packages/flutter/lib/src/cupertino/theme.dart - mirrors/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 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';

 import 'colors.dart';
 import 'icon_theme_data.dart';
 import 'text_theme.dart';

 export 'package:flutter/services.dart' show Brightness;

 // Values derived from https://developer.apple.com/design/resources/.
 const _CupertinoThemeDefaults _kDefaultTheme = _CupertinoThemeDefaults(
   null,
   CupertinoColors.systemBlue,
   CupertinoColors.systemBackground,
   CupertinoDynamicColor.withBrightness(
     color: Color(0xF0F9F9F9),
     darkColor: Color(0xF01D1D1D),
     // Values extracted from navigation bar. For toolbar or tabbar the dark color is 0xF0161616.
   ),
   CupertinoColors.systemBackground,
   _CupertinoTextThemeDefaults(CupertinoColors.label, CupertinoColors.inactiveGray),
 );

 /// Applies a visual styling theme to descendant Cupertino widgets.
 ///
 /// Affects the color and text styles of Cupertino widgets whose styling
 /// are not overridden when constructing the respective widgets instances.
 ///
 /// Descendant widgets can retrieve the current [CupertinoThemeData] by calling
 /// [CupertinoTheme.of]. An [InheritedWidget] dependency is created when
 /// an ancestor [CupertinoThemeData] is retrieved via [CupertinoTheme.of].
 ///
 /// The [CupertinoTheme] widget implies an [IconTheme] widget, whose
 /// [IconTheme.data] has the same color as [CupertinoThemeData.primaryColor]
 ///
 /// See also:
 ///
 ///  * [CupertinoThemeData], specifies the theme's visual styling.
 ///  * [CupertinoApp], which will automatically add a [CupertinoTheme] based on the
 ///    value of [CupertinoApp.theme].
 ///  * [Theme], a Material theme which will automatically add a [CupertinoTheme]
 ///    with a [CupertinoThemeData] derived from the Material [ThemeData].
 class CupertinoTheme extends StatelessWidget {
   /// Creates a [CupertinoTheme] to change descendant Cupertino widgets' styling.
   ///
   /// The [data] and [child] parameters must not be null.
   const CupertinoTheme({
     Key key,
     @required this.data,
     @required this.child,
   }) : assert(child != null),
        assert(data != null),
        super(key: key);

   /// The [CupertinoThemeData] styling for this theme.
   final CupertinoThemeData data;

   /// Retrieves the [CupertinoThemeData] from the closest ancestor [CupertinoTheme]
   /// widget, or a default [CupertinoThemeData] if no [CupertinoTheme] ancestor
   /// exists.
   ///
   /// Resolves all the colors defined in that [CupertinoThemeData] against the
   /// given [BuildContext] on a best-effort basis.
   static CupertinoThemeData of(BuildContext context) {
     final _InheritedCupertinoTheme inheritedTheme = context.dependOnInheritedWidgetOfExactType<_InheritedCupertinoTheme>();
     return (inheritedTheme?.theme?.data ?? const CupertinoThemeData()).resolveFrom(context, nullOk: true);
   }

   /// Retrieves the [Brightness] to use for descendant Cupertino widgets, based
   /// on the value of [CupertinoThemeData.brightness] in the given [context].
   ///
   /// If no [CupertinoTheme] can be found in the given [context], or its `brightness`
   /// is null, it will fall back to [MediaQueryData.brightness].
   ///
   /// Throws an exception if no valid [CupertinoTheme] or [MediaQuery] widgets
   /// exist in the ancestry tree, unless [nullOk] is set to true.
   ///
   /// See also:
   ///
   /// * [CupertinoThemeData.brightness], the property takes precedence over
   ///   [MediaQueryData.platformBrightness] for descendant Cupertino widgets.
   static Brightness brightnessOf(BuildContext context, { bool nullOk = false }) {
     final _InheritedCupertinoTheme inheritedTheme = context.dependOnInheritedWidgetOfExactType<_InheritedCupertinoTheme>();
     return inheritedTheme?.theme?.data?.brightness ?? MediaQuery.of(context, nullOk: nullOk)?.platformBrightness;
   }

   /// The widget below this widget in the tree.
   ///
   /// {@macro flutter.widgets.child}
   final Widget child;

   @override
   Widget build(BuildContext context) {
     return  _InheritedCupertinoTheme(
       theme: this,
       child: IconTheme(
         data: CupertinoIconThemeData(color: data.primaryColor),
         child: child,
       ),
     );
   }

   @override
   void debugFillProperties(DiagnosticPropertiesBuilder properties) {
     super.debugFillProperties(properties);
     data.debugFillProperties(properties);
   }
 }

 class _InheritedCupertinoTheme extends InheritedWidget {
   const _InheritedCupertinoTheme({
     Key key,
     @required this.theme,
     @required Widget child,
   }) : assert(theme != null),
        super(key: key, child: child);

   final CupertinoTheme theme;

