raduGaspar

export default class KeyboardEvents {
  static get KEY_UP() {
    return 'keyup'; // actual event name, don't change
  }
  static get KEY_DOWN() {
    return 'keydown'; // actual event name, don't change
  }
};

raduGaspar

import { KeyboardEvents, EventDispatcher } from '../'

let keyboardInstance;
let keysMap = {};

class KeyboardSingleton {
  constructor() {
    if(!keyboardInstance) {
      console.log('Keyboard instance created');
      keyboardInstance = this;

raduGaspar

let pubSubInstance;
const subjects = {};
const hOP = subjects.hasOwnProperty;

class PubSub {
  constructor() {
    if(!pubSubInstance) {
      console.log('EventDispatcher instance created');
      pubSubInstance = this;
    }

raduGaspar

export default class Utils {
  constructor() {
    let e = new Error('is a static class, no need to instantiate!');
    e.name = 'Utils';

    throw e.toString();
  }

  static toCamelCase(str) {
    return str.replace(/(?:^\w|[A-Z]|\b\w)/g, function(letter, index) {

raduGaspar

import Utils from './Utils';

let assetLoaderInstance;

export default class AssetsLoader {
  constructor() {
    if(!assetLoaderInstance) {
      console.log('AssetsLoader instance created');
      this.assets = {};
      assetLoaderInstance = this;

raduGaspar

export default class Game {
  constructor(scenes) {
    // check if the browser supports requestAnimationFrame
    if(!(typeof requestAnimationFrame)) {
      throw new Error('Your browser doesn\'t support requestAnimationFrame :(');
    }
    
    this.scenes = [];
    this.addScenes(scenes);
    this.play();

raduGaspar

let EventDispatcher = (function() {
  let instance = null;

  class EventDispatcher {
    constructor() {
      if(!instance) {
        instance = this;
      }

      return instance;

raduGaspar

// Design Patterns: Decorator
class Drink {
  constructor() {
    this.total = function() {
      return 0;
    }
  }
}

// decorator 1

raduGaspar

const swimmer = (state) => ({
  swim: () => console.log(state.name, 'is swimming')
})

const eater = (state) => ({
  eat: () => console.log(state.name, 'is eating')
})

const sleeper = (state) => ({
  sleep: () => console.log(state.name, 'is sleeping')

raduGaspar

class Animal {
  swim() {
    console.log('swimming');
  }
  eat() {
    console.log('eating');
  }
  sleep() {
    console.log('sleeping');
  }