ohmyform-ui/components/styled/color.change.ts
2020-06-09 16:27:56 +02:00

62 lines
1.3 KiB
TypeScript

/* eslint-disable */
/**
* @link https://css-tricks.com/snippets/javascript/lighten-darken-color/
*
* @author Chris Coyier
*/
function LightenDarkenColor(col, amt): string {
let usePound = false
if (col[0] == '#') {
col = col.slice(1)
usePound = true
}
const num = parseInt(col, 16)
let r = (num >> 16) + amt
if (r > 255) r = 255
else if (r < 0) r = 0
let b = ((num >> 8) & 0x00ff) + amt
if (b > 255) b = 255
else if (b < 0) b = 0
let g = (num & 0x0000ff) + amt
if (g > 255) g = 255
else if (g < 0) g = 0
return (usePound ? '#' : '') + (g | (b << 8) | (r << 16)).toString(16)
}
export const transparentize = (col: string, amt: number): string => {
if (col[0] == '#') {
col = col.slice(1)
}
const num = parseInt(col, 16)
let r = (num >> 16) + amt
if (r > 255) r = 255
else if (r < 0) r = 0
let b = ((num >> 8) & 0x00ff) + amt
if (b > 255) b = 255
else if (b < 0) b = 0
let g = (num & 0x0000ff) + amt
if (g > 255) g = 255
else if (g < 0) g = 0
return `rgba(${r}, ${b}, ${g}, ${1 - amt / 100})`
}
export const lighten = (color: string, amount: number): string => LightenDarkenColor(color, amount)
export const darken = (color: string, amount: number): string => LightenDarkenColor(color, -amount)