Last active
February 9, 2024 16:01
-
-
Save oriadam/396a4beaaad465ca921618f2f2444d49 to your computer and use it in GitHub Desktop.
javascript convert any color to array of rgba values
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// return array of [r,g,b,a] from any valid color. if failed returns undefined | |
function colorValues(color) | |
{ | |
if (!color) | |
return; | |
if (color.toLowerCase() === 'transparent') | |
return [0, 0, 0, 0]; | |
if (color[0] === '#') | |
{ | |
if (color.length < 7) | |
{ | |
// convert #RGB and #RGBA to #RRGGBB and #RRGGBBAA | |
color = '#' + color[1] + color[1] + color[2] + color[2] + color[3] + color[3] + (color.length > 4 ? color[4] + color[4] : ''); | |
} | |
return [parseInt(color.substr(1, 2), 16), | |
parseInt(color.substr(3, 2), 16), | |
parseInt(color.substr(5, 2), 16), | |
color.length > 7 ? parseInt(color.substr(7, 2), 16)/255 : 1]; | |
} | |
if (color.indexOf('rgb') === -1) | |
{ | |
// convert named colors | |
var temp_elem = document.body.appendChild(document.createElement('fictum')); // intentionally use unknown tag to lower chances of css rule override with !important | |
var flag = 'rgb(1, 2, 3)'; // this flag tested on chrome 59, ff 53, ie9, ie10, ie11, edge 14 | |
temp_elem.style.color = flag; | |
if (temp_elem.style.color !== flag) | |
return; // color set failed - some monstrous css rule is probably taking over the color of our object | |
temp_elem.style.color = color; | |
if (temp_elem.style.color === flag || temp_elem.style.color === '') | |
return; // color parse failed | |
color = getComputedStyle(temp_elem).color; | |
document.body.removeChild(temp_elem); | |
} | |
if (color.indexOf('rgb') === 0) | |
{ | |
if (color.indexOf('rgba') === -1) | |
color += ',1'; // convert 'rgb(R,G,B)' to 'rgb(R,G,B)A' which looks awful but will pass the regxep below | |
return color.match(/[\.\d]+/g).map(function (a) | |
{ | |
return +a | |
}); | |
} | |
} | |
/* | |
Examples: | |
colorValues('transparent'); // [0,0,0,0] | |
colorValues('white'); // [255, 255, 255, 1] | |
colorValues('teal'); // [0, 128, 128, 1] | |
colorValues('rgba(11,22,33,.44)'); // [11, 22, 33, 0.44] | |
colorValues('rgb(11,22,33)'); // [11, 22, 33, 1] | |
colorValues('#abc'); // [170, 187, 204, 1] | |
colorValues('#abc6'); // [170, 187, 204, 0.4] | |
colorValues('#aabbcc'); // [170, 187, 204, 1] | |
colorValues('#aabbcc66'); // [170, 187, 204, 0.4] | |
colorValues('asdf'); // undefined | |
colorValues(''); // undefined | |
colorValues(NaN); // Script Error | |
colorValues(123); // Script Error | |
*/ |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Nice one. I made a much shorter version that even accepts hsl and hexa colors:
https://gist.github.com/av01d/8f068dd43447b475dec4aad0a6107288