phaser/src/loader/Loader.js

/* jshint wsh:true */
/**
* @author       Richard Davey <rich@photonstorm.com>
* @copyright    2014 Photon Storm Ltd.
* @license      {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
*/

/**
* Phaser loader constructor.
* The Loader handles loading all external content such as Images, Sounds, Texture Atlases and data files.
* It uses a combination of Image() loading and xhr and provides progress and completion callbacks.
* @class Phaser.Loader
* @classdesc  The Loader handles loading all external content such as Images, Sounds, Texture Atlases and data files.
* It uses a combination of Image() loading and xhr and provides progress and completion callbacks.
* @constructor
* @param {Phaser.Game} game - A reference to the currently running game.
*/
Phaser.Loader = function (game) {

    /**
    * @property {Phaser.Game} game - Local reference to game.
    */
    this.game = game;

    /**
    * @property {array} _fileList - Contains all the assets file infos.
    * @private
    */
    this._fileList = [];

    /**
    * @property {number} _fileIndex - The index of the current file being loaded.
    * @private
    */
    this._fileIndex = 0;

    /**
    * @property {number} _progressChunk - Indicates the size of 1 file in terms of a percentage out of 100.
    * @private
    * @default
    */
    this._progressChunk = 0;

    /**
    * @property {XMLHttpRequest} - An XMLHttpRequest object used for loading text and audio data.
    * @private
    */
    this._xhr = new XMLHttpRequest();

    /**
    * @property {boolean} isLoading - True if the Loader is in the process of loading the queue.
    * @default
    */
    this.isLoading = false;

    /**
    * @property {boolean} hasLoaded - True if all assets in the queue have finished loading.
    * @default
    */
    this.hasLoaded = false;

    /**
    * @property {number} progress - The rounded load progress percentage value (from 0 to 100)
    * @default
    */
    this.progress = 0;

    /**
    * @property {number} progressFloat - The non-rounded load progress value (from 0.0 to 100.0)
    * @default
    */
    this.progressFloat = 0;

    /**
    * You can optionally link a sprite to the preloader.
    * If you do so the Sprites width or height will be cropped based on the percentage loaded.
    * @property {Phaser.Sprite|Phaser.Image} preloadSprite
    * @default
    */
    this.preloadSprite = null;

    /**
    * @property {boolean|string} crossOrigin - The crossOrigin value applied to loaded images. Very often this needs to be set to 'anonymous'.
    * @default
    */
    this.crossOrigin = false;

    /**
    * If you want to append a URL before the path of any asset you can set this here.
    * Useful if you need to allow an asset url to be configured outside of the game code.
    * MUST have / on the end of it!
    * @property {string} baseURL
    * @default
    */
    this.baseURL = '';

    /**
    * @property {Phaser.Signal} onFileComplete - Event signal.
    */
    this.onFileComplete = new Phaser.Signal();

    /**
    * @property {Phaser.Signal} onFileError - Event signal.
    */
    this.onFileError = new Phaser.Signal();

    /**
    * @property {Phaser.Signal} onLoadStart - Event signal.
    */
    this.onLoadStart = new Phaser.Signal();

    /**
    * @property {Phaser.Signal} onLoadComplete - Event signal.
    */
    this.onLoadComplete = new Phaser.Signal();

};

/**
* @constant
* @type {number}
*/
Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY = 0;

/**
* @constant
* @type {number}
*/
Phaser.Loader.TEXTURE_ATLAS_JSON_HASH = 1;

/**
* @constant
* @type {number}
*/
Phaser.Loader.TEXTURE_ATLAS_XML_STARLING = 2;

/**
* @constant
* @type {number}
*/
Phaser.Loader.PHYSICS_LIME_CORONA_JSON = 3;

/**
* @constant
* @type {number}
*/
Phaser.Loader.PHYSICS_PHASER_JSON = 4;

Phaser.Loader.prototype = {

    /**
    * You can set a Sprite to be a "preload" sprite by passing it to this method.
    * A "preload" sprite will have its width or height crop adjusted based on the percentage of the loader in real-time.
    * This allows you to easily make loading bars for games. Note that Sprite.visible = true will be set when calling this.
    *
    * @method Phaser.Loader#setPreloadSprite
    * @param {Phaser.Sprite|Phaser.Image} sprite - The sprite or image that will be cropped during the load.
    * @param {number} [direction=0] - A value of zero means the sprite will be cropped horizontally, a value of 1 means its will be cropped vertically.
    */
    setPreloadSprite: function (sprite, direction) {

        direction = direction || 0;

        this.preloadSprite = { sprite: sprite, direction: direction, width: sprite.width, height: sprite.height, rect: null };

        if (direction === 0)
        {
            //  Horizontal rect
            this.preloadSprite.rect = new Phaser.Rectangle(0, 0, 1, sprite.height);
        }
        else
        {
            //  Vertical rect
            this.preloadSprite.rect = new Phaser.Rectangle(0, 0, sprite.width, 1);
        }

        sprite.crop(this.preloadSprite.rect);

        sprite.visible = true;

