color-model/lib/component.js

Operate colors in popular color models and convert between them

module.exports = (function() { return Component; })();

/**
 * Color model Component
 * @param {String} name
 * @param {Number} from
 * @param {Number} to
 */
function Component(name, from, to) {
  if (!name) {
    throw new Error('Name not set');
  }
  this._name = name;

  from = parseFloat(from);
  to   = parseFloat(to);
  if (!(from < to)) {
    throw new Error('From must be less than to');
  }
  this._from = from;
  this._to   = to;

  this._value = null;
};

/**
 * @param {Number} value
 * @returns {Component}
 */
Component.prototype.set = function (value) {
  value = value ? parseFloat(value) : 0;
  if (isNaN(value)) {
    throw new Error('Value for ' + this._name + ' must be numeric');
  }

  if (value < this._from || value > this._to) {
    throw new Error('Value for ' + this._name + ' (' + value + ') must be between ' + this._from + ' and ' + this._to);
  }

  this._value = value;
  return this;
};

/**
 * @returns {Number}
 */
Component.prototype.get = function () {
  return this._value;
};

/**
 * @param {Component} that
 * @returns {Boolean}
 */
Component.prototype.equals = function (that) {
  return (that instanceof Component)
    && this._name  === that._name
    && this._value === that._value;
};