,
	OutlinedBorder? shape,
	MouseCursor? enabledMouseCursor,
	MouseCursor? disabledMouseCursor,
	VisualDensity? visualDensity,
	MaterialTapTargetSize? tapTargetSize,
	Duration? animationDuration,
	bool? enableFeedback,
	AlignmentGeometry? alignment,
	InteractiveInkFeatureFactory? splashFactory,
	}) {
	final MaterialStateProperty<Color?>? backgroundColor = (onSurface == null && primary == null)
	? null
	: _ElevatedButtonDefaultBackground(primary, onSurface);
	final MaterialStateProperty<Color?>? foregroundColor = (onSurface == null && onPrimary == null)
	? null
	: _ElevatedButtonDefaultForeground(onPrimary, onSurface);
	final MaterialStateProperty<Color?>? overlayColor = (onPrimary == null)
	? null
	: _ElevatedButtonDefaultOverlay(onPrimary);
	final MaterialStateProperty<double>? elevationValue = (elevation == null)
	? null
	: _ElevatedButtonDefaultElevation(elevation);
	final MaterialStateProperty<MouseCursor?>? mouseCursor = (enabledMouseCursor == null && disabledMouseCursor == null)
	? null
	: _ElevatedButtonDefaultMouseCursor(enabledMouseCursor, disabledMouseCursor);

	return ButtonStyle(
	textStyle: MaterialStateProperty.all<TextStyle?>(textStyle),
	backgroundColor: backgroundColor,
	foregroundColor: foregroundColor,
	overlayColor: overlayColor,
	shadowColor: ButtonStyleButton.allOrNull<Color>(shadowColor),
	elevation: elevationValue,
	padding: ButtonStyleButton.allOrNull<EdgeInsetsGeometry>(padding),
	minimumSize: ButtonStyleButton.allOrNull<Size>(minimumSize),
	fixedSize: ButtonStyleButton.allOrNull<Size>(fixedSize),
	maximumSize: ButtonStyleButton.allOrNull<Size>(maximumSize),
	side: ButtonStyleButton.allOrNull<BorderSide>(side),
	shape: ButtonStyleButton.allOrNull<OutlinedBorder>(shape),
	mouseCursor: mouseCursor,
	visualDensity: visualDensity,
	tapTargetSize: tapTargetSize,
	animationDuration: animationDuration,
	enableFeedback: enableFeedback,
	alignment: alignment,
	splashFactory: splashFactory,
	);
	}

