paper.js/src/color/Gradient.js
2012-03-04 19:14:13 +01:00

129 lines
3.2 KiB
JavaScript

/*
* Paper.js
*
* This file is part of Paper.js, a JavaScript Vector Graphics Library,
* based on Scriptographer.org and designed to be largely API compatible.
* http://paperjs.org/
* http://scriptographer.org/
*
* Copyright (c) 2011, Juerg Lehni & Jonathan Puckey
* http://lehni.org/ & http://jonathanpuckey.com/
*
* Distributed under the MIT license. See LICENSE file for details.
*
* All rights reserved.
*/
/**
* @name Gradient
*
* @class The Gradient object.
*/
var Gradient = this.Gradient = Base.extend(/** @lends Gradient# */{
// TODO: Should type here be called 'radial' and have it receive a
// boolean value?
/**
* Creates a gradient object
*
* @param {GradientStop[]} stops
* @param {String} [type='linear'] 'linear' or 'radial'
*/
initialize: function(stops, type) {
this.setStops(stops || ['white', 'black']);
this.type = type || 'linear';
},
/**
* Called by various setters whenever a gradient value changes
*/
_changed: function() {
// Loop through the gradient-colors that use this gradient and notify
// them, so they can notify the items they belong to.
for (var i = 0, l = this._owners && this._owners.length; i < l; i++)
this._owners[i]._changed();
},
/**
* Called by GradientColor#initialize
* This is required to pass on _changed() notifications to the _owners.
*/
_addOwner: function(color) {
if (!this._owners)
this._owners = [];
this._owners.push(color);
},
// TODO: Where and when should this be called:
/**
* Called by GradientColor whenever this gradient stops being used.
*/
_removeOwner: function(color) {
var index = this._owners ? this._owners.indexOf(color) : -1;
if (index != -1) {
this._owners.splice(index, 1);
if (this._owners.length == 0)
delete this._owners;
}
},
/**
* @return {Gradient} a copy of the gradient
*/
clone: function() {
var stops = [];
for (var i = 0, l = this._stops.length; i < l; i++)
stops[i] = this._stops[i].clone();
return new Gradient(stops, this.type);
},
/**
* The gradient stops on the gradient ramp.
*
* @type GradientStop[]
* @bean
*/
getStops: function() {
return this._stops;
},
setStops: function(stops) {
// If this gradient already contains stops, first remove
// this gradient as their owner.
if (this.stops) {
for (var i = 0, l = this._stops.length; i < l; i++) {
this._stops[i]._removeOwner(this);
}
}
if (stops.length < 2)
throw new Error(
'Gradient stop list needs to contain at least two stops.');
this._stops = GradientStop.readAll(stops);
// Now reassign ramp points if they were not specified.
for (var i = 0, l = this._stops.length; i < l; i++) {
var stop = this._stops[i];
stop._addOwner(this);
if (stop._defaultRamp)
stop.setRampPoint(i / (l - 1));
}
this._changed();
},
/**
* Checks whether the gradient is equal to the supplied gradient.
*
* @param {Gradient} gradient
* @return {Boolean} {@true they are equal}
*/
equals: function(gradient) {
if (gradient.type != this.type)
return false;
if (this._stops.length == gradient._stops.length) {
for (var i = 0, l = this._stops.length; i < l; i++) {
if (!this._stops[i].equals(gradient._stops[i]))
return false;
}
return true;
}
return false;
}
});