    },

    /**
    * Check whether asset exists with a specific key.
    *
    * @method Phaser.Loader#checkKeyExists
    * @param {string} type - The type asset you want to check.
    * @param {string} key - Key of the asset you want to check.
    * @return {boolean} Return true if exists, otherwise return false.
    */
    checkKeyExists: function (type, key) {

        if (this._fileList.length > 0)
        {
            for (var i = 0; i < this._fileList.length; i++)
            {
                if (this._fileList[i].type === type && this._fileList[i].key === key)
                {
                    return true;
                }
            }
        }

        return false;

    },

    /**
    * Gets the fileList index for the given key.
    *
    * @method Phaser.Loader#getAssetIndex
    * @param {string} type - The type asset you want to check.
    * @param {string} key - Key of the asset you want to check.
    * @return {number} The index of this key in the filelist, or -1 if not found.
    */
    getAssetIndex: function (type, key) {

        if (this._fileList.length > 0)
        {
            for (var i = 0; i < this._fileList.length; i++)
            {
                if (this._fileList[i].type === type && this._fileList[i].key === key)
                {
                    return i;
                }
            }
        }

        return -1;

    },

    /**
    * Gets the asset that is queued for load.
    *
    * @method Phaser.Loader#getAsset
    * @param {string} type - The type asset you want to check.
    * @param {string} key - Key of the asset you want to check.
    * @return {any} Returns an object if found that has 2 properties: index and file. Otherwise false.
    */
    getAsset: function (type, key) {

        if (this._fileList.length > 0)
        {
            for (var i = 0; i < this._fileList.length; i++)
            {
                if (this._fileList[i].type === type && this._fileList[i].key === key)
                {
                    return { index: i, file: this._fileList[i] };
                }
            }
        }

        return false;

    },

    /**
    * Reset loader, this will remove the load queue.
    *
    * @method Phaser.Loader#reset
    */
    reset: function () {

        this.preloadSprite = null;
        this.isLoading = false;
        this._fileList.length = 0;
        this._fileIndex = 0;

    },

    /**
    * Internal function that adds a new entry to the file list. Do not call directly.
    *
    * @method Phaser.Loader#addToFileList
    * @param {string} type - The type of resource to add to the list (image, audio, xml, etc).
    * @param {string} key - The unique Cache ID key of this resource.
    * @param {string} url - The URL the asset will be loaded from.
    * @param {object} properties - Any additional properties needed to load the file.
    * @protected
    */
    addToFileList: function (type, key, url, properties) {

        var entry = {
            type: type,
            key: key,
            url: url,
            data: null,
            error: false,
            loaded: false
        };

        if (typeof properties !== "undefined")
        {
            for (var prop in properties)
            {
                entry[prop] = properties[prop];
            }
        }

        if (this.checkKeyExists(type, key) === false)
        {
            this._fileList.push(entry);
        }

    },

    /**
    * Internal function that replaces an existing entry in the file list with a new one. Do not call directly.
    *
    * @method Phaser.Loader#replaceInFileList
    * @param {string} type - The type of resource to add to the list (image, audio, xml, etc).
    * @param {string} key - The unique Cache ID key of this resource.
    * @param {string} url - The URL the asset will be loaded from.
    * @param {object} properties - Any additional properties needed to load the file.
    * @protected
    */
    replaceInFileList: function (type, key, url, properties) {

        var entry = {
            type: type,
            key: key,
            url: url,
            data: null,
            error: false,
            loaded: false
        };

        if (typeof properties !== "undefined")
        {
            for (var prop in properties)
            {
                entry[prop] = properties[prop];
            }
        }

        var index = this.getAssetIndex(type, key);

        if (index === -1)
        {
            this._fileList.push(entry);
        }
        else
        {
            this._fileList[index] = entry;
        }

    },

    /**
    * Add an image to the Loader.
    *
    * @method Phaser.Loader#image
    * @param {string} key - Unique asset key of this image file.
    * @param {string} url - URL of image file.
    * @param {boolean} [overwrite=false] - If an unloaded file with a matching key already exists in the queue, this entry will overwrite it.
    * @return {Phaser.Loader} This Loader instance.
    */
    image: function (key, url, overwrite) {

        if (typeof overwrite === "undefined") { overwrite = false; }

        if (overwrite)
        {
            this.replaceInFileList('image', key, url);
        }
        else
        {
            this.addToFileList('image', key, url);
        }

        return this;

    },

    /**
    * Add a text file to the Loader.
    *
    * @method Phaser.Loader#text
    * @param {string} key - Unique asset key of the text file.
    * @param {string} url - URL of the text file.
    * @param {boolean} [overwrite=false] - If an unloaded file with a matching key already exists in the queue, this entry will overwrite it.
    * @return {Phaser.Loader} This Loader instance.
    */
    text: function (key, url, overwrite) {

        if (typeof overwrite === "undefined") { overwrite = false; }

        if (overwrite)
        {
            this.replaceInFileList('text', key, url);
        }
        else
        {
            this.addToFileList('text', key, url);
        }

        return this;