	/// Defines the button's default appearance.
	///
	/// The button [child]'s [Text] and [Icon] widgets are rendered with
	/// the [ButtonStyle]'s foreground color. The button's [InkWell] adds
	/// the style's overlay color when the button is focused, hovered
	/// or pressed. The button's background color becomes its [Material]
	/// color.
	///
	/// All of the ButtonStyle's defaults appear below. In this list
	/// "Theme.foo" is shorthand for `Theme.of(context).foo`. Color
	/// scheme values like "onSurface(0.38)" are shorthand for
	/// `onSurface.withOpacity(0.38)`. [MaterialStateProperty] valued
	/// properties that are not followed by a sublist have the same
	/// value for all states, otherwise the values are as specified for
	/// each state, and "others" means all other states.
	///
	/// The `textScaleFactor` is the value of
	/// `MediaQuery.of(context).textScaleFactor` and the names of the
	/// EdgeInsets constructors and `EdgeInsetsGeometry.lerp` have been
	/// abbreviated for readability.
	///
	/// The color of the [ButtonStyle.textStyle] is not used, the
	/// [ButtonStyle.foregroundColor] color is used instead.
	///
	/// * `textStyle` - Theme.textTheme.button
	/// * `backgroundColor`
	/// * disabled - Theme.colorScheme.onSurface(0.12)
	/// * others - Theme.colorScheme.primary
	/// * `foregroundColor`
	/// * disabled - Theme.colorScheme.onSurface(0.38)
	/// * others - Theme.colorScheme.onPrimary
	/// * `overlayColor`
	/// * hovered - Theme.colorScheme.onPrimary(0.08)
	/// * focused or pressed - Theme.colorScheme.onPrimary(0.24)
	/// * `shadowColor` - Theme.shadowColor
	/// * `elevation`
	/// * disabled - 0
	/// * default - 2
	/// * hovered or focused - 4
	/// * pressed - 8
	/// * `padding`
	/// * textScaleFactor <= 1 - horizontal(16)
	/// * `1 < textScaleFactor <= 2` - lerp(horizontal(16), horizontal(8))
	/// * `2 < textScaleFactor <= 3` - lerp(horizontal(8), horizontal(4))
	/// * `3 < textScaleFactor` - horizontal(4)
	/// * `minimumSize` - Size(64, 36)
	/// * `fixedSize` - null
	/// * `maximumSize` - Size.infinite
	/// * `side` - null
	/// * `shape` - RoundedRectangleBorder(borderRadius: BorderRadius.circular(4))
	/// * `mouseCursor`
	/// * disabled - SystemMouseCursors.forbidden
	/// * others - SystemMouseCursors.click
	/// * `visualDensity` - theme.visualDensity
	/// * `tapTargetSize` - theme.materialTapTargetSize
	/// * `animationDuration` - kThemeChangeDuration
	/// * `enableFeedback` - true
	/// * `alignment` - Alignment.center
	/// * `splashFactory` - InkRipple.splashFactory
	///
	/// The default padding values for the [ElevatedButton.icon] factory are slightly different:
	///
	/// * `padding`
	/// * `textScaleFactor <= 1` - start(12) end(16)
	/// * `1 < textScaleFactor <= 2` - lerp(start(12) end(16), horizontal(8))
	/// * `2 < textScaleFactor <= 3` - lerp(horizontal(8), horizontal(4))
	/// * `3 < textScaleFactor` - horizontal(4)
	///
	/// The default value for `side`, which defines the appearance of the button's
	/// outline, is null. That means that the outline is defined by the button
	/// shape's [OutlinedBorder.side]. Typically the default value of an
	/// [OutlinedBorder]'s side is [BorderSide.none], so an outline is not drawn.
	@override
	ButtonStyle defaultStyleOf(BuildContext context) {
	final ThemeData theme = Theme.of(context);
	final ColorScheme colorScheme = theme.colorScheme;

	final EdgeInsetsGeometry scaledPadding = ButtonStyleButton.scaledPadding(
	const EdgeInsets.symmetric(horizontal: 16),
	const EdgeInsets.symmetric(horizontal: 8),
	const EdgeInsets.symmetric(horizontal: 4),
	MediaQuery.maybeOf(context)?.textScaleFactor ?? 1,
	);

	return styleFrom(
	primary: colorScheme.primary,
	onPrimary: colorScheme.onPrimary,
	onSurface: colorScheme.onSurface,
	shadowColor: theme.shadowColor,
	elevation: 2,
	textStyle: theme.textTheme.button,
	padding: scaledPadding,
	minimumSize: const Size(64, 36),
	maximumSize: Size.infinite,
	shape: const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(4))),
	enabledMouseCursor: SystemMouseCursors.click,
	disabledMouseCursor: SystemMouseCursors.forbidden,
	visualDensity: theme.visualDensity,
	tapTargetSize: theme.materialTapTargetSize,
	animationDuration: kThemeChangeDuration,
	enableFeedback: true,
	alignment: Alignment.center,
	splashFactory: InkRipple.splashFactory,
	);
	}

	/// Returns the [ElevatedButtonThemeData.style] of the closest
	/// [ElevatedButtonTheme] ancestor.
	@override
	ButtonStyle? themeStyleOf(BuildContext context) {
	return ElevatedButtonTheme.of(context).style;
	}
	}

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

	final Color? primary;
	final Color? onSurface;

	@override
	Color? resolve(Set<MaterialState> states) {
	if (states.contains(MaterialState.disabled))
	return onSurface?.withOpacity(0.12);
	return primary;
	}
	}

