| // 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 Color, lerpDouble, hashValues; |
| |
| import 'package:flutter/foundation.dart'; |
| |
| double _getHue(double red, double green, double blue, double max, double delta) { |
| double hue; |
| if (max == 0.0) { |
| hue = 0.0; |
| } else if (max == red) { |
| hue = 60.0 * (((green - blue) / delta) % 6); |
| } else if (max == green) { |
| hue = 60.0 * (((blue - red) / delta) + 2); |
| } else if (max == blue) { |
| hue = 60.0 * (((red - green) / delta) + 4); |
| } |
| |
| /// Set hue to 0.0 when red == green == blue. |
| hue = hue.isNaN ? 0.0 : hue; |
| return hue; |
| } |
| |
| Color _colorFromHue( |
| double alpha, |
| double hue, |
| double chroma, |
| double secondary, |
| double match, |
| ) { |
| double red; |
| double green; |
| double blue; |
| if (hue < 60.0) { |
| red = chroma; |
| green = secondary; |
| blue = 0.0; |
| } else if (hue < 120.0) { |
| red = secondary; |
| green = chroma; |
| blue = 0.0; |
| } else if (hue < 180.0) { |
| red = 0.0; |
| green = chroma; |
| blue = secondary; |
| } else if (hue < 240.0) { |
| red = 0.0; |
| green = secondary; |
| blue = chroma; |
| } else if (hue < 300.0) { |
| red = secondary; |
| green = 0.0; |
| blue = chroma; |
| } else { |
| red = chroma; |
| green = 0.0; |
| blue = secondary; |
| } |
| return Color.fromARGB((alpha * 0xFF).round(), ((red + match) * 0xFF).round(), ((green + match) * 0xFF).round(), ((blue + match) * 0xFF).round()); |
| } |
| |
| /// A color represented using [alpha], [hue], [saturation], and [value]. |
| /// |
| /// An [HSVColor] is represented in a parameter space that's based on human |
| /// perception of color in pigments (e.g. paint and printer's ink). The |
| /// representation is useful for some color computations (e.g. rotating the hue |
| /// through the colors), because interpolation and picking of |
| /// colors as red, green, and blue channels doesn't always produce intuitive |
| /// results. |
| /// |
| /// The HSV color space models the way that different pigments are perceived |
| /// when mixed. The hue describes which pigment is used, the saturation |
| /// describes which shade of the pigment, and the value resembles mixing the |
| /// pigment with different amounts of black or white pigment. |
| /// |
| /// See also: |
| /// |
| /// * [HSLColor], a color that uses a color space based on human perception of |
| /// colored light. |
| /// * [HSV and HSL](https://en.wikipedia.org/wiki/HSL_and_HSV) Wikipedia |
| /// article, which this implementation is based upon. |
| @immutable |
| class HSVColor { |
| /// Creates a color. |
| /// |
| /// All the arguments must not be null and be in their respective ranges. See |
| /// the fields for each parameter for a description of their ranges. |
| const HSVColor.fromAHSV(this.alpha, this.hue, this.saturation, this.value) |
| : assert(alpha != null), |
| assert(hue != null), |
| assert(saturation != null), |
| assert(value != null), |
| assert(alpha >= 0.0), |
| assert(alpha <= 1.0), |
| assert(hue >= 0.0), |
| assert(hue <= 360.0), |
| assert(saturation >= 0.0), |
| assert(saturation <= 1.0), |
| assert(value >= 0.0), |
| assert(value <= 1.0); |
| |
| /// Creates an [HSVColor] from an RGB [Color]. |
| /// |
| /// This constructor does not necessarily round-trip with [toColor] because |
| /// of floating point imprecision. |
| factory HSVColor.fromColor(Color color) { |
| final double red = color.red / 0xFF; |
| final double green = color.green / 0xFF; |
| final double blue = color.blue / 0xFF; |
| |
| final double max = math.max(red, math.max(green, blue)); |
| final double min = math.min(red, math.min(green, blue)); |
| final double delta = max - min; |
| |
| final double alpha = color.alpha / 0xFF; |