    },

    /**
    * Add a json file to the Loader.
    *
    * @method Phaser.Loader#json
    * @param {string} key - Unique asset key of the json file.
    * @param {string} url - URL of the json file.
    * @param {boolean} [overwrite=false] - If an unloaded file with a matching key already exists in the queue, this entry will overwrite it.
    * @return {Phaser.Loader} This Loader instance.
    */
    json: function (key, url, overwrite) {

        if (typeof overwrite === "undefined") { overwrite = false; }

        if (overwrite)
        {
            this.replaceInFileList('json', key, url);
        }
        else
        {
            this.addToFileList('json', key, url);
        }

        return this;

    },

    /**
    * Add a JavaScript file to the Loader. Once loaded the JavaScript file will be automatically turned into a script tag (and executed), so be careful what you load!
    * You can also specify a callback. This will be executed as soon as the script tag has been created.
    *
    * @method Phaser.Loader#script
    * @param {string} key - Unique asset key of the script file.
    * @param {string} url - URL of the JavaScript file.
    * @param {function} [callback] - Optional callback that will be called after the script tag has loaded, so you can perform additional processing.
    * @param {function} [callbackContext] - The context under which the callback will be applied. If not specified it will use the callback itself as the context.
    * @return {Phaser.Loader} This Loader instance.
    */
    script: function (key, url, callback, callbackContext) {

        if (typeof callback === 'undefined') { callback = false; }
        if (callback !== false && typeof callbackContext === 'undefined') { callbackContext = callback; }

        this.addToFileList('script', key, url, { callback: callback, callbackContext: callbackContext });

        return this;

    },

    /**
    * Add a binary file to the Loader. It will be loaded via xhr with a responseType of "arraybuffer". You can specify an optional callback to process the file after load.
    * When the callback is called it will be passed 2 parameters: the key of the file and the file data.
    * WARNING: If you specify a callback, the file data will be set to whatever your callback returns. So always return the data object, even if you didn't modify it.
    *
    * @method Phaser.Loader#binary
    * @param {string} key - Unique asset key of the binary file.
    * @param {string} url - URL of the binary file.
    * @param {function} [callback] - Optional callback that will be passed the file after loading, so you can perform additional processing on it.
    * @param {function} [callbackContext] - The context under which the callback will be applied. If not specified it will use the callback itself as the context.
    * @return {Phaser.Loader} This Loader instance.
    */
    binary: function (key, url, callback, callbackContext) {

        if (typeof callback === 'undefined') { callback = false; }
        if (callback !== false && typeof callbackContext === 'undefined') { callbackContext = callback; }

        this.addToFileList('binary', key, url, { callback: callback, callbackContext: callbackContext });

        return this;

    },

    /**
    * Add a new sprite sheet to the loader.
    *
    * @method Phaser.Loader#spritesheet
    * @param {string} key - Unique asset key of the sheet file.
    * @param {string} url - URL of the sheet file.
    * @param {number} frameWidth - Width of each single frame.
    * @param {number} frameHeight - Height of each single frame.
    * @param {number} [frameMax=-1] - How many frames in this sprite sheet. If not specified it will divide the whole image into frames.
    * @param {number} [margin=0] - If the frames have been drawn with a margin, specify the amount here.
    * @param {number} [spacing=0] - If the frames have been drawn with spacing between them, specify the amount here.
    * @return {Phaser.Loader} This Loader instance.
    */
    spritesheet: function (key, url, frameWidth, frameHeight, frameMax, margin, spacing) {

        if (typeof frameMax === "undefined") { frameMax = -1; }
        if (typeof margin === "undefined") { margin = 0; }
        if (typeof spacing === "undefined") { spacing = 0; }

        this.addToFileList('spritesheet', key, url, { frameWidth: frameWidth, frameHeight: frameHeight, frameMax: frameMax, margin: margin, spacing: spacing });

        return this;

    },

    /**
    * Add a new audio file to the loader.
    *
    * @method Phaser.Loader#audio
    * @param {string} key - Unique asset key of the audio file.
    * @param {Array|string} urls - An array containing the URLs of the audio files, i.e.: [ 'jump.mp3', 'jump.ogg', 'jump.m4a' ] or a single string containing just one URL.
    * @param {boolean} autoDecode - When using Web Audio the audio files can either be decoded at load time or run-time. They can't be played until they are decoded, but this let's you control when that happens. Decoding is a non-blocking async process.
    * @return {Phaser.Loader} This Loader instance.
    */
    audio: function (key, urls, autoDecode) {

        if (typeof autoDecode === "undefined") { autoDecode = true; }

        this.addToFileList('audio', key, urls, { buffer: null, autoDecode: autoDecode });

        return this;

    },

    /**
    * Add a new tilemap loading request.
    *
    * @method Phaser.Loader#tilemap
    * @param {string} key - Unique asset key of the tilemap data.
    * @param {string} [mapDataURL] - The url of the map data file (csv/json)
    * @param {object} [mapData] - An optional JSON data object. If given then the mapDataURL is ignored and this JSON object is used for map data instead.
    * @param {number} [format=Phaser.Tilemap.CSV] - The format of the map data. Either Phaser.Tilemap.CSV or Phaser.Tilemap.TILED_JSON.
    * @return {Phaser.Loader} This Loader instance.
    */
    tilemap: function (key, mapDataURL, mapData, format) {

        if (typeof mapDataURL === "undefined") { mapDataURL = null; }
        if (typeof mapData === "undefined") { mapData = null; }
        if (typeof format === "undefined") { format = Phaser.Tilemap.CSV; }

        if (mapDataURL == null && mapData == null)
        {
            console.warn('Phaser.Loader.tilemap - Both mapDataURL and mapData are null. One must be set.');

            return this;
        }

        //  A map data object has been given
        if (mapData)
        {
            switch (format)
            {
                //  A csv string or object has been given
                case Phaser.Tilemap.CSV:
                    break;

