cryptpad/www/whiteboard/colors.js

53 lines
1.8 KiB
JavaScript

define(function () {
var padZero = function (str, len) {
len = len || 2;
var zeros = new Array(len).join('0');
return (zeros + str).slice(-len);
};
var invertColor = function (hex) {
if (hex.indexOf('#') === 0) {
hex = hex.slice(1);
}
// convert 3-digit hex to 6-digits.
if (hex.length === 3) {
hex = hex[0] + hex[0] + hex[1] + hex[1] + hex[2] + hex[2];
}
if (hex.length !== 6) {
console.error(hex);
throw new Error('Invalid HEX color.');
}
// invert color components
var r = (255 - parseInt(hex.slice(0, 2), 16)).toString(16),
g = (255 - parseInt(hex.slice(2, 4), 16)).toString(16),
b = (255 - parseInt(hex.slice(4, 6), 16)).toString(16);
// pad each with zeros and return
return '#' + padZero(r) + padZero(g) + padZero(b);
};
var rgb2hex = function (rgb) {
if (rgb.indexOf('#') === 0) { return rgb; }
rgb = rgb.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
var hex = function (x) {
return ("0" + parseInt(x).toString(16)).slice(-2);
};
return "#" + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);
};
var hex2rgba = function (hex, opacity) {
if (hex.indexOf('#') === 0) {
hex = hex.slice(1);
}
if (hex.length === 3) {
hex = hex[0] + hex[0] + hex[1] + hex[1] + hex[2] + hex[2];
}
if (!opacity) { opacity = 1; }
var r = parseInt(hex.slice(0,2), 16);
var g = parseInt(hex.slice(2,4), 16);
var b = parseInt(hex.slice(4,6), 16);
return 'rgba('+r+', '+g+', '+b+', '+opacity+')';
};
return {
invert: invertColor,
rgb2hex: rgb2hex,
hex2rgba: hex2rgba
};
});