import ResourceLoader from 'resource-loader';
import EventEmitter from 'eventemitter3';
import { blobMiddlewareFactory } from 'resource-loader/lib/middlewares/parsing/blob';
import TextureLoader from './TextureLoader';
/**
*
* The new loader, extends Resource Loader by Chad Engler: https://github.com/englercj/resource-loader
*
* ```js
* const loader = PIXI.Loader.shared; // PixiJS exposes a premade instance for you to use.
* //or
* const loader = new PIXI.Loader(); // you can also create your own if you want
*
* const sprites = {};
*
* // Chainable `add` to enqueue a resource
* loader.add('bunny', 'data/bunny.png')
* .add('spaceship', 'assets/spritesheet.json');
* loader.add('scoreFont', 'assets/score.fnt');
*
* // Chainable `pre` to add a middleware that runs for each resource, *before* loading that resource.
* // This is useful to implement custom caching modules (using filesystem, indexeddb, memory, etc).
* loader.pre(cachingMiddleware);
*
* // Chainable `use` to add a middleware that runs for each resource, *after* loading that resource.
* // This is useful to implement custom parsing modules (like spritesheet parsers, spine parser, etc).
* loader.use(parsingMiddleware);
*
* // The `load` method loads the queue of resources, and calls the passed in callback called once all
* // resources have loaded.
* loader.load((loader, resources) => {
* // resources is an object where the key is the name of the resource loaded and the value is the resource object.
* // They have a couple default properties:
* // - `url`: The URL that the resource was loaded from
* // - `error`: The error that happened when trying to load (if any)
* // - `data`: The raw data that was loaded
* // also may contain other properties based on the middleware that runs.
* sprites.bunny = new PIXI.TilingSprite(resources.bunny.texture);
* sprites.spaceship = new PIXI.TilingSprite(resources.spaceship.texture);
* sprites.scoreFont = new PIXI.TilingSprite(resources.scoreFont.texture);
* });
*
* // throughout the process multiple signals can be dispatched.
* loader.onProgress.add(() => {}); // called once per loaded/errored file
* loader.onError.add(() => {}); // called once per errored file
* loader.onLoad.add(() => {}); // called once per loaded file
* loader.onComplete.add(() => {}); // called once when the queued resources all load.
* ```
*
* @see https://github.com/englercj/resource-loader
*
* @class Loader
* @extends module:resource-loader.ResourceLoader
* @memberof PIXI
* @param {string} [baseUrl=''] - The base url for all resources loaded by this loader.
* @param {number} [concurrency=10] - The number of resources to load concurrently.
*/
export default class Loader extends ResourceLoader
{
constructor(baseUrl, concurrency)
{
super(baseUrl, concurrency);
EventEmitter.call(this);
for (let i = 0; i < Loader._plugins.length; ++i)
{
const plugin = Loader._plugins[i];
const { pre, use } = plugin;
if (pre)
{
this.pre(pre);
}
if (use)
{
this.use(use);
}
}
// Compat layer, translate the new v2 signals into old v1 events.
this.onStart.add((l) => this.emit('start', l));
this.onProgress.add((l, r) => this.emit('progress', l, r));
this.onError.add((e, l, r) => this.emit('error', e, l, r));
this.onLoad.add((l, r) => this.emit('load', l, r));
this.onComplete.add((l, r) => this.emit('complete', l, r));
/**
* If this loader cannot be destroyed.
* @member {boolean}
* @default false
* @private
*/
this._protected = false;
}
/**
* Destroy the loader, removes references.
*/
destroy()
{
if (!this._protected)
{
this.removeAllListeners();
this.reset();
}
}
/**
* A premade instance of the loader that can be used to load resources.
* @name shared
* @type {PIXI.Loader}
* @static
* @memberof PIXI.Loader
*/
static get shared()
{
let shared = Loader._shared;
if (!shared)
{
shared = new Loader();
shared._protected = true;
Loader._shared = shared;
}
return shared;
}
}
// Copy EE3 prototype (mixin)
Object.assign(Loader.prototype, EventEmitter.prototype);
/**
* Collection of all installed `use` middleware for Loader.
*
* @static
* @member {Array<PIXI.Loader~LoaderPlugin>}
* @memberof PIXI.Loader
* @private
*/
Loader._plugins = [];
/**
* Adds a Loader plugin for the global shared loader and all
* new Loader instances created.
*
* @static
* @method registerPlugin
* @memberof PIXI.Loader
* @param {PIXI.Loader~LoaderPlugin} plugin - The plugin to add
* @return {PIXI.Loader} Reference to PIXI.Loader for chaining
*/
Loader.registerPlugin = function registerPlugin(plugin)
{
Loader._plugins.push(plugin);
if (plugin.add)
{
plugin.add();
}
return Loader;
};
// parse any blob into more usable objects (e.g. Image)
Loader.registerPlugin({ use: blobMiddlewareFactory() });
// parse any Image objects into textures
Loader.registerPlugin(TextureLoader);
/**
* Plugin to be installed for handling specific Loader resources.
* @typedef {object} PIXI.Loader~LoaderPlugin
* @property {function} [plugin.add] - Function to call immediate after registering plugin.
* @property {PIXI.Loader~loaderMiddleware} [plugin.pre] - Middleware function to run before load, the
* arguments for this are `(resource, next)`
* @property {PIXI.Loader~loaderMiddleware} [plugin.use] - Middleware function to run after load, the
* arguments for this are `(resource, next)`
*/
/**
* @callback PIXI.Loader~loaderMiddleware
* @param {PIXI.LoaderResource} resource
* @param {function} next
*/