                //  An xml string or object has been given
                case Phaser.Tilemap.TILED_JSON:

                    if (typeof mapData === 'string')
                    {
                        mapData = JSON.parse(mapData);
                    }
                    break;
            }

            this.game.cache.addTilemap(key, null, mapData, format);
        }
        else
        {
            this.addToFileList('tilemap', key, mapDataURL, { format: format });
        }

        return this;

    },

    /**
    * Add a new physics data object loading request.
    * The data must be in Lime + Corona JSON format. Physics Editor by code'n'web exports in this format natively.
    *
    * @method Phaser.Loader#physics
    * @param {string} key - Unique asset key of the physics json data.
    * @param {string} [dataURL] - The url of the map data file (csv/json)
    * @param {object} [jsonData] - An optional JSON data object. If given then the dataURL is ignored and this JSON object is used for physics data instead.
    * @param {string} [format=Phaser.Physics.LIME_CORONA_JSON] - The format of the physics data.
    * @return {Phaser.Loader} This Loader instance.
    */
    physics: function (key, dataURL, jsonData, format) {

        if (typeof dataURL === "undefined") { dataURL = null; }
        if (typeof jsonData === "undefined") { jsonData = null; }
        if (typeof format === "undefined") { format = Phaser.Physics.LIME_CORONA_JSON; }

        if (dataURL == null && jsonData == null)
        {
            console.warn('Phaser.Loader.physics - Both dataURL and jsonData are null. One must be set.');

            return this;
        }

        //  A map data object has been given
        if (jsonData)
        {
            if (typeof jsonData === 'string')
            {
                jsonData = JSON.parse(jsonData);
            }

            this.game.cache.addPhysicsData(key, null, jsonData, format);
        }
        else
        {
            this.addToFileList('physics', key, dataURL, { format: format });
        }

        return this;

    },

    /**
    * Add a new bitmap font loading request.
    *
    * @method Phaser.Loader#bitmapFont
    * @param {string} key - Unique asset key of the bitmap font.
    * @param {string} textureURL - The url of the font image file.
    * @param {string} [xmlURL] - The url of the font data file (xml/fnt)
    * @param {object} [xmlData] - An optional XML data object.
    * @param {number} [xSpacing=0] - If you'd like to add additional horizontal spacing between the characters then set the pixel value here.
    * @param {number} [ySpacing=0] - If you'd like to add additional vertical spacing between the lines then set the pixel value here.
    * @return {Phaser.Loader} This Loader instance.
    */
    bitmapFont: function (key, textureURL, xmlURL, xmlData, xSpacing, ySpacing) {

        if (typeof xmlURL === "undefined") { xmlURL = null; }
        if (typeof xmlData === "undefined") { xmlData = null; }
        if (typeof xSpacing === "undefined") { xSpacing = 0; }
        if (typeof ySpacing === "undefined") { ySpacing = 0; }

        //  A URL to a json/xml file has been given
        if (xmlURL)
        {
            this.addToFileList('bitmapfont', key, textureURL, { xmlURL: xmlURL, xSpacing: xSpacing, ySpacing: ySpacing });
        }
        else
        {
            //  An xml string or object has been given
            if (typeof xmlData === 'string')
            {
                var xml;

                try  {
                    if (window['DOMParser'])
                    {
                        var domparser = new DOMParser();
                        xml = domparser.parseFromString(xmlData, "text/xml");
                    }
                    else
                    {
                        xml = new ActiveXObject("Microsoft.XMLDOM");
                        xml.async = 'false';
                        xml.loadXML(xmlData);
                    }
                }
                catch (e)
                {
                    xml = undefined;
                }

                if (!xml || !xml.documentElement || xml.getElementsByTagName("parsererror").length)
                {
                    throw new Error("Phaser.Loader. Invalid Bitmap Font XML given");
                }
                else
                {
                    this.addToFileList('bitmapfont', key, textureURL, { xmlURL: null, xmlData: xml, xSpacing: xSpacing, ySpacing: ySpacing });
                }
            }
        }

        return this;

    },

    /**
    * Add a new texture atlas to the loader. This atlas uses the JSON Array data format.
    *
    * @method Phaser.Loader#atlasJSONArray
    * @param {string} key - Unique asset key of the texture atlas file.
    * @param {string} textureURL - The url of the texture atlas image file.
    * @param {string} [atlasURL] - The url of the texture atlas data file (json/xml). You don't need this if you are passing an atlasData object instead.
    * @param {object} [atlasData] - A JSON or XML data object. You don't need this if the data is being loaded from a URL.
    * @return {Phaser.Loader} This Loader instance.
    */
    atlasJSONArray: function (key, textureURL, atlasURL, atlasData) {

        return this.atlas(key, textureURL, atlasURL, atlasData, Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY);

