@curiousmedia/createjs-scene-container/src/SceneContainer.js

A scene manager for CreateJS

const _scenes = {};
const _transitions = {};

let instance;

export default class SceneContainer extends createjs.Container
{
	constructor()
	{
		super();

		if ( instance ) throw new Error( "Only one instance of SceneContainer allowed" );

		this.anchorX = 0.5;
		this.anchorY = 0.5;

		this._last = null;
		this.lastID = "";
		this.current = null;
		this.currentID = "";
	}

	static get scenes()
	{
		return _scenes;
	}

	static get currentScene()
	{
		return SceneContainer.getCurrentScene();
	}

	static getInstance()
	{
		if ( !instance ) instance = new SceneContainer();
		return instance;
	}

	static getCurrentScene()
	{
		return instance && instance.current;
	}

	static registerScene( sceneId, SceneClass )
	{
		// console.log( "Registering Scene: ", sceneId );
		_scenes[sceneId] = { id: sceneId, sceneClass: SceneClass };
	}

	static registerTransition( transitionId, TransitionClass )
	{
		// console.log( "Registering Transition/Loader Scene: ", transitionId );
		_transitions[transitionId] = { id: transitionId, instance: new TransitionClass( transitionId ) };
	}

	static registerDefaultTransition( TransitionClass )
	{
		this.registerTransition( "default", TransitionClass);
	}

	static getSceneDefinition( sceneId )
	{
		return _scenes[sceneId] || false;
	}

	static getTransitionDefinition( transitionId )
	{
		return _transitions[transitionId] || false;
	}

	static gotoScene( sceneId, options, transitionId, transitionOptions )
	{
		instance.gotoScene( sceneId, options, transitionId, transitionOptions );
	}

	gotoScene( sceneId, options, transitionId = "default", transitionOptions = {} )
	{
		const current = this.current;

		const nextSceneDef = SceneContainer.getSceneDefinition( sceneId );
		if ( !nextSceneDef )
		{
			throw new Error( "No Scene with id: " + sceneId );
		}

		_log(" ------ ");
		_log("Starting Scene Change");

		// Start promise chain
		let promiseChain = Promise.resolve();


		let transition;

		// If there's a current scene
		if ( current )
		{
			_log("Removing Current Scene");
			promiseChain = promiseChain.then( () => current.end() ); // end it
			promiseChain = promiseChain.then( () => current.animateOut() ); // animate out

			// Transition

			const transitionDef = SceneContainer.getTransitionDefinition( transitionId );
			transition = transitionDef.instance;
			if ( transition )
			{
				_log("Adding Transition");
				promiseChain = promiseChain.then( () => this.addTransition( transition ) );
				promiseChain = promiseChain.then( () => transition.setup( transitionOptions ) );
				promiseChain = promiseChain.then( () => transition.animateIn() );
				promiseChain = promiseChain.then( () => transition.loadAssets() );
			}
		}

		_log("Next Scene: " + nextSceneDef.id);

		// Start prepping next scene
		const NextSceneClass = nextSceneDef.sceneClass;

		_log("Loading Next Scene");
		promiseChain = promiseChain.then( () => NextSceneClass.preload() );

		_log("Creating Next Scene");
		// Now make the next scene
		let next;
		promiseChain = promiseChain.then( () =>
		{
			next = new NextSceneClass( nextSceneDef.id, options );
			return Promise.resolve();
		} );

		// swap scenes
		promiseChain = promiseChain.then( () => this.swapScenes( current, next ) );
		promiseChain = promiseChain.then( () => next.setup( options ) );
		promiseChain = promiseChain.then( () => next.reset() );

		if ( transition )
		{
			_log("Removing Transition");
			promiseChain = promiseChain.then( () => transition.animateOut() );
			promiseChain = promiseChain.then( () =>
			{
				this.removeChild( transition );
				return Promise.resolve();
			} );
		}

		promiseChain = promiseChain.then( () => next.animateIn() );
		promiseChain.then( () => next.start() );
	}

	setScreenAnchors( anchorX = 0.5, anchorY = 0.5 )
	{
		this.anchorX = anchorX;
		this.anchorY = anchorY;
	}

	swapScenes( current, next )
	{
		if ( current )
		{
			current.destroy();
			this.removeChild( current );
		}

		this.addChildAt( next, 0 );
		this.current = next;

		const event = new Event( "change" );
		event.current = this.current;
		event.previous = current;
		this.dispatchEvent( event );

		return Promise.resolve();
	}

	addTransition( loaderOfTransition )
	{
		this.addChild( loaderOfTransition );

		return Promise.resolve();
	}

	transitOut()
	{
		return this.transitionOverlay.transitOut();
	}

	transitIn()
	{
		return this.transitionOverlay.transitIn();
	}

	_tick( evt )
	{
		super._tick( evt );

		const stage = this.stage;
		if ( stage && this.parent === stage )
		{
			this.x = Math.floor( stage.canvas.width * this.anchorX );
			this.y = Math.floor( stage.canvas.height * this.anchorY );
		}

		if ( this.current )
		{
			this.current.update( evt.delta / 1000 );
		}
	}
}

function _log( message )
{
	const promise = new Promise( resolve =>
	{
		console.log(message);
		resolve();
	});
	return promise;
}