packages/flutter/lib/src/material/color_scheme.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' show Brightness;
 import 'package:flutter/widgets.dart';

 import 'colors.dart';
 import 'theme_data.dart';

 /// A set of twelve colors based on the
 /// [Material spec](https://material.io/design/color/the-color-system.html)
 /// that can be used to configure the color properties of most components.
 ///
 /// The [Theme] has a color scheme, [ThemeData.colorScheme], which is constructed
 /// with [ColorScheme.fromSwatch].
 @immutable
 class ColorScheme with Diagnosticable {
   /// Create a ColorScheme instance.
   const ColorScheme({
     @required this.primary,
     @required this.primaryVariant,
     @required this.secondary,
     @required this.secondaryVariant,
     @required this.surface,
     @required this.background,
     @required this.error,
     @required this.onPrimary,
     @required this.onSecondary,
     @required this.onSurface,
     @required this.onBackground,
     @required this.onError,
     @required this.brightness,
   }) : assert(primary != null),
        assert(primaryVariant != null),
        assert(secondary != null),
        assert(secondaryVariant != null),
        assert(surface != null),
        assert(background != null),
        assert(error != null),
        assert(onPrimary != null),
        assert(onSecondary != null),
        assert(onSurface != null),
        assert(onBackground != null),
        assert(onError != null),
        assert(brightness != null);

   /// Create a ColorScheme based on a purple primary color that matches the
   /// [baseline Material color scheme](https://material.io/design/color/the-color-system.html#color-theme-creation).
   const ColorScheme.light({
     this.primary = const Color(0xff6200ee),
     this.primaryVariant = const Color(0xff3700b3),
     this.secondary = const Color(0xff03dac6),
     this.secondaryVariant = const Color(0xff018786),
     this.surface = Colors.white,
     this.background = Colors.white,
     this.error = const Color(0xffb00020),
     this.onPrimary = Colors.white,
     this.onSecondary = Colors.black,
     this.onSurface = Colors.black,
     this.onBackground = Colors.black,
     this.onError = Colors.white,
     this.brightness = Brightness.light,
   }) : assert(primary != null),
        assert(primaryVariant != null),
        assert(secondary != null),
        assert(secondaryVariant != null),
        assert(surface != null),
        assert(background != null),
        assert(error != null),
        assert(onPrimary != null),
        assert(onSecondary != null),
        assert(onSurface != null),
        assert(onBackground != null),
        assert(onError != null),
        assert(brightness != null);

   /// Create the recommended dark color scheme that matches the
   /// [baseline Material color scheme](https://material.io/design/color/dark-theme.html#ui-application).
   const ColorScheme.dark({
     this.primary = const Color(0xffbb86fc),
     this.primaryVariant = const Color(0xff3700B3),
     this.secondary = const Color(0xff03dac6),
     this.secondaryVariant = const Color(0xff03dac6),
     this.surface = const Color(0xff121212),
     this.background = const Color(0xff121212),
     this.error = const Color(0xffcf6679),
     this.onPrimary = Colors.black,
     this.onSecondary = Colors.black,
     this.onSurface = Colors.white,
     this.onBackground = Colors.white,
     this.onError = Colors.black,
     this.brightness = Brightness.dark,
   }) : assert(primary != null),
        assert(primaryVariant != null),
        assert(secondary != null),
        assert(secondaryVariant != null),
        assert(surface != null),
        assert(background != null),
        assert(error != null),
        assert(onPrimary != null),
        assert(onSecondary != null),
        assert(onSurface != null),
        assert(onBackground != null),
        assert(onError != null),
        assert(brightness != null);

