File:ImageLoader.js
/*
* ImageLoader
* Visit http://createjs.com/ for documentation, updates and examples.
*
*
* Copyright (c) 2012 gskinner.com, inc.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
// namespace:
this.createjs = this.createjs || {};
(function () {
"use strict";
// constructor
/**
* A loader for image files.
* @class ImageLoader
* @param {LoadItem|Object} loadItem
* @param {Boolean} preferXHR
* @extends AbstractLoader
* @constructor
*/
function ImageLoader (loadItem, preferXHR) {
this.AbstractLoader_constructor(loadItem, preferXHR, createjs.AbstractLoader.IMAGE);
// public properties
this.resultFormatter = this._formatResult;
// protected properties
this._tagSrcAttribute = "src";
// Check if the preload item is already a tag.
if (createjs.RequestUtils.isImageTag(loadItem)) {
this._tag = loadItem;
} else if (createjs.RequestUtils.isImageTag(loadItem.src)) {
this._tag = loadItem.src;
} else if (createjs.RequestUtils.isImageTag(loadItem.tag)) {
this._tag = loadItem.tag;
}
if (this._tag != null) {
this._preferXHR = false;
} else {
this._tag = document.createElement("img");
}
this.on("initialize", this._updateXHR, this);
};
var p = createjs.extend(ImageLoader, createjs.AbstractLoader);
var s = ImageLoader;
// static methods
/**
* Determines if the loader can load a specific item. This loader can only load items that are of type
* {{#crossLink "AbstractLoader/IMAGE:property"}}{{/crossLink}}.
* @method canLoadItem
* @param {LoadItem|Object} item The LoadItem that a LoadQueue is trying to load.
* @returns {Boolean} Whether the loader can load the item.
* @static
*/
s.canLoadItem = function (item) {
return item.type == createjs.AbstractLoader.IMAGE;
};
// public methods
p.load = function () {
if (this._tag.src != "" && this._tag.complete) {
this._sendComplete();
return;
}
var crossOrigin = this._item.crossOrigin;
if (crossOrigin == true) { crossOrigin = "Anonymous"; }
if (crossOrigin != null && !createjs.RequestUtils.isLocal(this._item.src)) {
this._tag.crossOrigin = crossOrigin;
}
this.AbstractLoader_load();
};
// protected methods
/**
* Before the item loads, set its mimeType and responseType.
* @property _updateXHR
* @param {Event} event
* @private
*/
p._updateXHR = function (event) {
event.loader.mimeType = 'text/plain; charset=x-user-defined-binary';
// Only exists for XHR
if (event.loader.setResponseType) {
event.loader.setResponseType("blob");
}
};
/**
* The result formatter for Image files.
* @method _formatResult
* @param {AbstractLoader} loader
* @returns {HTMLImageElement}
* @private
*/
p._formatResult = function (loader) {
var _this = this;
return function (done) {
var tag = _this._tag;
var URL = window.URL || window.webkitURL;
if (!_this._preferXHR) {
//document.body.removeChild(tag);
} else if (URL) {
var objURL = URL.createObjectURL(loader.getResult(true));
tag.src = objURL;
tag.onload = function () {
URL.revokeObjectURL(_this.src);
}
} else {
tag.src = loader.getItem().src;
}
if (tag.complete) {
done(tag);
} else {
tag.onload = function () {
done(this);
}
}
};
};
createjs.ImageLoader = createjs.promote(ImageLoader, "AbstractLoader");
}());