| final double hue = _getHue(red, green, blue, max, delta); |
| final double saturation = max == 0.0 ? 0.0 : delta / max; |
| |
| return HSVColor.fromAHSV(alpha, hue, saturation, max); |
| } |
| |
| /// Alpha, from 0.0 to 1.0. The describes the transparency of the color. |
| /// A value of 0.0 is fully transparent, and 1.0 is fully opaque. |
| final double alpha; |
| |
| /// Hue, from 0.0 to 360.0. Describes which color of the spectrum is |
| /// represented. A value of 0.0 represents red, as does 360.0. Values in |
| /// between go through all the hues representable in RGB. You can think of |
| /// this as selecting which pigment will be added to a color. |
| final double hue; |
| |
| /// Saturation, from 0.0 to 1.0. This describes how colorful the color is. |
| /// 0.0 implies a shade of grey (i.e. no pigment), and 1.0 implies a color as |
| /// vibrant as that hue gets. You can think of this as the equivalent of |
| /// how much of a pigment is added. |
| final double saturation; |
| |
| /// Value, from 0.0 to 1.0. The "value" of a color that, in this context, |
| /// describes how bright a color is. A value of 0.0 indicates black, and 1.0 |
| /// indicates full intensity color. You can think of this as the equivalent of |
| /// removing black from the color as value increases. |
| final double value; |
| |
| /// Returns a copy of this color with the [alpha] parameter replaced with the |
| /// given value. |
| HSVColor withAlpha(double alpha) { |
| return HSVColor.fromAHSV(alpha, hue, saturation, value); |
| } |
| |
| /// Returns a copy of this color with the [hue] parameter replaced with the |
| /// given value. |
| HSVColor withHue(double hue) { |
| return HSVColor.fromAHSV(alpha, hue, saturation, value); |
| } |
| |
| /// Returns a copy of this color with the [saturation] parameter replaced with |
| /// the given value. |
| HSVColor withSaturation(double saturation) { |
| return HSVColor.fromAHSV(alpha, hue, saturation, value); |
| } |
| |
| /// Returns a copy of this color with the [value] parameter replaced with the |
| /// given value. |
| HSVColor withValue(double value) { |
| return HSVColor.fromAHSV(alpha, hue, saturation, value); |
| } |
| |
| /// Returns this color in RGB. |
| Color toColor() { |
| final double chroma = saturation * value; |
| final double secondary = chroma * (1.0 - (((hue / 60.0) % 2.0) - 1.0).abs()); |
| final double match = value - chroma; |
| |
| return _colorFromHue(alpha, hue, chroma, secondary, match); |
| } |
| |
| HSVColor _scaleAlpha(double factor) { |
| return withAlpha(alpha * factor); |
| } |
| |
| /// Linearly interpolate between two HSVColors. |
| /// |
| /// The colors are interpolated by interpolating the [alpha], [hue], |
| /// [saturation], and [value] channels separately, which usually leads to a |
| /// more pleasing effect than [Color.lerp] (which interpolates the red, green, |
| /// and blue channels separately). |
| /// |
| /// If either color is null, this function linearly interpolates from a |
| /// transparent instance of the other color. This is usually preferable to |
| /// interpolating from [Colors.transparent] (`const Color(0x00000000)`) since |
| /// that will interpolate from a transparent red and cycle through the hues to |
| /// match the target color, regardless of what that color's hue is. |
| /// |
| /// {@macro dart.ui.shadow.lerp} |
| /// |
| /// Values outside of the valid range for each channel will be clamped. |
| static HSVColor lerp(HSVColor a, HSVColor b, double t) { |
| assert(t != null); |
| if (a == null && b == null) |
| return null; |
| if (a == null) |
| return b._scaleAlpha(t); |
| if (b == null) |
| return a._scaleAlpha(1.0 - t); |
| return HSVColor.fromAHSV( |
