stylus
Version:
Robust, expressive, and feature-rich CSS superset
365 lines (320 loc) • 7 kB
JavaScript
/*!
* Stylus - RGBA
* Copyright (c) Automattic <developer.wordpress.com>
* MIT Licensed
*/
/**
* Module dependencies.
*/
var Node = require('./node')
, HSLA = require('./hsla')
, functions = require('../functions')
, adjust = functions.adjust
, nodes = require('./');
exports = module.exports = class RGBA extends Node {
/**
* Initialize a new `RGBA` with the given r,g,b,a component values.
*
* @param {Number} r
* @param {Number} g
* @param {Number} b
* @param {Number} a
* @api public
*/
constructor(r, g, b, a) {
super();
this.r = clamp(r);
this.g = clamp(g);
this.b = clamp(b);
this.a = clampAlpha(a);
this.name = '';
this.rgba = this;
}
/**
* Return an `RGBA` without clamping values.
*
* @param {Number} r
* @param {Number} g
* @param {Number} b
* @param {Number} a
* @return {RGBA}
* @api public
*/
static withoutClamping(r, g, b, a) {
var rgba = new RGBA(0, 0, 0, 0);
rgba.r = r;
rgba.g = g;
rgba.b = b;
rgba.a = a;
return rgba;
};
/**
* Return a clone of this node.
*
* @return {Node}
* @api public
*/
clone() {
var clone = new RGBA(
this.r
, this.g
, this.b
, this.a);
clone.raw = this.raw;
clone.name = this.name;
clone.lineno = this.lineno;
clone.column = this.column;
clone.filename = this.filename;
return clone;
};
/**
* Return a JSON representation of this node.
*
* @return {Object}
* @api public
*/
toJSON() {
return {
__type: 'RGBA',
r: this.r,
g: this.g,
b: this.b,
a: this.a,
raw: this.raw,
name: this.name,
lineno: this.lineno,
column: this.column,
filename: this.filename
};
};
/**
* Return true.
*
* @return {Boolean}
* @api public
*/
toBoolean() {
return nodes.true;
};
/**
* Return `HSLA` representation.
*
* @return {HSLA}
* @api public
*/
get hsla() {
return HSLA.fromRGBA(this);
};
/**
* Return hash.
*
* @return {String}
* @api public
*/
get hash() {
return this.toString();
};
/**
* Add r,g,b,a to the current component values.
*
* @param {Number} r
* @param {Number} g
* @param {Number} b
* @param {Number} a
* @return {RGBA} new node
* @api public
*/
add(r, g, b, a) {
return new RGBA(
this.r + r
, this.g + g
, this.b + b
, this.a + a);
};
/**
* Subtract r,g,b,a from the current component values.
*
* @param {Number} r
* @param {Number} g
* @param {Number} b
* @param {Number} a
* @return {RGBA} new node
* @api public
*/
sub(r, g, b, a) {
return new RGBA(
this.r - r
, this.g - g
, this.b - b
, a == 1 ? this.a : this.a - a);
};
/**
* Multiply rgb components by `n`.
*
* @param {String} n
* @return {RGBA} new node
* @api public
*/
multiply(n) {
return new RGBA(
this.r * n
, this.g * n
, this.b * n
, this.a);
};
/**
* Divide rgb components by `n`.
*
* @param {String} n
* @return {RGBA} new node
* @api public
*/
divide(n) {
return new RGBA(
this.r / n
, this.g / n
, this.b / n
, this.a);
};
/**
* Operate on `right` with the given `op`.
*
* @param {String} op
* @param {Node} right
* @return {Node}
* @api public
*/
operate(op, right) {
if ('in' != op) right = right.first
switch (op) {
case 'is a':
if ('string' == right.nodeName && 'color' == right.string) {
return nodes.true;
}
break;
case '+':
switch (right.nodeName) {
case 'unit':
var n = right.val;
switch (right.type) {
case '%': return adjust(this, new nodes.String('lightness'), right);
case 'deg': return this.hsla.adjustHue(n).rgba;
default: return this.add(n, n, n, 0);
}
case 'rgba':
return this.add(right.r, right.g, right.b, right.a);
case 'hsla':
return this.hsla.add(right.h, right.s, right.l);
}
break;
case '-':
switch (right.nodeName) {
case 'unit':
var n = right.val;
switch (right.type) {
case '%': return adjust(this, new nodes.String('lightness'), new nodes.Unit(-n, '%'));
case 'deg': return this.hsla.adjustHue(-n).rgba;
default: return this.sub(n, n, n, 0);
}
case 'rgba':
return this.sub(right.r, right.g, right.b, right.a);
case 'hsla':
return this.hsla.sub(right.h, right.s, right.l);
}
break;
case '*':
switch (right.nodeName) {
case 'unit':
return this.multiply(right.val);
}
break;
case '/':
switch (right.nodeName) {
case 'unit':
return this.divide(right.val);
}
break;
}
return super.operate(op, right);
};
/**
* Return #nnnnnn, #nnn, or rgba(n,n,n,n) string representation of the color.
*
* @return {String}
* @api public
*/
toString() {
function pad(n) {
return n < 16
? '0' + n.toString(16)
: n.toString(16);
}
// special case for transparent named color
if ('transparent' == this.name)
return this.name;
if (1 == this.a) {
var r = pad(this.r)
, g = pad(this.g)
, b = pad(this.b);
// Compress
if (r[0] == r[1] && g[0] == g[1] && b[0] == b[1]) {
return '#' + r[0] + g[0] + b[0];
} else {
return '#' + r + g + b;
}
} else {
return 'rgba('
+ this.r + ','
+ this.g + ','
+ this.b + ','
+ (+this.a.toFixed(3)) + ')';
}
};
/**
* Return a `RGBA` from the given `hsla`.
*
* @param {HSLA} hsla
* @return {RGBA}
* @api public
*/
static fromHSLA(hsla) {
var h = hsla.h / 360
, s = hsla.s / 100
, l = hsla.l / 100
, a = hsla.a;
var m2 = l <= .5 ? l * (s + 1) : l + s - l * s
, m1 = l * 2 - m2;
var r = hue(h + 1 / 3) * 0xff
, g = hue(h) * 0xff
, b = hue(h - 1 / 3) * 0xff;
function hue(h) {
if (h < 0) ++h;
if (h > 1) --h;
if (h * 6 < 1) return m1 + (m2 - m1) * h * 6;
if (h * 2 < 1) return m2;
if (h * 3 < 2) return m1 + (m2 - m1) * (2 / 3 - h) * 6;
return m1;
}
return new RGBA(r, g, b, a);
};
};
/**
* Clamp `n` >= 0 and <= 255.
*
* @param {Number} n
* @return {Number}
* @api private
*/
function clamp(n) {
return Math.max(0, Math.min(n.toFixed(0), 255));
}
/**
* Clamp alpha `n` >= 0 and <= 1.
*
* @param {Number} n
* @return {Number}
* @api private
*/
function clampAlpha(n) {
return Math.max(0, Math.min(n, 1));
}