import { getApplication } from './globals.js';

/**

* @import { AppBase } from './app-base.js'

*/

/**

* @callback CreateScreenCallback

* Callback used by {@link script.createLoadingScreen}.

* @param {AppBase} app - The application.

* @returns {void}

*/

// flag to avoid creating multiple loading screens e.g. when

// loading screen scripts are reloaded

let _createdLoadingScreen = false;

/**

* The script namespace holds the createLoadingScreen function that is used to override the default

* PlayCanvas loading screen.

*

* @namespace

* @category Script

*/

const script = {

// set during script load to be used for initializing script

app: null,

/**

* Handles the creation of the loading screen of the application. A script can subscribe to the

* events of a {@link AppBase} to show a loading screen, progress bar etc. In order for

* this to work you need to set the project's loading screen script to the script that calls

* this method.

*

* @param {CreateScreenCallback} callback - A function which can set up and tear down a

* customized loading screen.

* @example

* pc.script.createLoadingScreen((app) => {

* const showSplashScreen = () => {};

* const hideSplashScreen = () => {};

* const showProgress = (progress) => {};

* app.on("preload:start", showSplashScreen);

* app.on("preload:progress", showProgress);

* app.on("start", hideSplashScreen);

* });

*/

createLoadingScreen(callback) {

if (_createdLoadingScreen) {

return;

}

_createdLoadingScreen = true;

const app = getApplication();

callback(app);

}

};

export { script };