| lerpDouble(a.alpha, b.alpha, t).clamp(0.0, 1.0) as double, |
| lerpDouble(a.hue, b.hue, t) % 360.0, |
| lerpDouble(a.saturation, b.saturation, t).clamp(0.0, 1.0) as double, |
| lerpDouble(a.value, b.value, t).clamp(0.0, 1.0) as double, |
| ); |
| } |
| |
| @override |
| bool operator ==(Object other) { |
| if (identical(this, other)) |
| return true; |
| return other is HSVColor |
| && other.alpha == alpha |
| && other.hue == hue |
| && other.saturation == saturation |
| && other.value == value; |
| } |
| |
| @override |
| int get hashCode => hashValues(alpha, hue, saturation, value); |
| |
| @override |
| String toString() => '${objectRuntimeType(this, 'HSVColor')}($alpha, $hue, $saturation, $value)'; |
| } |
| |
| /// A color represented using [alpha], [hue], [saturation], and [lightness]. |
| /// |
| /// An [HSLColor] is represented in a parameter space that's based up human |
| /// perception of colored light. The representation is useful for some color |
| /// computations (e.g., combining colors of light), because interpolation and |
| /// picking of colors as red, green, and blue channels doesn't always produce |
| /// intuitive results. |
| /// |
| /// HSL is a perceptual color model, placing fully saturated colors around a |
| /// circle (conceptually) at a lightness of ​0.5, with a lightness of 0.0 being |
| /// completely black, and a lightness of 1.0 being completely white. As the |
| /// lightness increases or decreases from 0.5, the apparent saturation decreases |
| /// proportionally (even though the [saturation] parameter hasn't changed). |
| /// |
| /// See also: |
| /// |
| /// * [HSVColor], a color that uses a color space based on human perception of |
| /// pigments (e.g. paint and printer's ink). |
| /// * [HSV and HSL](https://en.wikipedia.org/wiki/HSL_and_HSV) Wikipedia |
| /// article, which this implementation is based upon. |
| @immutable |
| class HSLColor { |
| /// Creates a color. |
| /// |
| /// All the arguments must not be null and be in their respective ranges. See |
| /// the fields for each parameter for a description of their ranges. |
| const HSLColor.fromAHSL(this.alpha, this.hue, this.saturation, this.lightness) |
| : assert(alpha != null), |
| assert(hue != null), |
| assert(saturation != null), |
| assert(lightness != null), |
| assert(alpha >= 0.0), |
| assert(alpha <= 1.0), |
| assert(hue >= 0.0), |
| assert(hue <= 360.0), |
| assert(saturation >= 0.0), |
| assert(saturation <= 1.0), |
| assert(lightness >= 0.0), |
| assert(lightness <= 1.0); |
| |
| /// Creates an [HSLColor] from an RGB [Color]. |
| /// |
| /// This constructor does not necessarily round-trip with [toColor] because |
| /// of floating point imprecision. |
| factory HSLColor.fromColor(Color color) { |
| final double red = color.red / 0xFF; |
| final double green = color.green / 0xFF; |
| final double blue = color.blue / 0xFF; |
| |
| final double max = math.max(red, math.max(green, blue)); |
| final double min = math.min(red, math.min(green, blue)); |
| final double delta = max - min; |
| |
| final double alpha = color.alpha / 0xFF; |
| final double hue = _getHue(red, green, blue, max, delta); |
| final double lightness = (max + min) / 2.0; |
| // Saturation can exceed 1.0 with rounding errors, so clamp it. |
| final double saturation = lightness == 1.0 |
| ? 0.0 |
| : ((delta / (1.0 - (2.0 * lightness - 1.0).abs())).clamp(0.0, 1.0) as double); |
| return HSLColor.fromAHSL(alpha, hue, saturation, lightness); |
| } |
| |
| /// Alpha, from 0.0 to 1.0. The describes the transparency of the color. |
| /// A value of 0.0 is fully transparent, and 1.0 is fully opaque. |
| final double alpha; |
| |
| /// Hue, from 0.0 to 360.0. Describes which color of the spectrum is |
