react-native-web/src/exports/StyleSheet/compiler/normalizeColor.js

React Native for Web

/**
 * Copyright (c) Nicolas Gallagher.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */

import isWebColor from '../../../modules/isWebColor';
import processColor from '../../../exports/processColor';

const normalizeColor = (
  color?: number | string,
  opacity?: number = 1
): void | string => {
  if (color == null) return;

  if (typeof color === 'string' && isWebColor(color)) {
    return color;
  }

  const colorInt = processColor(color);
  if (colorInt != null) {
    const r = (colorInt >> 16) & 255;
    const g = (colorInt >> 8) & 255;
    const b = colorInt & 255;
    const a = ((colorInt >> 24) & 255) / 255;
    const alpha = (a * opacity).toFixed(2);
    return `rgba(${r},${g},${b},${alpha})`;
  }
};

export default normalizeColor;