   @override
   bool updateShouldNotify(_InheritedCupertinoTheme old) => theme.data != old.theme.data;
 }

 /// Styling specifications for a [CupertinoTheme].
 ///
 /// All constructor parameters can be null, in which case a
 /// [CupertinoColors.activeBlue] based default iOS theme styling is used.
 ///
 /// Parameters can also be partially specified, in which case some parameters
 /// will cascade down to other dependent parameters to create a cohesive
 /// visual effect. For instance, if a [primaryColor] is specified, it would
 /// cascade down to affect some fonts in [textTheme] if [textTheme] is not
 /// specified.
 ///
 /// See also:
 ///
 ///  * [CupertinoTheme], in which this [CupertinoThemeData] is inserted.
 ///  * [ThemeData], a Material equivalent that also configures Cupertino
 ///    styling via a [CupertinoThemeData] subclass [MaterialBasedCupertinoThemeData].
 @immutable
 class CupertinoThemeData with Diagnosticable {
   /// Creates a [CupertinoTheme] styling specification.
   ///
   /// Unspecified parameters default to a reasonable iOS default style.
   const CupertinoThemeData({
     Brightness brightness,
     Color primaryColor,
     Color primaryContrastingColor,
     CupertinoTextThemeData textTheme,
     Color barBackgroundColor,
     Color scaffoldBackgroundColor,
   }) : this.raw(
         brightness,
         primaryColor,
         primaryContrastingColor,
         textTheme,
         barBackgroundColor,
         scaffoldBackgroundColor,
       );

   /// Same as the default constructor but with positional arguments to avoid
   /// forgetting any and to specify all arguments.
   ///
   /// Used by subclasses to get the superclass's defaulting behaviors.
   @protected
   const CupertinoThemeData.raw(
     Brightness brightness,
     Color primaryColor,
     Color primaryContrastingColor,
     CupertinoTextThemeData textTheme,
     Color barBackgroundColor,
     Color scaffoldBackgroundColor,
   ) : this._rawWithDefaults(
     brightness,
     primaryColor,
     primaryContrastingColor,
     textTheme,
     barBackgroundColor,
     scaffoldBackgroundColor,
     _kDefaultTheme,
   );

   const CupertinoThemeData._rawWithDefaults(
     this.brightness,
     this._primaryColor,
     this._primaryContrastingColor,
     this._textTheme,
     this._barBackgroundColor,
     this._scaffoldBackgroundColor,
     this._defaults,
   );

   final _CupertinoThemeDefaults _defaults;

   /// The brightness override for Cupertino descendants.
   ///
   /// Defaults to null. If a non-null [Brightness] is specified, the value will
   /// take precedence over the ambient [MediaQueryData.platformBrightness], when
   /// determining the brightness of descendant Cupertino widgets.
   ///
   /// If coming from a Material [Theme] and unspecified, [brightness] will be
   /// derived from the Material [ThemeData]'s `brightness`.
   ///
   /// See also:
   ///
   ///  * [MaterialBasedCupertinoThemeData], a [CupertinoThemeData] that defers
   ///    [brightness] to its Material [Theme] parent if it's unspecified.
   ///
   ///  * [CupertinoTheme.brightnessOf], a method used to retrieve the overall
   ///    [Brightness] from a [BuildContext], for Cupertino widgets.
   final Brightness brightness;

   /// A color used on interactive elements of the theme.
   ///
   /// This color is generally used on text and icons in buttons and tappable
   /// elements. Defaults to [CupertinoColors.activeBlue].
   ///
   /// If coming from a Material [Theme] and unspecified, [primaryColor] will be
   /// derived from the Material [ThemeData]'s `colorScheme.primary`. However, in
   /// iOS styling, the [primaryColor] is more sparsely used than in Material
   /// Design where the [primaryColor] can appear on non-interactive surfaces like
   /// the [AppBar] background, [TextField] borders etc.
   ///
   /// See also:
   ///
   ///  * [MaterialBasedCupertinoThemeData], a [CupertinoThemeData] that defers
   ///    [primaryColor] to its Material [Theme] parent if it's unspecified.
   Color get primaryColor => _primaryColor ?? _defaults.primaryColor;
   final Color _primaryColor;

   /// A color that must be easy to see when rendered on a [primaryColor] background.
   ///
   /// For example, this color is used for a [CupertinoButton]'s text and icons
   /// when the button's background is [primaryColor].
   ///
   /// If coming from a Material [Theme] and unspecified, [primaryContrastingColor]
   /// will be derived from the Material [ThemeData]'s `colorScheme.onPrimary`.
   ///
   /// See also:
   ///
   ///  * [MaterialBasedCupertinoThemeData], a [CupertinoThemeData] that defers
   ///    [primaryContrastingColor] to its Material [Theme] parent if it's unspecified.
   Color get primaryContrastingColor => _primaryContrastingColor ?? _defaults.primaryContrastingColor;
   final Color _primaryContrastingColor;