| /// represented. A value of 0.0 represents red, as does 360.0. Values in |
| /// between go through all the hues representable in RGB. You can think of |
| /// this as selecting which color filter is placed over a light. |
| final double hue; |
| |
| /// Saturation, from 0.0 to 1.0. This describes how colorful the color is. |
| /// 0.0 implies a shade of grey (i.e. no pigment), and 1.0 implies a color as |
| /// vibrant as that hue gets. You can think of this as the purity of the |
| /// color filter over the light. |
| final double saturation; |
| |
| /// Lightness, from 0.0 to 1.0. The lightness of a color describes how bright |
| /// a color is. A value of 0.0 indicates black, and 1.0 indicates white. You |
| /// can think of this as the intensity of the light behind the filter. As the |
| /// lightness approaches 0.5, the colors get brighter and appear more |
| /// saturated, and over 0.5, the colors start to become less saturated and |
| /// approach white at 1.0. |
| final double lightness; |
| |
| /// Returns a copy of this color with the alpha parameter replaced with the |
| /// given value. |
| HSLColor withAlpha(double alpha) { |
| return HSLColor.fromAHSL(alpha, hue, saturation, lightness); |
| } |
| |
| /// Returns a copy of this color with the [hue] parameter replaced with the |
| /// given value. |
| HSLColor withHue(double hue) { |
| return HSLColor.fromAHSL(alpha, hue, saturation, lightness); |
| } |
| |
| /// Returns a copy of this color with the [saturation] parameter replaced with |
| /// the given value. |
| HSLColor withSaturation(double saturation) { |
| return HSLColor.fromAHSL(alpha, hue, saturation, lightness); |
| } |
| |
| /// Returns a copy of this color with the [lightness] parameter replaced with |
| /// the given value. |
| HSLColor withLightness(double lightness) { |
| return HSLColor.fromAHSL(alpha, hue, saturation, lightness); |
| } |
| |
| /// Returns this HSL color in RGB. |
| Color toColor() { |
| final double chroma = (1.0 - (2.0 * lightness - 1.0).abs()) * saturation; |
| final double secondary = chroma * (1.0 - (((hue / 60.0) % 2.0) - 1.0).abs()); |
| final double match = lightness - chroma / 2.0; |
| |
| return _colorFromHue(alpha, hue, chroma, secondary, match); |
| } |
| |
| HSLColor _scaleAlpha(double factor) { |
| return withAlpha(alpha * factor); |
| } |
| |
| /// Linearly interpolate between two HSLColors. |
| /// |
| /// The colors are interpolated by interpolating the [alpha], [hue], |
| /// [saturation], and [lightness] channels separately, which usually leads to |
| /// a more pleasing effect than [Color.lerp] (which interpolates the red, |
| /// green, and blue channels separately). |
| /// |
| /// If either color is null, this function linearly interpolates from a |
| /// transparent instance of the other color. This is usually preferable to |
| /// interpolating from [Colors.transparent] (`const Color(0x00000000)`) since |
| /// that will interpolate from a transparent red and cycle through the hues to |
| /// match the target color, regardless of what that color's hue is. |
| /// |
| /// The `t` argument represents position on the timeline, with 0.0 meaning |
| /// that the interpolation has not started, returning `a` (or something |
| /// equivalent to `a`), 1.0 meaning that the interpolation has finished, |
| /// returning `b` (or something equivalent to `b`), and values between them |
| /// meaning that the interpolation is at the relevant point on the timeline |
| /// between `a` and `b`. The interpolation can be extrapolated beyond 0.0 and |
| /// 1.0, so negative values and values greater than 1.0 are valid |
| /// (and can easily be generated by curves such as [Curves.elasticInOut]). |
| /// |
| /// Values outside of the valid range for each channel will be clamped. |