   /// Create a color scheme from a [MaterialColor] swatch.
   ///
   /// This constructor is used by [ThemeData] to create its default
   /// color scheme.
   factory ColorScheme.fromSwatch({
     MaterialColor primarySwatch = Colors.blue,
     Color primaryColorDark,
     Color accentColor,
     Color cardColor,
     Color backgroundColor,
     Color errorColor,
     Brightness brightness = Brightness.light,
   }) {
     assert(primarySwatch != null);
     assert(brightness != null);

     final bool isDark = brightness == Brightness.dark;
     final bool primaryIsDark = _brightnessFor(primarySwatch) == Brightness.dark;
     final Color secondary = accentColor ?? (isDark ? Colors.tealAccent[200] : primarySwatch);
     final bool secondaryIsDark = _brightnessFor(secondary) == Brightness.dark;

     return ColorScheme(
       primary: primarySwatch,
       primaryVariant: primaryColorDark ?? (isDark ? Colors.black : primarySwatch[700]),
       secondary: secondary,
       secondaryVariant: isDark ? Colors.tealAccent[700] : primarySwatch[700],
       surface: cardColor ?? (isDark ? Colors.grey[800] : Colors.white),
       background: backgroundColor ?? (isDark ? Colors.grey[700] : primarySwatch[200]),
       error: errorColor ?? Colors.red[700],
       onPrimary: primaryIsDark ? Colors.white : Colors.black,
       onSecondary: secondaryIsDark ? Colors.white : Colors.black,
       onSurface: isDark ? Colors.white : Colors.black,
       onBackground: primaryIsDark ? Colors.white : Colors.black,
       onError: isDark ? Colors.black : Colors.white,
       brightness: brightness,
     );
   }

   static Brightness _brightnessFor(Color color) => ThemeData.estimateBrightnessForColor(color);

   /// The color displayed most frequently across your app’s screens and components.
   final Color primary;

   /// A darker version of the primary color.
   final Color primaryVariant;

   /// An accent color that, when used sparingly, calls attention to parts
   /// of your app.
   final Color secondary;

   /// A darker version of the secondary color.
   final Color secondaryVariant;

   /// The background color for widgets like [Card].
   final Color surface;

   /// A color that typically appears behind scrollable content.
   final Color background;

   /// The color to use for input validation errors, e.g. for
   /// [InputDecoration.errorText].
   final Color error;

   /// A color that's clearly legible when drawn on [primary].
   ///
   /// To ensure that an app is accessible, a contrast ratio of 4.5:1 for [primary]
   /// and [onPrimary] is recommended. See
   /// <https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html>.
   final Color onPrimary;

   /// A color that's clearly legible when drawn on [secondary].
   ///
   /// To ensure that an app is accessible, a contrast ratio of 4.5:1 for [secondary]
   /// and [onSecondary] is recommended. See
   /// <https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html>.
   final Color onSecondary;

   /// A color that's clearly legible when drawn on [surface].
   ///
   /// To ensure that an app is accessible, a contrast ratio of 4.5:1 for [surface]
   /// and [onSurface] is recommended. See
   /// <https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html>.
   final Color onSurface;

   /// A color that's clearly legible when drawn on [background].
   ///
   /// To ensure that an app is accessible, a contrast ratio of 4.5:1 for [background]
   /// and [onBackground] is recommended. See
   /// <https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html>.
   final Color onBackground;

   /// A color that's clearly legible when drawn on [error].
   ///
   /// To ensure that an app is accessible, a contrast ratio of 4.5:1 for [error]
   /// and [onError] is recommended. See
   /// <https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html>.
   final Color onError;

   /// The overall brightness of this color scheme.
   final Brightness brightness;

   /// Creates a copy of this color scheme with the given fields
   /// replaced by the non-null parameter values.
   ColorScheme copyWith({
     Color primary,
     Color primaryVariant,
     Color secondary,
     Color secondaryVariant,
     Color surface,
     Color background,
     Color error,
     Color onPrimary,
     Color onSecondary,
     Color onSurface,
     Color onBackground,
     Color onError,
     Brightness brightness,
   }) {
     return ColorScheme(
       primary: primary ?? this.primary,
       primaryVariant: primaryVariant ?? this.primaryVariant,
       secondary: secondary ?? this.secondary,
       secondaryVariant: secondaryVariant ?? this.secondaryVariant,
       surface: surface ?? this.surface,
       background: background ?? this.background,
       error: error ?? this.error,
       onPrimary: onPrimary ?? this.onPrimary,
       onSecondary: onSecondary ?? this.onSecondary,
       onSurface: onSurface ?? this.onSurface,
       onBackground: onBackground ?? this.onBackground,
       onError: onError ?? this.onError,
       brightness: brightness ?? this.brightness,
     );
   }