   /// Text styles used by Cupertino widgets.
   ///
   /// Derived from [primaryColor] if unspecified.
   CupertinoTextThemeData get textTheme {
     return _textTheme ?? _defaults.textThemeDefaults.createDefaults(primaryColor: primaryColor);
   }
   final CupertinoTextThemeData _textTheme;

   /// Background color of the top nav bar and bottom tab bar.
   ///
   /// Defaults to a light gray in light mode, or a dark translucent gray color in
   /// dark mode.
   Color get barBackgroundColor => _barBackgroundColor ?? _defaults.barBackgroundColor;
   final Color _barBackgroundColor;

   /// Background color of the scaffold.
   ///
   /// Defaults to [CupertinoColors.systemBackground].
   Color get scaffoldBackgroundColor => _scaffoldBackgroundColor ?? _defaults.scaffoldBackgroundColor;
   final Color _scaffoldBackgroundColor;

   /// Returns an instance of the [CupertinoThemeData] whose property getters
   /// only return the construction time specifications with no derived values.
   ///
   /// Used in Material themes to let unspecified properties fallback to Material
   /// theme properties instead of iOS defaults.
   CupertinoThemeData noDefault() {
     return _NoDefaultCupertinoThemeData(
       brightness,
       _primaryColor,
       _primaryContrastingColor,
       _textTheme,
       _barBackgroundColor,
       _scaffoldBackgroundColor,
     );
   }

   /// Returns a new `CupertinoThemeData` with all its colors resolved against the
   /// given [BuildContext].
   ///
   /// Called by [CupertinoTheme.of] to resolve colors defined in the retrieved
   /// [CupertinoThemeData].
   @protected
   CupertinoThemeData resolveFrom(BuildContext context, { bool nullOk = false }) {
     Color convertColor(Color color) => CupertinoDynamicColor.resolve(color, context, nullOk: nullOk);

     return CupertinoThemeData._rawWithDefaults(
       brightness,
       convertColor(_primaryColor),
       convertColor(_primaryContrastingColor),
       _textTheme?.resolveFrom(context, nullOk: nullOk),
       convertColor(_barBackgroundColor),
       convertColor(_scaffoldBackgroundColor),
       _defaults.resolveFrom(context, _textTheme == null, nullOk: nullOk),
     );
   }

   /// Creates a copy of [CupertinoThemeData] with specified attributes overridden.
   ///
   /// Only the current instance's specified attributes are copied instead of
   /// derived values. For instance, if the current [CupertinoThemeData.textTheme]
   /// is implied from the current [primaryColor] because it was not specified,
   /// copying with a different [primaryColor] will also change the copy's implied
   /// [textTheme].
   CupertinoThemeData copyWith({
     Brightness brightness,
     Color primaryColor,
     Color primaryContrastingColor,
     CupertinoTextThemeData textTheme,
     Color barBackgroundColor,
     Color scaffoldBackgroundColor,
   }) {
     return CupertinoThemeData._rawWithDefaults(
       brightness ?? this.brightness,
       primaryColor ?? _primaryColor,
       primaryContrastingColor ?? _primaryContrastingColor,
       textTheme ?? _textTheme,
       barBackgroundColor ?? _barBackgroundColor,
       scaffoldBackgroundColor ?? _scaffoldBackgroundColor,
       _defaults,
     );
   }

   @override
   void debugFillProperties(DiagnosticPropertiesBuilder properties) {
     super.debugFillProperties(properties);
     const CupertinoThemeData defaultData = CupertinoThemeData();
     properties.add(EnumProperty<Brightness>('brightness', brightness, defaultValue: null));
     properties.add(createCupertinoColorProperty('primaryColor', primaryColor, defaultValue: defaultData.primaryColor));
     properties.add(createCupertinoColorProperty('primaryContrastingColor', primaryContrastingColor, defaultValue: defaultData.primaryContrastingColor));
     properties.add(createCupertinoColorProperty('barBackgroundColor', barBackgroundColor, defaultValue: defaultData.barBackgroundColor));
     properties.add(createCupertinoColorProperty('scaffoldBackgroundColor', scaffoldBackgroundColor, defaultValue: defaultData.scaffoldBackgroundColor));
     textTheme.debugFillProperties(properties);
   }
 }

 class _NoDefaultCupertinoThemeData extends CupertinoThemeData {
   const _NoDefaultCupertinoThemeData(
     Brightness brightness,
     this.primaryColor,
     this.primaryContrastingColor,
     this.textTheme,
     this.barBackgroundColor,
     this.scaffoldBackgroundColor,
   ) : super._rawWithDefaults(
         brightness,
         primaryColor,
         primaryContrastingColor,
         textTheme,
         barBackgroundColor,
         scaffoldBackgroundColor,
         null,
       );