    },

    /**
    * Add a new texture atlas to the loader. This atlas uses the JSON Hash data format.
    *
    * @method Phaser.Loader#atlasJSONHash
    * @param {string} key - Unique asset key of the texture atlas file.
    * @param {string} textureURL - The url of the texture atlas image file.
    * @param {string} [atlasURL] - The url of the texture atlas data file (json/xml). You don't need this if you are passing an atlasData object instead.
    * @param {object} [atlasData] - A JSON or XML data object. You don't need this if the data is being loaded from a URL.
    * @return {Phaser.Loader} This Loader instance.
    */
    atlasJSONHash: function (key, textureURL, atlasURL, atlasData) {

        return this.atlas(key, textureURL, atlasURL, atlasData, Phaser.Loader.TEXTURE_ATLAS_JSON_HASH);

    },

    /**
    * Add a new texture atlas to the loader. This atlas uses the Starling XML data format.
    *
    * @method Phaser.Loader#atlasXML
    * @param {string} key - Unique asset key of the texture atlas file.
    * @param {string} textureURL - The url of the texture atlas image file.
    * @param {string} [atlasURL] - The url of the texture atlas data file (json/xml). You don't need this if you are passing an atlasData object instead.
    * @param {object} [atlasData] - A JSON or XML data object. You don't need this if the data is being loaded from a URL.
    * @return {Phaser.Loader} This Loader instance.
    */
    atlasXML: function (key, textureURL, atlasURL, atlasData) {

        return this.atlas(key, textureURL, atlasURL, atlasData, Phaser.Loader.TEXTURE_ATLAS_XML_STARLING);

    },

    /**
    * Add a new texture atlas to the loader.
    *
    * @method Phaser.Loader#atlas
    * @param {string} key - Unique asset key of the texture atlas file.
    * @param {string} textureURL - The url of the texture atlas image file.
    * @param {string} [atlasURL] - The url of the texture atlas data file (json/xml). You don't need this if you are passing an atlasData object instead.
    * @param {object} [atlasData] - A JSON or XML data object. You don't need this if the data is being loaded from a URL.
    * @param {number} [format] - A value describing the format of the data, the default is Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY.
    * @return {Phaser.Loader} This Loader instance.
    */
    atlas: function (key, textureURL, atlasURL, atlasData, format) {

        if (typeof atlasURL === "undefined") { atlasURL = null; }
        if (typeof atlasData === "undefined") { atlasData = null; }
        if (typeof format === "undefined") { format = Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY; }

        //  A URL to a json/xml file has been given
        if (atlasURL)
        {
            this.addToFileList('textureatlas', key, textureURL, { atlasURL: atlasURL, format: format });
        }
        else
        {
            switch (format)
            {
                //  A json string or object has been given
                case Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY:

                    if (typeof atlasData === 'string')
                    {
                        atlasData = JSON.parse(atlasData);
                    }
                    break;

                //  An xml string or object has been given
                case Phaser.Loader.TEXTURE_ATLAS_XML_STARLING:

                    if (typeof atlasData === 'string')
                    {
                        var xml;

                        try  {
                            if (window['DOMParser'])
                            {
                                var domparser = new DOMParser();
                                xml = domparser.parseFromString(atlasData, "text/xml");
                            }
                            else
                            {
                                xml = new ActiveXObject("Microsoft.XMLDOM");
                                xml.async = 'false';
                                xml.loadXML(atlasData);
                            }
                        }
                        catch (e)
                        {
                            xml = undefined;
                        }

                        if (!xml || !xml.documentElement || xml.getElementsByTagName("parsererror").length)
                        {
                            throw new Error("Phaser.Loader. Invalid Texture Atlas XML given");
                        }
                        else
                        {
                            atlasData = xml;
                        }
                    }
                    break;
            }

            this.addToFileList('textureatlas', key, textureURL, { atlasURL: null, atlasData: atlasData, format: format });

        }

        return this;

    },

    /**
    * Remove loading request of a file.
    *
    * @method Phaser.Loader#removeFile
    * @param {string} type - The type of resource to add to the list (image, audio, xml, etc).
    * @param {string} key - Key of the file you want to remove.
    */
    removeFile: function (type, key) {

        var file = this.getAsset(type, key);

        if (file !== false)
        {
            this._fileList.splice(file.index, 1);
        }

    },

    /**
    * Remove all file loading requests.
    *
    * @method Phaser.Loader#removeAll
    */
    removeAll: function () {

        this._fileList.length = 0;

    },

    /**
    * Start loading the assets. Normally you don't need to call this yourself as the StateManager will do so.
    *
    * @method Phaser.Loader#start
    */
    start: function () {

        if (this.isLoading)
        {
            return;
        }

        this.progress = 0;
        this.progressFloat = 0;
        this.hasLoaded = false;
        this.isLoading = true;

        this.onLoadStart.dispatch(this._fileList.length);

        if (this._fileList.length > 0)
        {
            this._fileIndex = 0;
            this._progressChunk = 100 / this._fileList.length;
            this.loadFile();
        }
        else
        {
            this.progress = 100;
            this.progressFloat = 100;
            this.hasLoaded = true;
            this.onLoadComplete.dispatch();
        }