   /// Linearly interpolate between two [ColorScheme] objects.
   ///
   /// {@macro flutter.material.themeData.lerp}
   static ColorScheme lerp(ColorScheme a, ColorScheme b, double t) {
     return ColorScheme(
       primary: Color.lerp(a.primary, b.primary, t),
       primaryVariant: Color.lerp(a.primaryVariant, b.primaryVariant, t),
       secondary: Color.lerp(a.secondary, b.secondary, t),
       secondaryVariant: Color.lerp(a.secondaryVariant, b.secondaryVariant, t),
       surface: Color.lerp(a.surface, b.surface, t),
       background: Color.lerp(a.background, b.background, t),
       error: Color.lerp(a.error, b.error, t),
       onPrimary: Color.lerp(a.onPrimary, b.onPrimary, t),
       onSecondary: Color.lerp(a.onSecondary, b.onSecondary, t),
       onSurface: Color.lerp(a.onSurface, b.onSurface, t),
       onBackground: Color.lerp(a.onBackground, b.onBackground, t),
       onError: Color.lerp(a.onError, b.onError, t),
       brightness: t < 0.5 ? a.brightness : b.brightness,
     );
   }

   @override
   bool operator ==(Object other) {
     if (identical(this, other))
       return true;
     if (other.runtimeType != runtimeType)
       return false;
     return other is ColorScheme
         && other.primary == primary
         && other.primaryVariant == primaryVariant
         && other.secondary == secondary
         && other.secondaryVariant == secondaryVariant
         && other.surface == surface
         && other.background == background
         && other.error == error
         && other.onPrimary == onPrimary
         && other.onSecondary == onSecondary
         && other.onSurface == onSurface
         && other.onBackground == onBackground
         && other.onError == onError
         && other.brightness == brightness;
   }

   @override
   int get hashCode {
     return hashValues(
       primary,
       primaryVariant,
       secondary,
       secondaryVariant,
       surface,
       background,
       error,
       onPrimary,
       onSecondary,
       onSurface,
       onBackground,
       onError,
       brightness,
     );
   }

   @override
   void debugFillProperties(DiagnosticPropertiesBuilder properties) {
     super.debugFillProperties(properties);
     const ColorScheme defaultScheme = ColorScheme.light();
     properties.add(ColorProperty('primary', primary, defaultValue: defaultScheme.primary));
     properties.add(ColorProperty('primaryVariant', primaryVariant, defaultValue: defaultScheme.primaryVariant));
     properties.add(ColorProperty('secondary', secondary, defaultValue: defaultScheme.secondary));
     properties.add(ColorProperty('secondaryVariant', secondaryVariant, defaultValue: defaultScheme.secondaryVariant));
     properties.add(ColorProperty('surface', surface, defaultValue: defaultScheme.surface));
     properties.add(ColorProperty('background', background, defaultValue: defaultScheme.background));
     properties.add(ColorProperty('error', error, defaultValue: defaultScheme.error));
     properties.add(ColorProperty('onPrimary', onPrimary, defaultValue: defaultScheme.onPrimary));
     properties.add(ColorProperty('onSecondary', onSecondary, defaultValue: defaultScheme.onSecondary));
     properties.add(ColorProperty('onSurface', onSurface, defaultValue: defaultScheme.onSurface));
     properties.add(ColorProperty('onBackground', onBackground, defaultValue: defaultScheme.onBackground));
     properties.add(ColorProperty('onError', onError, defaultValue: defaultScheme.onError));
     properties.add(DiagnosticsProperty<Brightness>('brightness', brightness, defaultValue: defaultScheme.brightness));
   }
 }
	// 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' show Brightness;
	import 'package:flutter/widgets.dart';

	import 'colors.dart';
	import 'theme_data.dart';

