flutter_color_models

pub package

A wrapper for the color_models plugin that implements Flutter's Color class.

For use without Flutter, see: https://pub.dev/packages/color_models

Check out flutter_palette, a package for creating, generating, and modifying color palettes.

Usage

import 'package:flutter_color_models/flutter_color_models.dart';

Color Spaces

color_models exposes models for the CMYK, HSI, HSL, HSP, HSB, LAB, RGB, and XYZ color spaces; represented as CmykColor, HsiColor, HslColor, HspColor, HsbColor, LabColor, RgbColor, and XyzColor respectively.

Each model is constant and extends ColorModel.

Creating Colors

Colors can be created by constructing a ColorModel directly, or with the fromList or extrapolate constructors. extrapolate accepts each model's respective values on a 0 to 1 scale, and extrapolates them to their normal scale.

Each model posesses values for each property of their respective acronyms, as well as an optional alpha value.

// Each of the below colors is red at 100% opacity.

// RGB without alpha
RgbColor(255, 0, 0);
RgbColor.fromList(<num>[255, 0, 0]);
RgbColor.extrapolate(<num>[1.0, 0.0, 0.0]);

// RGB with alpha
RgbColor(255, 0, 0, 1.0);
RgbColor.fromList(<num>[255, 0, 0, 255]);
RgbColor.extrapolate(<num>[1.0, 0.0, 0.0, 255]);

// CMYK without alpha
CmykColor(0.0, 100.0, 100.0, 0.0);
CmykColor.fromList(<num>[0.0, 100.0, 100.0, 0.0]);
CmykColor.extrapolate(<num>[0.0, 1.0, 1.0, 0.0]);

// CMYK with alpha
CmykColor(0.0, 100.0, 100.0, 0.0, 1.0);
CmykColor.fromList(<num>[0.0, 100.0, 100.0, 0.0, 255]);
CmykColor.extrapolate(<num>[0.0, 1.0, 1.0, 0.0, 255]);

// HSL without alpha
HslColor(0.0, 100.0, 50.0);
HslColor.fromList(<num>[0.0, 100.0, 50.0]);
HslColor.extrapolate(<num>[0.0, 1.0, 0.5]);

// HSL with alpha
HslColor(0.0, 100.0, 50.0, 1.0);
HslColor.fromList(<num>[0.0, 100.0, 50.0, 255]);
HslColor.extrapolate(<num>[0.0, 1.0, 0.5, 255]);

Casting Color to and from the ColorModels

Each color model has method toColor() a static method fromColor() that will cast a Color to a ColorModel and vice versa, converting the color to desired color space if not called on RgbColor.

Color color = Color(0xFFFFFF00); // yellow

CmykColor cmykColor = CmykColor.fromColor(color);
color = cmykColor.toColor();

HsiColor hsiColor = HsiColor.fromColor(color);
color = hsiColor.toColor();

HslColor hslColor = HslColor.fromColor(color);
color = hslColor.toColor();

HspColor hspColor = HspColor.fromColor(color);
color = hspColor.toColor();

HsvColor hsvColor = HsvColor.fromColor(color);
color = hsvColor.toColor();

LabColor labColor = LabColor.fromColor(color);
color = labColor.toColor();

RgbColor rgbColor = RgbColor.fromColor(color);
color = rgbColor.toColor();

XyzColor xyzColor = XyzColor.fromColor(color);
color = xyzColor.toColor();

Due to the nature of this implementation, the base ColorModel lacks the toColor method. Instead, the global toColor method can be used.

// Cast a [ColorModel] to a [Color].
var color = toColor(color);

Converting Colors Between Spaces

Each color model has methods to convert itself to each of the other color models.

CmykColor toCmykColor();

HsiColor toHsiColor();

HslColor toHslColor();

HspColor toHspColor();

HsbColor toHsbColor();

LabColor toLabColor();

RgbColor toRgbColor();

XyzColor toXyzColor();

Altenatively, each color model has a constructor ColorModel.from that can accept a color from any color space and returns its own type (T).

// Create a HSB color
HsbColor originalColor = HsbColor(0.3, 0.8, 0.7);

// Convert it to RGB => RgbColor(64, 179, 36)
RgbColor rgbColor = RgbColor.from(originalColor);

// Then to CMYK => CmykColor(64.25, 0, 79.89, 29.8)
CmykColor cmykColor = CmykColor.from(rgbColor);

// Back to HSB => HsbColor(0.3, 0.8, 0.7)
HsbColor hsbColor = HsbColor.from(cmykColor);

Note: All color conversions use the RGB color space as an intermediary. To minimize the loss of precision when converting between other color spaces, RgbColor privately stores the RGB values as nums rather than ints. The num values can be returned as a list with RgbColor's toPreciseList() method.

Color Adjustments

For convenience, each ColorModel has 2 getters, inverted and opposite, and 3 methods, cooler, warmer and rotateHue, for generating new colors.

inverted inverts the colors properties within their respective ranges, excluding hue, which is instead rotated 180 degrees.

final orange = RgbColor(255, 144, 0);

print(orange.inverted); // RgbColor(0, 111, 255);

opposite returns the color with the hue opposite this. opposite is shorthand for color.rotateHue(180).

rotateHue rotates the hue of the color by the amount specified in degrees. Colors in the CMYK, LAB, RGB, and XYZ color spaces will be converted to and from the HSL color space where the hue will be rotated.

final orange = RgbColor(255, 144, 0);

print(orange.opposite); // RgbColor(0, 111, 255);

print(orange.rotateHue(30)); // RgbColor(239, 255, 0);

print(orange.rotateHue(-30)); // RgbColor(255, 17, 0);

warmer and cooler will rotate the hue of the color by the amount specified towards 90 degrees and 270 degrees, respectively. The hue's value will be capped at 90 or 270.

final orange = RgbColor(255, 144, 0);

print(orange.warmer(30)); // RgbColor(239, 255, 0);

print(orange.cooler(30)); // RgbColor(255, 17, 0);

Interpolating Between Colors

Each color model has a method, lerpTo, that calculates a specified number of steps between this color and a color provided to the method, returning all of the colors inbetween the two colors in a list. Colors will be returned in the color space of the color the method is called on.

final color1 = RgbColor(255, 0, 0); // red
final color2 = RgbColor(0, 0, 255); // blue

/// Calculate a [List<RgbColor>] of 5 colors: [color1], [color2] and the 3 steps inbetween.
final colors = color1.lerpTo(color2, 3);

// [RgbColor(255, 0, 0, 255), RgbColor(191, 0, 64, 255), RgbColor(128, 0, 128, 255), RgbColor(64, 0, 191, 255), RgbColor(0, 0, 255, 255)]
print(colors);

/// To return only the steps in between [color1] and [color2], the [excludeOriginalColors] parameter can be set to `true`.
final steps = color1.lerpTo(color2, 3, excludeOriginalColors: true);

// [RgbColor(191, 0, 64, 255), RgbColor(128, 0, 128, 255), RgbColor(64, 0, 191, 255)]
print(steps);

Libraries

flutter_color_models