    },

    /**
    * Load files. Private method ONLY used by loader.
    *
    * @method Phaser.Loader#loadFile
    * @private
    */
    loadFile: function () {

        if (!this._fileList[this._fileIndex])
        {
            console.warn('Phaser.Loader loadFile invalid index ' + this._fileIndex);
            return;
        }

        var file = this._fileList[this._fileIndex];
        var _this = this;

        //  Image or Data?
        switch (file.type)
        {
            case 'image':
            case 'spritesheet':
            case 'textureatlas':
            case 'bitmapfont':
                file.data = new Image();
                file.data.name = file.key;
                file.data.onload = function () {
                    return _this.fileComplete(_this._fileIndex);
                };
                file.data.onerror = function () {
                    return _this.fileError(_this._fileIndex);
                };
                if (this.crossOrigin)
                {
                    file.data.crossOrigin = this.crossOrigin;
                }
                file.data.src = this.baseURL + file.url;
                break;

            case 'audio':
                file.url = this.getAudioURL(file.url);

                if (file.url !== null)
                {
                    //  WebAudio or Audio Tag?
                    if (this.game.sound.usingWebAudio)
                    {
                        this._xhr.open("GET", this.baseURL + file.url, true);
                        this._xhr.responseType = "arraybuffer";
                        this._xhr.onload = function () {
                            return _this.fileComplete(_this._fileIndex);
                        };
                        this._xhr.onerror = function () {
                            return _this.fileError(_this._fileIndex);
                        };
                        this._xhr.send();
                    }
                    else if (this.game.sound.usingAudioTag)
                    {
                        if (this.game.sound.touchLocked)
                        {
                            //  If audio is locked we can't do this yet, so need to queue this load request. Bum.
                            file.data = new Audio();
                            file.data.name = file.key;
                            file.data.preload = 'auto';
                            file.data.src = this.baseURL + file.url;
                            this.fileComplete(this._fileIndex);
                        }
                        else
                        {
                            file.data = new Audio();
                            file.data.name = file.key;
                            file.data.onerror = function () {
                                return _this.fileError(_this._fileIndex);
                            };
                            file.data.preload = 'auto';
                            file.data.src = this.baseURL + file.url;
                            file.data.addEventListener('canplaythrough', Phaser.GAMES[this.game.id].load.fileComplete(this._fileIndex), false);
                            file.data.load();
                        }
                    }
                }
                else
                {
                    this.fileError(this._fileIndex);
                }

                break;

            case 'json':
                this._xhr.open("GET", this.baseURL + file.url, true);
                this._xhr.responseType = "text";
                this._xhr.onload = function () {
                    return _this.jsonLoadComplete(_this._fileIndex);
                };
                this._xhr.send();
                break;

            case 'tilemap':
                this._xhr.open("GET", this.baseURL + file.url, true);
                this._xhr.responseType = "text";

                if (file.format === Phaser.Tilemap.TILED_JSON)
                {
                    this._xhr.onload = function () {
                        return _this.jsonLoadComplete(_this._fileIndex);
                    };
                }
                else if (file.format === Phaser.Tilemap.CSV)
                {
                    this._xhr.onload = function () {
                        return _this.csvLoadComplete(_this._fileIndex);
                    };
                }
                else
                {
                    throw new Error("Phaser.Loader. Invalid Tilemap format: " + file.format);
                }

                this._xhr.onerror = function () {
                    return _this.dataLoadError(_this._fileIndex);
                };
                this._xhr.send();
                break;

            case 'text':
            case 'script':
            case 'physics':
                this._xhr.open("GET", this.baseURL + file.url, true);
                this._xhr.responseType = "text";
                this._xhr.onload = function () {
                    return _this.fileComplete(_this._fileIndex);
                };
                this._xhr.onerror = function () {
                    return _this.fileError(_this._fileIndex);
                };
                this._xhr.send();
                break;

            case 'binary':
                this._xhr.open("GET", this.baseURL + file.url, true);
                this._xhr.responseType = "arraybuffer";
                this._xhr.onload = function () {
                    return _this.fileComplete(_this._fileIndex);
                };
                this._xhr.onerror = function () {
                    return _this.fileError(_this._fileIndex);
                };
                this._xhr.send();
                break;
        }

    },

    /**
    * Private method ONLY used by loader.
    * @method Phaser.Loader#getAudioURL
    * @param {array|string} urls - Either an array of audio file URLs or a string containing a single URL path.
    * @private
    */
    getAudioURL: function (urls) {

        var extension;

        if (typeof urls === 'string') { urls = [urls]; }

        for (var i = 0; i < urls.length; i++)
        {
            extension = urls[i].toLowerCase();
            extension = extension.substr((Math.max(0, extension.lastIndexOf(".")) || Infinity) + 1);

            if (this.game.device.canPlayAudio(extension))
            {
                return urls[i];
            }

