materialuiupgraded
Version:
Material-UI's workspace package
252 lines (214 loc) • 7.93 kB
JavaScript
/* eslint-disable no-use-before-define */
import warning from 'warning';
/**
* Returns a number whose value is limited to the given range.
*
* @param {number} value The value to be clamped
* @param {number} min The lower boundary of the output range
* @param {number} max The upper boundary of the output range
* @returns {number} A number in the range [min, max]
*/
function clamp(value, min = 0, max = 1) {
warning(
value >= min && value <= max,
`Material-UI: the value provided ${value} is out of range [${min}, ${max}].`,
);
if (value < min) {
return min;
}
if (value > max) {
return max;
}
return value;
}
/**
* Converts a color from CSS hex format to CSS rgb format.
*
* @param {string} color - Hex color, i.e. #nnn or #nnnnnn
* @returns {string} A CSS rgb color string
*/
export function convertHexToRGB(color) {
color = color.substr(1);
const re = new RegExp(`.{1,${color.length / 3}}`, 'g');
let colors = color.match(re);
if (colors && colors[0].length === 1) {
colors = colors.map(n => n + n);
}
return colors ? `rgb(${colors.map(n => parseInt(n, 16)).join(', ')})` : '';
}
/**
* Converts a color from CSS rgb format to CSS hex format.
*
* @param {string} color - RGB color, i.e. rgb(n, n, n)
* @returns {string} A CSS rgb color string, i.e. #nnnnnn
*/
export function rgbToHex(color) {
// Pass hex straight through
if (color.indexOf('#') === 0) {
return color;
}
function intToHex(c) {
const hex = c.toString(16);
return hex.length === 1 ? `0${hex}` : hex;
}
let { values } = decomposeColor(color);
values = values.map(n => intToHex(n));
return `#${values.join('')}`;
}
/**
* Returns an object with the type and values of a color.
*
* Note: Does not support rgb % values.
*
* @param {string} color - CSS color, i.e. one of: #nnn, #nnnnnn, rgb(), rgba(), hsl(), hsla()
* @returns {object} - A MUI color object: {type: string, values: number[]}
*/
export function decomposeColor(color) {
if (color.charAt(0) === '#') {
return decomposeColor(convertHexToRGB(color));
}
const marker = color.indexOf('(');
const type = color.substring(0, marker);
let values = color.substring(marker + 1, color.length - 1).split(',');
values = values.map(value => parseFloat(value));
if (process.env.NODE_ENV !== 'production') {
if (['rgb', 'rgba', 'hsl', 'hsla'].indexOf(type) === -1) {
throw new Error(
[
`Material-UI: unsupported \`${color}\` color.`,
'We support the following formats: #nnn, #nnnnnn, rgb(), rgba(), hsl(), hsla().',
].join('\n'),
);
}
}
return { type, values };
}
/**
* Converts a color object with type and values to a string.
*
* @param {object} color - Decomposed color
* @param {string} color.type - One of: 'rgb', 'rgba', 'hsl', 'hsla'
* @param {array} color.values - [n,n,n] or [n,n,n,n]
* @returns {string} A CSS color string
*/
export function recomposeColor(color) {
const { type } = color;
let { values } = color;
if (type.indexOf('rgb') !== -1) {
// Only convert the first 3 values to int (i.e. not alpha)
values = values.map((n, i) => (i < 3 ? parseInt(n, 10) : n));
}
if (type.indexOf('hsl') !== -1) {
values[1] = `${values[1]}%`;
values[2] = `${values[2]}%`;
}
return `${color.type}(${values.join(', ')})`;
}
/**
* Calculates the contrast ratio between two colors.
*
* Formula: https://www.w3.org/TR/WCAG20-TECHS/G17.html#G17-tests
*
* @param {string} foreground - CSS color, i.e. one of: #nnn, #nnnnnn, rgb(), rgba(), hsl(), hsla()
* @param {string} background - CSS color, i.e. one of: #nnn, #nnnnnn, rgb(), rgba(), hsl(), hsla()
* @returns {number} A contrast ratio value in the range 0 - 21.