   @override
   final Color primaryColor;
   @override
   final Color primaryContrastingColor;
   @override
   final CupertinoTextThemeData textTheme;
   @override
   final Color barBackgroundColor;
   @override
   final Color scaffoldBackgroundColor;

   @override
   _NoDefaultCupertinoThemeData resolveFrom(BuildContext context, { bool nullOk = false }) {
     Color convertColor(Color color) => CupertinoDynamicColor.resolve(color, context, nullOk: nullOk);

     return _NoDefaultCupertinoThemeData(
       brightness,
       convertColor(primaryColor),
       convertColor(primaryContrastingColor),
       textTheme?.resolveFrom(context, nullOk: nullOk),
       convertColor(barBackgroundColor),
       convertColor(scaffoldBackgroundColor),
     );
   }

   @override
   CupertinoThemeData copyWith({
     Brightness brightness,
     Color primaryColor,
     Color primaryContrastingColor,
     CupertinoTextThemeData textTheme,
     Color barBackgroundColor ,
     Color scaffoldBackgroundColor,
   }) {
     return _NoDefaultCupertinoThemeData(
       brightness ?? this.brightness,
       primaryColor ?? this.primaryColor,
       primaryContrastingColor ?? this.primaryContrastingColor,
       textTheme ?? this.textTheme,
       barBackgroundColor ?? this.barBackgroundColor,
       scaffoldBackgroundColor ?? this.scaffoldBackgroundColor,
     );
   }
 }

 @immutable
 class _CupertinoThemeDefaults {
   const _CupertinoThemeDefaults(
     this.brightness,
     this.primaryColor,
     this.primaryContrastingColor,
     this.barBackgroundColor,
     this.scaffoldBackgroundColor,
     this.textThemeDefaults,
   );

   final Brightness brightness;
   final Color primaryColor;
   final Color primaryContrastingColor;
   final Color barBackgroundColor;
   final Color scaffoldBackgroundColor;
   final _CupertinoTextThemeDefaults textThemeDefaults;

   _CupertinoThemeDefaults resolveFrom(BuildContext context, bool resolveTextTheme, { @required bool nullOk }) {
     assert(nullOk != null);
     Color convertColor(Color color) => CupertinoDynamicColor.resolve(color, context, nullOk: nullOk);

     return _CupertinoThemeDefaults(
       brightness,
       convertColor(primaryColor),
       convertColor(primaryContrastingColor),
       convertColor(barBackgroundColor),
       convertColor(scaffoldBackgroundColor),
       resolveTextTheme ? textThemeDefaults?.resolveFrom(context, nullOk: nullOk) : textThemeDefaults,
     );
   }
 }

 @immutable
 class _CupertinoTextThemeDefaults {
   const _CupertinoTextThemeDefaults(
     this.labelColor,
     this.inactiveGray,
   );

   final Color labelColor;
   final Color inactiveGray;

   _CupertinoTextThemeDefaults resolveFrom(BuildContext context, { @required bool nullOk }) {
     return _CupertinoTextThemeDefaults(
       CupertinoDynamicColor.resolve(labelColor, context, nullOk: nullOk),
       CupertinoDynamicColor.resolve(inactiveGray, context, nullOk: nullOk),
     );
   }

   CupertinoTextThemeData createDefaults({ @required Color primaryColor }) {
     assert(primaryColor != null);
     return _DefaultCupertinoTextThemeData(
       primaryColor: primaryColor,
       labelColor: labelColor,
       inactiveGray: inactiveGray,
     );
   }
 }

 // CupertinoTextThemeData with no text styles explicitly specified.
 // The implementation of this class may need to be updated when any of the default
 // text styles changes.
 class _DefaultCupertinoTextThemeData extends CupertinoTextThemeData {
   const _DefaultCupertinoTextThemeData({
     @required this.labelColor,
     @required this.inactiveGray,
     @required Color primaryColor,
   }) : assert(labelColor != null),
        assert(inactiveGray != null),
        assert(primaryColor != null),
        super(primaryColor: primaryColor);

   final Color labelColor;
   final Color inactiveGray;

   @override
   TextStyle get textStyle => super.textStyle.copyWith(color: labelColor);

   @override
   TextStyle get tabLabelTextStyle => super.tabLabelTextStyle.copyWith(color: inactiveGray);

   @override
   TextStyle get navTitleTextStyle => super.navTitleTextStyle.copyWith(color: labelColor);

   @override
   TextStyle get navLargeTitleTextStyle => super.navLargeTitleTextStyle.copyWith(color: labelColor);

   @override
   TextStyle get pickerTextStyle => super.pickerTextStyle.copyWith(color: labelColor);