        }

        return null;

    },

    /**
    * Error occured when loading a file.
    *
    * @method Phaser.Loader#fileError
    * @param {number} index - The index of the file in the file queue that errored.
    */
    fileError: function (index) {

        this._fileList[index].loaded = true;
        this._fileList[index].error = true;

        this.onFileError.dispatch(this._fileList[index].key, this._fileList[index]);

        console.warn("Phaser.Loader error loading file: " + this._fileList[index].key + ' from URL ' + this._fileList[index].url);

        this.nextFile(index, false);

    },

    /**
    * Called when a file is successfully loaded.
    *
    * @method Phaser.Loader#fileComplete
    * @param {number} index - The index of the file in the file queue that loaded.
    */
    fileComplete: function (index) {

        if (!this._fileList[index])
        {
            console.warn('Phaser.Loader fileComplete invalid index ' + index);
            return;
        }

        var file = this._fileList[index];
        file.loaded = true;

        var loadNext = true;
        var _this = this;

        switch (file.type)
        {
            case 'image':

                this.game.cache.addImage(file.key, file.url, file.data);
                break;

            case 'spritesheet':

                this.game.cache.addSpriteSheet(file.key, file.url, file.data, file.frameWidth, file.frameHeight, file.frameMax, file.margin, file.spacing);
                break;

            case 'textureatlas':

                if (file.atlasURL == null)
                {
                    this.game.cache.addTextureAtlas(file.key, file.url, file.data, file.atlasData, file.format);
                }
                else
                {
                    //  Load the JSON or XML before carrying on with the next file
                    loadNext = false;
                    this._xhr.open("GET", this.baseURL + file.atlasURL, true);
                    this._xhr.responseType = "text";

                    if (file.format == Phaser.Loader.TEXTURE_ATLAS_JSON_ARRAY || file.format == Phaser.Loader.TEXTURE_ATLAS_JSON_HASH)
                    {
                        this._xhr.onload = function () {
                            return _this.jsonLoadComplete(index);
                        };
                    }
                    else if (file.format == Phaser.Loader.TEXTURE_ATLAS_XML_STARLING)
                    {
                        this._xhr.onload = function () {
                            return _this.xmlLoadComplete(index);
                        };
                    }
                    else
                    {
                        throw new Error("Phaser.Loader. Invalid Texture Atlas format: " + file.format);
                    }

                    this._xhr.onerror = function () {
                        return _this.dataLoadError(index);
                    };
                    this._xhr.send();
                }
                break;

            case 'bitmapfont':

                if (file.xmlURL == null)
                {
                    this.game.cache.addBitmapFont(file.key, file.url, file.data, file.xmlData, file.xSpacing, file.ySpacing);
                }
                else
                {
                    //  Load the XML before carrying on with the next file
                    loadNext = false;
                    this._xhr.open("GET", this.baseURL + file.xmlURL, true);
                    this._xhr.responseType = "text";

                    this._xhr.onload = function () {
                        return _this.xmlLoadComplete(index);
                    };

                    this._xhr.onerror = function () {
                        return _this.dataLoadError(index);
                    };
                    this._xhr.send();
                }
                break;

            case 'audio':

                if (this.game.sound.usingWebAudio)
                {
                    file.data = this._xhr.response;

                    this.game.cache.addSound(file.key, file.url, file.data, true, false);

                    if (file.autoDecode)
                    {
                        var that = this;
                        var key = file.key;

                        this.game.cache.updateSound(key, 'isDecoding', true);

                        this.game.sound.context.decodeAudioData(file.data, function (buffer) {
                            if (buffer)
                            {
                                that.game.cache.decodedSound(key, buffer);
                                that.game.sound.onSoundDecode.dispatch(key, that.game.cache.getSound(key));
                            }
                        });
                    }
                }
                else
                {
                    file.data.removeEventListener('canplaythrough', Phaser.GAMES[this.game.id].load.fileComplete);
                    this.game.cache.addSound(file.key, file.url, file.data, false, true);
                }
                break;

            case 'text':
                file.data = this._xhr.responseText;
                this.game.cache.addText(file.key, file.url, file.data);
                break;

            case 'physics':
                var data = JSON.parse(this._xhr.responseText);
                this.game.cache.addPhysicsData(file.key, file.url, data, file.format);
                break;

            case 'script':
                file.data = document.createElement('script');
                file.data.language = 'javascript';
                file.data.type = 'text/javascript';
                file.data.defer = false;
                file.data.text = this._xhr.responseText;
                document.head.appendChild(file.data);
                if (file.callback)
                {
                    file.data = file.callback.call(file.callbackContext, file.key, this._xhr.responseText);
                }
                break;

            case 'binary':
                if (file.callback)
                {
                    file.data = file.callback.call(file.callbackContext, file.key, this._xhr.response);
                }
                else
                {
                    file.data = this._xhr.response;
                }

                this.game.cache.addBinary(file.key, file.data);

                break;
        }

        if (loadNext)
        {
            this.nextFile(index, true);
        }

    },

    /**
    * Successfully loaded a JSON file.
    *
    * @method Phaser.Loader#jsonLoadComplete
    * @param {number} index - The index of the file in the file queue that loaded.
    */
    jsonLoadComplete: function (index) {

        if (!this._fileList[index])
        {
            console.warn('Phaser.Loader jsonLoadComplete invalid index ' + index);
            return;
        }

        var file = this._fileList[index];
        var data = JSON.parse(this._xhr.responseText);

        file.loaded = true;

        if (file.type === 'tilemap')
        {
            this.game.cache.addTilemap(file.key, file.url, data, file.format);
        }
        else if (file.type === 'json')
        {
            this.game.cache.addJSON(file.key, file.url, data);
        }
        else
        {
            this.game.cache.addTextureAtlas(file.key, file.url, file.data, data, file.format);
        }

        this.nextFile(index, true);