*/
export function getContrastRatio(foreground, background) {
const lumA = getLuminance(foreground);
const lumB = getLuminance(background);
return (Math.max(lumA, lumB) + 0.05) / (Math.min(lumA, lumB) + 0.05);
}
/**
* The relative brightness of any point in a color space,
* normalized to 0 for darkest black and 1 for lightest white.
*
* Formula: https://www.w3.org/TR/WCAG20-TECHS/G17.html#G17-tests
*
* @param {string} color - CSS color, i.e. one of: #nnn, #nnnnnn, rgb(), rgba(), hsl(), hsla()
* @returns {number} The relative brightness of the color in the range 0 - 1
*/
export function getLuminance(color) {
const decomposedColor = decomposeColor(color);
if (decomposedColor.type.indexOf('rgb') !== -1) {
const rgb = decomposedColor.values.map(val => {
val /= 255; // normalized
return val <= 0.03928 ? val / 12.92 : ((val + 0.055) / 1.055) ** 2.4;
});
// Truncate at 3 digits
return Number((0.2126 * rgb[0] + 0.7152 * rgb[1] + 0.0722 * rgb[2]).toFixed(3));
}
// else if (decomposedColor.type.indexOf('hsl') !== -1)
return decomposedColor.values[2] / 100;
}
/**
* Darken or lighten a colour, depending on its luminance.
* Light colors are darkened, dark colors are lightened.
*
* @param {string} color - CSS color, i.e. one of: #nnn, #nnnnnn, rgb(), rgba(), hsl(), hsla()
* @param {number} coefficient=0.15 - multiplier in the range 0 - 1
* @returns {string} A CSS color string. Hex input values are returned as rgb
*/
export function emphasize(color, coefficient = 0.15) {
return getLuminance(color) > 0.5 ? darken(color, coefficient) : lighten(color, coefficient);
}
/**
* Set the absolute transparency of a color.
* Any existing alpha values are overwritten.
*
* @param {string} color - CSS color, i.e. one of: #nnn, #nnnnnn, rgb(), rgba(), hsl(), hsla()
* @param {number} value - value to set the alpha channel to in the range 0 -1
* @returns {string} A CSS color string. Hex input values are returned as rgb
*/
export function fade(color, value) {
warning(color, `Material-UI: missing color argument in fade(${color}, ${value}).`);
if (!color) return color;
color = decomposeColor(color);
value = clamp(value);
if (color.type === 'rgb' || color.type === 'hsl') {
color.type += 'a';
}
color.values[3] = value;
return recomposeColor(color);
}
/**
* Darkens a color.
*
* @param {string} color - CSS color, i.e. one of: #nnn, #nnnnnn, rgb(), rgba(), hsl(), hsla()
* @param {number} coefficient - multiplier in the range 0 - 1
* @returns {string} A CSS color string. Hex input values are returned as rgb
*/
export function darken(color, coefficient) {
warning(color, `Material-UI: missing color argument in darken(${color}, ${coefficient}).`);
if (!color) return color;
color = decomposeColor(color);
coefficient = clamp(coefficient);
if (color.type.indexOf('hsl') !== -1) {
color.values[2] *= 1 - coefficient;
} else if (color.type.indexOf('rgb') !== -1) {
for (let i = 0; i < 3; i += 1) {
color.values[i] *= 1 - coefficient;
}
}
return recomposeColor(color);
}
/**
* Lightens a color.
*
* @param {string} color - CSS color, i.e. one of: #nnn, #nnnnnn, rgb(), rgba(), hsl(), hsla()
* @param {number} coefficient - multiplier in the range 0 - 1
* @returns {string} A CSS color string. Hex input values are returned as rgb
*/
export function lighten(color, coefficient) {
warning(color, `Material-UI: missing color argument in lighten(${color}, ${coefficient}).`);
if (!color) return color;
color = decomposeColor(color);
coefficient = clamp(coefficient);
if (color.type.indexOf('hsl') !== -1) {
color.values[2] += (100 - color.values[2]) * coefficient;
} else if (color.type.indexOf('rgb') !== -1) {
for (let i = 0; i < 3; i += 1) {
color.values[i] += (255 - color.values[i]) * coefficient;
}
}
return recomposeColor(color);
}