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Merge pull request #260 from kutsan/master

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Update `hexToRGB()` with additional supports and fixes
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Angelos Chalaris
2017-12-19 16:43:02 +02:00
committed by GitHub
parent 209a606157 30ec59f179
commit 1343c364af
1 changed files with 17 additions and 10 deletions
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snippets/hexToRGB.md
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@ -1,16 +1,23 @@
### hexToRGB
Converts a colorcode to a `rgb()` string.
Converts a color code to a `rgb()` or `rgba()` string if alpha value is provided.
Use bitwise right-shift operator and mask bits with `&` (and) operator to convert a hexadecimal color code (prefixed with `#`) to a string with the RGB values. In case it's a 3-digit-colorcode, do the same with the 6-digit-colorcode extended by the extendHex() function (ref. `extendHex` snippet)
Use bitwise right-shift operator and mask bits with `&` (and) operator to convert a hexadecimal color code (with or without prefixed with `#`) to a string with the RGB values. If it's 3-digit color code, first convert to 6-digit version. If any alpha value is provided alongside 6-digit hex, give `rgba()` string in return.
```js
const hexToRgb = hex => {
const extendHex = shortHex =>
'#' + shortHex.slice(shortHex.startsWith('#') ? 1 : 0).split('').map(x => x+x).join('');
const extendedHex = hex.slice(hex.startsWith('#') ? 1 : 0).length === 3 ? extendHex(hex) : hex;
return `rgb(${parseInt(extendedHex.slice(1), 16) >> 16}, ${(parseInt(extendedHex.slice(1), 16) & 0x00ff00) >> 8}, ${parseInt(extendedHex.slice(1), 16) & 0x0000ff})`;
}
// hexToRgb('#27ae60') -> 'rgb(39, 174, 96)'
// hexToRgb('#acd') -> 'rgb(170, 204, 221)'
const hexToRGB = hex => {
let alpha = false, h = hex.slice(hex.startsWith('#') ? 1 : 0);
if (h.length === 3) h = [...h].map(x => x + x).join('');
else if (h.length === 8) alpha = true;
h = parseInt(h, 16);
return 'rgb' + (alpha ? 'a' : '') + '('
+ (h >>> (alpha ? 24 : 16)) + ', '
+ ((h & (alpha ? 0x00ff0000 : 0x00ff00)) >>> (alpha ? 16 : 8)) + ', '
+ ((h & (alpha ? 0x0000ff00 : 0x0000ff)) >>> (alpha ? 8 : 0))
+ (alpha ? `, ${(h & 0x000000ff)}` : '') + ')';
};
// hexToRGB('#27ae60ff') -> 'rgba(39, 174, 96, 255)'
// hexToRGB('27ae60') -> 'rgb(39, 174, 96)'
// hexToRGB('#fff') -> 'rgb(255, 255, 255)'
```