    },

    /**
    * Successfully loaded a CSV file.
    *
    * @method Phaser.Loader#csvLoadComplete
    * @param {number} index - The index of the file in the file queue that loaded.
    */
    csvLoadComplete: function (index) {

        if (!this._fileList[index])
        {
            console.warn('Phaser.Loader csvLoadComplete invalid index ' + index);
            return;
        }

        var file = this._fileList[index];
        var data = this._xhr.responseText;

        file.loaded = true;

        this.game.cache.addTilemap(file.key, file.url, data, file.format);

        this.nextFile(index, true);

    },

    /**
    * Error occured when load a JSON.
    *
    * @method Phaser.Loader#dataLoadError
    * @param {number} index - The index of the file in the file queue that errored.
    */
    dataLoadError: function (index) {

        var file = this._fileList[index];

        file.loaded = true;
        file.error = true;

        console.warn("Phaser.Loader dataLoadError: " + file.key);

        this.nextFile(index, true);

    },

    /**
    * Successfully loaded an XML file.
    *
    * @method Phaser.Loader#xmlLoadComplete
    * @param {number} index - The index of the file in the file queue that loaded.
    */
    xmlLoadComplete: function (index) {

        var data = this._xhr.responseText;
        var xml;

        try
        {
            if (window['DOMParser'])
            {
                var domparser = new DOMParser();
                xml = domparser.parseFromString(data, "text/xml");
            }
            else
            {
                xml = new ActiveXObject("Microsoft.XMLDOM");
                xml.async = 'false';
                xml.loadXML(data);
            }
        }
        catch (e)
        {
            xml = undefined;
        }

        if (!xml || !xml.documentElement || xml.getElementsByTagName("parsererror").length)
        {
            throw new Error("Phaser.Loader. Invalid XML given");
        }

        var file = this._fileList[index];
        file.loaded = true;

        if (file.type == 'bitmapfont')
        {
            this.game.cache.addBitmapFont(file.key, file.url, file.data, xml, file.xSpacing, file.ySpacing);
        }
        else if (file.type == 'textureatlas')
        {
            this.game.cache.addTextureAtlas(file.key, file.url, file.data, xml, file.format);
        }

        this.nextFile(index, true);

    },

    /**
    * Handle loading next file.
    *
    * @param {number} previousIndex - Index of the previously loaded asset.
    * @param {boolean} success - Whether the previous asset loaded successfully or not.
    * @private
    */
    nextFile: function (previousIndex, success) {

        this.progressFloat += this._progressChunk;
        this.progress = Math.round(this.progressFloat);

        if (this.progress > 100)
        {
            this.progress = 100;
        }

        if (this.preloadSprite !== null)
        {
            if (this.preloadSprite.direction === 0)
            {
                this.preloadSprite.rect.width = Math.floor((this.preloadSprite.width / 100) * this.progress);
                this.preloadSprite.sprite.crop(this.preloadSprite.rect);
            }
            else
            {
                this.preloadSprite.rect.height = Math.floor((this.preloadSprite.height / 100) * this.progress);
                this.preloadSprite.sprite.crop(this.preloadSprite.rect);
            }
        }

        this.onFileComplete.dispatch(this.progress, this._fileList[previousIndex].key, success, this.totalLoadedFiles(), this._fileList.length);

        if (this.totalQueuedFiles() > 0)
        {
            this._fileIndex++;
            this.loadFile();
        }
        else
        {
            this.hasLoaded = true;
            this.isLoading = false;

            this.removeAll();

            this.onLoadComplete.dispatch();
        }

    },

    /**
    * Returns the number of files that have already been loaded, even if they errored.
    *
    * @return {number} The number of files that have already been loaded (even if they errored)
    */
    totalLoadedFiles: function () {

        var total = 0;

        for (var i = 0; i < this._fileList.length; i++)
        {
            if (this._fileList[i].loaded)
            {
                total++;
            }
        }

        return total;

    },

    /**
    * Returns the number of files still waiting to be processed in the load queue. This value decreases as each file is in the queue is loaded.
    *
    * @return {number} The number of files that still remain in the load queue.
    */
    totalQueuedFiles: function () {

        var total = 0;

        for (var i = 0; i < this._fileList.length; i++)
        {
            if (this._fileList[i].loaded === false)
            {
                total++;
            }
        }

        return total;

    }

};

Phaser.Loader.prototype.constructor = Phaser.Loader;