	/// A set of twelve colors based on the
	/// [Material spec](https://material.io/design/color/the-color-system.html)
	/// that can be used to configure the color properties of most components.
	///
	/// The [Theme] has a color scheme, [ThemeData.colorScheme], which is constructed
	/// with [ColorScheme.fromSwatch].
	@immutable
	class ColorScheme with Diagnosticable {
	/// Create a ColorScheme instance.
	const ColorScheme({
	@required this.primary,
	@required this.primaryVariant,
	@required this.secondary,
	@required this.secondaryVariant,
	@required this.surface,
	@required this.background,
	@required this.error,
	@required this.onPrimary,
	@required this.onSecondary,
	@required this.onSurface,
	@required this.onBackground,
	@required this.onError,
	@required this.brightness,
	}) : assert(primary != null),
	assert(primaryVariant != null),
	assert(secondary != null),
	assert(secondaryVariant != null),
	assert(surface != null),
	assert(background != null),
	assert(error != null),
	assert(onPrimary != null),
	assert(onSecondary != null),
	assert(onSurface != null),
	assert(onBackground != null),
	assert(onError != null),
	assert(brightness != null);

	/// Create a ColorScheme based on a purple primary color that matches the
	/// [baseline Material color scheme](https://material.io/design/color/the-color-system.html#color-theme-creation).
	const ColorScheme.light({
	this.primary = const Color(0xff6200ee),
	this.primaryVariant = const Color(0xff3700b3),
	this.secondary = const Color(0xff03dac6),
	this.secondaryVariant = const Color(0xff018786),
	this.surface = Colors.white,
	this.background = Colors.white,
	this.error = const Color(0xffb00020),
	this.onPrimary = Colors.white,
	this.onSecondary = Colors.black,
	this.onSurface = Colors.black,
	this.onBackground = Colors.black,
	this.onError = Colors.white,
	this.brightness = Brightness.light,
	}) : assert(primary != null),
	assert(primaryVariant != null),
	assert(secondary != null),
	assert(secondaryVariant != null),
	assert(surface != null),
	assert(background != null),
	assert(error != null),
	assert(onPrimary != null),
	assert(onSecondary != null),
	assert(onSurface != null),
	assert(onBackground != null),
	assert(onError != null),
	assert(brightness != null);

	/// Create the recommended dark color scheme that matches the
	/// [baseline Material color scheme](https://material.io/design/color/dark-theme.html#ui-application).
	const ColorScheme.dark({
	this.primary = const Color(0xffbb86fc),
	this.primaryVariant = const Color(0xff3700B3),
	this.secondary = const Color(0xff03dac6),
	this.secondaryVariant = const Color(0xff03dac6),
	this.surface = const Color(0xff121212),
	this.background = const Color(0xff121212),
	this.error = const Color(0xffcf6679),
	this.onPrimary = Colors.black,
	this.onSecondary = Colors.black,
	this.onSurface = Colors.white,
	this.onBackground = Colors.white,
	this.onError = Colors.black,
	this.brightness = Brightness.dark,
	}) : assert(primary != null),
	assert(primaryVariant != null),
	assert(secondary != null),
	assert(secondaryVariant != null),
	assert(surface != null),
	assert(background != null),
	assert(error != null),
	assert(onPrimary != null),
	assert(onSecondary != null),
	assert(onSurface != null),
	assert(onBackground != null),
	assert(onError != null),
	assert(brightness != null);