   @override
   TextStyle get dateTimePickerTextStyle => super.dateTimePickerTextStyle.copyWith(color: labelColor);
 }
	// 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:flutter/foundation.dart';
	import 'package:flutter/services.dart';
	import 'package:flutter/widgets.dart';

	import 'colors.dart';
	import 'icon_theme_data.dart';
	import 'text_theme.dart';

	export 'package:flutter/services.dart' show Brightness;

	// Values derived from https://developer.apple.com/design/resources/.
	const _CupertinoThemeDefaults _kDefaultTheme = _CupertinoThemeDefaults(
	null,
	CupertinoColors.systemBlue,
	CupertinoColors.systemBackground,
	CupertinoDynamicColor.withBrightness(
	color: Color(0xF0F9F9F9),
	darkColor: Color(0xF01D1D1D),
	// Values extracted from navigation bar. For toolbar or tabbar the dark color is 0xF0161616.
	),
	CupertinoColors.systemBackground,
	_CupertinoTextThemeDefaults(CupertinoColors.label, CupertinoColors.inactiveGray),
	);

	/// Applies a visual styling theme to descendant Cupertino widgets.
	///
	/// Affects the color and text styles of Cupertino widgets whose styling
	/// are not overridden when constructing the respective widgets instances.
	///
	/// Descendant widgets can retrieve the current [CupertinoThemeData] by calling
	/// [CupertinoTheme.of]. An [InheritedWidget] dependency is created when
	/// an ancestor [CupertinoThemeData] is retrieved via [CupertinoTheme.of].
	///
	/// The [CupertinoTheme] widget implies an [IconTheme] widget, whose
	/// [IconTheme.data] has the same color as [CupertinoThemeData.primaryColor]
	///
	/// See also:
	///
	/// * [CupertinoThemeData], specifies the theme's visual styling.
	/// * [CupertinoApp], which will automatically add a [CupertinoTheme] based on the
	/// value of [CupertinoApp.theme].
	/// * [Theme], a Material theme which will automatically add a [CupertinoTheme]
	/// with a [CupertinoThemeData] derived from the Material [ThemeData].
	class CupertinoTheme extends StatelessWidget {
	/// Creates a [CupertinoTheme] to change descendant Cupertino widgets' styling.
	///
	/// The [data] and [child] parameters must not be null.
	const CupertinoTheme({
	Key key,
	@required this.data,
	@required this.child,
	}) : assert(child != null),
	assert(data != null),
	super(key: key);

	/// The [CupertinoThemeData] styling for this theme.
	final CupertinoThemeData data;

	/// Retrieves the [CupertinoThemeData] from the closest ancestor [CupertinoTheme]
	/// widget, or a default [CupertinoThemeData] if no [CupertinoTheme] ancestor
	/// exists.
	///
	/// Resolves all the colors defined in that [CupertinoThemeData] against the
	/// given [BuildContext] on a best-effort basis.
	static CupertinoThemeData of(BuildContext context) {
	final _InheritedCupertinoTheme inheritedTheme = context.dependOnInheritedWidgetOfExactType<_InheritedCupertinoTheme>();
	return (inheritedTheme?.theme?.data ?? const CupertinoThemeData()).resolveFrom(context, nullOk: true);
	}

	/// Retrieves the [Brightness] to use for descendant Cupertino widgets, based
	/// on the value of [CupertinoThemeData.brightness] in the given [context].
	///
	/// If no [CupertinoTheme] can be found in the given [context], or its `brightness`
	/// is null, it will fall back to [MediaQueryData.brightness].
	///
	/// Throws an exception if no valid [CupertinoTheme] or [MediaQuery] widgets
	/// exist in the ancestry tree, unless [nullOk] is set to true.
	///
	/// See also:
	///
	/// * [CupertinoThemeData.brightness], the property takes precedence over
	/// [MediaQueryData.platformBrightness] for descendant Cupertino widgets.
	static Brightness brightnessOf(BuildContext context, { bool nullOk = false }) {
	final _InheritedCupertinoTheme inheritedTheme = context.dependOnInheritedWidgetOfExactType<_InheritedCupertinoTheme>();
	return inheritedTheme?.theme?.data?.brightness ?? MediaQuery.of(context, nullOk: nullOk)?.platformBrightness;
	}

	/// The widget below this widget in the tree.
	///
	/// {@macro flutter.widgets.child}
	final Widget child;

	@override
	Widget build(BuildContext context) {
	return _InheritedCupertinoTheme(
	theme: this,
	child: IconTheme(
	data: CupertinoIconThemeData(color: data.primaryColor),
	child: child,
	),
	);
	}

	@override
	void debugFillProperties(DiagnosticPropertiesBuilder properties) {
	super.debugFillProperties(properties);
	data.debugFillProperties(properties);
	}
	}

	class _InheritedCupertinoTheme extends InheritedWidget {
	const _InheritedCupertinoTheme({
	Key key,
	@required this.theme,
	@required Widget child,
	}) : assert(theme != null),
	super(key: key, child: child);

	final CupertinoTheme theme;