| /// |
| /// Values for `t` are usually obtained from an [Animation<double>], such as |
| /// an [AnimationController]. |
| static HSLColor lerp(HSLColor a, HSLColor b, double t) { |
| assert(t != null); |
| if (a == null && b == null) |
| return null; |
| if (a == null) |
| return b._scaleAlpha(t); |
| if (b == null) |
| return a._scaleAlpha(1.0 - t); |
| return HSLColor.fromAHSL( |
| lerpDouble(a.alpha, b.alpha, t).clamp(0.0, 1.0) as double, |
| lerpDouble(a.hue, b.hue, t) % 360.0, |
| lerpDouble(a.saturation, b.saturation, t).clamp(0.0, 1.0) as double, |
| lerpDouble(a.lightness, b.lightness, t).clamp(0.0, 1.0) as double, |
| ); |
| } |
| |
| @override |
| bool operator ==(Object other) { |
| if (identical(this, other)) |
| return true; |
| return other is HSLColor |
| && other.alpha == alpha |
| && other.hue == hue |
| && other.saturation == saturation |
| && other.lightness == lightness; |
| } |
| |
| @override |
| int get hashCode => hashValues(alpha, hue, saturation, lightness); |
| |
| @override |
| String toString() => '${objectRuntimeType(this, 'HSLColor')}($alpha, $hue, $saturation, $lightness)'; |
| } |
| |
| /// A color that has a small table of related colors called a "swatch". |
| /// |
| /// The table is indexed by values of type `T`. |
| /// |
| /// See also: |
| /// |
| /// * [MaterialColor] and [MaterialAccentColor], which define material design |
| /// primary and accent color swatches. |
| /// * [material.Colors], which defines all of the standard material design |
| /// colors. |
| class ColorSwatch<T> extends Color { |
| /// Creates a color that has a small table of related colors called a "swatch". |
| /// |
| /// The `primary` argument should be the 32 bit ARGB value of one of the |
| /// values in the swatch, as would be passed to the [new Color] constructor |
| /// for that same color, and as is exposed by [value]. (This is distinct from |
| /// the specific index of the color in the swatch.) |
| const ColorSwatch(int primary, this._swatch) : super(primary); |
| |
| @protected |
| final Map<T, Color> _swatch; |
| |
| /// Returns an element of the swatch table. |
| Color operator [](T index) => _swatch[index]; |
| |
| @override |
| bool operator ==(Object other) { |
| if (identical(this, other)) |
| return true; |
| if (other.runtimeType != runtimeType) |
| return false; |
| return super == other |
| && other is ColorSwatch<T> |
| && other._swatch == _swatch; |
| } |
| |
| @override |
| int get hashCode => hashValues(runtimeType, value, _swatch); |
| |
| @override |
| String toString() => '${objectRuntimeType(this, 'ColorSwatch')}(primary value: ${super.toString()})'; |
| } |
| |
| /// [DiagnosticsProperty] that has an [Color] as value. |
| class ColorProperty extends DiagnosticsProperty<Color> { |
| /// Create a diagnostics property for [Color]. |
| /// |
| /// The [showName], [style], and [level] arguments must not be null. |
| ColorProperty( |
| String name, |
| Color value, { |
| bool showName = true, |
| Object defaultValue = kNoDefaultValue, |
| DiagnosticsTreeStyle style = DiagnosticsTreeStyle.singleLine, |
| DiagnosticLevel level = DiagnosticLevel.info, |
| }) : assert(showName != null), |
| assert(style != null), |
| assert(level != null), |
| super(name, value, |
| defaultValue: defaultValue, |
| showName: showName, |
| style: style, |
| level: level, |
| ); |
| |
| @override |
| Map<String, Object> toJsonMap(DiagnosticsSerializationDelegate delegate) { |
| final Map<String, Object> json = super.toJsonMap(delegate); |
| if (value != null) { |
| json['valueProperties'] = <String, Object>{ |
| 'red': value.red, |
| 'green': value.green, |
| 'blue': value.blue, |
| 'alpha': value.alpha, |
| }; |
| } |
| return json; |
| } |
| } |