hexToRgbA.js

hexToRgbA.js

// 個別にopacityを置くために
/**
  ex)
  hexToRgbA('#777777', 0.8)
  -> "rgba(119,119,119,0.8)"
  hexToRgbA('#777777', 0.9)
  -> "rgba(119,119,119,0.9)"
  hexToRgbA('#777777', 0.6)
  -> "rgba(119,119,119,0.6)"
*/
const hexToRgbA = (hex: string, opacity: number = 1) => {
  let c;
  if (/^#([A-Fa-f0-9]{3}){1,2}$/.test(hex)) {
    c = hex.substring(1).split('');
    if (c.length === 3) {
      c = [c[0], c[0], c[1], c[1], c[2], c[2]];
    }
    c = `0x${c.join('')}`;
    return `rgba(${[(c >> 16) & 255, (c >> 8) & 255, c & 255].join(',')},${opacity})`; // eslint-disable-line
  }
  throw new Error('Bad Hex');
};