moonlight-skulk/src/pixi/loaders/JsonLoader.js

/**
 * @author Mat Groves http://matgroves.com/ @Doormat23
 */

/**
 * The json file loader is used to load in JSON data and parse it
 * When loaded this class will dispatch a 'loaded' event
 * If loading fails this class will dispatch an 'error' event
 *
 * @class JsonLoader
 * @uses EventTarget
 * @constructor
 * @param url {String} The url of the JSON file
 * @param crossorigin {Boolean} Whether requests should be treated as crossorigin
 */
PIXI.JsonLoader = function (url, crossorigin) {
    PIXI.EventTarget.call(this);

    /**
     * The url of the bitmap font data
     *
     * @property url
     * @type String
     */
    this.url = url;

    /**
     * Whether the requests should be treated as cross origin
     *
     * @property crossorigin
     * @type Boolean
     */
    this.crossorigin = crossorigin;

    /**
     * [read-only] The base url of the bitmap font data
     *
     * @property baseUrl
     * @type String
     * @readOnly
     */
    this.baseUrl = url.replace(/[^\/]*$/, '');

    /**
     * [read-only] Whether the data has loaded yet
     *
     * @property loaded
     * @type Boolean
     * @readOnly
     */
    this.loaded = false;

};

// constructor
PIXI.JsonLoader.prototype.constructor = PIXI.JsonLoader;

/**
 * Loads the JSON data
 *
 * @method load
 */
PIXI.JsonLoader.prototype.load = function () {

    var scope = this;

    if(window.XDomainRequest)
    {
        this.ajaxRequest = new window.XDomainRequest();

        // XDomainRequest has a few querks. Occasionally it will abort requests
        // A way to avoid this is to make sure ALL callbacks are set even if not used
        // More info here: http://stackoverflow.com/questions/15786966/xdomainrequest-aborts-post-on-ie-9
        this.ajaxRequest.timeout = 3000;

        this.ajaxRequest.onerror = function () {
            scope.onError();
        };
           
        this.ajaxRequest.ontimeout = function () {
            scope.onError();
        };

        this.ajaxRequest.onprogress = function() {};

    }
    else if (window.XMLHttpRequest)
    {
        this.ajaxRequest = new window.XMLHttpRequest();
    }
    else
    {
        this.ajaxRequest = new window.ActiveXObject('Microsoft.XMLHTTP');
    }

    

    this.ajaxRequest.onload = function(){

        scope.onJSONLoaded();
    };

    this.ajaxRequest.open('GET',this.url,true);

    this.ajaxRequest.send();
};

/**
 * Invoke when JSON file is loaded
 *
 * @method onJSONLoaded
 * @private
 */
PIXI.JsonLoader.prototype.onJSONLoaded = function () {
    
    if(!this.ajaxRequest.responseText )
    {
        this.onError();
        return;
    }
   
    this.json = JSON.parse(this.ajaxRequest.responseText);

    if(this.json.frames)
    {
        // sprite sheet
        var scope = this;
        var textureUrl = this.baseUrl + this.json.meta.image;
        var image = new PIXI.ImageLoader(textureUrl, this.crossorigin);
        var frameData = this.json.frames;

        this.texture = image.texture.baseTexture;
        image.addEventListener('loaded', function() {
            scope.onLoaded();
        });

        for (var i in frameData) {
            var rect = frameData[i].frame;
            if (rect) {
                PIXI.TextureCache[i] = new PIXI.Texture(this.texture, {
                    x: rect.x,
                    y: rect.y,
                    width: rect.w,
                    height: rect.h
                });

                // check to see ifthe sprite ha been trimmed..
                if (frameData[i].trimmed) {

                    var texture =  PIXI.TextureCache[i];
                    
                    var actualSize = frameData[i].sourceSize;
                    var realSize = frameData[i].spriteSourceSize;

                    texture.trim = new PIXI.Rectangle(realSize.x, realSize.y, actualSize.w, actualSize.h);
                }
            }
        }

        image.load();

    }
    else if(this.json.bones)
    {
        // spine animation
        var spineJsonParser = new spine.SkeletonJson();
        var skeletonData = spineJsonParser.readSkeletonData(this.json);
        PIXI.AnimCache[this.url] = skeletonData;
        this.onLoaded();
    }
    else
    {
        this.onLoaded();
    }
};

/**
 * Invoke when json file loaded
 *
 * @method onLoaded
 * @private
 */
PIXI.JsonLoader.prototype.onLoaded = function () {
    this.loaded = true;
    this.dispatchEvent({
        type: 'loaded',
        content: this
    });
};

/**
 * Invoke when error occured
 *
 * @method onError
 * @private
 */
PIXI.JsonLoader.prototype.onError = function () {

    this.dispatchEvent({
        type: 'error',
        content: this
    });
};