	/// Create a color scheme from a [MaterialColor] swatch.
	///
	/// This constructor is used by [ThemeData] to create its default
	/// color scheme.
	factory ColorScheme.fromSwatch({
	MaterialColor primarySwatch = Colors.blue,
	Color primaryColorDark,
	Color accentColor,
	Color cardColor,
	Color backgroundColor,
	Color errorColor,
	Brightness brightness = Brightness.light,
	}) {
	assert(primarySwatch != null);
	assert(brightness != null);

	final bool isDark = brightness == Brightness.dark;
	final bool primaryIsDark = _brightnessFor(primarySwatch) == Brightness.dark;
	final Color secondary = accentColor ?? (isDark ? Colors.tealAccent[200] : primarySwatch);
	final bool secondaryIsDark = _brightnessFor(secondary) == Brightness.dark;

	return ColorScheme(
	primary: primarySwatch,
	primaryVariant: primaryColorDark ?? (isDark ? Colors.black : primarySwatch[700]),
	secondary: secondary,
	secondaryVariant: isDark ? Colors.tealAccent[700] : primarySwatch[700],
	surface: cardColor ?? (isDark ? Colors.grey[800] : Colors.white),
	background: backgroundColor ?? (isDark ? Colors.grey[700] : primarySwatch[200]),
	error: errorColor ?? Colors.red[700],
	onPrimary: primaryIsDark ? Colors.white : Colors.black,
	onSecondary: secondaryIsDark ? Colors.white : Colors.black,
	onSurface: isDark ? Colors.white : Colors.black,
	onBackground: primaryIsDark ? Colors.white : Colors.black,
	onError: isDark ? Colors.black : Colors.white,
	brightness: brightness,
	);
	}

	static Brightness _brightnessFor(Color color) => ThemeData.estimateBrightnessForColor(color);

	/// The color displayed most frequently across your app’s screens and components.
	final Color primary;

	/// A darker version of the primary color.
	final Color primaryVariant;

	/// An accent color that, when used sparingly, calls attention to parts
	/// of your app.
	final Color secondary;

	/// A darker version of the secondary color.
	final Color secondaryVariant;

	/// The background color for widgets like [Card].
	final Color surface;

	/// A color that typically appears behind scrollable content.
	final Color background;

	/// The color to use for input validation errors, e.g. for
	/// [InputDecoration.errorText].
	final Color error;

	/// A color that's clearly legible when drawn on [primary].
	///
	/// To ensure that an app is accessible, a contrast ratio of 4.5:1 for [primary]
	/// and [onPrimary] is recommended. See
	/// <https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html>.
	final Color onPrimary;

	/// A color that's clearly legible when drawn on [secondary].
	///
	/// To ensure that an app is accessible, a contrast ratio of 4.5:1 for [secondary]
	/// and [onSecondary] is recommended. See
	/// <https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html>.
	final Color onSecondary;

	/// A color that's clearly legible when drawn on [surface].
	///
	/// To ensure that an app is accessible, a contrast ratio of 4.5:1 for [surface]
	/// and [onSurface] is recommended. See
	/// <https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html>.
	final Color onSurface;

	/// A color that's clearly legible when drawn on [background].
	///
	/// To ensure that an app is accessible, a contrast ratio of 4.5:1 for [background]
	/// and [onBackground] is recommended. See
	/// <https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html>.
	final Color onBackground;

	/// A color that's clearly legible when drawn on [error].
	///
	/// To ensure that an app is accessible, a contrast ratio of 4.5:1 for [error]
	/// and [onError] is recommended. See
	/// <https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html>.
	final Color onError;

	/// The overall brightness of this color scheme.
	final Brightness brightness;

	/// Creates a copy of this color scheme with the given fields
	/// replaced by the non-null parameter values.
	ColorScheme copyWith({
	Color primary,
	Color primaryVariant,
	Color secondary,
	Color secondaryVariant,
	Color surface,
	Color background,
	Color error,
	Color onPrimary,
	Color onSecondary,
	Color onSurface,
	Color onBackground,
	Color onError,
	Brightness brightness,
	}) {
	return ColorScheme(
	primary: primary ?? this.primary,
	primaryVariant: primaryVariant ?? this.primaryVariant,
	secondary: secondary ?? this.secondary,
	secondaryVariant: secondaryVariant ?? this.secondaryVariant,
	surface: surface ?? this.surface,
	background: background ?? this.background,
	error: error ?? this.error,
	onPrimary: onPrimary ?? this.onPrimary,
	onSecondary: onSecondary ?? this.onSecondary,
	onSurface: onSurface ?? this.onSurface,
	onBackground: onBackground ?? this.onBackground,
	onError: onError ?? this.onError,
	brightness: brightness ?? this.brightness,
	);
	}