	@override
	bool updateShouldNotify(_InheritedCupertinoTheme old) => theme.data != old.theme.data;
	}

	/// Styling specifications for a [CupertinoTheme].
	///
	/// All constructor parameters can be null, in which case a
	/// [CupertinoColors.activeBlue] based default iOS theme styling is used.
	///
	/// Parameters can also be partially specified, in which case some parameters
	/// will cascade down to other dependent parameters to create a cohesive
	/// visual effect. For instance, if a [primaryColor] is specified, it would
	/// cascade down to affect some fonts in [textTheme] if [textTheme] is not
	/// specified.
	///
	/// See also:
	///
	/// * [CupertinoTheme], in which this [CupertinoThemeData] is inserted.
	/// * [ThemeData], a Material equivalent that also configures Cupertino
	/// styling via a [CupertinoThemeData] subclass [MaterialBasedCupertinoThemeData].
	@immutable
	class CupertinoThemeData with Diagnosticable {
	/// Creates a [CupertinoTheme] styling specification.
	///
	/// Unspecified parameters default to a reasonable iOS default style.
	const CupertinoThemeData({
	Brightness brightness,
	Color primaryColor,
	Color primaryContrastingColor,
	CupertinoTextThemeData textTheme,
	Color barBackgroundColor,
	Color scaffoldBackgroundColor,
	}) : this.raw(
	brightness,
	primaryColor,
	primaryContrastingColor,
	textTheme,
	barBackgroundColor,
	scaffoldBackgroundColor,
	);

	/// Same as the default constructor but with positional arguments to avoid
	/// forgetting any and to specify all arguments.
	///
	/// Used by subclasses to get the superclass's defaulting behaviors.
	@protected
	const CupertinoThemeData.raw(
	Brightness brightness,
	Color primaryColor,
	Color primaryContrastingColor,
	CupertinoTextThemeData textTheme,
	Color barBackgroundColor,
	Color scaffoldBackgroundColor,
	) : this._rawWithDefaults(
	brightness,
	primaryColor,
	primaryContrastingColor,
	textTheme,
	barBackgroundColor,
	scaffoldBackgroundColor,
	_kDefaultTheme,
	);

	const CupertinoThemeData._rawWithDefaults(
	this.brightness,
	this._primaryColor,
	this._primaryContrastingColor,
	this._textTheme,
	this._barBackgroundColor,
	this._scaffoldBackgroundColor,
	this._defaults,
	);

	final _CupertinoThemeDefaults _defaults;

	/// The brightness override for Cupertino descendants.
	///
	/// Defaults to null. If a non-null [Brightness] is specified, the value will
	/// take precedence over the ambient [MediaQueryData.platformBrightness], when
	/// determining the brightness of descendant Cupertino widgets.
	///
	/// If coming from a Material [Theme] and unspecified, [brightness] will be
	/// derived from the Material [ThemeData]'s `brightness`.
	///
	/// See also:
	///
	/// * [MaterialBasedCupertinoThemeData], a [CupertinoThemeData] that defers
	/// [brightness] to its Material [Theme] parent if it's unspecified.
	///
	/// * [CupertinoTheme.brightnessOf], a method used to retrieve the overall
	/// [Brightness] from a [BuildContext], for Cupertino widgets.
	final Brightness brightness;

	/// A color used on interactive elements of the theme.
	///
	/// This color is generally used on text and icons in buttons and tappable
	/// elements. Defaults to [CupertinoColors.activeBlue].
	///
	/// If coming from a Material [Theme] and unspecified, [primaryColor] will be
	/// derived from the Material [ThemeData]'s `colorScheme.primary`. However, in
	/// iOS styling, the [primaryColor] is more sparsely used than in Material
	/// Design where the [primaryColor] can appear on non-interactive surfaces like
	/// the [AppBar] background, [TextField] borders etc.
	///
	/// See also:
	///
	/// * [MaterialBasedCupertinoThemeData], a [CupertinoThemeData] that defers
	/// [primaryColor] to its Material [Theme] parent if it's unspecified.
	Color get primaryColor => _primaryColor ?? _defaults.primaryColor;
	final Color _primaryColor;

	/// A color that must be easy to see when rendered on a [primaryColor] background.
	///
	/// For example, this color is used for a [CupertinoButton]'s text and icons
	/// when the button's background is [primaryColor].
	///
	/// If coming from a Material [Theme] and unspecified, [primaryContrastingColor]
	/// will be derived from the Material [ThemeData]'s `colorScheme.onPrimary`.
	///
	/// See also:
	///
	/// * [MaterialBasedCupertinoThemeData], a [CupertinoThemeData] that defers
	/// [primaryContrastingColor] to its Material [Theme] parent if it's unspecified.
	Color get primaryContrastingColor => _primaryContrastingColor ?? _defaults.primaryContrastingColor;
	final Color _primaryContrastingColor;