	@immutable
	class _ElevatedButtonDefaultForeground extends MaterialStateProperty<Color?> with Diagnosticable {
	_ElevatedButtonDefaultForeground(this.onPrimary, this.onSurface);

	final Color? onPrimary;
	final Color? onSurface;

	@override
	Color? resolve(Set<MaterialState> states) {
	if (states.contains(MaterialState.disabled))
	return onSurface?.withOpacity(0.38);
	return onPrimary;
	}
	}

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

	final Color onPrimary;

	@override
	Color? resolve(Set<MaterialState> states) {
	if (states.contains(MaterialState.hovered))
	return onPrimary.withOpacity(0.08);
	if (states.contains(MaterialState.focused) \|\| states.contains(MaterialState.pressed))
	return onPrimary.withOpacity(0.24);
	return null;
	}
	}

	@immutable
	class _ElevatedButtonDefaultElevation extends MaterialStateProperty<double> with Diagnosticable {
	_ElevatedButtonDefaultElevation(this.elevation);

	final double elevation;

	@override
	double resolve(Set<MaterialState> states) {
	if (states.contains(MaterialState.disabled))
	return 0;
	if (states.contains(MaterialState.hovered))
	return elevation + 2;
	if (states.contains(MaterialState.focused))
	return elevation + 2;
	if (states.contains(MaterialState.pressed))
	return elevation + 6;
	return elevation;
	}
	}

	@immutable
	class _ElevatedButtonDefaultMouseCursor extends MaterialStateProperty<MouseCursor?> with Diagnosticable {
	_ElevatedButtonDefaultMouseCursor(this.enabledCursor, this.disabledCursor);

	final MouseCursor? enabledCursor;
	final MouseCursor? disabledCursor;

	@override
	MouseCursor? resolve(Set<MaterialState> states) {
	if (states.contains(MaterialState.disabled))
	return disabledCursor;
	return enabledCursor;
	}
	}

	class _ElevatedButtonWithIcon extends ElevatedButton {
	_ElevatedButtonWithIcon({
	Key? key,
	required VoidCallback? onPressed,
	VoidCallback? onLongPress,
	ValueChanged<bool>? onHover,
	ValueChanged<bool>? onFocusChange,
	ButtonStyle? style,
	FocusNode? focusNode,
	bool? autofocus,
	Clip? clipBehavior,
	required Widget icon,
	required Widget label,
	}) : assert(icon != null),
	assert(label != null),
	super(
	key: key,
	onPressed: onPressed,
	onLongPress: onLongPress,
	onHover: onHover,
	onFocusChange: onFocusChange,
	style: style,
	focusNode: focusNode,
	autofocus: autofocus ?? false,
	clipBehavior: clipBehavior ?? Clip.none,
	child: _ElevatedButtonWithIconChild(icon: icon, label: label),
	);

	@override
	ButtonStyle defaultStyleOf(BuildContext context) {
	final EdgeInsetsGeometry scaledPadding = ButtonStyleButton.scaledPadding(
	const EdgeInsetsDirectional.fromSTEB(12, 0, 16, 0),
	const EdgeInsets.symmetric(horizontal: 8),
	const EdgeInsetsDirectional.fromSTEB(8, 0, 4, 0),
	MediaQuery.maybeOf(context)?.textScaleFactor ?? 1,
	);
	return super.defaultStyleOf(context).copyWith(
	padding: MaterialStateProperty.all<EdgeInsetsGeometry>(scaledPadding),
	);
	}
	}

	class _ElevatedButtonWithIconChild extends StatelessWidget {
	const _ElevatedButtonWithIconChild({ Key? key, required this.label, required this.icon }) : super(key: key);

	final Widget label;
	final Widget icon;

	@override
	Widget build(BuildContext context) {
	final double scale = MediaQuery.maybeOf(context)?.textScaleFactor ?? 1;
	final double gap = scale <= 1 ? 8 : lerpDouble(8, 4, math.min(scale - 1, 1))!;
	return Row(
	mainAxisSize: MainAxisSize.min,
	children: <Widget>[icon, SizedBox(width: gap), Flexible(child: label)],
	);
	}
	}