	/// Linearly interpolate between two [ColorScheme] objects.
	///
	/// {@macro flutter.material.themeData.lerp}
	static ColorScheme lerp(ColorScheme a, ColorScheme b, double t) {
	return ColorScheme(
	primary: Color.lerp(a.primary, b.primary, t),
	primaryVariant: Color.lerp(a.primaryVariant, b.primaryVariant, t),
	secondary: Color.lerp(a.secondary, b.secondary, t),
	secondaryVariant: Color.lerp(a.secondaryVariant, b.secondaryVariant, t),
	surface: Color.lerp(a.surface, b.surface, t),
	background: Color.lerp(a.background, b.background, t),
	error: Color.lerp(a.error, b.error, t),
	onPrimary: Color.lerp(a.onPrimary, b.onPrimary, t),
	onSecondary: Color.lerp(a.onSecondary, b.onSecondary, t),
	onSurface: Color.lerp(a.onSurface, b.onSurface, t),
	onBackground: Color.lerp(a.onBackground, b.onBackground, t),
	onError: Color.lerp(a.onError, b.onError, t),
	brightness: t < 0.5 ? a.brightness : b.brightness,
	);
	}

	@override
	bool operator ==(Object other) {
	if (identical(this, other))
	return true;
	if (other.runtimeType != runtimeType)
	return false;
	return other is ColorScheme
	&& other.primary == primary
	&& other.primaryVariant == primaryVariant
	&& other.secondary == secondary
	&& other.secondaryVariant == secondaryVariant
	&& other.surface == surface
	&& other.background == background
	&& other.error == error
	&& other.onPrimary == onPrimary
	&& other.onSecondary == onSecondary
	&& other.onSurface == onSurface
	&& other.onBackground == onBackground
	&& other.onError == onError
	&& other.brightness == brightness;
	}

	@override
	int get hashCode {
	return hashValues(
	primary,
	primaryVariant,
	secondary,
	secondaryVariant,
	surface,
	background,
	error,
	onPrimary,
	onSecondary,
	onSurface,
	onBackground,
	onError,
	brightness,
	);
	}

	@override
	void debugFillProperties(DiagnosticPropertiesBuilder properties) {
	super.debugFillProperties(properties);
	const ColorScheme defaultScheme = ColorScheme.light();
	properties.add(ColorProperty('primary', primary, defaultValue: defaultScheme.primary));
	properties.add(ColorProperty('primaryVariant', primaryVariant, defaultValue: defaultScheme.primaryVariant));
	properties.add(ColorProperty('secondary', secondary, defaultValue: defaultScheme.secondary));
	properties.add(ColorProperty('secondaryVariant', secondaryVariant, defaultValue: defaultScheme.secondaryVariant));
	properties.add(ColorProperty('surface', surface, defaultValue: defaultScheme.surface));
	properties.add(ColorProperty('background', background, defaultValue: defaultScheme.background));
	properties.add(ColorProperty('error', error, defaultValue: defaultScheme.error));
	properties.add(ColorProperty('onPrimary', onPrimary, defaultValue: defaultScheme.onPrimary));
	properties.add(ColorProperty('onSecondary', onSecondary, defaultValue: defaultScheme.onSecondary));
	properties.add(ColorProperty('onSurface', onSurface, defaultValue: defaultScheme.onSurface));
	properties.add(ColorProperty('onBackground', onBackground, defaultValue: defaultScheme.onBackground));
	properties.add(ColorProperty('onError', onError, defaultValue: defaultScheme.onError));
	properties.add(DiagnosticsProperty<Brightness>('brightness', brightness, defaultValue: defaultScheme.brightness));
	}
	}