	/// Text styles used by Cupertino widgets.
	///
	/// Derived from [primaryColor] if unspecified.
	CupertinoTextThemeData get textTheme {
	return _textTheme ?? _defaults.textThemeDefaults.createDefaults(primaryColor: primaryColor);
	}
	final CupertinoTextThemeData _textTheme;

	/// Background color of the top nav bar and bottom tab bar.
	///
	/// Defaults to a light gray in light mode, or a dark translucent gray color in
	/// dark mode.
	Color get barBackgroundColor => _barBackgroundColor ?? _defaults.barBackgroundColor;
	final Color _barBackgroundColor;

	/// Background color of the scaffold.
	///
	/// Defaults to [CupertinoColors.systemBackground].
	Color get scaffoldBackgroundColor => _scaffoldBackgroundColor ?? _defaults.scaffoldBackgroundColor;
	final Color _scaffoldBackgroundColor;

	/// Returns an instance of the [CupertinoThemeData] whose property getters
	/// only return the construction time specifications with no derived values.
	///
	/// Used in Material themes to let unspecified properties fallback to Material
	/// theme properties instead of iOS defaults.
	CupertinoThemeData noDefault() {
	return _NoDefaultCupertinoThemeData(
	brightness,
	_primaryColor,
	_primaryContrastingColor,
	_textTheme,
	_barBackgroundColor,
	_scaffoldBackgroundColor,
	);
	}

	/// Returns a new `CupertinoThemeData` with all its colors resolved against the
	/// given [BuildContext].
	///
	/// Called by [CupertinoTheme.of] to resolve colors defined in the retrieved
	/// [CupertinoThemeData].
	@protected
	CupertinoThemeData resolveFrom(BuildContext context, { bool nullOk = false }) {
	Color convertColor(Color color) => CupertinoDynamicColor.resolve(color, context, nullOk: nullOk);

	return CupertinoThemeData._rawWithDefaults(
	brightness,
	convertColor(_primaryColor),
	convertColor(_primaryContrastingColor),
	_textTheme?.resolveFrom(context, nullOk: nullOk),
	convertColor(_barBackgroundColor),
	convertColor(_scaffoldBackgroundColor),
	_defaults.resolveFrom(context, _textTheme == null, nullOk: nullOk),
	);
	}

	/// Creates a copy of [CupertinoThemeData] with specified attributes overridden.
	///
	/// Only the current instance's specified attributes are copied instead of
	/// derived values. For instance, if the current [CupertinoThemeData.textTheme]
	/// is implied from the current [primaryColor] because it was not specified,
	/// copying with a different [primaryColor] will also change the copy's implied
	/// [textTheme].
	CupertinoThemeData copyWith({
	Brightness brightness,
	Color primaryColor,
	Color primaryContrastingColor,
	CupertinoTextThemeData textTheme,
	Color barBackgroundColor,
	Color scaffoldBackgroundColor,
	}) {
	return CupertinoThemeData._rawWithDefaults(
	brightness ?? this.brightness,
	primaryColor ?? _primaryColor,
	primaryContrastingColor ?? _primaryContrastingColor,
	textTheme ?? _textTheme,
	barBackgroundColor ?? _barBackgroundColor,
	scaffoldBackgroundColor ?? _scaffoldBackgroundColor,
	_defaults,
	);
	}

	@override
	void debugFillProperties(DiagnosticPropertiesBuilder properties) {
	super.debugFillProperties(properties);
	const CupertinoThemeData defaultData = CupertinoThemeData();
	properties.add(EnumProperty<Brightness>('brightness', brightness, defaultValue: null));
	properties.add(createCupertinoColorProperty('primaryColor', primaryColor, defaultValue: defaultData.primaryColor));
	properties.add(createCupertinoColorProperty('primaryContrastingColor', primaryContrastingColor, defaultValue: defaultData.primaryContrastingColor));
	properties.add(createCupertinoColorProperty('barBackgroundColor', barBackgroundColor, defaultValue: defaultData.barBackgroundColor));
	properties.add(createCupertinoColorProperty('scaffoldBackgroundColor', scaffoldBackgroundColor, defaultValue: defaultData.scaffoldBackgroundColor));
	textTheme.debugFillProperties(properties);
	}
	}

	class _NoDefaultCupertinoThemeData extends CupertinoThemeData {
	const _NoDefaultCupertinoThemeData(
	Brightness brightness,
	this.primaryColor,
	this.primaryContrastingColor,
	this.textTheme,
	this.barBackgroundColor,
	this.scaffoldBackgroundColor,
	) : super._rawWithDefaults(
	brightness,
	primaryColor,
	primaryContrastingColor,
	textTheme,
	barBackgroundColor,
	scaffoldBackgroundColor,
	null,
	);

