antd-color-editor/es/utils/getAlphaColor.js

An open-source color editor for designing color system

function _slicedToArray(arr, i) { return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _unsupportedIterableToArray(arr, i) || _nonIterableRest(); }
function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); }
function _unsupportedIterableToArray(o, minLen) { if (!o) return; if (typeof o === "string") return _arrayLikeToArray(o, minLen); var n = Object.prototype.toString.call(o).slice(8, -1); if (n === "Object" && o.constructor) n = o.constructor.name; if (n === "Map" || n === "Set") return Array.from(o); if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen); }
function _arrayLikeToArray(arr, len) { if (len == null || len > arr.length) len = arr.length; for (var i = 0, arr2 = new Array(len); i < len; i++) arr2[i] = arr[i]; return arr2; }
function _iterableToArrayLimit(r, l) { var t = null == r ? null : "undefined" != typeof Symbol && r[Symbol.iterator] || r["@@iterator"]; if (null != t) { var e, n, i, u, a = [], f = !0, o = !1; try { if (i = (t = t.call(r)).next, 0 === l) { if (Object(t) !== t) return; f = !1; } else for (; !(f = (e = i.call(t)).done) && (a.push(e.value), a.length !== l); f = !0); } catch (r) { o = !0, n = r; } finally { try { if (!f && null != t.return && (u = t.return(), Object(u) !== u)) return; } finally { if (o) throw n; } } return a; } }
function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }
import chroma from 'chroma-js';
function isStableColor(color) {
  return color >= 0 && color <= 255;
}
function arrayToRgb(rgbArray) {
  return rgbArray.length < 4 ? "rgb(".concat(rgbArray.join(','), ")") : "rgba(".concat(rgbArray.join(','), ")");
}
function getAlphaColor(frontColor, backgroundColor) {
  var _chroma$rgb = chroma(frontColor).rgb(),
    _chroma$rgb2 = _slicedToArray(_chroma$rgb, 3),
    fR = _chroma$rgb2[0],
    fG = _chroma$rgb2[1],
    fB = _chroma$rgb2[2];
  var _chroma$rgb3 = chroma(backgroundColor).rgb(),
    _chroma$rgb4 = _slicedToArray(_chroma$rgb3, 3),
    bR = _chroma$rgb4[0],
    bG = _chroma$rgb4[1],
    bB = _chroma$rgb4[2];
  for (var fA = 0.01; fA <= 1; fA += 0.01) {
    var r = Math.round((fR - bR * (1 - fA)) / fA);
    var g = Math.round((fG - bG * (1 - fA)) / fA);
    var b = Math.round((fB - bB * (1 - fA)) / fA);
    if (isStableColor(r) && isStableColor(g) && isStableColor(b)) return chroma(arrayToRgb([r, g, b, Math.round(fA * 100) / 100])).hex();
  }
  return chroma(arrayToRgb([fR, fG, fB, 1])).hex();
}
export default getAlphaColor;