	@override
	final Color primaryColor;
	@override
	final Color primaryContrastingColor;
	@override
	final CupertinoTextThemeData textTheme;
	@override
	final Color barBackgroundColor;
	@override
	final Color scaffoldBackgroundColor;

	@override
	_NoDefaultCupertinoThemeData resolveFrom(BuildContext context, { bool nullOk = false }) {
	Color convertColor(Color color) => CupertinoDynamicColor.resolve(color, context, nullOk: nullOk);

	return _NoDefaultCupertinoThemeData(
	brightness,
	convertColor(primaryColor),
	convertColor(primaryContrastingColor),
	textTheme?.resolveFrom(context, nullOk: nullOk),
	convertColor(barBackgroundColor),
	convertColor(scaffoldBackgroundColor),
	);
	}

	@override
	CupertinoThemeData copyWith({
	Brightness brightness,
	Color primaryColor,
	Color primaryContrastingColor,
	CupertinoTextThemeData textTheme,
	Color barBackgroundColor ,
	Color scaffoldBackgroundColor,
	}) {
	return _NoDefaultCupertinoThemeData(
	brightness ?? this.brightness,
	primaryColor ?? this.primaryColor,
	primaryContrastingColor ?? this.primaryContrastingColor,
	textTheme ?? this.textTheme,
	barBackgroundColor ?? this.barBackgroundColor,
	scaffoldBackgroundColor ?? this.scaffoldBackgroundColor,
	);
	}
	}

	@immutable
	class _CupertinoThemeDefaults {
	const _CupertinoThemeDefaults(
	this.brightness,
	this.primaryColor,
	this.primaryContrastingColor,
	this.barBackgroundColor,
	this.scaffoldBackgroundColor,
	this.textThemeDefaults,
	);

	final Brightness brightness;
	final Color primaryColor;
	final Color primaryContrastingColor;
	final Color barBackgroundColor;
	final Color scaffoldBackgroundColor;
	final _CupertinoTextThemeDefaults textThemeDefaults;

	_CupertinoThemeDefaults resolveFrom(BuildContext context, bool resolveTextTheme, { @required bool nullOk }) {
	assert(nullOk != null);
	Color convertColor(Color color) => CupertinoDynamicColor.resolve(color, context, nullOk: nullOk);

	return _CupertinoThemeDefaults(
	brightness,
	convertColor(primaryColor),
	convertColor(primaryContrastingColor),
	convertColor(barBackgroundColor),
	convertColor(scaffoldBackgroundColor),
	resolveTextTheme ? textThemeDefaults?.resolveFrom(context, nullOk: nullOk) : textThemeDefaults,
	);
	}
	}

	@immutable
	class _CupertinoTextThemeDefaults {
	const _CupertinoTextThemeDefaults(
	this.labelColor,
	this.inactiveGray,
	);

	final Color labelColor;
	final Color inactiveGray;

	_CupertinoTextThemeDefaults resolveFrom(BuildContext context, { @required bool nullOk }) {
	return _CupertinoTextThemeDefaults(
	CupertinoDynamicColor.resolve(labelColor, context, nullOk: nullOk),
	CupertinoDynamicColor.resolve(inactiveGray, context, nullOk: nullOk),
	);
	}

	CupertinoTextThemeData createDefaults({ @required Color primaryColor }) {
	assert(primaryColor != null);
	return _DefaultCupertinoTextThemeData(
	primaryColor: primaryColor,
	labelColor: labelColor,
	inactiveGray: inactiveGray,
	);
	}
	}

	// CupertinoTextThemeData with no text styles explicitly specified.
	// The implementation of this class may need to be updated when any of the default
	// text styles changes.
	class _DefaultCupertinoTextThemeData extends CupertinoTextThemeData {
	const _DefaultCupertinoTextThemeData({
	@required this.labelColor,
	@required this.inactiveGray,
	@required Color primaryColor,
	}) : assert(labelColor != null),
	assert(inactiveGray != null),
	assert(primaryColor != null),
	super(primaryColor: primaryColor);

	final Color labelColor;
	final Color inactiveGray;

	@override
	TextStyle get textStyle => super.textStyle.copyWith(color: labelColor);

	@override
	TextStyle get tabLabelTextStyle => super.tabLabelTextStyle.copyWith(color: inactiveGray);

	@override
	TextStyle get navTitleTextStyle => super.navTitleTextStyle.copyWith(color: labelColor);

	@override
	TextStyle get navLargeTitleTextStyle => super.navLargeTitleTextStyle.copyWith(color: labelColor);

	@override
	TextStyle get pickerTextStyle => super.pickerTextStyle.copyWith(color: labelColor);

	@override
	TextStyle get dateTimePickerTextStyle => super.dateTimePickerTextStyle.copyWith(color: labelColor);
	}